Dissertations / Theses: 'Power transmission planning'

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Liu, Haifeng. "Planning reactive power control for transmission enhancement." [Ames, Iowa : Iowa State University], 2007.

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Lee, Cheuk-wing. "Transmission expansion planning in a restructured electricity market." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38959410.

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Jia, Jundi. "Transmission Expansion Planning in Large Power SystemsUsing Power System Equivalencing Techniques." Thesis, KTH, Elektriska energisystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149679.

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With an increasing demand for electric power, new transmission lines should be constructed with a rational plan in the long run to guarantee a reliable and economic operation. The transmission expansion planning (TEP) is a mixed integer non-linear programming (MINLP) optimization problem in nature, which requires tremendous computational efforts especially when it comes to a large-scale power system. Although a diversity of simplifications and computational techniques has been applied to TEP, it is still challenging to derive an optimal plan within little simulation time. Since equivalencing technique is able to reduce the size of a large-scale power system and help achieve remarkable computational performance, it is possibly effective and efficient to handle the intrinsic complexity of TEP problem. In this thesis, based on a detailed literature review, a mixed integer linear programming (MILP) approach in DC model is firstly formulated for a dynamic TEP problem considering N – 1 security criterion. Then, two traditional power flow based equivalencing techniques that are appropriate for simplifying TEP, REI and WARD, with necessary modifications, are respectively implemented in the initial TEP problem. The proposed algorithms are simulated on IEEE 24-bus reliability test system (RTS) to compare optimal plans between the original and equivalent system. Further assumptions and adjustments are searched and tested to get more accurate optimal plans. The results show that both modified equivalencing techniques can significantly decrease the simulation time. Regarding IEEE 24-bus RTS, the proposed algorithm for modified REI method can achieve relatively precise optimal plan with few errors while modified WARD method is not as good as modified REI method. Therefore, the modified REI method has a potential to be implemented in TEP problem to reduce the complexity and computational effort for large power system without jeopardizing accuracy. Further studies are needed to tune the modified REI method and revise the obtained optimal plan.

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Song, Fei. "Deregulated power transmission analysis and planning in congested networks." Thesis, Brunel University, 2008. http://bura.brunel.ac.uk/handle/2438/4819.

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In this thesis, methods of charging for the transmission system and optimising the expansion of the transmission network under the competitive power market are described. The first part of this thesis considers transmission tariff design. In the proposed approach, not only is all the necessary investment in the transmission system recovered, but also an absolute economic signal is offered which is very useful in the competitive power market. A fair power market opportunity is given to every participant by the new nodal-use method. The second part of this thesis considers transmission system expansion. All the tests are based on the Three Gorges Project in China. In this thesis, to optimally expand the transmission system, the LMP (Locational Marginal Price) selection method and the CBEP (Congestion-Based transmission system Expansion Planning) method are introduced. The LMP selection method is used to select optional plans for transmission system expansion. It is especially suitable for large transmission systems. The outstanding advantages of the LMP selection method are simplicity and computational efficiency. The CBEP method produces the optimal system expansion plan. For the first time, generation congestion and transmission congestion are separated within the system expansion problem. For this reason the CBEP method can be used in a supply-side power market and is suitable for the Chinese power market. In this thesis, the issue of how to relax the congestion in the transmission system have been solved. The transmission system can obtain enough income to recover the total required cost. For this reason more and more investment will come into the transmission system from investors. The risk for the independent generators is also under control in the CBEP method. Even when the system is congested, the uncertainty of LMP is taken into consideration.

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He, Yang. "Electricity Generation and Transmission Planning in Deregulated Power Markets." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/196013.

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This dissertation addresses the long-term planning of power generation and transmission facilities in a deregulated power market. Three models with increasing complexities are developed, primarily for investment decisions in generation and transmission capacity. The models are presented in a two-stage decision context where generation and transmission capacity expansion decisions are made in the first stage, while power generation and transmission service fees are decided in the second stage. Uncertainties that exist in the second stage affect the capacity expansion decisions in the first stage. The first model assumes that the electric power market is not constrained by transmission capacity limit. The second model, which includes transmission constraints, considers the interactions between generation firms and the transmission network operator. The third model assumes that the generation and transmission sectors make capacity investment decisions separately. These models result in Nash-Cournot equilibrium among the unregulated generation firms, while the regulated transmission network operator supports the competition among generation firms. Several issues in the deregulated electric power market can be studied with these models such as market powers of generation firms and transmission network operator, uncertainties of the future market, and interactions between the generation and transmission sectors. Results deduced from the developed models include (a) regulated transmission network operator will not reserve transmission capacity to gain extra profits; instead, it will make capacity expansion decisions to support the competition in the generation sector; (b) generation firms will provide more power supplies when there is more demand; (c) in the presence of future uncertainties, the generation firms will add more generation capacity if the demand in the future power market is expected to be higher; and (d) the transmission capacity invested by the transmission network operator depends on the characteristic of the power market and the topology of the transmission network. Also, the second model, which considers interactions between generation and transmission sectors, yields higher social welfare in the electric power market, than the third model where generation firms and transmission network operator make investment decisions separately.

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Lee, Cheuk-wing, and 李卓穎. "Transmission expansion planning in a restructured electricity market." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38959410.

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Sozer, Sevin Park Chan S. "Transmission expansion planning to alleviate congestion in deregulated power markets." Auburn, Ala., 2006. http://repo.lib.auburn.edu/Send%206-15-07/SOZER_SEVIN_35.pdf.

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Chebbo, Hind Munzer. "Power transmission planning using heuristic optimisation techniques : deterministic crowding genetic algorithms and ant colony search methods." Thesis, Brunel University, 2000. http://bura.brunel.ac.uk/handle/2438/5781.

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The goal of transmission planning in electric power systems is a robust network which is economical, reliable, and in harmony with its environment taking into account the inherent uncertainties. For reasons of practicality, transmission planners have normally taken an incremental approach and tended to evaluate a relatively small number of expansion alternatives over a relatively short time horizon. In this thesis, two new planning methodologies namely the Deterministic Crowding Genetic Algorithm and the Ant Colony System are applied to solve the long term transmission planning problem. Both optimisation techniques consider a 'green field' approach, and are not constrained by the existing network design. They both identify the optimal transmission network over an extended time horizon based only on the expected pattern of electricity demand and generation sources. Two computer codes have been developed. An initial comparative investigation of the application of Ant Colony Optimisation and a Genetic Algorithm to an artificial test problem has been undertaken. It was found that both approaches were comparable for the artificial test problem.

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Zhang, Fan. "Solving Large Security-Constrained Optimal Power Flow for Power Grid Planning and Operations." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1592567584117811.

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Aryal, Durga. "Analysis and Planning of Power Transmission System Subject to Uncertainties in the Grid." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/87401.

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Power transmission systems frequently experience new power flow pattern due to several factors that increase uncertainties in the system. For instance, load shape uncertainty, uncertainty due to penetration of renewable sources, changing standards, and energy de-regulation threaten the reliability and security of power transmission systems. This demands for more rigorous analysis and planning of power transmission systems. Stability issues in power transmission system are more pronounced with the penetration of utility-scale Photo-Voltaic (PV) sources. Synchronous generators provide inertia that helps in damping oscillations that arise due to fluctuations in the power system. Therefore, as PV generators replace the conventional synchronous generators, power transmission systems become vulnerable to these abnormalities. In this thesis, we study the effect of reduced inertia due to the penetration of utility-scale PV on the transient stability of power transmissions systems. In addition, the effect of increased PV penetration level in the system during normal operating condition is also analyzed. The later study illustrates that the PV penetration level and the placement of PV sources play crucial roles in determining the stability of power transmission systems. Given increasing uncertainties in power transmission systems, there is a need to seek an alternative to deterministic planning approach because it inherently lacks capability to cover all the uncertainties. One practical alternative is the probabilistic planning approach. In probabilistic planning approach, an analysis is made with a wide variety of scenarios by considering the probability of occurrence of each scenario and the probability of contingencies. Then, the severity of the contingencies risk associated with each planning practice is calculated. However, due to the lack of techniques and tools to select wide varieties of scenarios along with their probability of occurrence, the probabilistic transmission planning approach has not been implemented in real-world power transmission systems. This thesis presents a technique that can select wide varieties of scenarios along with their probability of occurrence to facilitate probabilistic planning in Electricity Reliability Council of Texas (ERCOT) systems.
Master of Science
Reliability of power transmission systems are threatened due to the increasing uncertainties arising from penetration of renewable energy sources, load growth, energy de-regulation and changing standards. Stability issues become more prevalent than in past due to increasing load growth as the demand for reactive power increases. Several researchers have been studying the impact of increased load growth and increased penetration of renewables on the dynamic stability of the distribution system. However, far less emphasis has been given to the power transmission system. This thesis presents the transient stability analysis of power transmission systems during overloading conditions. Our study also facilitates identification of weak areas of the transmission system during overloading condition. In addition, the impact of replacing conventional synchronous generator by Photovoltaics (PV) on voltage stability of the system is also analyzed. With increasing uncertainties in transmission systems, it is necessary to carefully analyze a wide variety of scenarios while planning the system. The current approach to transmission planning i.e., the deterministic approach does not sufficiently cover all the uncertainties. This has imposed the need for the probabilistic transmission planning approach where the overall system is planned based on the analysis of wide varieties of scenarios. In addition, by considering the probability of occurrence of a scenario, the probability of contingencies and severity of contingencies risk associated with each planning practice is calculated. However, there is no well-established approach that is capable of selecting wide varieties of scenarios based on their probability of occurrence. Due to this limitation, probabilistic approach is not widely implemented in real-world power transmission systems. To address this issue, this thesis presents a new technique, based on K-means clustering, to select scenarios based on their probability of occurrence.

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Farrokhseresht, Mana. "Reactive Power Planning with Voltage Stability Constraints for Increasing Cross-Border Transmission Capacity." Thesis, KTH, Elektriska energisystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170831.

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In this work Reactive Power Planning (RPP) is studied. It is the method which aims at locating reactive compensators of optimal size at an optimal location in order to achieve or optimize a certain objective. In this work, the reactive compensators are placed in such away that they keep the voltages in a grid longer stable and within an acceptable range of values while power flows through the grid. Usually, this power flow disturbs the voltages. The RPP was applied in this work in order to allow a larger power flow from one grid area to another grid area. The first area is called the Source area and it contains generators which can produce power at a cheap price. The second area is called the Sink area and it is willing to import this cheap power so that it has to produce less power by itself. The two areas are connected to each other with a tie-line, which has a certain capacity (called Net Transfer Capacity or NTC). The capacity is restricted by stability requirements: exceeding the capacity would cause voltages to become unstable in either of the two grid areas. Installing reactive power compensators allows to increase the capacity of the line, keeping the voltages stable when the power flow over the tie-line increases. Reactive Power Planning therefore has an economic benefit, and different methods to optimize it will be investigated in this work. This work is divided into three parts. In the first part the relationship is studied between reactive power compensation on the one hand and the increase of the NTC of the tie-line on the other hand. The grid which is used to illustrate this is the Swedish grid, connected to the grids of Denmark and Finland. It is observed that not only increasing the loads can lead to voltage instability in the grid, but that voltage problems can also arise within the Swedish grid from the exchange of power,owing through the Swedish grid, between its neighbouring countries. It is shown that reactive power compensation is a technique which can potentially increase the NTC-value of the tie-lines between Sweden and Denmark and between Sweden and Finland. Depending on where the reactive power compensators are installed, the NTC increases with different values. In the next two parts however, we focus on the economic analysis of the reactive power compensation. In these two parts, an Optimal Power Flow (OPF) problem is designed, leading to the optimal placement and choice of the reactive power compensators. The optimal compensators increase the NTC so that the benefit of the decreased cost of power generationin the Sink area is maximized with respect to the cost of the reactive compensators. The difference between these two parts is in the algorithms that are applied for solving the OPF. In the second part a heuristic method based on a Genetic Algorithm (GA), NSGA-II, is used to optimize this benefit. The reason why first a heuristic method is used is that the NTC of the tie-line cannot be expressed as an analytical, closed-form function of the reactive power ratings. Therefore, a heuristic optimization method is chosen to solve the OPF and the algorithm NSGA-II is used because of its good convergence properties and ease of implementation. However, the algorithm is also able to perform multi-objective optimization and this ability is used to optimize both the economic benefit and the voltage stability index of the Sink area. It is seen that there is a trade-off between voltage stability and economic benefit and it is up to the grid operators to make choices regarding this trade-off. In the third part of this work a mathematical method is used to maximize the economic benefit of the Sink area with respect to the cost of the reactive compensators. As much as possible mathematical expressions will be used in this part. As the NTC cannot be expressed as a closed-form function, some approximations need to be made. Two methods were proposed to approximate the NTC: approximation by piecewise linear functions and by polynomials obtained with statistical regression. This mathematical method leads to a Voltage Stability Constrained OPF (VSCOPF). It is programmed in GAMS and formulated as a Mixed-Integer Non-Linear Programming problem (MINLP).

