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1
Kanchanaharuthai, Adirak. "Small-Signal Stability, Transient Stability and Voltage Regulation Enhancement of Power Systems with Distributed Renewable Energy Resources." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1321988036.
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Pashaei, Afshin. "Distributed static series compensator in 11kV networks." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/3354.
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Series compensation techniques can be very effective when applied in an electrical network to increase the power transfer capacity of existing power lines. Distributed Static Series Compensation (DSSC) is a power electronics based series compensation scheme in which a DSSC device comprises of a single-phase H-bridge voltage source converter, a dc link capacitor and a low pass filter suspended from the power line via a single turn transformer. The application of DSSC in the 11kV distribution network is investigated in this thesis. This is followed by a study of existing control strategies employed in DSSC and Static Synchronies Series Compensation (SSSC) schemes. Most of these controllers are based on dq transformation methods in which balanced conditions are assumed and zero sequence currents are assumed to be negligible. While this might be a reasonable assumption at transmission level voltages, but it can be argued that in the presence of unbalanced loads and currents (a common feature of lower voltage distribution networks) these strategies can be inaccurate, leading to the wrong amount of compensation being injected. In addition some of the studied controllers are based on the 90° phase shift of line current. Practically, the injection angle must be slightly different in order to compensate the internal losses of the DSSC. The need for the diversion from the 90° can change over the time and this can threaten the stability of the system. A new single-phase control strategy based on the instantaneous power exchange between the DSSC devices and each of the three phase conductors is proposed in this thesis to address this issue. The new control method does not employ a dq transformation and is immune from the probable errors resulting from the presence of unbalanced network conditions. In the same time the injection angle is not fixed and it is adjusted by the controller. The operation of DSSC can be categorized in two modes and transfer function of system is obtained based on these two modes. The transfer function is used in the design of controller. This is followed by analyzing immunity of the designed controller against change of system parameters. The proposed scheme is simulated (using PSCAD software) to examine the operation of the new control method and the resulting impact on the 11kV distribution feeder, including the ability to divert power from one line to another and the ability to improve network voltage profiles. Performance of DSSC using the proposed controller is compared with performance of DSSC when the traditional controllers are employed.
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Yong, Sut Khan. "Grid-tie Quasi Z-Source Inverter-Based Static Synchronous Compensator." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/75945.
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This research work proposes intensive study and mathematical modelling analysis of transformer-less quasi Z-source inverter (qZSI) based static synchronous compensator (STATCOM) system. In this work, a single-phase qZSI is acted as a STATCOM system to compensate the grid reactive power at the point of coupling under different loading conditions. A new controller-based lead compensator is developed to achieve fast DC-link voltage balance across each qZS network. Simulation studies are conducted to evaluate the controller’s performance.
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LEITE, ARMANDO GONCALVES. "STATIC AND DYNAMIC SIMULATION OF VOLTAGE CONTROL BY GENERATOR AND SYNCHRONOUS COMPENSATOR." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12362@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>O tema abordado neste trabalho é a observação e análise, em
regime permanente e dinâmico, da ocorrência de um fenômeno
que já foi observado em condições reais de operação do
sistema elétrico brasileiro, que é a relação oposta entre a
tensão de excitação de geradores e compensadores síncronos
e a tensão controlada. Nessas situações, a
capacidade nominal de um gerador / compensador síncrono,
por exemplo, não seria útil para manter a tensão
controlada. Em virtude da relação oposta, um aumento na
excitação da máquina abaixaria a tensão controlada. O
controle automático continuaria agindo, abaixando ainda
mais a tensão. Este mecanismo pode levar o sistema ao
colapso. A abordagem do problema baseou-se na verificação
do comportamento do gerador / compensador como dispositivo
de controle de tensão, em regime permanente e dinâmico,
ante as diversas situações normais de um sistema elétrico,
tais como variações do valor da tensão de referência
(tensão controlada) e de carga. A análise em regime
permanente utilizou um algoritmo de fluxo de carga,
enquanto a análise em regime dinâmico utilizou a simulação
no domínio do tempo. A real existência do fenômeno foi
comprovada através de várias destas análises, mostrando
inclusive a mudança da região de operação em
algumas delas. Em outros casos, os resultados da análise em
regime permanente não coincidiram com os da análise em
regime dinâmico.<br>The aim of this work is to investigate, in steady state and
dynamic performance, the phenomenon of the opposite
relationship, already observed at real operation conditions
of the Brazilian Electric System, between generators and
synchronous compensators excitation voltage and the
controlled one. In these situations, the generator /
synchronous compensator nominal capacity, for example,
would not be useful to keep the voltage controlled. Due the
opposite relationship, an increase in the excitation
voltage would reduce the controlled voltage. The automatic
control would keep acting and reducing more the voltage.
