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1
Pan, Fei. "Multifrequency Averaging in Power Electronic Systems." UKnowledge, 2014. http://uknowledge.uky.edu/ece_etds/62.
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Power electronic systems have been widely used in the electrical power processing for applications with power levels ranging from less than one watt in battery-operated portable devices to more than megawatts in the converters, inverters and rectifiers of the utility power systems. These systems typically involve the passive elements such as inductors, capacitors, and resistors, the switching electronic components such as IGBTs, MOSFETS, and diodes, and other electronic circuits. Multifrequency averaging is one of the widely used modeling and simulation techniques today for the analysis and design of power electronic systems. This technique is capable of providing the average behavior as well as the ripple behavior of power electronic systems. This work begins with the extension of multifrequency averaging to represent uniformly sampled PWM converters. A new multifrequency averaging method of solving an observed issue with model stability is proposed and validated. Multifrequency averaging can also be applied to study the instability phenomenon in power electronic systems. In particular, a reduced-order multifrequency averaging method, along with a genetic algorithm based procedure, is proposed in this work to estimate the regions of attraction of power electronic converters. The performance of this method is shown by comparing the accuracy and efficiency with the existing methods. Finally, a new continuous-time multifrequency averaging method of representing discrete-time systems is proposed. The proposed method is applied to model digitally controlled PWM converters. Simulation and hardware results show that the proposed method is capable of predicting the average behavior as well as the ripple behavior of the closed-loop systems. Future research in the area of multifrequency averaging is proposed.
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Kulworawanichpong, Thanatchai. "Optimising AC electric railway power flows with power electronic control." Thesis, University of Birmingham, 2004. http://etheses.bham.ac.uk//id/eprint/4/.
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The latest generation of AC-fed traction drives, employing high-speed switching devices, is able to control the reactive power drawn from the overhead line by each equipment. If the conditions at each locomotive or train could be fed back to a central control point, it is possible for a centrally located controller to calculate optimal values for the reactive power in each drive and to send those commands back to the individual equipment. In this thesis, AC railway power flows are optimised in real time and the results are used to achieve some particular system objective via control of the PWM equipment as mobile reactive power compensators. The system voltage profile and the total power losses can be improved while the overall power factor at the feeder substation is also made nearer to unity. For off-line simulation purposes, high execution speeds and low storage requirements are not generally significant with the latest computer hardware. However, this real-time control employs on-line optimising controllers, which need embedded power solvers running many times faster than real time. Thus, a fast and efficient algorithm for AC railway power flow calculation was developed. The proposed scheme is compared to a conventional reactive power compensation, e.g. SVC, and found to be less expensive to implement. Several test cases for AC electric railway systems are examined. The centralised area control system leads to the best improvement where an existing fleet of diode or thyristor phase-angle controlled locomotives is partially replaced with PWM ones, compared to that obtained without compensation or to classical track-side Var compensation methods. From these results, the potential for PWM locomotives to improve overall system performance is confirmed.
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Luo, Xiaozhong. "Direct power control of AC motors." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1472963.
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Oukati, Sadegh Mahmoud. "Control of power electronic devices (FACTS) to enhance power system stability." Thesis, University of Strathclyde, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275177.
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Hoff, Erik Stjernholm. "Distributed Generation - Power Electronic Converters, Communication and Control." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1620.
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This thesis tries to explain the changes in the control of power electronic converters that are possible by the use of communication. Many of the renewable energy sources such as photovoltaic panels are geographically dispersed. The power rating per generator is therefore typically low. If this kind of energy source should dominate an electrical grid, the number of generators must be high. There should also be means of controlling this large number of generators simultaneously and safely. The cost of safe communication may be too high compared to the power contribution of a single generator. The Internet offers a low-cost solution, but it cannot guarantee real-time properties. Similarly to the Internet itself, it is shown how communication errors can be detected and handled in a safe manner by the end-system, in this case the generator. The generator can detect a communication timeout, and change control algorithms in order to guard itself and the connected electricity grid. When necessary, it can also disconnect and work as a local standalone power supply. In order to be able to supply all kinds of loads, the generator (in this case an inverter) is primarily voltage controlled. This results in challenges concerning current distortion. The use of feed-forward for cancellation of common grid voltage harmonics is discussed, simulated and measured. An anti-islanding algorithm for voltage controlled inverters is also developed, simulated and measured in this thesis. A DC/DC-converter for optimized connection of a photovoltaic panel is built, exploiting the photovoltaic panel properties to reduce the size and the losses significantly. Although most contributions are connected to details and parts of the system, the interactions between communication and control are emphasized.
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Bendre, Vijay. "Power Electronic Control of a Partial Core Transformer." Thesis, University of Canterbury. Electrical and Computer Engineering, 2010. http://hdl.handle.net/10092/4927.
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The research programme at the University of Canterbury includes the development and applications of partial core inductors and transformers for high voltage testing of
generator insulation. Unlike a conventional full core transformer, a partial core transformer has no limbs and yokes. A partial core transformer is a compromise
between a full core and coreless transformer. It is superior to its full core counterpart as far as cost, weight and ease of transportation are concerned.
Partial core transformers have a low magnetising reactance and hence draw a high magnetising current. This characteristic makes them a perfect fit in applications
where the load is capacitive in nature, such as a.c. power frequency high voltage testing of generator insulation and cable testing etc.
The work carried out for this thesis focuses on automatically controlling the amount of reactive power on the supply side of a partial core transformer. The considered design includes a third winding around the existing two windings. A power electronic controller is connected to the third winding, which modifies the VAr
absorption characteristics of the magnetically coupled supply winding.
Two options are considered to achieve continuous reactive power control in the partial core transformer as explained below.
First, a thyristor controlled reactor (TCR) is proposed as the VAr controller. It is modelled using PSCAD/EMTDC software. Simulations reveal the design criteria,
overall performance and the limitations of the suggested proposal. The TCR connected tertiary winding takes the capacitive burden of the supply. The model demonstrates the ability of the automatically controlled TCR to provide a continuous variation of reactive power without significant under or over compensation. This feature limits the supply current to its real component only, so the supply provides
only the losses of the system.
Second, a voltage source converter is considered as the VAr controller. This is modelled in PSCAD/EMTDC and a hardware prototype is designed and built. Based on the analysis, the control algorithm (including a digital PI controller) is implemented using an 8 bit micro-controller, PIC18LF4680. The prototype is tested in the laboratory for both active and inductive load conditions as seen from the
supply side. Performance of the hardware prototype is discussed in detail.
The PSCAD/EMTDC model and the hardware prototype successfully demonstrate the feasibility of a STATCOM controlled partial core transformer. The proposed
system is capable of compensating a wide range of capacitive loads as compared with its TCR counterpart.
It is proved that the system is very robust and remains dynamically stable for a large system disturbance such as change in load from full capacitive to inductive and vice
versa. This confirms that the system is capable of providing continuous VAr control.