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Wu, Zhi. "Transmission expansion planning and unit commitment with large-scale integration of wind power." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6738/.

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The large-scale integration of wind generation into the power system brings great challenges to transmission expansion planning (TEP) and unit commitment (UC). The intermittence nature of wind generation needs to be fully considered in these two problems, which stimulates the research of this thesis. The selection of candidate lines is the prerequisite for the TEP problem. Considering the limitations of manual selection approach, a method to select candidate lines automatically is proposed, which consists of five stages to reinforce existing corridors and new corridors. Results of the two test systems illustrate that the locational marginal price difference is neither sufficient nor necessary condition for candidate lines. The uncertainty of load demand and wind power is studied both in the TEP and UC problems. In the term of TEP, a two-stage stochastic formulation of TEP is proposed. The stochastic dual dynamic programming (SDDP) approach is applied to consider the uncertainty, and the whole model is solved by Benders decomposition (BD) technique. In the term of UC, the chance-constrained two-stage programming formulation is proposed for the day-ahead UC problem. The chance-constrained stochastic programming formulation is converted into an equivalent deterministic formulation by a sequence of approximation and verification.

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Mitchell-Colgan, Elliott. "Modeling Considerations for the Long-Term Generation and Transmission Expansion Power System Planning Problem." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/78068.

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Judicious Power System Planning ensures the adequacy of infrastructure to support continuous reliability and economy of power system operations. Planning processes have a long and rather successful history in the United States, but the recent infl‚ux of unpredictable, nondispatchable generation such as Wind Energy Conversion Systems (WECS) necessitates the re-evaluation of the merit of planning methodologies in the changing power system context. Traditionally, planning has followed a logical progression through generation, transmission, reactive power, and finally auxiliary system planning using expertise and ranking schemes. However, it is challenging to incorporate all of the inherent dependencies between expansion candidates' system impacts using these schemes. Simulation based optimization provides a systematic way to explore acceptable expansion plans and choose one or several "best" plans while considering those complex dependencies. Using optimization to solve the minimum-cost, reliability-constrained Generation and Transmission Expansion Problem (GTEP) is not a new concept, but the technology is not mature. This work inspects: load uncertainty modeling; sequential (GEP then TEP) versus unified (GTEP) models; and analyzes the impact on the methodologies achieved near-optimal plan. A sensitivity simulation on the original system and final, upgraded system is performed.
Master of Science

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Tor, Osman Bulent. "Congestion-driven Transmission Planning Considering Incentives For Generator Investments." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609625/index.pdf.

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This thesis study focuses on transmission expansion planning (TEP) problem for restructured power systems and addresses challenges specifically in countries where electricity market is in developing phase after liberalization of power industry for establishing a competitive market, like Turkey. A novel multi-year TEP approach is developed which considers generation investment cost and transmission congestion level in the planning horizon. The model assesses the impact of generation investments on TEP problem. Benders decomposition methodology is utilized successfully to decompose the complex mixed-integer programming TEP problem into a master problem and two subproblems. Security subproblem assesses single-contingency criteria. Transmission congestion cost is considered within operational subproblem given that congestion level is a proper criterion for measuring competitiveness level of an electricity market. The proposed approach is applied to the Turkish power system. The proposed approach could be utilized to provide indicative plans, which might be quite necessary particularly during development of a competitive market. However, there is no guarantee that independent power producers (IPPs) will follow those plans which concern the maximization of social-welfare. Given the necessity of coordinating monopoly transmission and decentralized generator investment decisions, the proposed approach is improved further to include promoting decentralized generator investments through incentive payments. Such incentives might be necessary to trigger IPPs earlier than their projections, as illustrated by numerical examples including IEEE 30-bus system.

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Zeraatzade, Mahbube. "Transmission congestion management by optimal placement of FACTS devices." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4710.

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This thesis describes the implementation of the Flexible AC Transmission Systems (FACTS) devices to develop a market-based approach to the problem of transmission congestion management in a Balancing Market. The causes, remedies and pricing methods of transmission congestion are briefly reviewed. Balancing Market exists in markets in which most of the trading is done via decentralized bilateral contracts. In these markets only final adjustments necessary to ensure secure system operation is carried out at a centralized Balancing Market. Each market player can participate in the Balancing Market by submitting offers and bids to increase and decrease its initially submitted active generation output. In this research a method is proposed to reduce costs associated with congestion re-dispatch in a Balancing Market by optimal placement of FACTS devices, and in particular Thyristor Controlled Phase Shifter Transformers (TCPST). The proposed technique is applicable to both Mixed Integer Linear Programming (MILP) and Mixed Integer Non-Linear Programming (MINLP). In the MILP a power system network is represented by a simplified DC power flow under a MILP structure and the Market participants' offers and bids are also represented by linear models. Results show that applications of FACTS devices can significantly reduce costs of congestion re-dispatch. The application of the method based on the MINLP creates a nonlinear and non-convex AC OPF problem that might be trapped in local sub-optima solutions. The reliability of the solution that determines the optimal placement of FACTS devices is an important issue and is carried out by investigation of alternative solvers. The behavior of the MINLP solvers is presented and finally the best solvers for this particular optimization problem are introduced. The application of DC OPF is very common in industry. The accuracy of the DC OPF results is investigated and a comparison between the DC and AC OPF is presented.

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Setréus, Johan. "On Reliability Methods Quantifying Risks to Transfer Capability in Electric Power Transmission Systems." Licentiate thesis, KTH, Electromagnetic Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10258.

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In the operation, planning and design of the transmission system it is of greatest concern to quantify the reliability security margin to unwanted conditions. The deterministic N-1 criterion has traditionally provided this security margin to reduce the consequences of severe conditions such as widespread blackouts. However, a deterministic criterion does not include the likelihood of different outage events. Moreover, experience from blackouts shows, e.g. in Sweden-Denmark September 2003, that the outages were not captured by the N-1 criterion. The question addressed in this thesis is how this system security margin can be quantified with probabilistic methods. A quantitative measure provides one valuable input to the decision-making process of selecting e.g. system expansions alternatives and maintenance actions in the planning and design phases. It is also beneficial for the operators in the control room to assess the associated security margin of existing and future network conditions.

This thesis presents a method that assesses each component's risk to an insufficient transfer capability in the transmission system. This shows on each component's importance to the system security margin. It provides a systematic analysis and ranking of outage events' risk of overloading critical transfer sections (CTS) in the system. The severity of each critical event is quantified in a risk index based on the likelihood of the event and the consequence of the section's transmission capacity. This enables a comparison of the risk of a frequent outage event with small CTS consequences, with a rare event with large consequences.

The developed approach has been applied for the generally known Roy Billinton Test System (RBTS). The result shows that the ranking of the components is highly dependent on the substation modelling and the studied system load level.

With the restriction of only evaluating the risks to the transfer capability in a few CTSs, the method provides a quantitative ranking of the potential risks to the system security margin at different load levels. Consequently, the developed reliability based approach provides information which could improve the deterministic criterion for transmission system planning.

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Kreikebaum, Frank Karl. "Control of transmission system power flows." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50392.

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Power flow (PF) control can increase the utilization of the transmission system and connect lower cost generation with load. While PF controllers have demonstrated the ability to realize dynamic PF control for more than 25 years, PF control has been sparsely implemented. This research re-examines PF control in light of the recent development of fractionally-rated PF controllers and the incremental power flow (IPF) control concept. IPF control is the transfer of an incremental quantity of power from a specified source bus to specified destination bus along a specified path without influencing power flows on circuits outside of the path. The objectives of the research are to develop power system operation and planning methods compatible with IPF control, test the technical viability of IPF control, develop transmission planning frameworks leveraging PF and IPF control, develop power system operation and planning tools compatible with PF control, and quantify the impacts of PF and IPF control on multi-decade transmission planning. The results suggest that planning and operation of the power system are feasible with PF controllers and may lead to cost savings. The proposed planning frameworks may incent transmission investment and be compatible with the existing transmission planning process. If the results of the planning tool demonstration scale to the national level, the annual savings in electricity expenditures would be $13 billion per year (2010$). The proposed incremental packetized energy concept may facilitate a reduction in the environmental impact of energy consumption and lead to additional cost savings.

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Ng, Kwok-kei Simon. "A game-theoretic study of the strategic interaction between transmission and generation expansion planning in a restructured electricity market." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39343534.

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Newham, Nikki. "Power System Investment Planning using Stochastic Dual Dynamic Programming." Thesis, University of Canterbury. Electrical and Computer Engineering, 2008. http://hdl.handle.net/10092/1975.

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Generation and transmission investment planning in deregulated markets faces new challenges particularly as deregulation has introduced more uncertainty to the planning problem. Tradi- tional planning techniques and processes cannot be applied to the deregulated planning problem as generation investments are profit driven and competitive. Transmission investments must facilitate generation access rather than servicing generation choices. The new investment plan- ning environment requires the development of new planning techniques and processes that can remain flexible as uncertainty within the system is revealed. The optimisation technique of Stochastic Dual Dynamic Programming (SDDP) has been success- fully used to optimise continuous stochastic dynamic planning problems such as hydrothermal scheduling. SDDP is extended in this thesis to optimise the stochastic, dynamic, mixed integer power system investment planning problem. The extensions to SDDP allow for optimisation of large integer variables that represent generation and transmission investment options while still utilising the computational benefits of SDDP. The thesis also details the development of a math- ematical representation of a general power system investment planning problem and applies it to a case study involving investment in New Zealand’s HVDC link. The HVDC link optimisation problem is successfully solved using the extended SDDP algorithm and the output data of the optimisation can be used to better understand risk associated with capital investment in power systems. The extended SDDP algorithm offers a new planning and optimisation technique for deregulated power systems that provides a flexible optimal solution and informs the planner about investment risk associated with uncertainty in the power system.

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FALEYE, OMOBOBOLA. "Modelling Demand Uncertainties in Generation-Transmission Expansion planning : A case study of the Nigerian Power System." Thesis, KTH, Elektriska energisystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91523.

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The Nigerian power system is one plagued with incessant load shedding due to inadequate generation and transmission capacities. Currently, less than 40% of the population is connected to the national grid and less than 50% of the available installed capacity is actively used in meeting demand. A new wave of energy reforms is on-going in the nation. There are proposed generation and expansion plans. These reforms have only fully taken into consideration present demands and not future energy demands. This means that even with new plants and transmission lines being constructed; there may still be inefficient generation and transmission capacities due to demand increase. This thesis models the uncertain future demands in the integrated generation-transmission planning model. An optimal investment plan is found using the deterministic optimization model of integrated generationtransmission planning. A decision analysis method was initially used to study the introduction of uncertain demand into the deterministic model. Then, a two-stage stochastic model of the generation-transmission planning taking into account uncertainties in energy demand is developed using scenario-wise decomposition method. The demand was modelled as taking discrete values with certain probabilities. These models are mixed-integer linear programming problems. They are implemented in the GAMS platform and solved using the CPLEX solver. A stylized version of the Nigerian power system is developed and tested. A thorough analysis and comparison of results from the models were carried out using the developed version of the Nigerian transmission grid.