This mechanism can lead the system to the collapse. The
study of this problem was based in the generator /
compensator behavior as a control voltage device, in steady-
state and dynamic performance, front of several operation
situations of electric power system, like reference voltage
(controlled voltage) variation and load changing. The
steady state analysis used a load flow algorithm, while the
time domain simulation was utilized for the dynamic
performance analysis. The real existence of the phenomenon
was verified through these analyses, emphasizing the
operation region changing in some of them. In other cases,
the analyses results in the steady-state were different of
the dynamic performance results.
5
Goodchild, Jordan. "Development of a low voltage static synchronous compensator STATCOM for educational use." Thesis, Goodchild, Jordan (2016) Development of a low voltage static synchronous compensator STATCOM for educational use. Honours thesis, Murdoch University, 2016. https://researchrepository.murdoch.edu.au/id/eprint/30804/.
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Electrical power quality is essential in the effective transmission and distribution of power to consumers. With the increase in non-linear loads it is becoming more prevalent to maintain the quality of power supplied. Voltage sagging or swelling and power factor are two of the major power quality issues. By introducing a static synchronous compensator (STATCOM) into a system these power-quality issues can be significantly reduced and maintained effectively.
This project developed and tested the idea of constructing a low voltage static synchronous compensator for educational use, in which students could safely experiment with the concept and tools of power quality control. The end design goal was to construct a device capable of displaying the concepts of a STATCOM by producing a low voltage Alternating Current (AC) waveform to supply the given loads. Features of this project were to include a real-time display of system parameters and a switch with the ability to change between voltage control and power factor control.
The project incorporates the use of various components to achieve the desired STATCOM. Integrated into this system is an Arduino Uno microcontroller. This controller produces the triangular carrier waveform through direct digital synthesis. Additionally, it is responsible for the measurement and display of system data. The control signals produced by the comparison of the filtered Direct Digital Synthesis (DDS) triangular waveform with a sinusoidal control signal are fed into an Infineon Dual Half-Bridge. Following this the output of the bridge is fed through a low pass filter to produce the required output sinusoid for the STATCOM.
Through several experiments the output waveform of the STATCOM was monitored and recorded. One of the parameters monitored for the STATCOM output was the total harmonic distortion of the output waves. At low amplitude modulation values the output waveform resembles a sinusoidal output however as expected at higher values the output waveforms begin to distort and resemble a square wave.
The major recommended future works are to design a control algorithms capable of performing voltage control and power factor control to display the concepts of power quality control. In addition to this a method of switching between the two control modes will require installation.
The project is unfortunately not considered to be at a completed, ready to implement stage. However, sufficient work has been undertaken and completed for another willing student to finalise the project.
6
Terek, Cristina I. "A new static synchronous series compensator for real power control on AC transmission lines." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0007/MQ42103.pdf.
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Siaw, Teck Ung. "Vector Control of Multilevel Cascaded H-Bridge Inverter Based Static Synchronous Compensator with Simultaneous Functionalities." Thesis, Curtin University, 2020. http://hdl.handle.net/20.500.11937/81991.