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Ravindran, Vinoth Kumar. "Reactive power control functions for distributed PV sources." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/6835.
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The integration of distributed generation is one of the biggest changes facing the power
industry, with greenhouse gas mitigation and the smart grid initiative. With result of the
increasing penetration of grid-connected distributed generators, such as solar photovoltaic (PV)
sources the system voltage regulation becomes challenging. Specifically, capacitor banks and
step voltage regulators that normally boost voltage slightly may push utilization voltages either
above or below the adopted ANSI voltage limits because of the variable nature of PV sources.
This can adversely affect the expected reliability requirements for the utility and also decrease
the life span of voltage-regulating equipment due to excessive operations. This thesis work
studies the effects of large-scale penetration of distributed PV sources using several IEEE radial
distribution test feeders. Based on the simulation results, tap-changer excessive operations,
voltage fluctuations, and voltage rise in the feeders are identified, and the additional capacity of
reactive power control of inverters to minimize the voltage fluctuations is analyzed.
With the presence of a communication infrastructure, it is expected that distributed
generators could be more efficiently operated, especially the inverters, which will be able to
perform several grid support functions including voltage regulation and reactive power support.
Therefore, this work also focuses on developing a power loss minimization technique while
utilizing the additional benefits of dispatchable reactive power from a cluster of distributed
resources. The proposed technique is tested using IEEE 13- and 34-node test feeders, and the
results show that the proposed technique will minimize the real power loss in the radial
distribution feeders.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science
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Rasouli, Disfani Vahid. "Optimization and Control for Microgrid and Power Electronic Converters." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5764.
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The proposed dissertation research investigates Optimization and Control for Microgrid and Power Electronic Converters. The research has two major parts:
i- Microgrid Operation and Control,
ii- Power Electronic Converter Control and Optimization.
In the first part, three focuses are investigated. First, a completely distributed algorithm is developed for dc optimal power flow problem for power distribution systems as one of the necessary functions considered in unit-commitment problem in day-ahead markets. This method is derived based upon the partial primal-dual representation of the economic dispatch problem, which is finally translated to DC-OPF problem. Second, the optimal interaction between the utility and communities will be studied, due to its improtance in real-time markets. The objective of this section will be to develop an iterative agent-based algorithm for optimal utility-community control. The algorithm will consider the AC power system constraints to maintain power system stability. In this algorithm, a simplified model of microgrid is considered. In the third focus, a comprehensive model of microgrid is taken into account. The optimal operation of the microgrid considering energy storage systems and renewable energy resources is investigated. The interaction of such microgrids with the main grid to define the optimal operation of the entire embedded system is studied through two iterative methods. In the microgrid's internal problem, a moving-horizon algorithm is considered to define the optimal dispatch of all distributed energy resources while considering the time-correlated constraints of energy storage systems. A thorough analysis of the effects of the size of storage systems on energy and reserve market parameters are also performed.
In the second part, the focus of research is to develop optimal control strategies for Power Electronic Converters. A Model Predictive Control (MPC) switching method is proposed for Modular Multilevel Converters (MMC). The optimal solution of MPC problem is then represented as an optimization problem. Due to lack of efficient algorithms to seek the optimal solution, a fast algorithm will be proposed in this research. The method proposed reduces the number of possible solutions and computation efforts dramatically.
9
Ming, Wen-Long. "Active control of voltage ripples in power electronic converters." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12343/.
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Two major challenges, i.e., bulky electrolytic capacitors and isolation transformers, remain as critical obstacles for further improvement on reliability, power density and efficiency of power electronic converters, which are mainly used to reduce low-frequency voltage ripples and high-frequency common-mode voltage ripples, respectively. In order to overcome the two challenges, the most straightforward way is to simply combine existing solutions developed for each of them. However, this would considerably increase system complexity and cost, which should be avoided if possible. In this thesis, these two challenges are innovatively addressed in a holistic way by using active control techniques. This thesis first focuses on the reduction of low-frequency voltage ripples in conventional half-bridge converters, after adding an actively-controlled neutral leg. As a direct application of this strategy, a single-phase to three-phase conversion is then proposed. After that, a ρ-converter with only four switches is proposed to significantly reduce both low-frequency ripples and high-frequency common-mode ripples in a holistic way. It is found that the total capacitance can be reduced by more than 70 times compared to that in conventional full-bridge converters. As a result, there is no longer a need to use bulky electrolytic capacitors and isolation transformers. Then, the ρ-converter equipped with the synchronverter technology is operated as an inverter for PV applications. Another converter is also proposed for the same purpose but with reduced voltage stress. In order to further reduce the total capacitance and to reduce the neutral inductor in the ρ-converter, a new type of converter, called the θ-converter, is proposed. Finally, two actively-controlled ripple eliminators are proposed to reduce low-frequency ripples in general DC systems while the aforementioned research is focused on some specific topologies. Extensive experimental results are presented to validate most of the developed systems while the rest are validated with simulation results.
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Radi, Mohammed A. M. "Power electronics considerations for voltage regulation and VAR control approaches in LV distribution networks-hybrid power electronic modules." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/14697.
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The future substation depends on finding a way to mitigate the effects of the drawbacks of the conventional legacy by employing the efficiency of the solid state switches in light of changing the loading features by time such as Electrical Vehicles (EV) and Photo-voltaic (PV) cells. In distribution transformers the ratio between the primary voltage and the secondary voltage cannot be changed, and the use of the on-load taps changers are limited. Poor voltage regulation and reactive power transmission is a direct reason for losses and shortening the life of several devices. This research discusses the considerations of applying Power Electronics (PE) approaches and designs that provide additional functions in regulating the voltage and controlling the reactive power that is injected in the distribution network, using embedded fractional rated converters attached partially with the windings of the LV transformer. These approaches studies the possible considerations that have the potentials to enhance the unit with more flexibility in controlling the voltage and reactive power at the last mile of the network, in order to decrease the losses and meet the future expectations for low voltage networks modifications, and that by using a Power Electronic (PE) approach has less losses and more functionality depending on the reliability of transformer and intelligence of PE solutions. The approach of a hybrid distribution transformer is introduced and its functionality in regulating the voltage and injecting reactive power is illustrated. A back-to-back converter is controlled according to the immediate need for voltage control and reactive power in Low Voltage (LV) networks, and for the purpose of controlling three unbalanced phases using two control strategies; resonant controller and vector control. The overall controller adds or decreases voltage (10%-20%) to/from the total output voltage in order to control the whole output voltage of the transformer. In addition, some loads need high amount of reactive power at last mile of the network, therefore the consideration of using switched capacitors technique is introduced to serve at the end user side whereby its ability to provide automatic variable reactive power compensation in a closed loop system is illustrated. The considerations results indicate significant potentials for deploying PE in the last mile of the network by using innovative designs and suitable control functions with less losses and costs.