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Fitiwi, Desta Zahlay. "Strategies, Methods and Tools for Solving Long-term Transmission Expansion Planning in Large-scale Power Systems." Doctoral thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-192363.

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Driven by a number of factors, the electric power industry is expected to undergo a paradigm shift with a considerably increased level of variable energy sources. A significant integration of such sources requires heavy transmission investments over geographically wide and large-scale networks. However, the stochastic nature of such sources, along with the sheer size of network systems, results in problems that may become intractable. Thus, the challenge addressed in this work is to design efficient and reasonably accurate models, strategies and tools that can solve large-scale TEP problems under uncertainty. A long-term stochastic network planning tool is developed, considering a multi-stage decision framework and a high level integration of renewables. Such a tool combines the need for short-term decisions with the evaluation of long-term scenarios, which is the practical essence of a real-world planning. Furthermore, in order to significantly reduce the combinatorial solution search space, a specific heuristic solution strategy is devised. This works by decomposing the original problem into successive optimization phases.One of the modeling challenges addressed in this work is to select the right network model for power flow and congestion evaluation: complex enough to capture the relevant features but simple enough to be computationally fast. Another relevant contribution is a domain-driven clustering process of snapshots which is based on a “moments” technique. Finally, the developed models, methods and solution strategies have been tested on standard and real-life systems. This thesis also presents numerical results of an aggregated 1060-node European network system considering multiple RES development scenarios. Generally, test results show the effectiveness of the proposed TEP model, since—as originally intended—it contributes to a significant reduction in computational effort while fairly maintaining optimality of the solutions.
Driven by several techno-economic, environmental and structural factors, the electric energy industry is expected to undergo a paradigm shift with a considerably increased level of renewables (mainly variable energy sources such as wind and solar), gradually replacing conventional power production sources. The scale and the speed of integrating such sources of energy are of paramount importance to effectively address a multitude of global and local concerns such as climate change, sustainability and energy security. In recent years, wind and solar power have been attracting large-scale investments in many countries, especially in Europe. The favorable agreements of states to curb greenhouse gas emissions and mitigate climate change, along with other driving factors, will further accelerate the renewable integration in power systems. Renewable energy sources (RESs), wind and solar in particular, are abundant almost everywhere, although their energy intensities differ very much from one place to another. Because of this, a significant integration of such energy sources requires heavy investments in transmission infrastructures. In other words, transmission expansion planning (TEP) has to be carried out in geographically wide and large-scale networks. This helps to effectively accommodate the RESs and optimally exploit their benefits while minimizing their side effects. However, the uncertain nature of most of the renewable sources, along with the size of the network systems, results in optimization problems that may become intractable in practice or require a huge computational effort. Thus, the challenge addressed in this work is to design models, strategies and tools that may solve large-scale and uncertain TEP problems, being computationally efficient and reasonably accurate. Of course, the specific definition of the term “reasonably accurate” is the key issue of the thesis work, since it requires a deep understanding of the main cost and technical drivers of adequate TEP investment decisions. A new formulation is proposed in this dissertation for a long-term planning of transmission investments under uncertainty, with a multi-stage decision framework and considering a high level of renewable sources integration. This multi-stage strategy combines the need for short-term decisions with the evaluation of long-term scenarios, which is the practical essence of a real-world planning. The TEP problem is defined as a stochastic mixed-integer linear programming (S-MILP) optimization, an exact solution method. This allows the use of effective off-the-shelf solvers to obtain solutions within a reasonable computational time, enhancing overall problem tractability. Furthermore, in order to significantly reduce the combinatorial solution search (CSS) space, a specific heuristic solution strategy is devised. In this global heuristic strategy, the problem is decomposed into successive optimization phases. Each phase uses more complex optimization models than the previous one, and uses the results of the previous phase so that the combinatorial solution search space is reduced after each phase. Moreover, each optimization phase is defined and solved as an independent problem; thus, allowing the use of specific decomposition techniques, or parallel computation when possible. A relevant feature of the solution strategy is that it combines deterministic and stochastic modeling techniques on a multi-stage modeling framework with a rolling-window planning concept. The planning horizon is divided into two sub-horizons: medium- and long-term, both having multiple decision stages. The first sub-horizon is characterized by a set of investments, which are good enough for all scenarios, in each stage while scenario-dependent decisions are made in the second sub-horizon. One of the first modeling challenges of this work is to select the right network model for power flow and congestion evaluation: complex enough to capture the relevant features but simple enough to be computationally fast. The thesis includes extensive analysis of existing and improved network models such as AC, linearized AC, “DC”, hybrid and pipeline models, both for the existing and the candidate lines. Finally, a DC network model is proposed as the most suitable option. This work also analyzes alternative losses models. Some of them are already available and others are proposed as original contributions of the thesis. These models are evaluated in the context of the target problem, i.e., in finding the right balance between accuracy and computational effort in a large-scale TEP problem subject to significant RES integration. It has to be pointed out that, although losses are usually neglected in TEP studies because of computational limitations, they are critical in network expansion decisions. In fact, using inadequate models may lead not only to cost-estimation errors, but also to technical errors such as the so-called “artificial losses”. Another relevant contribution of this work is a domain-driven clustering process to handle operational states. This allows a more compact and efficient representation of uncertainty with little loss of accuracy. This is relevant because, together with electricity demand and other traditional sources of uncertainty, the integration of variable energy sources introduces an additional operational variability and uncertainty. A substantial part of this uncertainty and variability is often handled by a set of operational states, here referred to as “snapshots”, which are generation-demand patterns of power systems that lead to optimal power flow (OPF) patterns in the transmission network. A large set of snapshots, each one with an estimated probability, is then used to evaluate and optimize the network expansion. In a long-term TEP problem of large networks, the number of operational states must be reduced. Hence, from a methodological perspective, this thesis shows how the snapshot reduction can be achieved by means of clustering, without relevant loss of accuracy, provided that a good selection of classification variables is used in the clustering process. The proposed method relies on two ideas. First, the snapshots are characterized by their OPF patterns (the effects) instead of the generation-demand patterns (the causes). This is simply because the network expansion is the target problem, and losses and congestions are the drivers to network investments. Second, the OPF patterns are classified using a “moments” technique, a well-known approach in Optical Pattern Recognition problems. The developed models, methods and solution strategies have been tested on small-, medium- and large-scale network systems. This thesis also presents numerical results of an aggregated 1060-node European network system obtained considering multiple RES development scenarios. Generally, test results show the effectiveness of the proposed TEP model, since—as originally intended—it contributes to a significant reduction in computational effort while fairly maintaining optimality of the solutions.

QC 20160919

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Alraddadi, Musfer. "Toward Fully Renewable Power Systems in Regions with HighSolar Irradiation: Long-Term Planning and Operations." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1605791220407664.

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Ng, Kwok-kei Simon, and 吳國基. "A game-theoretic study of the strategic interaction between transmission and generation expansion planning in a restructuredelectricity market." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39343534.

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Ayala, Zelaya Marcos Alexander. "Steady-State Analysis in Transmission System Planning per Latest TPL-001-4 NERC Standard." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/64471.

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Several cascading outages that have occurred in the past have shown the importance of performing appropriate and coordinated transmission system planning between the different Planning Coordinators and Transmission Planners in a power system. In very large, interconnected systems, this coordinated planning is necessary due to the inherent complexity that characterizes non-lineal electric power systems. A major task in transmission system planning is to conduct contingency studies that would determine the consequences in the system when single or multiple of its elements trip due to failure or are disconnected during scheduled maintenance outages. This work develops general programs aimed at facilitating the performance of such contingency studies based on the latest Transmission System Planning Performance Requirement standard issued by NERC, TPL-001-4. The focus of this work is on the requirements for the steady state analysis described in the standard, which includes specific steady state performance planning events. The developed programs have been tested in a few base cases and have demonstrated their ability to facilitate contingency studies with any system regardless of its size.
Master of Science

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Miranda, de Loureiro Manuel Valentim. "Transmission and Interconnection Planning in Power Systems: Contributions to Investment Under Uncertainty and Cross-Border Cost Allocation." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/1105.

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Electricity transmission network investments are playing a key role in the integration process of power systems in the European Union. Given the magnitude of investment costs, their irreversibility, and their impact in the overall development of a region, accounting for the role of uncertainties as well as the involvement of multiple parties in the decision process allows for improved and more robust investment decisions. Even though the creation of this internal energy market requires attention to flexibility and strategic decision-making, existing literature and practitioners have not given proper attention to these topics. Using portfolios of real options, we present two stochastic mixed integer linear programming models for transmission network expansion planning. We study the importance of explicitly addressing uncertainties, the option to postpone decisions and other sources of flexibility in the design of transmission networks. In a case study based on the Azores archipelago we show how renewables penetration can increase by introducing contingency planning into the decision process considering generation capacity uncertainty. We also present a two-party Nash-Coase bargaining transmission capacity investment model. We illustrate optimal fair share cost allocation policies with a case study based on the Iberian market. Lastly, we develop a new model that considers both interconnection expansion planning under uncertainty and cross-border cost allocation based on portfolios of real options and Nash-Coase bargaining. The model is illustrated using Iberian transmission and market data.