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Multilevel cascaded inverter based static synchronous compensator (STATCOM) system and its control scheme were designed and implemented to achieve low-switching frequency and high-bandwidth power control. The gain parameters of PI-controller were also formulated to obtain the best values for achieving good dynamic and transient performances. To verify and validate the aforementioned work with Matlab/simulink, the proposed system was simulated to provide different simultaneous functionalities: namely, (i) reactive power compensation and (ii) active harmonic filtration at th epoint of common coupliing under balanced loading conditions.
8
Wenjuan, D. U. "Power System Small Signal Oscillation Stability as Affected by Static Synchronous Compensator (STATCOM) and Energy Storage System (ESS) Control." Thesis, University of Bath, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516943.
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Arsoy, Aysen. "Electromagnetic Transient and Dynamic Modeling and Simulation of a StatCom-SMES Compensator in Power Systems." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/27225.
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Electromagnetic transient and dynamic modeling and simulation studies are presented for a StatCom-SMES compensator in power systems. The transient study aims to better understand the transient process and interaction between a high power/high voltage SMES coil and its power electronics interface, dc-dc chopper. The chopper is used to attach the SMES coil to a StatCom. Following the transient study, the integration of a StatCom with SMES was explored to demonstrate the effectiveness of the combined compensator in damping power oscillations. The transient simulation package PSCAD/EMTDC has been used to perform the integrated modeling and simulation studies.
A state of the art review of SMES technology was conducted. Its applications in power systems were discussed chronologically. The cost effective and feasible applications of this technology were identified. Incorporation of a SMES coil into an existing StatCom controller is one of the feasible applications, which can provide improved StatCom operation, and therefore much more flexible and controllable power system operation.
The SMES coil with the following unique design characteristics of 50MW (96 MW peak), 100 MJ, 24 kV interface has been used in this study. As a consequence of the high power/ high voltage interface, special care needs to be taken with overvoltages that can stress the insulation of the coil. This requires an investigation of transient overvoltages through a detailed modeling of SMES and its power electronics interface. The electrical model for the SMES coil was developed based on geometrical dimensions of the coil. The interaction between the SMES coil and its power electronics interface (dc-dc chopper for the integration to StatCom) was modeled and simulated to identify transient overvoltages. Transient suppression schemes were developed to reduce these overvoltages. Among these are MOV implementation, surge capacitors, different configurations of the dc-dc chopper.
The integration of the SMES coil to a StatCom controller was developed, and its dynamic behavior in damping oscillations following a three-phase fault was investigated through a number of simulation case studies. The results showed that the addition of energy storage to a StatCom controller can improve the StatCom-alone operation and can possibly reduce the MVA rating requirement for the StatCom operating alone. The effective location selection of a StatCom-SMES controller in a generic power system is also discussed.<br>Ph. D.
10
Jalboub, Mohamed K. "Investigation of the application of UPFC controllers for weak bus systems subjected to fault conditions. An investigation of the behaviour of a UPFC controller: the voltage stability and power transfer capability of the network and the effect of the position of unsymmetrical fault conditions." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5699.
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In order to identify the weakest bus in a power system so that the Unified Power Flow Controller could be connected, an investigation of static and dynamic voltage stability is presented. Two stability indices, static and dynamic, have been proposed in the thesis. Multi-Input Multi-Output (MIMO) analysis has been used for the dynamic stability analysis. Results based on the Western System Coordinate Council (WSCC) 3-machine, 9-bus test system and IEEE 14 bus Reliability Test System (RTS) shows that these indices detect with the degree of accuracy the weakest bus, the weakest line and the voltage stability margin in the test system before suffering from voltage collapse.