11
Chen, Zhe. "Advanced wind energy convertors using electronic power conversion." Thesis, Durham University, 1997. http://etheses.dur.ac.uk/1632/.
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Somayajula, Deepak. "Control aspects of a double-input buckboost power electronic converter." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Somayajula_2009_09007dcc8070c9e2.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 17, 2009) Includes bibliographical references (p. 67-70).
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Loh, Poh Chiang 1973. "A universal flux/charge modulation strategy for three-phase power electronic converters." Monash University, Dept. of Electrical and Computer Systems Engineering, 2002. http://arrow.monash.edu.au/hdl/1959.1/8087.
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Insleay, Allan. "Neural network applications in the control of power electronic converters." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ26003.pdf.
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Musallam, Mahera. "Real-time power electronic device junction temperature estimation and control." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420031.
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Al-Numay, Mohammed Saleh. "Discrete-time modeling and tracking control of pulse-width modulated systems." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15387.
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Du, Toit J. A. (Jacques Andre). "Development and analysis of a distributed control strategy for power electronic converters." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52761.
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Thesis (PhD)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: The dissertation presents an alternative approach to the control of power electronic converters. The conventional approach is to use a centralized controller with one or more measurement systems providing feedback. As converters become larger, in both power rating and complexity, a number of drawbacks to this approach emerge. The number of physical data paths increases and voltage isolation becomes a problem. This has an adverse effect on the manufacturability as well as the reliable operation of the system as a whole. An alternative is to use a distributed control approach, where a number of smaller integrated control and measurement units are used. These units communicate with the central controller via a serial daisy-chain communications link. The dissertation investigates the design of such a controller as well as the application of distributed control in a number of emerging converter topologies. It was shown that centralized control has its limitations in modem power electronics in terms of reliability, maintainability and manufacturability. A feasible distributed control strategy was proposed and implemented and the operation was verified in an experimental converter system.
AFRIKAANSE OPSOMMING: Die proefskrif ondersoek 'n alternatiewe manier om drywings omsetters te beheer. Huidiglik word die meerderheid van omsetters beheer vanaf 'n sentrale beheereenheid, wat dan stelsel data versamel vanaf een of meer meetstelsels. Soos die drywingsvermoë van die omsetters toeneem, raak spannings isolasie en die aantal beheerseine 'n probleem, wat nadelig is vir die betroubaarheid en vervaardigbaarheid van die stelsel. As 'n alternatief, kan 'n aantal kleiner beheereenhede en meetstelsels gebruik word. Die beheerders kommunikeer met mekaar, sowel as die hoof stelselbeheerder deur middel van 'n optiese vesel netwerk, verbind in 'n ring struktuur. Die proefskrif ondersoek die ontwerp van die beheerder en die toepassing van gedesentraliseerde beheer in 'n aantal nuwe omsetter topologië. Die studie toon dat sentrale beheer problematies kan raak soos die omsetters meer kompleks raak. Die studie bewys dat 'n stelsel suksesvol bedryf kan word deur gebruik te maak van gedesentraliseerde beheer deur dit in 'n praktiese opstelling toe te pas.
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Junyent, Ferré Adrià. "Control of power electronic converters for the operation of wind generation." Doctoral thesis, Universitat Politècnica de Catalunya, 2011. http://hdl.handle.net/10803/108501.
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The present PhD thesis analyzes the modelling and control of the two main topologies of large scale variable speed wind turbines, the doubly fed induction generator and the permanent magnet synchronous generator wind turbines, to operate under different types of voltage sags. The first part of the thesis deals with the modelling of the wind turbine from the mechanics to the different types of generators and the power converter. The second part deals with the control of the wind turbine. First, three different control schemes of the doubly fed induction machine are analyzed, starting with the most basic one, the conventional vector control meant for balanced operation which is simulated and compared to experimental measurements from a voltage sag test, and then moving to the dual synchronous reference frame and the stationary reference frame control, two different schemes that allow the operation of the machine under unbalanced voltage sags. Then, different reference calculation methods for the operation of grid connected voltage source converters under grid unbalances are analyzed and tested on a experimental platform. Finally, the vector control scheme of the permanent magnet synchronous generator and a ride-through strategy for this type of turbine for balanced voltage sags is presented and tested on a small scale experimental platform.Aquesta tesi analitza la modelització i el control per a l'operació sota diferents tipus de sots de tensió de les dues topologies més comunes d'aerogeneradors de velocitat variable de gran escala, la basada en generador d'inducció doblement alimentat i la de màquina síncrona d'imants permanents. La primera part de la tesi tracta el modelat de la turbina eòlica des de la mecànica fins als diferents tipus de generadors i el convertidor. La segona part tracta el control de l'aerogenerador. Primer, s'analitzen tres esquemes de control diferents de la màquina d'inducció doblement alimentada, començant pel tipus més bàsic, el control vectorial convencional, pensat per l'operació en equilibri, que és simulat i comparat amb mesures experimentals d'un assaig de sot de tensió, i tractant a continuació l'anomenat control vectorial amb doble referència de sincronisme i el control en referència estacionària, dos esquemes de control diferents que permeten l'operació de la màquina sota sots de tensió desequilibrats. A continuació s'analitzen i comproven experimentalment diferents mètodes de càlcul de referències pel control de convertidors amb font de tensió sota desequilibris de xarxa. Finalment, es presenta l'esquema de control vectorial de màquina síncrona d'imants permanents i una estratègia de ride-through per a aquest tipus d'aerogenerador que és avaluada en una plataforma experimental.
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Prabhala, Venkata Anand Kishore. "Control and applications of double input DC-DC power electronic converters." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2010. http://scholarsmine.mst.edu/thesis/pdf/Prabhala_09007dcc807bbcfe.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2010.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed June 29, 2010) Includes bibliographical references (p. 95-100).
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Natsheh, Ammar Nimer. "Analysis, simulation and control of chaotic behaviour and power electronic converters." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/5739.
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The thesis describes theoretical and experimental studies on the chaotic behaviour of a peak current-mode controlled boost converter, a parallel two-module peak current-mode controlled DC-DC boost converter, and a peak current-mode controlled power factor correction (PFC) boost converter. The research concentrates on converters which do not have voltage control loops, since the main interest is in the intrinsic mechanism of chaotic behaviour. These converters produce sub-harmonics of the clock frequency at certain values of the reference current I[ref] and input voltage V[in], and may behave in a chaotic manner, whereby the frequency spectrum of the inductor becomes continuous. Non-linear maps for each of the converters are derived using discrete time modelling and numerical iteration of the maps produce bifurcation diagrams which indicate the presence of subharmonics and chaotic operation. In order to check the validity of the analysis, MATLAB/SIMULINK models for the converters are developed. A comparison is made between waveforms obtained from experimental converters, with those produced by the MATLAB/SIMULINK models of the converters. The experimental and theoretical results are also compared with the bifurcation points predicted by the bifurcation diagrams. The simulated waveforms show excellent agreement, with both the experimental waveforms and the transitions predicted by the bifurcation diagrams. The thesis presents the first application of a delayed feedback control scheme for eliminating chaotic behaviour in both the DC-DC boost converter and the PFC boost converter. Experimental results and FORTRAN simulations show the effectiveness and robustness of the scheme. FORTRAN simulations are found to be in close agreement with experimental results and the bifurcation diagrams. A theoretical comparison is made between the above converters controlled using delayed feedback control and the popular slope compensation method. It is shown that delayed feedback control is a simpler scheme and has a better performance than that for slope compensation.