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SILVA, ALEXANDRE MOREIRA DA. "TWO-STAGE ROBUST OPTIMIZATION MODELS FOR POWER SYSTEM OPERATION AND PLANNING UNDER JOINT GENERATION AND TRANSMISSION SECURITY CRITERIA." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24754@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Recentes apagões em todo o mundo fazem da confiabilidade de sistemas de potência, no tocante a contingências múltiplas, um tema de pesquisa mundial. Dentro desse contexo, se faz importante investigar métodos eficientes de proteger o sistema contra falhas de alguns de seus componentes, sejam elas dependentes e/ou independentes de outras falhas. Nesse sentido, se tornou crucial a incorporação de critérios de segurança mais rigorosos na operação e planejamento de sistemas de potência. Contingências múltiplas são mais comuns e desastrosas do que falhas naturais e independentes. A principal razão para isso reside na complexidade da estabilidade dinâmica de sistemas de potência. Além disso, o sistema de proteção que opera em paralelo ao sistema de distribuição não é livre de falhas. Portanto, interrupções naturais podem causar contingências em cascata em decorrência do mau funcionamento de mecanismos de proteção ou da instabilidade do sistema elétrico como um todo. Nesse contexto, se dá a motivação pela busca de critérios de segurança mais severos como, por exemplo, o n - K, onde K pode ser maior do que 2. Nesse trabalho, o principal objetivo é incorporar o crtitério de segurança geral n-K para geração e transmissão em modelos de operação e planejamento de sistemas de potência. Além de interrupções em geradores, restrições de rede, bem como falhas em linhas de transmiss˜ao também são modeladas. Esse avanço leva a novos desafios computacionais, para os quais formulamos metodologias de solução eficientes baseadas em decomposição de Benders. Considerando operação, duas abordagens são apresentadas. A primeira propõe um modelo de otimização trinível para decidir o despacho ótimo de energia e reservas sob um critério de segurançaa n - K. Nessa abordagem, a alta dimensionalidade do problema, por contemplar restrições de rede, bem como falhas de geradores e de linhas de transmissão, é contornada por meio da implícita consideração do conjunto de possíveis contingências. No mesmo contexto, a segunda abordagem leva em conta a incerteza da carga a ser suprida e a correlação entre demandas de diferentes barras. Considerando planejamento de expansão da transmissão, outro modelo de otimização trinível é apresentado no intuito de decidir quais linhas de transmissão, dentro de um conjunto de candidatas, devem ser construídas para atender a um critério de segurança n - K e, consequentemente, aumentar a confiabilidade do sistema como um todo. Portanto, as principais contribuições do presente trabalho são as seguintes: 1) modelos de otimização trinível para considerar o critério de segurança n - K em operação e planejamento de sistemas de potência, 2) consideração implícita de todo o conjunto de contingências por meio de uma abordagem de otimização robusta ajustável, 3) otimização conjunta de energia e reserva para operação de sistemas de potência, considerando restrições de rede e garantindo a entregabilidade das reservas em todos os estados pós-contingência considerados, 4) metodologias de solução eficientes baseadas em decomposição de Benders que convergem em passos finitos para o ótimo global e 5) desenvolvimento de restrições válidas que alavancam a eficiência computacional. Estudos de caso ressaltam a eficácia das metodologias propostas em capturar os efeitos econômicos de demanda nodal correlacionada sob um critério de segurançaa n - 1, em reduzir o esfor¸co computacional para considerar os critérios de seguran¸ca convencionais n-1 e n-2 e em considerar critérios de segurança mais rigorosos do que o n - 2, um problema intratável até então.
Recent major blackouts all over the world have been a driving force to make power system reliability, regarding multiple contingencies, a subject of worldwide research. Within this context, it is important to investigate efficient methods of protecting the system against dependent and/or independent failures. In this sense, the incorporation of tighter security criteria in power systems operation and planning became crucial. Multiple contingencies are more common and dangerous than natural independent faults. The main reason for this lies in the complexity of the dynamic stability of power systems. In addition, the protection system, that operates in parallel to the supply system, is not free of failures. Thus, natural faults can cause subsequent contingencies (dependent on earlier contingencies) due to the malfunction of the protection mechanisms or the instability of the overall system. These facts drive the search for more stringent safety criteria, for example, n - K, where K can be greater than 2. In the present work, the main objective is to incorporate the joint generation and transmission general security criteria in power systems operation and planning models. Here, in addition to generators outages, network constraints and transmission lines failures are also accounted for. Such improvement leads to new computational challenges, for which we design efficient solution methodologies based on Benders decomposition. Regarding operation, two approaches are presented. The first one proposes a trilevel optimization model to decide the optimal scheduling of energy and reserve under an n - K security criterion. In such approach, the high dimensionality curse of considering network constraints as well as outages of generators and transmission assets is withstood by implicitly taking into account the set of possible contingencies. The second approach includes correlated nodal demand uncertainty in the same framework. Regarding transmission expansion planning, another trilevel optimization model is proposed to decide which transmission assets should be built within a set of candidates in order to meet an n - K security criterion, and, consequently, boost the power system reliability. Therefore, the main contributions of this work are the following: 1) trilevel models to consider general n - K security criteria in power systems operation and planning, 2) implicit consideration of the whole contingency set by means of an adjustable robust optimization approach, 3) co-optimization of energy and reserves for power systems operation, regarding network constraints and ensuring the deliverability of reserves in all considered post-contingency states, 4) efficient solution methodologies based on Benders decomposition that finitely converges to the global optimal solution, and 5) development of valid constraints to boost computational efficiency. Case studies highlight the effectiveness of the proposed methodologies in capturing the economic effect of nodal demand correlation on power system operation under an n - 1 security criterion, in reducing the computational effort to consider conventional n-1 and n-2 security criteria, and in considering security criteria tighter than n - 2, an intractable problem heretofore.

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Iveson, Kieron. "Perceptions of justice and equity in energy infrastructure : stakeholder perspectives on electricity transmission infrastructure planning : where does power lie?" Thesis, Bangor University, 2018. https://research.bangor.ac.uk/portal/en/theses/perceptions-of-justice-and-equity-in-energy-infrastructure(f0d43186-dbee-4448-a554-1a1825bc9f9f).html.

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In response to the twin challenges of climate change and energy security, the UK government’s energy strategy includes new nuclear power stations. Large scale centralised generation of this type requires transmission infrastructure to carry electricity from where it is generated to where it is needed. This transmission infrastructure, specifically High Voltage Overhead Transmission Lines (HVOTLs), has met with significant community opposition, even where a new nuclear power station appears to be generally accepted. Acceptance of one major development and rejection of another suggests something other than NIMBYism. This research seeks to unpick perceptions of new electricity transmission infrastructure within the context of whole energy system change. The research comprises a case study of Anglesey, the location of the Wylfa Newydd nuclear power station development and associated transmission infrastructure. The research examines stakeholder perceptions of the planning of this new transmission infrastructure and the consultation which forms a part of that process. The research extends common notions of energy justice to include fairness in siting infrastructure and is informed by Lukes’ Radical View of Power and Rawls’ Justice as Fairness. Twenty two in depth semi-structured interviews were carried out with a range of stakeholders including community members, political representatives and electricity industry representatives. From the interviews the following themes were identified: trust; NIMBYism; sense of place; remember Tryweryn; the white elephant in the room; it’s all about the jobs; consultation, representation and democracy; together but separate / separate but together; comparison, conflation and confusion. The fairness of the process by which transmission infrastructure is determined is called into question. Strategic decisions are made upstream of any community engagement. National Grid are viewed as a force from outside imposing their preferred solution. Power for decision making rests firmly outside the community which hosts the infrastructure and stakeholders report that they have little influence on the outcome of the development. While development may be seen as fair or just on a utilitarian basis and on a wider geographical scale, it falls short of more recent formulations of justice. Earlier deliberative engagement with community members may alleviate dissent and contribute to fairer and more just development.

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Santos, Milana Lima dos. "Transmissão de energia elétrica em meia-onda e em corrente contínua - análise técnico-econômica." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-29102012-114533/.

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Ao buscar alternativas para interligação entre importantes centros de geração de energia elétrica localizados no Norte do Brasil e centros consumidores no Nordeste e Sudeste, o setor elétrico brasileiro se depara com o desafio de transpor distâncias superiores a 2000 km. A alternativa em corrente contínua já é bastante utilizada, com desempenho satisfatório. Já a transmissão em meia-onda, ainda não utilizada comercialmente em país algum do mundo, é uma alternativa sugerida por alguns artigos como adequada a esse propósito. Este trabalho se propõe a apresentar uma metodologia de comparação econômica entre alternativas de transmissão e aplicá-la à comparação entre a meia-onda e a corrente contínua, utilizando um cenário muito próximo ao brasileiro. Para possibilitar esta comparação, são apresentados detalhes do funcionamento da linha de meia-onda, já que pouco foi publicado sobre o assunto. São mencionados alguns aspectos adversos de seu comportamento transitório e também são descritas etapas de definição de alternativas de transmissão a serem avaliadas.
In order to connect important power generation plants located in Northern region to the major load centers in the Northeast and Southeast parts of the country, the Brazilian electric sector should deal with the challenge of planning transmission systems to cover distances of more than 2000 km. The HVDC transmission alternative, which has shown satisfactory response and performance to also carry bulk power over long distances, is already used in many countries. Still, the half-wavelength power transmission line (HWLL), not yet commercially used in any country, is an alternative suggested by some papers as suitable for this purpose. Thus, the objective of this work is to present a methodology for the economic comparison amongst the transmission alternatives present today, to thereafter apply it to the HWLL and HVDC transmission technologies. To do so, a closest scenario to that of the Brazilian case will be used. In order to perform this comparison, some details of the HWLL operation are explored, since little was published on this subject. Also, some adverse aspects of the HWLL transient behavior as well as the steps for defining the transmission alternatives to be evaluated are presented.

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Barreto, Alferez Wilmer Edilberto 1976. "Estudo de variantes da particle swarm optimization aplicadas ao planejamento da expansão de sistemas de transmissão." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261312.

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Orientadores: Carlos Alberto de Castro Júnior, Santiago Patricio Torres Contreras
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-23T20:25:48Z (GMT). No. of bitstreams: 1 BarretoAlferez_WilmerEdilberto_M.pdf: 1213079 bytes, checksum: be23433dda22950612c8e4039b4ebba4 (MD5) Previous issue date: 2013
Resumo: O planejamento da expansão da transmissão (PET) consiste em determinar todas as alterações necessárias na infraestrutura do sistema de transmissão, ou seja, ampliações e reforços, a fim de permitir o equilíbrio entre a demanda prevista e o suprimento de energia elétrica, procurando o investimento mínimo ao longo do horizonte de planejamento. O PET é um problema de grande extensão, inteiro misto, não linear, e não convexo. Portanto, mais técnicas de otimização devem ser investigadas para resolvê-lo de forma eficiente. Neste trabalho de pesquisa, o foco do estudo foi a metaheurística de otimização por enxame de partículas (PSO) aplicada ao problema PET estático. Os desempenhos das variantes Global (GPSO) e Local (LPSO) são comparados com quatro novas variantes do PSO baseado no comportamento quântico de otimização por enxame de partículas (QPSO). QPSO considera um comportamento quântico dos movimentos de partículas, de acordo com a mecânica quântica, que, em teoria, levaria a uma melhor convergência global do que o tradicional PSO. Esta pesquisa utiliza o modelo DC das redes de potência, considerando restrições de segurança usando o critério . Os conhecidos sistemas Garver, IEEE de 24 barras, e equivalente sul brasileiro de 46 barras são usados para apresentar os resultados deste trabalho de pesquisa
Abstract: The Transmission Expansion Planning (TEP) consists of determining all the changes needed in the transmission system infrastructure, i.e. additions and reinforcements, in order to allow the balance between the projected demand and the power supply, at minimum investment along the planning horizon. The TEP is a large scale, mixed-integer, non-linear and non-convex problem. Therefore more optimization techniques must be investigated to solve it in an efficient way. In this research work, the focus was on the study of the optimization metaheuristics by particle swarm (PSO) applied to the static version of the TEP problem. The performances of the Global (GPSO) and Local (LPSO) variants are compared against four new PSO variants based on the Quantum-behaved Particle Swarm Optimization (QPSO). QPSO considers a quantum behavior of particles' movements, according to quantum mechanics, which in theory would lead to a better global convergence than traditional PSO. This research uses the DC model for the network and takes into account security constraints using the well-known criterion. The well-known Garver, IEEE 24-bus, and the 46-bus Southern Brazilian equivalent networks will be used to present the results of this research work
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica

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Rigolin, Pascoal Henrique da Costa. "Avaliação global dos modos energéticos de transporte do gás natural inclusive como energia secundária." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-05092007-161143/.