Recently, Flexible Alternating Current Transmission systems (FACTs) have become significant due to the need to strengthen existing power systems. The UPFC has been identified in literature as the most comprehensive and complex FACTs equipment that has emerged for the control and optimization of power flow in AC transmission systems. Significant research has been done on the UPFC. However, the extent of UPFC capability, connected to the weakest bus in maintaining the power flows under fault conditions, not only in the line where it is installed, but also in adjacent parallel lines, remains to be studied. In the literature, it has normally been assumed the UPFC is disconnected during a fault period. In this investigation it has been shown that fault conditions can affect the UPFC significantly, even if it occurred on far buses of the power system. This forms the main contribution presented in this thesis. The impact of UPFC in minimizing the disturbances in voltages, currents and power flows under fault conditions are investigated. The WSCC 3-machine, 9-bus test system is used to investigate the effect of an unsymmetrical fault type and position on the operation of UPFC controller in accordance to the G59 protection, stability and regulation. Results show that it is necessary to disconnect the UPFC controller from the power system during unsymmetrical fault conditions.<br>Libyan Government
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Jalboub, Mohamed. "Investigation of the application of UPFC controllers for weak bus systems subjected to fault conditions : an investigation of the behaviour of a UPFC controller : the voltage stability and power transfer capability of the network and the effect of the position of unsymmetrical fault conditions." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5699.
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In order to identify the weakest bus in a power system so that the Unified Power Flow Controller could be connected, an investigation of static and dynamic voltage stability is presented. Two stability indices, static and dynamic, have been proposed in the thesis. Multi-Input Multi-Output (MIMO) analysis has been used for the dynamic stability analysis. Results based on the Western System Coordinate Council (WSCC) 3-machine, 9-bus test system and IEEE 14 bus Reliability Test System (RTS) shows that these indices detect with the degree of accuracy the weakest bus, the weakest line and the voltage stability margin in the test system before suffering from voltage collapse. Recently, Flexible Alternating Current Transmission systems (FACTs) have become significant due to the need to strengthen existing power systems. The UPFC has been identified in literature as the most comprehensive and complex FACTs equipment that has emerged for the control and optimization of power flow in AC transmission systems. Significant research has been done on the UPFC. However, the extent of UPFC capability, connected to the weakest bus in maintaining the power flows under fault conditions, not only in the line where it is installed, but also in adjacent parallel lines, remains to be studied. In the literature, it has normally been assumed the UPFC is disconnected during a fault period. In this investigation it has been shown that fault conditions can affect the UPFC significantly, even if it occurred on far buses of the power system. This forms the main contribution presented in this thesis. The impact of UPFC in minimizing the disturbances in voltages, currents and power flows under fault conditions are investigated. The WSCC 3-machine, 9-bus test system is used to investigate the effect of an unsymmetrical fault type and position on the operation of UPFC controller in accordance to the G59 protection, stability and regulation. Results show that it is necessary to disconnect the UPFC controller from the power system during unsymmetrical fault conditions.
12
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.
13
Ladjavardi, Marjan. "Improving small signal stability of power systems in the presence of harmonics." Thesis, Curtin University, 2008. http://hdl.handle.net/20.500.11937/511.