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Waheed, M. A. "Microprocessor control of power electronic devices using pulse width modulation techniques." Thesis, Robert Gordon University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379122.
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Wan, Kai. "Advanced current-mode control techniques for DC-DC power electronic converters." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Wan_09007dcc80642d38.pdf.
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Thesis (Ph. D.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 4, 2009) Includes bibliographical references.
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Veal, Christopher Michael John. "The damping of power system oscillators by generator control." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47695.
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Gezgin, Cahit. "Simultaneous control-structure optimization of power converters." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/15796.
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Jooste, Charl Roelof. "Development of a generic digital controller for power electronic applications." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/2210.
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Thesis (MTech (Electrical Engineering)))--Cape Peninsula University of Technology, 2011.This thesis presents an investigation into the generic tools, hardware and firmware, involved in power electronic converter control and feedback. The aim was to determine the optimal controller architecture through research of existing controllers. As soon as the architecture was established, design of the controller commenced. Explanations for the various components selected were provided. The design considerations when designing a printed circuit board (PCB) with mixed signals was also presented. The theory behind the control of a multicell converter as well the practical implementation of the control scheme in firmware was presented.
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Uys, Jacobus Johannes. "Dynamic digital control schemes for three-phase UPS inverters." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52810.
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Thesis (MScEng)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: This thesis presents the design and implementation of a voltage controller for an Uninterruptible Power Supply (UPS) Inverter. The inverter is capable of producing a nearly sinusoidal output voltage waveform, thereby keeping the Total Harmonic Distortion (THD) to a minimum. Digital controllers introduce a time delay in the control law that causes system instability. Various control techniques, which includes Pade approximations and system augmentation, are investigated to eliminate the effect of the time delay. These controllers employ classical control as well as modem control techniques. The selection of the various control parameters is verified by mathematical equations. A load-disturbance compensation scheme, implementing feed-forward and gain scheduling, is also developed to improve voltage distortion when varying loads, such as non-linear loads, are connected to the system. It is shown that the constructed pulse-width modulated (PWM) control scheme can achieve fast dynamic response as well as a low THD.
AFRIKAANSE OPSOMMING: Hierdie verhandeling ondersoek die ontwerp en implementering van 'n spanningsbeheerder vir 'n ononderbroke kragtoevoer omsetter. Die stelsel produseer 'n uittree spannigsgolfvorm met 'n lae Totale Harmoniese Distorisie (THD). Digital beheerders veroorsaak 'n tydvertraging in die beheerwet wat stelsel onstabiliteit kan veroorsaak. Verskeie beheertegnieke wat gebaseer is op die Pade benaderings van die tydvertraging en stelsel aanpassings, is ondersoek. Hierdie beheerders maak gebruik van klassieke en moderne beheertegnieke. Die seleksie van die verskeie beheerderveranderlikes word gestaaf deur wiskundige vergelykings. Spannigsvervorming word tot 'n minimum beperk deur gebruik te maak van 'n lasveranderings-kompensasietegniek wat onderskeidelik vorentoe-voer en aanwins skedulering implementeer. Verder word daar bewys dat die pulswydte modulasie (PWM) beheerskema vinnige dinamiese gedrag asook 'n lae THD bewerkstellig.
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Nsumbu, Cassandra Daviane. "Development of a soft-core based power electronic conversion controller." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/2379.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2014.The application of digital control techniques has become dominant in power electronics owing to several advantages they present, when compared to analogue solutions. Their development is based on the use of microprocessors and microcontrollers, such as Application Specific Integrated Circuit (ASIC), Digital signal processors (DSP), Field Programmable Gate Arrays (FPGA), or a combination of these devices. This thesis presents an investigation of a soft-core based FPGA control system as a solution for power electronic applications. The aim was the development and implementation of a conversion controller, which purpose is to supply control inputs in the form of digital Pulse Width Modulation (PWM) signals, to a number of power electronic applications, such as single half and full bridge DC-DC converters, three phase and multicell inverters. The PWM control technique is achieved via their power semiconductor switching devices. These PWM control signals are necessary for the high frequency conversion of an analog input voltage (AC, DC or unregulated) to an analog output voltage of another level (AC or DC). This was intended to be achieved by exploiting and combining the advantages that FPGA and embedded processors provide such as high reconfigurability and multipurpose ability. This controller’s digital outputs, namely PWM switching signals, can be directly delivered to an analog signal amplification circuit to create an adequate voltage level before being processed by the converters’ switches.
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Solhall, Axel, and Edvin Guéry. "Coordination of Wind Power and Hydro Power." Thesis, KTH, Industriell ekologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210740.
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The goal of this project was to calculate how much wind power could be balanced with hydro power in our designated area consisting of five hydro power stations, four villages which consume power, possible locations for wind power and one connection to the national grid. To achieve this a simulation model was constructed in the GAMS software with the goal of achieving the maximum profit from the hydro power plants by considering electricity prices, inflow of water, the physical construction of the power plants and the time of year. When this was achieved, restriction for the maximum transmission load on the power grid was added as well as local wind power production as to simulate the implementation of new power sources on an old system and power grid. This would result in a maximum income in SEK as well as the most wind power which could be maintained and balanced by the designated system. This project shows how to find the optimal way to use hydro power and wind power as well as how the integration between different sources of electricity production could work, which is vital for a future powered by renewable energy and will help towards lowering emissions.
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Sun, Bo. "A FPGA-based power electronics controller for three-phase four-wire hybrid active power filters." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2547180.
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Glamheden, Mikael. "Stabilization of Constant Power Loads Using Model Predictive Control." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284685.