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O objetivo do trabalho é fazer a avaliação global de alguns dos modos energéticos de transporte do gás natural (gasodutos, GNL e GNC), inclusive como energia secundária (eletricidade e GTL). Para a escolha do melhor modo de transporte, além dos custos de cada projeto, serão considerados outros três fatores, que são: impactos ambientais, impactos sociais e riscos políticos. Para isto foi escolhida uma ferramenta de análise conhecida como Avaliação de Custos Completos (ACC), sendo que esta considera os quatro fatores citados anteriormente como de mesma importância na avaliação para um planejamento que vise a sustentabilidade. Para melhor visualização e entendimento do trabalho, foi feito um estudo de caso para o transporte de energia (gás natural e/ou eletricidade) para atender mercados consumidores na região de fronteira entre o Brasil e a Bolívia. Fundamentalmente o estudo do transporte foi feito em solo boliviano, correspondente entre os campos produtores de gás, localizados em Margarita, até a região de fronteira próxima a Corumbá no Mato Grosso do Sul (MS), e também próxima a uma região com grandes jazidas de minério de ferro conhecida como El Mutún. Metodologicamente dentro das quatro dimensões consideradas, foram usados alguns subcritérios mais relevantes para esta análise. Para todos os sub-critérios foram atribuídas notas específicas, de acordo com a região e com o tipo de transporte de energia, e após isto os dados foram passados para um software de tomada de decisão chamado Decision Lens, obtendo assim um rank das melhores opções transporte para a região. Como resultado, o mais coerente para atender a região, são gasodutos de transporte para as demandas elétricas e de gás natural (consumo do MS mais Mutún) e trens carregados com derivados líquidos do gás natural (GTL) para atender a demanda de diesel do MS.
The objective of this work is to make a global evaluation of some energy ways of transport of natural gas (gas-pipelines, LNG and CNG), as well as secondary energy (electricity and GTL). For the selection of a better way of transport, beyond the costs of each project, others three factors were considered: environmental impacts, social impacts and political risks. To perform this, a tool of analysis known as Evaluation of Complete Costs (ACC in portuguese) was chosen. This tool considers the four factors above mentioned as having the same importance in the evaluation process for planning that aims towards sustainability. For better visualization and understanding of the work, a case study for energy transport was made (natural gas and/or electricity) to supply the consumer markets in the region bordering Brazil and Bolivia. Basically the study of the transport was made in Bolivian territory; at the producing gas fields located in Margarita as far as the region bordering Corumbá in the Mato Grosso do Sul area, and also next to a region with great known iron ore deposits known as El Mutún. Methodologically, within the four dimensions above, some more relevant sub-criteria for the analysis were used. For all the sub-criteria considered specific ranks were taken, in accordance with the region and type of transported energy, and after this the data was fed to a software called Decision Lens, thus getting a rank of the best options to carry gas to the region. The results, most coherent way to supply gas to the region, happens to be gas-pipelines of transport for the electric and natural gas demands (consumption in MS plus Mutún) and trains with liquid derivatives of natural gas (GTL) to supply care of the demand of diesel of MS.

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Silveira, Patrícia Oliveira da. "Planejamento de sistemas de transmissão em área com fonte de geração intermitente, apoiado no uso de tecnologias avançadas." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-27062017-105858/.

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O Brasil é um país de dimensões continentais, onde existe uma considerável distância entre a geração e os principais centros de consumo. Dessa forma, o estudo e desenvolvimento de novas tecnologias de transmissão a longas distâncias é de fundamental importância para o desenvolvimento do país. A solução mais utilizada atualmente é a transmissão em corrente alternada. Entretanto a transmissão em corrente continua também é uma solução viável para longas distâncias. O sistema brasileiro é composto principalmente por linhas 500 kV em corrente alternada (também há 230; 345; 440 e 750 kV), bem como em corrente continua (em ±600 e ±800 kV). O presente estudo apresenta uma solução de transmissão em corrente alternada por linhas de 1000 kV, que se mostrou mais econômico na transmissão de potências superiores a 3.500 MW e distâncias de 1400km. Nos próximos anos, a geração de energia elétrica no Brasil será expandida de forma significativa, ocorrerá um aumento principalmente na geração de energia eólica e solar, localizadas em sua maioria na região Nordeste do país. Esse aumento na geração exigirá a transmissão de grandes blocos de energia elétrica por distâncias significativas, devido à falta de proximidade entre a geração e os principais centros consumidores, que estão localizados no Sudeste. Neste estudo, serão mostradas as etapas de definição de condutor economicamente mais adequado e projeto da geometria da torre. Com base nos dados obtidos, será feita a avaliação do desempenho da linha 1000 kV, durante a operação normal de fluxo de carga, curtos-circuitos e estabilidade.
Brazil, a country of continental proportions, have significant distance between the power generation centers and the main consumer centers. In such way, the study and development of new transmission technologies over long distances is of fundamental importance for the development of the country. Nowadays, the most commonly used solution is alternating current transmission. However, direct current transmission is also a viable solution for long distances. The Brazilian system mainly consists of 500 kV alternating current lines (along with 230, 345, 440 and 750 kV) and direct current lines (± 600 and ± 800 kV). This study provides a solution for transmission in alternating current by lines of 1000 kV, which proved to be more economical in power transmission over 3,500 MW and distances beyond 1400km. In the coming years, the electric power generation in Brazil will expand significantly; a boost will take place mainly in wind and solar power generation, located mostly in the Northeast of the country. This generation expansion will require transmission of large blocks of electric power over considerable distances, due to the lack of proximity between generation sites and main consumer centers located in the Southeast. This study will show the setting stages of the most economically applicable conductor and tower geometry design. Based on the data obtained, the performance of the 1000 kV line will be evaluated during the regular load flow operation, short circuits and stability.

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Melchor, Gutiérrez José Nicolás. "Meta-heurísticas aplicadas ao modelo AC no planejamento da expansão de sistemas de transmissão /." Ilha Solteira, 2019. http://hdl.handle.net/11449/182488.

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Orientador: Rubén Augusto Romero Lázaro
Resumo: Os sistemas elétricos do futuro próximo terão um comportamento dinâmico porque grandes fontes renováveis de geração, principalmente geração eólica e solar, serão construídas nos sistemas de potência de vários países do mundo incluindo o Brasil. A incerteza introduzida pelas fontes renováveis de energia é um problema que deve ser solucionado. Para resolver o problema da incerteza é necessário criar uma rede mais flexível. A alocação de armazenadores de energia no sistema de potência será necessária para lidar com as novas incertezas e para manter o funcionamento adequado do sistema. Adicionalmente, o sistema de transmissão deve-se tornar muito mais ativo através do uso de novas tecnologias flexíveis que permitirão ter um controle ótimo do sistema. As novas tecnologias incluem Sistemas Flexíveis de Transmissão em Corrente Alternada (FACTS), sistemas de transmissão de corrente continua (HVDC) e outras tecnologias que permitirão controlar as direções dos fluxos de potência sem alterar a geração ou demanda do sistema. Portanto, nesta tese são estudadas diferentes representações matemáticas para os problemas de fluxo de potência ótimo (FPO), planejamento da transmissão de longo prazo (PERT) e alocação de fontes de reativos (AFR) usando as equações de fluxo de potência de corrente alternada (CA). Adicionalmente, são propostas novas formulações para representar os problemas de fluxo de potência ótimo multiperíodo para sistemas de transmissão ativos que incluem FACTS, sistemas HVDC e ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The future power systems will have a dynamic behaviour due to a significant amount of renewable generation, especially wind and solar generation, will be installed in the power systems of many countries in the world including Brazil.The uncertainty introduced by the renewable energy resources is a problem that has to be solved. The development of a flexible network is necessary to solve the aforementioned problem. The installation of energy storage in the power system will be necessary to manage the new uncertainties and to maintain the adequate system’s operation. Additionally, the transmission system will become more active though new flexible technologies, which allows having an optimal control of the power system. The new technologies include Flexible AC Transmission System (FACTS), High Voltage Direct current (HVDC) transmission systems and other technologies, which allow controlling the power flow direction without changing the power injections of generation or demand. Therefore, in this thesis are studied different mathematical formulations using the AC power flow equations for the optimal power flow (OPF) problem, the transmission expansion planning (TEP) problem and the reactive power planning (RPP) problem. Furthermore, two additional contributions have been made. The first contribution is the development of new mathematical formulations for the multiperiod optimal power flow for active transmission systems that includes FACTS, HVDC and batteries. The second contrib... (Complete abstract click electronic access below)
Doutor

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Ramos, Dorel Soares. "Maximização de limites de carregamento e padronização de subestações e linhas de transmissão: um suporte ao planejamento de redes elétricas em ambiente de restrições financeiras." Universidade de São Paulo, 1996. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-03072017-105114/.

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Este trabalho tem por meta focalizar a adaptação necessária na metodologia de planejamento atual, norteada segundo uma ótica determinística e conservadora, afim de permitir a elaboração de Programas de Obras de Transmissão/Subtransmissão, condicionados por limitações de teto no montante de investimento a curto e médio prazos. Para tanto, como tema central, busca-se desenvolver uma base conceitual e metodológica, para permitir uma exploração maximizada das possibilidades de carregamento de equipamentos e instalações do sistema de transmissão, contemplando a especificação das ferramentas computacionais necessárias para dar consequência prática à proposta. Considerando o potencial de análise proporcionado por métodos e técnicas de natureza probabilística, aplicados ao planejamento de Sistemas Elétricos, a espinha dorsal da evolução metodológica delineada no texto repousa sobre a avaliação de confiabilidade global e quantificação de riscos operativos. O texto foi estruturado em 8 capítulos onde, a partir de um capítulo introdutório, enfoca-se sequencialmente os temas: * Conceitos e Metodologias para Maximização do Carregamento de Transformadores de Potência. * Conceitos e Metodologias para Maximização do Carregamento de Linhas aéreas de Transmissão. * Impacto das Restrições Financeiras no planejamento e possibilidade de atuação a nível técnico para administrar o conflito entre qualidade de serviço e recursos limitados. * Conceitos e Metodologias para relaxação dos Critérios limitantes para o carregamento máximo de componentes do sistema, em ambiente de severas restrições financeiras, no horizonte de curto prazo. * Resultados obtidos em aplicações concretas a situações do Setor Elétrico, visando caracterizar o alcance do ferramental preconizado nos capítulos anteriores. * Critérios e Procedimentos para Padronização de Subestações e Linhas de Transmissão , coerentes com os conceitos de maximização de carregamento introduzidos nos dois primeiros capítulos. Ao final do texto, incluiu-se um capítulo de \"Conclusões\", com o objetivo de sumarizar os aspectos mais relevantes abordados no texto, assim como indicar linhas de ação e novos desenvolvimentos, necessários para permitir a efetivação prática da metodologia proposta.
An important problem posed to power system planners in developing countries is now becoming commonplace, even in developed countries, and concerns on how to fit an expansion plan into a tight budget, with the least reduction in reliability levels. This problem is known as power system planning under financial constraints and a series of methods is now available to deal with it. So, this work addresses the necessary adjustments in order to permit the Transmission / Sub-transmission Expansion Program establishment when there are investments constraints in a medium/short term range. The main emphasis is on the development of a methodological and conceptual framework, aiming at a maximizes exploration of the loading capability of transformers and transmission lines of the power network. In this context, a new methodological framework for transmission system planning in a financial constrained environment is presented. The proposed approach combines transmission projects priority evaluation and ranking as well as criteria flexibilization, being particularly suitable for short-term planning. The problem to be faced is to operate the system after a project postponement, while the service quality is kept so adequate as it is possible. One of the main issues to be focused is the transmission system uprating since a maximized equipment utilization can contribute to avoid a more significant restriction to the costumers. Therefore, a detailed description of the models for transmission lines and transformers loading limits assessment is presented, with emphasis on the main concepts and the application of probabilistic tools to circumvent the inherent conservatism of deterministic methods. A summary of the contents is presented in what follows: * Concepts and Methodology for Transformers loading maximization. * Concepts and Methodology for Transmission Lines loading maximization. * Financial Restrictions impacts on Expansion Planning Process and the possibilities to manager the conflict between service quality and investment constraints. * Concepts and Methodologies to the relaxation of Criteria that limits the loading capability of transmission lines, aiming at short term Planning under severe financial restrictions, * Obtained results in concrete applications of the proposed methodology and computational tools to Brazilian Electric Power System. * Methods and Criteria to standardization of Substations and Transmission Lines, according the main issues formerly introduced. * Conclusion and Future Research.

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Klas, Juliana. "Planejamento da expansão do sistema de transmissão com dispositivos FACTS e links CC empregando metodologia Branch-and-Bound adaptada." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/108467.

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Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento.
This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.

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Hayat, Hassan. "Polar vortex and generation fuel diversity." Kansas State University, 2015. http://hdl.handle.net/2097/19094.