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This thesis investigates the impact of harmonics as a power quality issue on the dynamic behaviour of the power systems. The effectiveness of the power system stabilizers in distorted conditions is also investigated. This thesis consists of three parts as follows:The first part focuses on the operation of the power system under distorted conditions. The conventional model of a synchronous generator in the dq-frame of reference is modified to include the impact of time and space harmonics. To do this, the synchronous generator is first modelled in the harmonic domain. This model helps in calculating the additional parts of the generator fundamental components due to the harmonics. Then the Park transformation is used for calculating the modified fundamental components of the synchronous generator in dq axes. The modified generator rotor angle due to the presence of harmonics is calculated and the impact of damper windings under the influence of harmonics is investigated. This model is used to study the small-signal stability of a distorted Single Machine Infinite Bus (SMIB) system. The eigenvalue analysis method is employed and the system state space equations are calculated by linearizing the differential equations around the operating point using an analytical method. The simulation results are presented for a distorted SMIB system under the influence of different harmonic levels. The impact of damper windings and also harmonics phase angles are also investigated.In the second part of the thesis, the effectiveness of the power system damping controllers under distorted conditions is studied. This investigation is done based on a distorted SMIB system installed with a Static Synchronous Series Compensator (SSSC). In the first step, the system state space equations are derived. A Power Oscillation Damping (POD) controller with a conventional structure is installed on the SSSC to improve the system dynamic behaviour. A genetic-fuzzy algorithm is proposed for tuning the POD parameters. This method along with the observability matrix is employed to design a POD controller under sinusoidal and distorted conditions. The impact of harmonics on the effectiveness of the POD controller under distorted conditions is investigated.In the last part, the steady state and dynamic operation of an actual distributed generation system under sinusoidal and distorted conditions are studied. A decoupled harmonic power flow program is employed for steady state analysis. The nonlinear loads are modelled as decoupled harmonic current sources and the nonlinear model of synchronous generator in harmonic domain is used to calculate the injected current harmonics. For the system dynamic stability study, the power system toolbox with the modified model of the synchronous generator is used. The system eigenvalues are calculated and the effectiveness of the installed Power System Stabilisers (PSS) is investigated under sinusoidal and distorted conditions. Simulation results show that in order to guarantee the effectiveness of a PSS in distorted conditions, it is necessary to consider the harmonics in tuning its parameters.
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Pereira, André Luiz Silva [UNESP]. "Utilização de redes neurais artificiais no ajuste de controladores suplementares e dispositivo FACTS STATCOM para a melhoria da estabilidade a pequenas perturbações do sistema elétrico de potência." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/100315.
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pereira_als_dr_ilha.pdf: 1505539 bytes, checksum: 8b3fa09211b5f80a63a93c6fd21675aa (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Este trabalho apresenta estudos referentes à inclusão do dispositivo FACTS STATCOM e a utilização de Redes Neurais Artificiais para o ajuste dos parâmetros de sinais adicionais estabilizantes (PSS’s e POD’s) no sistema de potência multimáquinas. O objetivo é a melhoria da estabilidade frente às pequenas perturbações do sistema de energia elétrica. O modelo matemático utilizado para o estudo das oscilações eletromecânicas de baixa freqüência em sistemas de energia elétrica foi o Modelo de Sensibilidade de Potência (MSP), modificado para permitir a inclusão do dispositivo STATCOM. Este modelo baseia-se no princípio de que o balanço de potência ativa e reativa deve ser satisfeito continuamente em qualquer barra do sistema durante um processo dinâmico. Prosseguindo na realização do trabalho foram desenvolvidos os modelos matemáticos para a inclusão dos PSS’s e POD’s no sistema elétrico, bem como foi realizada uma discussão a respeito da escolha do local de instalação destes controladores e técnicas clássicas para o ajuste de seus parâmetros. A partir disto foram utilizadas redes neurais artificiais (RNA’s) com o objetivo de ajustar os parâmetros dos controladores. A rede utilizada para este fim foi a do tipo Perceptron Multicamadas, sendo utilizado para o seu treinamento o algoritmo Backpropagation. Simulações foram realizadas e os resultados obtidos para os sistemas testes Sul Brasileiro, Simétrico de Duas Áreas e New England são comentados<br>This work presents studies about the inclusion of FACTS STATCOM devices using neural networks tune stability additional signal parameters (PSS’s and POD’s) on a multi-machine power system. The objective is to improve the stability to small perturbations in electric power systems. The mathematical model used for studying the lower frequency electromechanical oscillations is the Power Sensitivity Model (PSM), modified to allow the inclusion of the STATCOM device. This model is based on the principle that the active and reactive power balance must be continuously satisfied in every bus of the system during the dynamical process. Mathematical models were developed to include the PSS’s and POD’s on the electrical system, as well as the local to install these control devices and the classical techniques to adjust these parameters. Afterwards, the neural networks were used to adjust the parameters of the controllers. The neural network used is a Perceptron Multi Layer, with the training by backpropagation. Simulations were effectuated for the South Brazilian Power System, the Two Areas Symmetrical Power System and the New England Power System
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Cetin, Alper. "Design And Implementation Of A Voltage Source Converter Based Statcom For Reactive Power Compensation And Harmonic Filtering." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608307/index.pdf.