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This thesis considers stabilization of constant power loads (CPLs) fed by a dcpower source through an input filter, using model predictive control (MPC).Train propulsion systems generally utilize electrical motors whose output torqueis tightly regulated by power converters. Often, these systems behave as CPLs.When a CPL is coupled with an input filter it can lead to a stability problemknown as the negative impedance instability problem. Current state ofthe art regulators deal with this problem using classical frequency domainoptimization-based controllers, such asH1. This thesis instead proposes a linearparameter-varying model predictive controller (LPV-MPC). This advancedcontrol method solves the negative impedance instability problem while alsobeing capable of explicitly addressing signal constraints, which often exist inpower converter applications. The regulator is evaluated in MATLAB/Simulinkas well as in a software-in-the-loop (SIL) simulator. It has furthermore beenrealized in a real-time hardware-in-the-loop (HIL) simulator and tested in apower laboratory. Theoretical results show improved performance over conventionalH1 controllers, in terms of damping and control input use, undercertain operating conditions where the control input is limited. The resultscan be used as a benchmark of theoretical performance limits for design ofother regulators.Detta examensarbete avhandlar stabilisering av konstanta effektlaster (CPL)matade med dc-effekt via ett ingångfilter, med hjälp av modellprediktiv reglering(MPC). Drivsystem i tåg använder vanligen elektriska motorer varsmoment regleras hårt utav effektomriktare. Dessa system beter sig ofta somen CPL. När en CPL sammankopplas med ett ingångfilter kan det leda till ettstabilitetsproblem känt som the negative impedance instability problem (ung.negativ-impedans-instabilitetsproblemet). Dagens främsta regulatorer angriperdetta problem genom att använda klassiska regulatorer baserade på optimeringi frekvensdomän, till exempel H1. I detta examensarbete föreslås iställeten linjär parametervarierande modellprediktiv regulator (LPV-MPC). Dennaavancerade reglermetod löser stabilitetsproblemet och kan samtidigt hanterasignalbegränsningar explicit. Signalbegränsningar är något som ofta finnsi tillämpningar som involverar kraftomriktare. Regulatorn utvärderas i MATLAB/Simulink samt i en mjukvarusimuleringsmiljö. Regulatorn har dessutomförverkligats i en hårvarusimuleringsmiljö och testats i ett labb för kraftelektronik.Teoretiska resultat visar på förbättrad prestanda i jämförelse med konventionellaH1-regulatorer, vad gäller dämpning och användning av styrsignal,i vissa arbetsfall när styrsignalen är begränsad. Resultaten kan användassom ett riktmärke som visar på gränser för teoretisk prestanda vid design avandra regulatorer.
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Farrag, Mohamed. "Investigation of advanced control for the unified power flow controller (UPFC)." Thesis, Northumbria University, 2002. http://nrl.northumbria.ac.uk/3300/.
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The Unified Power Flow Controller (UPFC) is the versatile FACTS controller that can control up to three transmission system parameters individually or simultaneously in appropriate combinations. The work presented in this thesis is concentrated on the modelling and control of the UPFC. The overall aim is to provide effective tools for optimising the impact of the UPFC in the reinforcement of a transmission system. Existing modelling techniques for the UPFC together with the associated control strategies have been systematically reviewed. An exact power injection model is proposed which is based on the polar representation of the UPFC parameters and includes the reactive power capability of the shunt inverter. In addition, a steady-state model based on an ideal controlled voltage source has been developed using MATLAB/SIMULINK which provides a useful tool to analyse and develop the UPFC control system. The UPFC internal limits have been identified and accordingly, the feasible operating area of a transmission system incorporating a UPFC has been determined based on the UPFC maximum limits. The influence of both the series and shunt inverters on this controlled area has been analysed. The impact of a change in the system short circuit level on the UPFC operation and the size of the feasible area has also been investigated. Three modern controllers have been designed and tested for controlling the UPFC in a power flow mode for the series part and a voltage control mode for the shunt part. These controllers are: a fuzzy knowledge based controller, an artificial neural network based controller and a neuro-fuzzy based controller. For the former, the fuzzy rules are deduced from the relationship between the controlled power system parameters and the UPFC control variables. The second is a simple RBFNN controller which is constructed from a single neuron and trained on-line by a gradient descent algorithm. The third controller is designed using the adaptive capabilities of neural networks to estimate and tune the fuzzy rules. Computer simulation and experimental implementation of a UPFC using DS 1103 data acquisition board have been used to verify the proposed control strategies. In the experimental lab model, two 6-pulse inverters implementing the SPWM technique have been used to realise the UPFC system.
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Van, Heerden Gerhard Johann. "Design and implementation of a DSP based controller for power electronic applications." Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/16454.
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Thesis (MScIng)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: In the field of power electronic engineering, there is a need for a reconfigurable power electronic controller. Such a controller will enable engineers to stay focussed on their main field of study, not being side-tracked by the process of designing a high-speed digital controller to implement their ideas with. The design, construction and implementation of such a controller is presented in this paper. The design process involved defining the specifications of the controller and finding electronic components to satisfy them. After suitable components had been identified, a schematic design of the system was done. The netlist of the schematic was exported to a printed circuit board (PCB) design program, where the final layout was done and the connections between the devices routed. Before the PCB was manufactured, the firmware for the programmable logic devices (PLDs) was written to ensure that it fits in the selected PLDs of the system. After the PCB was manufactured and all its components fitted, it was tested and eventually used to implement the control of a shunt active power filter.
AFRIKAANSE OPSOMMING: Wanneer navorsing gedoen word in die drywings-elektronika gebied, word ’n behoefte vir ’n heropstelbare drywings-elektroniese beheerder ondervind. So ’n beheerder sal ingenieurs in staat stel om gefokus te bly op hulle hoof studieveld, sonder dat hulle aandag hoef te skenk daaraan om ’n ho¨e spoed digitale beheerder te ontwerp om hulle idees mee te implementeer. Die ontwerp, konstruksie en implementering van so ’n beheerder word in hierdie tesis voorgelˆe. Die ontwerp behels die bepaling van die spesifikasies van die beheerder en die opsporing van elektroniese komponente wat hierdie spesifikasies sal bevredig. Nadat geskikte komponente gevind is, is ’n skematiese ontwerp van die hele beheerder gedoen. Die lys van die verbindings tussen die komponente (Eng. netlist) is na die stroombaanbord ontwerp program gestuur, waar die finale uitleg van die bord gedoen is. Voordat die bord gemaak kon word, is die programmatuur vir die programmeerbare logikatoestelle geskryf om te verseker dat dit in die toestelle wat in die sisteem gebruik word, sal pas. Nadat die stroombaanborde vervaardig is en al die komponente daarop gemonteer is, is die bord getoets en uiteindelik gebruik om die beheer van ’n aktiewe drywingsfilter te implementeer.
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Andresen, Markus [Verfasser]. "Active thermal control of power electronic modules in smart transformer applications / Markus Andresen." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1138980102/34.
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Midtsund, Tarjei. "Control of Power Electronic Converters in Distributed Power Generation Systems : Evaluation of Current Control Structures for Voltage Source Converters operating under Weak Grid Conditions." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11413.