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Master of Science
Department of Electrical and Computer Engineering
Anil Pahwa
The unusual weather events during the polar vortex of 2014 illuminated the needs for fuel diversity for power generation in order to allow reliable operation of the electricity grid. A system wide reliability assessment for winter months should be undertaken in addition to the summer months to ensure reliable operation of the electricity grid throughout the year. Severe weather conditions that lead to equipment malfunction during the polar vortex should be thoroughly investigated and remediations to ensure satisfactory future performance of the grid must be undertaken. Environmentally unfriendly emissions from power plants must be minimized but diversity of generation fuel must be maintained. Future energy policies must be formulated with consideration that approximately 14 GW of coal generation in Pennsylvania Jersey Maryland Regional Transmission Organization’s control area available during the polar vortex will be retired by 2015 and replaced with plants that utilize fuel types other than coal.

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Rider, Flores Marcos Julio 1975. "Planejamento da expansão de sistemas de transmissão usando os modelos CC - CA e tecnicas de programação não-linear." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260508.

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Orientador: Ariovaldo Verandio Garcia, Ruben Augusto Romero Lazaro
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Neste trabalho são propostos modelos matemáticos e técnicas de solução para resolver o problema de planejamento da expansão de sistemas de transmissão através de três enfoques. a) Usando o modelo de corrente alternada do sistema de transmissão e um algoritmo heurístico construtivo especializado para resolver o problema de planejamento, e, ainda, realiza-se uma primeira tentativa de alocação de fontes de potência reativas; b) Usando o modelo de corrente contínua e técnicas de programação não-linear especializadas. Nesse caso emprega-se uma versão relaxada do problema de planejamento da expansão de sistemas de transmissão usando o modelo de corrente contínua, onde a integralidade das variáveis de investimento é desprezada. Resolve-se o problema de programação não-linear, modelado de forma matricial com um algoritmo de otimização especializado e, além disso, um algoritmo heurístico construtivo especializado é utilizado para resolver o problema de planejamento. c) Usando o modelo de corrente contínua e um algoritmo Branch and Bound (B&B) sem empregar técnicas de decomposição. Para isso foram redefinidos os chamados testes de sondagem no algoritmo B&B e em cada nó da árvore de B&B tem-se um problema de programação não-linear que são resolvidos usando a metodologia desenvolvida no item (b). Os ítens (a), (b) e (c) requerem a solução de problemas de programação não-linear diferenciados. Uma revisão das características principais da resolução iterativa dos métodos de pontos interiores é apresentada. Foi desenvolvida uma técnica baseada em uma combinação de métodos de pontos interiores de alta ordem (MPI-AO) para resolver os problemas de programação não-linear de forma rápida, eficiente e robusta. Essa combinação dos MPI-AO tem como objetivo colocar num único método as características particulares de cada um dos MPI-AO e melhorar o desempenho computacional comparado com os MPI-AO de forma individual
Abstract: In this work mathematical models and solution techniques are proposed to solve the power system transmission expansion planning problem through three approaches: a) Using the nonlinear model ofthe transmission system (AC model) and a specialized constructive heuristic algorithm to solve the problem and, yet, a first attempt to allocate reactive power sources is also considered; b) Using the direct-current (DC) model and specialized techniques of nonlinear programming. In this case a version of the power system transmission expansion planning problem using the DC model where the integrality of the investment variables is relaxed is used. The nonlinear programming problem is solved with a specialized optimization algorithm and, moreover, a constructive heuristic algorithm is employed to solve the planning problem. c) Using the DC model and Branch and Bound (B&B) algorithm without the use of decomposition techniques. The so called fathoming tests of the B&B were redefined and at each node of the tree a nonlinear programming problem is solved using the method developed in b). Items a), b) and c) require the solution of distinct problems of nonlinear programming. A revision of the main characteristics of the iterative solution of the interior points methods is presented. An optimization technique based on a combination of the higher order interior point methods (HO-IPM) had been developed to solve the nonlinear programming problems in a fast, efficient and robust way. This combination of the HO-IPM has as objective to explore the particular characteristics of each method in a single one and to improve the comparative computational performance with the HO-IPM of individual form
Doutorado
Energia Eletrica
Doutor em Engenharia Elétrica

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Villajuan, Montes Cristiam Victor [UNESP]. "Modelos de programação linear inteira mista para resolver problemas de planejamento da expansão e da operação de sistemas de transmissão de energia elétrica." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143075.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Os problemas de planejamento da expansão de sistemas de transmissão e de fluxo de potência ótimo são de grande importância na área de sistemas de transmissão de energia elétrica. O primeiro consiste em determinar a expansão ótima do sistema, que deve ocorrer com o menor gasto monetário possível. No problema fluxo de potência ótimo deve-se encontrar o estado de operação do sistema de forma a minimizar um objetivo, no caso, os custos de geração. Ambos problemas possuem modelos de programação não-linear inteira mista. Além disto, o resultado ótimo de ambos deve cumprir com restrições operacionais, como o limite de tensão nas barras, os limites de fluxos nos ramos e os limites dos geradores. Para resolver os problemas citados, neste trabalho são apresentados modelos matemáticos de programação linear inteiro misto, aproximados, baseados em um modelo linearizado de fluxo de carga AC, que considera a presença da potência reativa, das perdas no sistema e magnitudes de tensões nas barras diferentes do valor nominal. Todos os modelos foram escritos na linguagem de modelagem matemática AMPL e resolvidos com o solver comercial CPLEX. Os modelos propostos foram testados com os sistemas IEEE de 14, 30, 57, 118 e 300 barras e com o sistema Garver para o planejamento da expansão de sistemas de transmissão. Os resultados foram comparados utilizando-se um fluxo de carga não linear, para verificar-se a precisão dos modelos propostos.
The transmission network expansion planning and the optimal power flow problems are of great importance in the field of electricity transmission systems. The first consists in determining the optimal expansion of the system, which must be done with the least possible investment. In the optimal power flow problem it must found the operating status of the system in order to minimize an objective, in this case, generation costs. Both problems have mixed-integer nonlinear programming models. In addition, the optimal solution of both must comply with operating constraints, such as the voltage limit on buses, the limits flows in branches and the limits of the generators. To solve the problems cited, in this work are presented approximate mixed integer linear programming models based on a linearized AC load flow model, which considers the presence of reactive power, the losses in the system and of nominal bus voltage magnitudes. All models were written in mathematical modeling language AMPL and solved with the commercial solver CPLEX. The proposed models were tested with the IEEE systems of 14, 30, 57, 118 and 300 buses and with the Garver system for transmission network expansion planning. Results were compared using a nonlinear load flow model, to verify the accuracy of the proposed models.

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38

Villajuan, Montes Cristiam Victor. "Modelos de programação linear inteira mista para resolver problemas de planejamento da expansão e da operação de sistemas de transmissão de energia elétrica /." Ilha Solteira, 2016. http://hdl.handle.net/11449/143075.

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Orientador: Marcos Julio Rider Flores
Resumo: Os problemas de planejamento da expansão de sistemas de transmissão e de fluxo de potência ótimo são de grande importância na área de sistemas de transmissão de energia elétrica. O primeiro consiste em determinar a expansão ótima do sistema, que deve ocorrer com o menor gasto monetário possível. No problema fluxo de potência ótimo deve-se encontrar o estado de operação do sistema de forma a minimizar um objetivo, no caso, os custos de geração. Ambos problemas possuem modelos de programação não-linear inteira mista. Além disto, o resultado ótimo de ambos deve cumprir com restrições operacionais, como o limite de tensão nas barras, os limites de fluxos nos ramos e os limites dos geradores. Para resolver os problemas citados, neste trabalho são apresentados modelos matemáticos de programação linear inteiro misto, aproximados, baseados em um modelo linearizado de fluxo de carga AC, que considera a presença da potência reativa, das perdas no sistema e magnitudes de tensões nas barras diferentes do valor nominal. Todos os modelos foram escritos na linguagem de modelagem matemática AMPL e resolvidos com o solver comercial CPLEX. Os modelos propostos foram testados com os sistemas IEEE de 14, 30, 57, 118 e 300 barras e com o sistema Garver para o planejamento da expansão de sistemas de transmissão. Os resultados foram comparados utilizando-se um fluxo de carga não linear, para verificar-se a precisão dos modelos propostos.
Abstract: The transmission network expansion planning and the optimal power flow problems are of great importance in the field of electricity transmission systems. The first consists in determining the optimal expansion of the system, which must be done with the least possible investment. In the optimal power flow problem it must found the operating status of the system in order to minimize an objective, in this case, generation costs. Both problems have mixed-integer nonlinear programming models. In addition, the optimal solution of both must comply with operating constraints, such as the voltage limit on buses, the limits flows in branches and the limits of the generators. To solve the problems cited, in this work are presented approximate mixed integer linear programming models based on a linearized AC load flow model, which considers the presence of reactive power, the losses in the system and of nominal bus voltage magnitudes. All models were written in mathematical modeling language AMPL and solved with the commercial solver CPLEX. The proposed models were tested with the IEEE systems of 14, 30, 57, 118 and 300 buses and with the Garver system for transmission network expansion planning. Results were compared using a nonlinear load flow model, to verify the accuracy of the proposed models.
Mestre

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39

Rodrigues, Luiz Giovani Lopes. "Estudo do acoplamento elétrico-energético no planejamento da operação de curto-curtíssimo prazo utilizando FPOCA." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-26052017-105300/.

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Este trabalho traz um estudo inicial do acoplamento elétrico-energético no planejamento da operação de curto-curtíssimo prazo utilizando Fluxo de Potência Ótimo em Corrente Alternada (FPOCA) com o objetivo de averiguar possíveis desvios entre o planejamento energético e o planejamento elétrico. É feita uma análise da influência dos aspectos elétricos do sistema de transmissão no planejamento energético de curto prazo utilizando-se um FPOCA, juntamente com a minimização do custo da geração e das perdas na transmissão. A minimização do custo da geração é feita através de uma otimização do sistema hidrotérmico utilizando-se um Programa de Otimização de Sistema Hidrotérmico (POSH) baseado em um algoritmo simplex convexo e na aplicação da teoria de fluxo em rede, enquanto que a minimização das perdas na transmissão é feita utilizando-se um FPOCA baseado no método Dual-Newton. Estas ferramentas permitem analisar a necessidade de ajustes para compatibilizar a otimização energética e a otimização elétrica de um sistema eletroenergético, e buscar um planejamento \"ótimo\" que atenda os planejamentos energético e elétrico. Dessa forma, a interface elétrico-energética se torna mais \"forte\", pois as metas de geração obtidas pelo planejamento de curto prazo que serão passadas para o planejamento de curtíssimo prazo, já incluem o efeito dos aspectos elétricos do sistema. Isto proporciona um controle dos desvios da trajetória \"ótima\" do sistema, o que contribui para melhorar a otimização global do planejamento da operação eletroenergética.
This work brings a beginning study of the electric-energetic coupling in the short-shortest term operation planning using Optimal Power Flow in Alternate Current (OPFAC) aiming to inquire possible mismatches between the energetic planning and the eletric planning. It is made an analysis of the electrical aspects influence in the short term energetic planning using OPFAC together with the minimization of generation cost and the transmission losses. The generation cost minimization is made for the hidrothermal system optimization using a Hydrothermal System Optimization Program (POSH) based on a convex simplex algorithm and the application of the network flow theory, while the transmission losses minimization is made using an OPFAC based on the Dual-Newton method. These tools allow to analyze the necessity of adjustments to make compatible the energetic optimization and the electric optimization of the power system, and to search an \"optimal\" planning that attends both the energetic planning and electric planning. Like this, the electric-energetic interface becomes strongest, therefore the generation goals gotten by the short-term planning, that will be passed to the shortest-term planning, already includes the effect of the electric system aspects. These one provide the mismatches control in the optimal trajectory of the system and it contributes to improve the global optimization of power system operation planning. The analyzed system is the 440 kV Equivalent System of CESP (Energetic Company of São Paulo), with 53 bus, being 7 generation bus, 85 transmission lines and 48 transformers.

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Poubel, Raphael Paulo Braga. "Planejamento dinâmico da expansão de sistemas de transmissão de energia elétrica." Universidade Federal de Juiz de Fora (UFJF), 2016. https://repositorio.ufjf.br/jspui/handle/ufjf/3146.