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In this thesis, design and implementation of a distribution-type, voltage source converter (VSC) based static synchronous compensator (D-STATCOM) having the
simplest converter and coupling transformer topologies have been carried out. The VSC STATCOM is composed of a +/- 750 kVAr full-bridge VSC employing selective harmonic elimination technique, a low-pass input filter, and a &<br>#8710<br>/Y
connected coupling transformer for connection to medium voltage bus. The power stage of VSC based STATCOM is composed of water-cooled high voltage IGBT modules switched at 850 Hz for the elimination of 5th, 7th, 11th, 13th, 17th, 19th, 23rd,and 25th voltage harmonics. Special care has been taken in the laminated busbar design to minimize stray inductances between power semiconductors and dc link
capacitor. Reactive power control is achieved by applying the phase angle control technique. The effect of input filter on total demand distortion has been investigated theoretically by mathematical derivations.
The proposed VSC STATCOM has been implemented for reactive power compensation of Coal Preparation System in Kemerkö<br>y Thermal Power Plant. The field test results have shown the success of the implemented system in view of fast
response in reactive power compensation, and minimum input current harmonic content, and compliance with the IEEE Std. 519-1992 even for the weakest power systems. The application of selective harmonic elimination technique and phase angle control to VSC STATCOM has led to optimum switching frequency and device utilization for high voltage IGBTs at the expense of slower response as compared to other PWM techniques.
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Hock, Júnior Rubens Tadeu. "Regulador de tensão móvel controlado em tensão com rastreamento do ponto de mínima potência aparente." Universidade do Estado de Santa Catarina, 2015. http://tede.udesc.br/handle/handle/2082.
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Previous issue date: 2015-02-24<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>This paper presents a mobile voltage regulator based in a Distribution Static Synchronous Compensator (DSTATCOM) applied to low voltage distribution grids. The DSTATCOM consists in a three-phase four-wire inverter connected to the grid through a second order low pass filter. The control structure is composed of three output voltage loops with active damping and the two dc bus loops. In addition, a new concept of Minimum Power Point Tracking (mPPT) is introduced, forcing the DSTATCOM to operate with the minimum power. In certain conditions, this means no compensation. The dynamic models of the converter are presented, as well as the control design. Simulation results show the capacity of voltage regulation and the features of the mPPT, even under grid and load unbalances and nonlinear loads. This work is concluded with the construction of a 30 kVA prototype and validation through experimental results proves the proper functioning of the voltage regulator.<br>Esse trabalho apresenta um regulador de tensão móvel baseado em um compensador estático de reativos (DSTATCOM) aplicado a redes de distribuição de baixa tensão. O DSTATCOM consiste em um inversor trifásico a quatro fios conectado à rede através de um filtro de segunda ordem. A estrutura de controle é composta por três malhas de tensão de saída com amortecimento ativo e duas malhas de tensão do barramento cc. Em adição, um novo conceito de rastreamento da mínima potência (mPPT) é introduzido, forçando o DSTATCOM a operar com a mínima potência. Em certas ocasiões, isso significa nenhuma compensação. Os modelos dinâmicos do conversor são apresentados, assim como o projeto de controle. Resultados de simulação mostram a capacidade de regulação da tensão e as características do mPPT, mesmo com desequilíbrios na rede e/ou na carga e com cargas não lineares. O trabalho é concluído com a construção de um protótipo de 30 kVA e validação dos estudos através de resultados experimentais obtidos comprovam o bom funcionamento do regulador de tensão.