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The performance of different current controller structures for Voltage Source Converters (VSC) under weak grid conditions caused by large grid impedance is investigated. The VSC is synchronized to the grid by a Phase Locked Loop (PLL). Current control techniques and PLL techniques for handling both symmetrical and asymmetrical conditions are presented and discussed. The investigated current control structures are; the conventional Proportional Integral (PI)-controller in the synchronous rotating reference frame, dual PI-controllers implemented in positive- and negative-sequence rotating reference frame, the Proportional Resonant (PR)-controller in the stationary reference frame, the phase current hysteresis controller, and a space vector base hysteresis controller in the synchronous rotating reference frame. The PLL-techniques used for synchronization are; a conventional synchronous rotating reference frame PLL, a PLL with notch filter, and a Decoupled Double Synchronous Reference frame PLL (DDSRF-PLL).The different current control strategies and PLL-techniques are studied by simulations. The results show how large grid impedance can influence the dynamic response of the system and how the interaction between the PLLs, the current controllers and the large grid inductance can even trigger instability when the voltage measurements are highly influenced by the operation of the converter. The PI-controllers in the synchronous rotating reference frames are particularly sensitive to oscillations that can be reinforced when the measured voltage feed-forward terms are used in the control system. The response of the PR-controller is instead slowed down by the interaction with the PLL, while both the hysteresis controllers are quickly tracking the reference value as long as the interaction with the PLL is not leading to instability.Operation under asymmetrical weak grid conditions are investigated for current controllers that exploit PLL techniques designed to remove the oscillations that occur in the positive sequence reference frame voltage during unbalanced grid voltage. The simulations show that the DDSRF-PLL has a shorter transient period than the PLL with notch filter, but with a small steady state 100 Hz oscillation under the weak asymmetrical grid conditions.The results indicate that the tuning of the PLL is of large importance for the stability of the control system, and that a slower PLL can lead to less interaction with the current controllers at the cost of a slower and less accurate dynamic overall control performance.
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Alzatari, Mazen [Verfasser], and Holger [Akademischer Betreuer] Hirsch. "Power Electronic Control Device for High Voltage Test Transformers / Mazen Alzatari. Betreuer: Holger Hirsch." Duisburg, 2016. http://d-nb.info/1081302992/34.
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Peng, Ming. "A Game Theoretic Approach to Power Control in Vehicula rCommunication Systems." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234908.
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Vehicular-to-network (V2N) communications are a key enabler in various intelligenttransportation system services currently investigated by global standards bodiesand European projects. In this master thesis, we study the impact of pilot and datapower setting on the uplink performance of V2N communications. Specifically, weconsider the “urban” and “rural” scenarios of the 5GCAR project, using the recommendedbase station and vehicular user equipment parameters in the 5.9 GHz band.We study a distributed non-cooperative game theoretic algorithm to determine thepilot-data power ratio for each vehicle. Numerical results indicate that the proposeddistributed algorithm converges to the Nash equilibrium, and that the mean squarederror (MSE) of the received data symbols decreases by 0.6 − 1.2 dB as comparedwith the MSE obtained by a centralized benchmark algorithm. The proposed algorithmachieves this improvement over a centralized benchmarking algorithm at theexpense of only a few iterations.Vehicle-to-network (V2N) -kommunikation har många möjligheter i olika intelligen- ta transportsystem tjänster och det för närvarande undersöks av olika standardorgan och europeiska projekt. I detta examensarbete, Vi studerar effekterna av inställning- en av pilot- och data energy på upplänkprestanda för V2N-kommunikation. I syn- nerhet tar vi hänsyn till de "urbanaöch landsbygd-scenarierna i 5GCAR-projektet, med hjälp av parametrarna för rekommenderad användarutrustning av basstation och fordonet i 5, 9 GHz-bandet. Vi studerar en distribuerad icke-kooperativ spelteo- retisk algoritm för bestämning av pilot-data-effektförhållandet för varje fordon. Nu- meriska resultat indikerar att den föreslagna distribuerade algoritmen konvergerar mot Nash-jämvikten, och att medelkvadratfelet (MSE) för de mottagna datasymbo- lerna minskar med 0, 6 1, 2 dB jämfört med MSE erhållen genom en centraliseradreferensalgoritm.
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Samir, Karmacharya. "Modelling and control of micro-combined heat and power (CHP) to optimise energy conversion and support power distribution networks." Thesis, Northumbria University, 2013. http://nrl.northumbria.ac.uk/21424/.
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Climate change and continuously increasing energy prices have driven the need for low carbon and renewable energy technologies from different sectors, including the domestic sector, by installing higher energy efficiency technologies. One of these technologies is the Stirling engine based micro-combined heat and power (CHP) which has the potential to achieve lower overall carbon emissions by generating both heat and electricity locally. Its successful implementation to meet the energy demands (thermal and electrical) throughout the year depends on several factors such as the size and type of building and demand profiles. In addition, the deployment of large number of micro-CHPs may have significant impact on the performance of the power distribution networks.
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Darbyshire, James. "Multi-function power electronic interface for hybrid mini-grid systems." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/2394.
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In the past five years, global interest regarding the development of renewable energy technologies has significantly increased. The conventional electric power generation methods sourced from fossil fuels is now problematic, from both the supply and emission points of view. Fossil fuels are non-renewable limited resources that have taken millions of years to form; eventually they will be exhausted and the current cost of automotive fuel is evidence of them becoming diminished. The carbon dioxide emissions created through the energy conversion process are causing an increase in the overall atmospheric concentrations, which through global warming may have serious consequences for humanity.Natural sources of energy production can be derived from the Sun through the use of solar and wind generation methods. Converting these sources to electricity requires the technology of power electronics, the central area of research for this dissertation. Solar energy can most easily be harnessed through the photo-electric effect which creates DC electricity. However, the majority of electric loads and transmission require AC electricity. The inverter is the electronic device required for this power conversion. Wind turbines usually create variable voltage and frequency AC that is rectified to DC and then converted to grid type AC through an inverter.Voltage source inverters, their topologies and control are investigated within this dissertation. Voltage control methods are adopted for both stand-alone and grid connected techniques where control of active and reactive power is required. Current control techniques in the form of PI and hysteresis are applied to allow novel interfaces between generation sources to be achieved. Accurate control of the power electronics allows an enhancement in the power production from the renewable energy source. The power electronic device of the DC-DC converter, either buck or boost is controlled to allow the renewable resource to operate at its optimum power point. The control aspects and algorithms of these converters are central to this research. The solar algorithms of perturb and observe, and incremental conductance are developed with the latter being more favourable to changing levels of irradiation. The author draws a parallel between rapidly changing solar conditions with normally changing wind states. This analogy with an understanding of the mechanics of PMSG allows a novel wind MPPT algorithm to be developed which is simulated in PSIM. Methods to analyse the usefulness of the algorithm are developed and general conclusions are drawn.Another aim central to the research is the efficient combination of renewable energy sources into a single reliable power