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O presente trabalho propõe um modelo não linear inteiro misto para o planejamento dinâmico da expansão da transmissão. Para a representação do modelo, se fez uso do ﬂuxo de carga CC. As equações básicas do ﬂuxo CC foram modiﬁcadas e expandidas de forma a incluir as variáveis de decisão e o acoplamento temporal entre os investimentos. Para a solução do modelo, de forma a mitigar as diﬁculdades inerentes à programação inteira, foram propostas técnicas de solução passo a passo. Em cada uma das técnicas as variáveis inteiras foram substituídas por uma função contínua de forma a se obter tempos computacionaisviáveis. Adiscretizaçãodasvariáveisinteirassedácomoauxíliodeíndices de sensibilidade apropriados, calculados a partir do modelo acoplado. O trabalho também investiga metodologias para o planejamento dinâmico de linhas de transmissão, buscando um equilíbrio entre a economia e a conﬁabilidade no processo de decisão dos investimentos. O critério determinístico N-1 foi escolhido para garantir maior conﬁabilidade ao sistema.
This work proposes a non-linear mixed integer model for dynamic transmission lines expansion planning. The DC load ﬂow was used to represent the model. The basic equationsoftheDCloadﬂowweremodiﬁedandexpandedtoincludethedecisionvariables and the temporal coupling between investments. For the model solution, in order to mitigate the diﬃculties inherent of integer programming, step-by-step processes were proposed. In each of the techniques the integer variables have been replaced with a continuous function to obtain viable computational time. The discretization of the integer variables is made with the aid of appropriate sensitivity indexes, calculated from the coupled model. The work also suggests methods for dynamic transmission planning, seeking a balance between the economy and reliability in the investment decision process. The N-1 deterministic criteria was chosen to ensure system reliability.

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"Transmission Expansion Planning for Large Power Systems." Doctoral diss., 2013. http://hdl.handle.net/2286/R.I.18820.

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abstract: Transmission expansion planning (TEP) is a complex decision making process that requires comprehensive analysis to determine the time, location, and number of electric power transmission facilities that are needed in the future power grid. This dissertation investigates the topic of solving TEP problems for large power systems. The dissertation can be divided into two parts. The first part of this dissertation focuses on developing a more accurate network model for TEP study. First, a mixed-integer linear programming (MILP) based TEP model is proposed for solving multi-stage TEP problems. Compared with previous work, the proposed approach reduces the number of variables and constraints needed and improves the computational efficiency significantly. Second, the AC power flow model is applied to TEP models. Relaxations and reformulations are proposed to make the AC model based TEP problem solvable. Third, a convexified AC network model is proposed for TEP studies with reactive power and off-nominal bus voltage magnitudes included in the model. A MILP-based loss model and its relaxations are also investigated. The second part of this dissertation investigates the uncertainty modeling issues in the TEP problem. A two-stage stochastic TEP model is proposed and decomposition algorithms based on the L-shaped method and progressive hedging (PH) are developed to solve the stochastic model. Results indicate that the stochastic TEP model can give a more accurate estimation of the annual operating cost as compared to the deterministic TEP model which focuses only on the peak load.
Dissertation/Thesis
Ph.D. Electrical Engineering 2013

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Oloomi, Buygi Majid. "Transmission Expansion Planning in Deregulated Power Systems." Phd thesis, 2004. https://tuprints.ulb.tu-darmstadt.de/486/1/PhD_Thesis_Oloomi.pdf.

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The main goal of this thesis is to present a centralized static approach for transmission expansion planning in deregulated power systems. Restructuring and deregulation have unbundled the roles of network stakeholders. They exposed transmission planner to the new objectives and uncertainties. Unbundling the roles has brought new challenges for stakeholders. In these environments, stakeholders have different desires and expectations from the performance and expansion of the system. Therefore, new incentives and disincentives have emerged regarding transmission expansion decisions. This research work is involving with considering new objectives and uncertainties in transmission expansion planning. This research work is handled in six main parts. In the first part a probabilistic tool is presented for analyzing the performance of electric markets. In this part probability density function of locational marginal prices are computed for analysis electric market. The approach was applied to an 8-bus network. The effects of load curtailment and wheeling power on nodal prices were studied. The study shows wheeling transactions affect the locational marginal prices of the control area which transmit through them. It also shows that making wheeling transaction in proper directions can reduce the transmission congestion and postpone transmission expansion. In the second part, two market based criteria are presented to measure how much an expansion plan facilitates and promotes competition. The criteria are “average congestion cost” and “weighted standard deviation of mean of locational marginal prices”. Different weights are used in order to provide a competitive environment for more power system participants. Justification of costs is very important in competitive environments. Therefore the presented criteria are extended in order to consider transmission expansion costs. In the third part of the work, a transmission expansion planning approach is presented for deregulated environments. This approach consists of scenario technique and probabilistic optimal power flow which was presented in the first part. Scenario technique is used to take into account the non-random uncertainties. Probabilistic optimal power flow is used to consider the random uncertainties. The approach uses the market based criteria to measure the goodness of expansion plans. Market based criteria provide a non-discriminatory competitive environment for stakeholders. Minimax regret criterion is used in scenario technique for risk assessment and selecting the final plan. To determine which criterion leads to zero congestion cost and flat price profile at minimum cost or at minimum number of expansion plans, the presented approach was applied on IEEE 30 bus test system. The conventional risk assessment has some drawbacks. In the fourth part, drawbacks of scenario technique criteria are pointed out. New criteria are defined for the scenario technique. Fuzzy multi criteria decision making is used for the risk assessment of solutions. In this method a fuzzy appropriateness index is defined for selecting the final plan. The fuzzy appropriateness index is computed by aggregation of importance degrees of decision criteria and appropriateness degrees of expansion plans versus decision criteria. The presented approach is applied to IEEE 30 bus test system. The result was compared with conventional risk assessment in different cases. The comparison shows that fuzzy risk assessment overcomes the shortcomings of conventional risk assessment method. In the fifth part of the work, a transmission expansion planning approach with consideration given to stakeholders’ desires is presented. The approach considers the desires of demand customers, power producers, network owner(s), system operator, and regulator in transmission expansion planning. Stakeholders’ desires can be sought in competition, reliability, flexibility, network charge and environmental impacts. Fuzzy decision making is used for taking into account the desires of all stakeholders. A fuzzy appropriateness index is defined for measuring the goodness of expansion plans. The appropriateness index is defined by aggregating importance weights of stakeholders in decision making, importance degrees of stakeholders’ desires from the viewpoint of different stakeholders, and appropriateness degrees of expansion plans versus stakeholders’ desires. The approach was applied to IEEE 30 bus test systems to find the plan which compromise between stakeholders’ desires. The presented approach in the fifth part can not consider non-random uncertainties. In the sixth part, the presented approach is extended to consider stakeholders’ desires under non-random uncertainties. Fuzzy appropriateness index is defined to measure the goodness of each expansion plan in each scenario with considering the stakeholders’ desires. Fuzzy regret is defined with considering the occurrence degrees of future scenarios. Fuzzy regret of plan k in scenario l is equal to difference between the fuzzy appropriateness index of plan k in scenario l and fuzzy appropriateness index of optimal plan of scenario l. Fuzzy risk assessment is used to find the final plan. The steps of planning were described in details by applying the approach to an eight bus system. The following results were obtained from the simulation. The criteria “average congestion cost” and “weighted standard deviation of mean of locational marginal prices” with the weight “sum of mean of generation and load” are the best criteria for providing a competitive electric market. “Average congestion cost” is more insensitive that other criteria to the occurrence degrees of future scenarios. Fuzzy risk assessment overcomes the shortcomings of conventional risk assessment method. The presented approach selects the final plan by compromising between stakeholders’ desires.

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Chen, Ping-Jung, and 陳平榮. "Data Mining on Planning HSDPA Power Transmission." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/74880026985589710842.

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碩士
世新大學
資訊管理學研究所(含碩專班)
95
3G (Third Generation Telecommunoication) operators in Taiwan launched their commercial 3G network in year 2005 and ushered us in a new era of telecommunication. Without doubt, this wide band service has provided all kinds of the value-added service a great platform to play. In 2006 Q4, all 3G operators introduced HSDPA (High Speed Downlink Packet Access) service to their existing UMTS (Universal Mobile Telecommunications System) network which has leap forward user throughput to mega-bit per second level. In the meantime, UMTS technology has enrolled the towering position of mobile communication network and threatens with the replacing of the fix line DSL service. Operator can introduce HSDPA service without additional hardware resource at the initial phase due to low utilization. HSDPA service share all system resource including radio resource with existing 3G services. Thus existing 3G service quality may degrade if we are not focusing on the network resource planning especially to the radio resources. This research is to introduce data mining skills to process huge amount of radio network parameters and figures. The main object is to find out the compromise between radio network quality and HSDPA user throughput before the HSDPA service is on-air.

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Kosterev, Dmitry N. "Planning for controllable network devices in power transmission systems." Thesis, 1996. http://hdl.handle.net/1957/34617.

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The full capacity of the existing transmission lines is often underutilized due to the system stability requirements. Controllable network devices represent the effective means of improving the system stability, and their deployment allows better use of the existing transmission facilities and can help to avoid construction of new lines. This dissertation addresses system analysis and modeling of controllable network devices. Transient angle stability is one of the major requirements limiting transfer capability of the power transmission systems. The theoretical concepts of transient angle controllability using controllable network devices are considered in this dissertation. The main results are derived for a general transmission network structure and applied to series and shunt compensators as well as braking resistors. The proposed approach allows to quantify controllability and to relate it to the control device size, type and location in the transmission network. Transient stability controllers are needed to maximize the device effect on the transient angle stability enhancement. The transient stability controller functional structure is discussed and the design requirements for each component are specified. The examples of controller designs are presented. Emerging technologies such as Thyristor-Controlled Series Compensators and Synchronous Voltage Sources offer superior control capabilities and performance characteristics as compared to conventional compensators. Unlike conventional compensators, the new controllable network devices are very complex dynamical systems and require more comprehensive modeling for time-domain studies and controller designs. Detailed models of a Thyristor-Controlled Series Compensator and a Synchronous Voltage Source for powerflow, transient stability, and electro-magnetic transient studies are presented. Finally, a detailed planning study for increasing transfer capability of the Montana transmission system using controlled series compensation is presented. A variety of design and performance requirements is considered in this study, which makes it a useful reference for similar planning projects.
Graduation date: 1996

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"HTLS UPGRADES FOR POWER TRANSMISSION EXPANSION PLANNING AND OPERATION." Master's thesis, 2014. http://hdl.handle.net/2286/R.I.24825.

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abstract: Renewable portfolio standards prescribe for penetration of high amounts of re-newable energy sources (RES) that may change the structure of existing power systems. The load growth and changes in power flow caused by RES integration may result in re-quirements of new available transmission capabilities and upgrades of existing transmis-sion paths. Construction difficulties of new transmission lines can become a problem in certain locations. The increase of transmission line thermal ratings by reconductoring using High Temperature Low Sag (HTLS) conductors is a comparatively new technology introduced to transmission expansion. A special design permits HTLS conductors to operate at high temperatures (e.g., 200oC), thereby allowing passage of higher current. The higher temperature capability increases the steady state and emergency thermal ratings of the transmission line. The main disadvantage of HTLS technology is high cost. The high cost may place special emphasis on a thorough analysis of cost to benefit of HTLS technology im-plementation. Increased transmission losses in HTLS conductors due to higher current may be a disadvantage that can reduce the attractiveness of this method. Studies described in this thesis evaluate the expenditures for transmission line re-conductoring using HTLS and the consequent benefits obtained from the potential decrease in operating cost for thermally limited transmission systems. Studies performed consider the load growth and penetration of distributed renewable energy sources according to the renewable portfolio standards for power systems. An evaluation of payback period is suggested to assess the cost to benefit ratio of HTLS upgrades. The thesis also considers the probabilistic nature of transmission upgrades. The well-known Chebyshev inequality is discussed with an application to transmission up-grades. The Chebyshev inequality is proposed to calculate minimum payback period ob-tained from the upgrades of certain transmission lines. The cost to benefit evaluation of HTLS upgrades is performed using a 225 bus equivalent of the 2012 summer peak Arizona portion of the Western Electricity Coordi-nating Council (WECC).
Dissertation/Thesis
M.S. Electrical Engineering 2014

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Oloomi, Buygi Majid [Verfasser]. "Transmission expansion planning in deregulated power systems / Majid Oloomi Buygi." 2004. http://d-nb.info/972516883/34.