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Carvalho, Marcelo Moreira de. "Análise da influência de diferentes tipos de cargas no desempenho da proteção anti-ilhamento de geradores distribuídos." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-10102014-103332/.
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A conexão de geradores distribuídos nas redes de subtransmissão e de distribuição de energia elétrica se mostra cada vez mais crescente devido aos inúmeros benefícios técnicos e econômicos alcançados com essa tecnologia. No entanto, há importantes implicações técnicas que precisam ser analisadas antes que um gerador distribuído seja conectado em paralelo ao sistema elétrico. Um aspecto a ser analisado, e que é comum entre as concessionárias de energia elétrica é a adequação da proteção anti-ilhamento, a qual tem a função de detectar essa condição e, automaticamente, desconectar os geradores distribuídos, dentro de um tempo pré-determinado, e assim mantê-los até que o fornecimento de energia seja restabelecido. Neste contexto, este trabalho analisará o desempenho dos relés de proteção anti-ilhamento em face de diferentes tipos de cargas que acabam afetando o tempo de detecção do ilhamento. Com isso, pretende-se obter subsídios para que os ajustes desses relés sejam calculados de forma eficiente. Os relés estudados são o relé de sub/sobrefrequência e o relé de taxa de variação da frequência, e o gerador distribuído é do tipo síncrono equipado com controle de tensão. As análises mostraram que no instante em que ocorre um ilhamento os fatores que mais influenciam no desempenho dos relés de proteção anti-ilhamento são as condições de carga e geração, tempo de detecção estabelecido, tipo do relé adotado, ajuste do mesmo e modelo de carga utilizado.<br>The connection of distributed generators to power subtransmission and distribution networks has been increasing recently due to the technical and economic benefits that such technology can provide. However, there are important technical issues that need to be carefully analyzed before a distributed generator is connected to electrical systems. One issue to be analyzed, which is common sense among utility companies, is the anti-islanding protection, whose main goal is to detect unintentional islanding and, automatically, disconnect the distributed generators within a required time-interval. In this context, this work will analyze the performance of anti-islanding protection relays in face of different load types. With this study, one intend to get support for adjusting these relays efficiently. The relays studied in this work are the under/over frequency and the rate of change of frequency relays, and the distributed generator is a synchronous machine equipped with an automatic voltage regulator. The analyzes showed that the moment a islanding occurs the most important factors influencing the performance of relays anti-islanding protection are the conditions of load and generation, detection time set, type and relay setting adopted and load model.
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Banejad, Mahdi. "Identification of damping contribution from power system controllers." Thesis, Queensland University of Technology, 2004. https://eprints.qut.edu.au/15851/1/Mahdi_Banejad_Thesis.pdf.
Full textAbstract:
With the growth of power system interconnections, the economic drivers encourage the electric companies to load the transmission lines near their limits, therefore it is critical to know those limits well. One important limiting issue is the damping of inter-area oscillation (IAO) between groups of synchronous machines. In this Ph.D. thesis, the contribution of power system components such as load and static var compensators (SVC) that affect the IAO of the power system, are analysed. The original contributions of this thesis are as follows: 1-Identification of eigenvalues and mode shapes of the IAO: In the first contribution of this thesis, the eigenvalues of the IAO are identified using a correlation based method. Then, the mode shape at each identified resonant frequency is determined to show how the synchronous generators swing against each other at the specific resonant frequencies. 2-Load modelling and load contribution to damping: The first part of this contribution lies in identification of the load model using cross-correlation and autocorrelation functions . The second aspect is the quantification of the load contribution to damping and sensitivity of system eigenvalues with respect to the load. 3- SVC contribution to damping: In this contribution the criteria for SVC controller redesign based on complete testing is developed. Then the effect of the SVC reactive power on the measured power is investigated. All of the contributions of this thesis are validated by simulation on test systems. In addition, there are some specific application of the developed methods to real data to find a.) the mode shape of the Australian electricity network, b.) the contribution of the Brisbane feeder load to damping and c.) the effect of the SVC reactive power of the Blackwall substations on the active power supplying Brisbane.