system. This forms the multi-function aspect of the research. The interconnection of the sources on the AC or DC sides is investigated for both stand-alone and grid connected topologies. A requirement of the stand-alone system is to provide power when no renewable resources are available causing some form of energy storage to be utilised. Conventional batteries are used, causing the VC-VSI to become bi-directional allowing charging. This is simulated in PSIM and demonstrated as part of the Denmark and Eco Beach projects. Many differing topologies of stand alone, grid connected and edge of grid systems are developed, simulated and some are demonstrated.While investigating the currently used topologies the author invents the novel complimentary hybrid system concept. This idea allows a single inverter to be used to feed energy from either the wind or solar resource. With careful engineering of the PV array and wind turbine characteristics only a small loss of energy is caused, deemed the crossover loss. This original concept is mathematically modelled, simulated and demonstrated with results presented from the Denmark project. The strength of this idea is from the quite complimentary nature of wind and solar resources, for only a small proportion of the year are high solar and strong wind conditions occurring simultaneously.Compared to a solar resource, the wind resource is much more complicated to model. An analysis of readily available wind source data is presented with a statistical analysis of the scaling methods; a novel box and whiskers plot is used to convey this information. New software is presented to allow a more accurate and digital model of a power curve to be recreated, allowing a more precise annual energy generation calculation. For various wind turbines a capacity factor analysis is presented with its disadvantages explained. To overcome these issues the concepts of economic efficiency and conversion efficiency are explained. These prevent some of the typical methods to enhance the standard capacity factor expression. The combination of these three methods allows selection of the most suitable wind turbine for a site.The concept of a mini-grid is an isolated power generation and distribution system, which can have its renewable energy sources, centralised or decentralised. The methods used to coalesce conventional generation with renewable energy technology forms another key piece of this research. A design methodology for the development of a hybrid power system is created with examples used from projects attributed to the author. The harmonising of the renewable energy sources with the conventional generation while providing a stable and robust grid is explained in detail with respect to the generator loading and control. The careful control of the renewable resource output is shown to allow a greater overall penetration of renewable energy into the network while continuing network stability. The concept of frequency shift control is presented, simulated and demonstrated with reference to the Eco Beach project. This project epitomises much of the research that has been presented in this dissertation. It combines centralised and decentralised inverters, with battery storage and the control of diesel generators. An overall controller dictates the optimum times to charge or draw from the battery based upon the local environmental and time of day variables. Finally, the monitoring aspects of this project are representative of a future smart grid where loads may be shed on demand through under frequency or direct control.
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Anttila, Sara. "Power control strategies for renewable energy systems : The inverter's role in future power systems." Licentiate thesis, Uppsala universitet, Institutionen för elektroteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-421009.
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Connecting more non-dispatchable renewable energy sources (RESs) will result in a higher power variability and a lower system inertia when the synchronous generators are replaced by inverter-connected RES. Inverter control can be divided in three categories: grid-following, grid-forming (GFM) and grid-supporting. A literature review of inverter control strategies identifies the GFM control as having an important role in maintaining system stability assuming near 100 % inverter-connected RES. Critical aspects of the inverter control are also identified; the control need to function autonomously, be able to remain connected during transient events and be insensitive to grid topology. Combining various RES is also shown to improve system stability. The combination of RES that has been investigated in most studies is wind, solar and wave power. Wave power is still a young technology compared to solar and wind power. It generates higher power fluctuations over short time periods with a significant difference between average and maximum power. Additionally, wave power parks (WPPs) are often connected via long cables which contribute reactive power to the grid. These challenges has to be considered to maintain system stability and power quality when connecting a WPP to the grid. In a Power Hardware-In-the-Loop study of how a WPP affects the power quality at the point of common coupling (PCC), it is found that the impact is highest for WPPs with fewer generators as the variability is reduced when several generators are excited at different times. Energy storage is also shown to have a significant impact on the power quality at the PCC with reduced flicker, total harmonic distortion and power and voltage variability. A simulation study also shows the positive impact of energy storage on power variability and the role of inverter control in reactive power compensation.
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Ng, Chong H. "Control of active filters to attenuate harmonic resonance in power distribution networks." Thesis, Northumbria University, 2007. http://nrl.northumbria.ac.uk/1440/.
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Harmonic resonance occurs when the network equivalent shunt harmonic capacitive reactance is associated with the network series harmonic inductive reactance. When such resonance occurs, it amplifies harmonic components with frequency close to the resonance point. Solutions used to solve harmonic resonance problems can be divided into two main categories. One is to reduce the content of harmonic components in the network (e.g. by using active or passive harmonic filters, etc.) and the other is to remove the resonance stimulating factor by shifting away the resonance frequency to a non-critical frequency range (e.g. detuning PFC capacitors, redesigning feeder transformers, etc.). Studies show that these techniques are not adequate to solve harmonic resonance problems in power distribution networks which are dynamic by their nature and with complex interconnections. Due to this, solutions in the category one are designed for localised harmonic distortion compensation, while solutions in the category two lack real-time operation feature. Therefore, it was identified that there is a need for real-time harmonic resonance attenuation that is suitable for power distribution networks. In this thesis, a new real-time Harmonic Resonance Attenuation (HRA) technique is proposed. This technique may be used with ordinary shunt harmonic filters to make them behave like a virtual shunt capacitor or inductor. Thus, looking from the harmonic current source side, the filter alters the network harmonic impedance and hence results in harmonic resonance attenuation. In order to implement the HRA technique, fast measurement of system harmonics in real-time is required. Therefore, in this work, a fast individual harmonic extraction (FIHE) technique is developed to enhance the desired real-time operation of the HRA. The proposed FIHE needs only one sixth of the fundamental cycle to extract any individual harmonic component which is faster than other methods currently available. In addition to the speed, the proposed FIHE provides overshoot free, oscillation free and ripple free extraction characteristics. The proposed HRA and FIHE techniques are described in this thesis with detailed analysis to illustrate their operating principles. A series of simulations and experiments are conducted to evaluate their functionality and performance. Results of the evaluation are presented and discussed in this thesis together with details of the experimental HRA model developed to verify the theoretical and simulation results.
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Yano, Hiroshi. "Control of Electronic Characteristics at SiO_2/SiC Interface for SiC Power Metal-Oxide-Semiconductor Devices." 京都大学 (Kyoto University), 2001. http://hdl.handle.net/2433/150681.
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Malik, Naveed ur Rehman. "Modelling, Analysis, and Control Aspects of a Rotating Power Electronic Brushless Doubly-Fed Induction Generator." Doctoral thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174349.