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Lin, Wei-Che, and 林維哲. "Study on Assessment Method of Regional Power Transmission Grid Planning Projects." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ueq6ds.

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碩士
國立臺灣科技大學
電機工程系
104
This study aims to explore the regional power transmission grid projects to set up their assessment method of planning. Other than satisfy load demand in the given future and removing the foreseeable bottlenecks, regional power transmission grid planning and establishment plays a more important role in reducing circuit losses and uplifting power supply reliability and quality. Satisfying the future load demand and removing the foreseeable bottlenecks is the basic issue for building up the regional power transmission grid. First, it is essential to find the reliable mesoscale mid long term load forecasting. Next, the bottlenecks of regional power transmission grid year after year need be grasp. Bringing up the proper and feasible assessment method of planning to satisfy the future load demand. Furthermore, it is essential to completely grasp the assessment about the feasibility and suitable construction period of potential transmission lines. Finally bringing up the planning project step by step to obtain the expected effect. This study aims to investigate the regional power transmission grid projects to set up their assessment method of planning. It can effectively assess each planning’s feasibility and construction period by systemic method and assess financial and economic effect of planning project to serve as the basic of decision and reference for regional power transmission grid planning. First of all, this study integrates and explores the framework of the current trends of power transmission grid planning method, assessment process and technology development domestically and abroad, which can serve as the reference and foundation for this research. Besides, this study explores the characteristic of regional power transmission grid to establish the suitable assessment method of regional power transmission grid planning. The assessment method based on load forecasting in the given future to assess the feasibility and suitable construction period of potential transmission lines. In addition, the operation integrates with graph theory and Boolean algebra to find the bottlenecks of regional power transmission grid and appear years from the simulation of systemic method. The assessment method which this study brings up can quickly produce planning project of regional power transmission grid and corresponding construction period. The research results can serve as the reference and application for regional power transmission grid planning and feasibility assessment in the future. Besides, it can uplift power supply reliability and quality and assure the operational efficiency.

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Park, Heejung. "Electric transmission system expansion planning for the system with uncertain intermittent renewable resources." 2013. http://hdl.handle.net/2152/22990.

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This dissertation proposes a new transmission planning method for electric power systems with large planned additions of uncertain intermittent renewable resources. The major contribution of this dissertation is applying stochastic programming that represents two uncertain parameters, wind and load, to transmission planning. We apply an ad hoc partition method to approximate the bivariate random variables of load and wind. A two-stage stochastic transmission planning problem is repeatedly solved by replacing continuous random variables with approximations that have a more refined partition at each iteration. A candidate solution is provided when improvement is not observed at an optimal value, even with more refined approximations. Numerical results show the efficiency of the method. However, if the number of samples is not sufficient to represent the original random variable's characteristics, the solution may be poor. Therefore, we employ a sampling method using Gaussian copula in order to generate as many random samples as necessary. The problem is replicated and solved using a fixed number of samples generated by Gaussian copula. In order to asses solution quality, a 95\%-confidence interval on the optimality gap is formed. A candidate stochastic solution for transmission investment is used to simulate the operation of a utility-scale storage system. A mixed integer program (MIP) is applied to this formulation. As a case study, the Electric Reliability Council of Texas (ERCOT) wind and load data is employed, along with a simplified model of the transmission system. Energy storage is also considered. The storage operation shifts wind power from off-peak hours to on-peak hours, and its wind power generation shows a close character to that of a base load generator.
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Vrey, Deon Johann. "Value-based planning methodology for the restructuring and expansion of an electric utility sub-transmission network." Diss., 1999. http://hdl.handle.net/2263/30444.

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The main objective of this study is to develop a methodology to assist in the reconfiguration and expansion of an electrical sub-transmission network within the framework of Value-based planning. This methodology applies to typical municipal networks found in South Africa. A literature study indicates that most of the fundamental concepts for power system reliability is well established with extensive research done in North America, and other parts of the world. Reliability worth assessment of sub-transmission networks in South Africa, which include composite networks and substation reliability, is however not well developed. From a Value-¬based point of view the literature further does not provide much linkage to the evaluation of alternative long-term network options. This is especially true in terms of the life cycle cost assessment of network alternatives, which include the prediction of customer damages as a function of network performance. In this dissertation a methodology is proposed which utilises the basic network reliability concepts to assess the performance of existing and future alternative network options. The load point Expected Unserved Energy is used to quantify network performance and is obtained through a contingency enumeration process. An existing Geographical Load Forecasting technique defines all customers connected to a load point, on a homogeneous level. This information along with Sector Customer Damage Functions is used to predict existing and future Composite Customer Damage Functions at the associated load point in the sub-transmission network. To arrive at the total minimum cost, which is the objective of Value-based planning, the present worth for each alternative is obtained from the annual utility and customer cost over the life cycle of the alternative. The alternative that result in the lowest present worth is identified as the preferred alternative. A case study is conducted on the sub-transmission network of the Greater Pretoria Metropolitan Council (GPMC) in order to prove the methodology. The entire network is analysed in order to identify the sub-system with the worst performance from a reliability point of view. Alternative network options are identified and the methodology is used for the evaluation of these alternatives. The application of this methodology provides the network planner with the ability to make better decisions with regard to the allocation of reliability. Through the calculation of reliability indices, tangible guidelines can be provided to quantitatively assess the impact of different network alternatives. These guidelines assess contingency probabilities explicitly and along with reliability worth evaluation provide a fundamental tool to conduct Value-based planning. The application of this methodology can lead to significant savings in capital investment while maintaining an acceptable level of reliability.
Dissertation (M Eng (Electrical Engineering))--University of Pretoria, 2006.
Electrical, Electronic and Computer Engineering
unrestricted

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Chintamani, Vyjayanthi. "Planning And Operational Aspects Of Real And Reactive Power In Deregulated Power Systems." Thesis, 2010. http://etd.iisc.ernet.in/handle/2005/2269.

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The transition of the power sector from vertically integrated utility (VIU) to deregulated system has resulted in reshaping of generation, transmission and distribution components. Some of the objectives of restructuring are to ensure a secure and reliable supply of electricity, encourage competition in all segments, sustain future economic and technological growth, etc. There are many challenges that arise in fulfilling these objectives. The thesis addresses some of them related to planning and operational aspects of real and reactive power, covering the following areas: Real power tracing, loss allocation and pricing Reactive power tracing, loss allocation and pricing Power system generation expansion planning Power transfer capability in interregional grids Voltage stability enhancement by improving reactive power margins In deregulated power systems, it has become important to identify the generation and transmission entities responsible in meeting loads. This is done by tracing the power flows through the transmission network. Power tracing is required to assess the extent of network usage by the participants, so as to allocate the transmission losses and charges. Many loss allocation methods are presented in the literature. The loss allocation method implemented in this thesis is a circuit based method. For obtaining the generators contribution towards meeting system loads and transmission losses, an approach of relative electrical distance (RED) between the generation and the load buses, is presented. The method is used to trace both real and reactive power flows. In the case of real power, the generators are the only sources and loads are the only sinks. However, reactive sources and sinks are distributed all along the transmission system. The reactive power sources considered are generators, switchable VAR sources (shunt capacitor banks) and line charging susceptances; and the reactive sinks are shunt reactors and reactive inductive loads. While tracing their flows the actual sources or sinks are to be identified which is obtained after adding reactive injections and absorptions at each bus. If the net value is absorbing, the bus is a reactive sink and if the net value is injecting, the bus is a reactive source. The transmission line charge susceptances contribution to the system’s reactive flows; and its aid extended in reducing the reactive generation at the generator buses is also discussed. A reactive power optimization technique is applied to optimally adjust the reactive controller settings of transformer taps, generator excitations and switched capacitors, so that the available reactive resources can be fully utilized. In the thesis, a methodology for evaluation of real and reactive power load and loss sharing proportions; and cost allocation towards transmission utilization is presented. Due to the ever growing increase in demands; on one hand the existing transmission networks are getting overloaded at some locations and on the other hand, the available generation is becoming insufficient to cater to the additional demand. To handle this problem, generation and transmission expansions become inevitable. Hence, additional public sector units or independent power producers and transmission providers are to be brought in. However in a restructured system, generally there is no central planning for new generation capacity or transmission additions. The reason being, these investments need huge capital and long period of commitment. While making a generation investment decision, expectations concerning future electricity demand, spot market prices, variations of regulatory policies, etc., are the major considerations. The locations, capacities and timing of new power plants are basically at the generation companies’ own discretion. Also, generation companies do not have any obligation to ensure sufficient supply of electricity to meet present and future requirements. Hence, it is a matter of concern as to how adequate generation capacity can be secured in the long run. Optimal siting and sizing of these new generation locations is also an issue of concern. In this thesis a new index called as ‘Tindex’ is proposed, which identifies prospective new generation expansion locations. The index is formulated based on the transmission network information, and it helps in identifying the most suitable new generation expansion locations. To implement this methodology each of the load bus is treated as a generation bus, one at a time, and the maximum generation capacity that can be installed at the location is computed from the approach. This method ensures minimum transmission expansion. Interconnected power systems help in exchanging power from one area to other areas at times of power deficiency in their own area. To enable this, their tieline capability to transfer power has to be sufficient, which is determined using total transfer capability (TTC) computation. TTC is an important index in power markets with large volume of interarea power exchanges and wheeling transactions taking place on an hourly basis. In the thesis, the total transfer capability (TTC) of interconnected tielines, under normal and contingency conditions is evaluated. The contingency cases evaluated are single line contingency, tieline contingency and generator outage. The most critical lines in each zone are identified using Fuzzy set theory. Unified power flow controller (UPFC), a flexible AC transmission system (FACTS) device is incorporated to improve the power transfers under contingency conditions. The best locations for UPFC placement are identified by analysing the power flow results obtained after considering the contingencies. For each of the normal and contingency cases, a base case and a limiting case are formed and the TTC is evaluated. Limiting case is formed by increasing the load in small steps till a point after which bus voltages or line loadings start to violate their stability constraints. To improve the system conditions in the limiting case, reactive power optimization and UPFC installation is carried out. The results reflect the improvement in system conditions and total transfer capability margins. Availability of sufficient generator reactive margins is very essential to ensure system’s voltage stability, without which even minor disturbances may lead to catastrophe. The amount of reactive power margin available in a system determines its proximity to voltage instability under normal and emergency conditions. One way of improving the reactive margin of a synchronous generator, is to reduce the real power generation within its MVA ratings. However this real power reduction will affect the real power contract agreements formed while power trading. The real power contracts are not disturbed and the reactive power margins are improved by optimally adjusting the other available reactive controllers, namely, generator exciter, transformer taps and shunt compensators. To have further control on the reactive flows, UPFC device is incorporated at appropriate locations. The thesis discusses how reactive margins are computed and subsequently improved using a reactive power optimization technique and UPFC. Case studies are carried out on typical sample 6bus, 8bus, 10bus, 16bus, 20bus, IEEE 30bus, IEEE 39bus systems, and reallife equivalents of Indian southern grid 24bus, 72bus, 87bus and 205bus systems to illustrate the proposed approaches.

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Dissertations / Theses on the topic 'Power transmission planning'

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