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This thesis deals with the modeling, analysis and control of a novel brushlessgenerator for wind power application. The generator is named as rotatingpower electronic brushless doubly-fed induction machine/generator (RPEBDFIM/G). A great advantage of the RPE-BDFIG is that the slip power recoveryis realized in a brushless manner. This is achieved by introducing an additionalmachine termed as exciter together with the rotating power electronicconverters, which are mounted on the shaft of a DFIG. It is shown that theexciter recovers the slip power in a mechanical manner, and delivers it backto the grid. As a result, slip rings and carbon brushes can be eliminated,increasing the robustness of the system, and reducing the maintenance costsand down-time of the turbine. To begin with, the dynamic model of the RPE-BDFIG is developed andanalyzed. Using the dynamic model, the working principle of the generatoris understood and its operation explained. The analysis is carried out atspeeds, ±20% around the synchronous speed of the generator. Moreover, thedynamics of the generator due to external load-torque disturbances are investigated.Additionally, the steady-state model is also derived and analyzed forthe machine, when operating in motor mode. As a next step, the closed-loop control of the generator is considered indetail. The power and speed control of the two machines of the generator andthe dc-link voltage control is designed using internal model control (IMC)principles. It is found that it is possible to maintain the stability of thegenerator against load-torque disturbances from the turbine and the exciter,at the same time maintain a constant dc-link voltage of the rotor converter.The closed-loop control is also implemented and the operation of the generatorwith the control theory is confirmed through experiments.In the third part of the thesis, the impact of grid faults on the behaviourof the generator is investigated. The operation of the generator and its responseis studied during symmetrical and unsymmetrical faults. An approachto successful ride through of the symmetrical faults is presented, using passiveresistive network (PRN). Moreover, in order to limit the electrical and mechanicaloscillations in the generator during unsymmetrical faults, the dualvector control (DVC) is implemented. It is found that DVC to a certain extentcan be used to safeguard the converter against large oscillations in rotorcurrents. Finally, for completeness of the thesis, a preliminary physical design ofthe rotating power electronic converter has been done in a finite elementsoftware called ANSYS. The thermal footprint and the cooling capability,with estimates of the heatsink and fan sizes, are presented. Besides, another variant of a rotating electronic induction machine whichis based on the Lindmark concept and operating in a single-fed mode is also investigated. It’s steady-state model is developed and verified through experiments.QC 20151006
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Almoosa, Nawaf I. "Sensitivity analysis for online management of processor power and performance." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51805.
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The shift to manycore architectures has highlighted the need for runtime power and performance management schemes to improve the reliability, performance, and energy-efficiency of processors. However, the design of management algorithms is challenging since power and performance are strongly dependent on the workload, which cannot be determined apriori and exhibit wide and rapid runtime variations.
This dissertation seeks to show that sensitivity analysis (derivative estimation) provides runtime power and performance information that enables the design of adaptive and low-complexity management algorithms. The contributions of the dissertation include: 1) controllers that achieve rapid regulation of the power and throughput of processor cores, 2) a chip-level power control solution that maximizes the performance of manycore processors subject to the power constraints set by the cooling system, and 3) an iterative algorithm for optimizing the energy consumption of cache memories. The proposed algorithms use runtime derivative estimation to adapt to the rapid power and performance variations caused by workload, and their efficacy is demonstrated via formal analysis and simulation experiments.
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Wilson, Candace N. (Candace Nicola). "Development of a laboratory course in power electronic control circuitry based on a PWM buck controller." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37090.
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Thesis (M. Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (leaf 153).
Due to the constraints on time and resources within the typical electrical engineering curriculum, it is difficult for students to obtain Integrated Circuit design experience prior to entering industry. This project establishes the foundation for a new laboratory course in power electronics and analog circuit design. There is an introduction to power electronics, particularly the buck converter, and several basic analog circuit building blocks are introduced. A process consisting of circuit design, simulation, construction, and evaluation is developed to provide students with an introduction to Integrated Circuit design. A peak current mode PWM controller for a buck converter is developed to illustrate the fundamental power electronic and analog circuit concepts that are presented.
by Candace N. Wilson.
M.Eng.and S.B.
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Mabuchi, Yuichi. "A Study on Electromagnetic Interferences Related to Power Supplies for Micro-controllers in Electronic Control Units." 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/142223.
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Mann, Jaspreet Kaur. "On-line health monitoring of passive electronic components using digitally controlled power converter." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/10778.
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This thesis presents System Identification based On-Line Health Monitoring to analyse the dynamic behaviour of the Switch-Mode Power Converter (SMPC), detect, and diagnose anomalies in passive electronic components. The anomaly detection in this research is determined by examining the change in passive component values due to degradation. Degradation, which is a long-term process, however, is characterised by inserting different component values in the power converter. The novel health-monitoring capability enables accurate detection of passive electronic components despite component variations and uncertainties and is valid for different topologies of the switch-mode power converter. The need for a novel on-line health-monitoring capability is driven by the need to improve unscheduled in-service, logistics, and engineering costs, including the requirement of Integrated Vehicle Health Management (IVHM) for electronic systems and components. The detection and diagnosis of degradations and failures within power converters is of great importance for aircraft electronic manufacturers, such as Thales, where component failures result in equipment downtime and large maintenance costs. The fact that existing techniques, including built-in-self test, use of dedicated sensors, physics-of-failure, and data-driven based health-monitoring, have yet to deliver extensive application in IVHM, provides the motivation for this research ... [cont.].
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Adnan, Muhammad Wasif. "Implementation of an FPGA based Emulator for High Speed Power Electronic Systems." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175752.
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During development of control systems for power electronic systems, it is desirable to test the controller in real-time, by interfacing it with an emulator device. In this context, this work comprises the development of an emulator that can model accurately the dynamics of high speed power electronic systems and provides interfaces that are compatible with the real hardware. The realtime state calculations, based on discrete models, were performed on custom logic, implemented on an FPGA. The realized system allows to emulate Linear Parameter Varying (LPV) systems, achieving sampling rates up to 12MHz using a low cost Xilinx FPGA. As a result, power electronic systems with very high switching frequencies can be modeled. In addition, the FPGA incorporates a soft-core processor that allows a designer to easily re-configure the system model through software. The emulator system has been validated for a multiphase DC-DC converter, by comparing its results with the real hardware setup.
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Ramayya, George Joseph. "Two-Speed Control Of Compressors In Residentlial Air-Conditioning Systems." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401726439.
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Dietmannsberger, Markus [Verfasser]. "Voltage and Frequency Control of Embedded Low-Voltage Islanded Grids with Power-Electronic Generation Units / Markus Dietmannsberger." Hamburg : Helmut-Schmidt-Universität, Bibliothek, 2018. http://d-nb.info/115593329X/34.
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Lindström, Anton. "Design and implementation of a power distribution network for control equipment for electric vehicle charging." Thesis, Linköpings universitet, Fysik och elektroteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-137674.
Full textAbstract:
This thesis treats the design and implementation of a power distribution network for a controller PCB for controlling charging of electric vehicles. The controller PCB is powered by mains power, and thus needs both AC to DC conversion and DC to DC conversion in order to operate. The thesis focuses on the design of an isolated flyback topology AC to DC converter, while also describing the design and implementation of the DC to DC converters needed for the controller PCB to operate. The work started with some theoretical study, and then progressed into designing the converters. The AC to DC and the DC to DC converters where designed in parallel. After the design phase was complete the converters where implemented on PCBs for evaluation. The evaluation of the AC to DC converter involved evaluation of several different transformers from different suppliers, as well as evaluation of the circuit design itself. All converters designed proved functional after evaluation.