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Banejad, Mahdi. "Identification of Damping Contribution from Power System Controllers." Queensland University of Technology, 2004. http://eprints.qut.edu.au/15851/.
Full textAbstract:
With the growth of power system interconnections, the economic drivers encourage the electric companies to load the transmission lines near their limits, therefore it is critical to know those limits well. One important limiting issue is the damping of inter-area oscillation (IAO) between groups of synchronous machines. In this Ph.D. thesis, the contribution of power system components such as load and static var compensators (SVC) that affect the IAO of the power system, are analysed. The original contributions of this thesis are as follows: 1-Identification of eigenvalues and mode shapes of the IAO: In the first contribution of this thesis, the eigenvalues of the IAO are identified using a correlation based method. Then, the mode shape at each identified resonant frequency is determined to show how the synchronous generators swing against each other at the specific resonant frequencies. 2-Load modelling and load contribution to damping: The first part of this contribution lies in identification of the load model using cross-correlation and autocorrelation functions . The second aspect is the quantification of the load contribution to damping and sensitivity of system eigenvalues with respect to the load. 3- SVC contribution to damping: In this contribution the criteria for SVC controller redesign based on complete testing is developed. Then the effect of the SVC reactive power on the measured power is investigated. All of the contributions of this thesis are validated by simulation on test systems. In addition, there are some specific application of the developed methods to real data to find a.) the mode shape of the Australian electricity network, b.) the contribution of the Brisbane feeder load to damping and c.) the effect of the SVC reactive power of the Blackwall substations on the active power supplying Brisbane.
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Sadeghzadeh, Nokhodberiz Seyed Mohammad. "Amélioration de la stabilité transitoire des oscillations d'un réseau électrique à l'aide de SMES et de SSSC." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0033.
Full textAbstract:
Dans ce travail, la stabilité transitoire et l'amortissement des oscillations dans les réseaux électriques sont améliorés en utilisant la commande en ligne du SMES (Superconducting Magnetic Energy Storage) et du SSSC (Static Synchronous Series Compensator). Les commandes proposées sont basées sur la théorie de la logique floue. Dans le cas du SSSC, elle est associée à la fonction d'énergie transitoire. Nous avons également associé une loi de type mode glissant pour éliminer le lien hors ligne entre la commande du SMES et le centre de contrôle des réseaux. Ceci permet un maintien du fonctionnement du régulateur en l'absence de phase d'apprentissage. Le SMES et le SSSC sont connectés à un point intermédiaire d'une longue ligne qui relie deux parties du réseau. Une réalisation pratique du régulateur à été étudié et les mesures nécessaires pour la commande peuvent s'obtenir à partir du noeud auquel est connecté le régulateur. Afin de valider les commandes proposées, elles ont été implantées en simulation sur deux exemples de réseaux : un réseau comportant une ligne et le réseau de New England. Les résultats obtenus montrent une amélioration considérable du temps critique d'élimination du défaut ainsi que l'amortissement des oscillations après le défaut. Notre méthode a également apporté une augmentation de la capacité de transfert correspondant aux lignes de transmission
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Loureiro, Pedro da Cruz. "Controle de tensão e harmônicos por compensador estático de reativos com ajuste de parâmetros via redes neurais artificiais." Universidade Federal de Juiz de Fora, 2012. https://repositorio.ufjf.br/jspui/handle/ufjf/1785.
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Previous issue date: 2012-04-16<br>CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Neste trabalho é proposta a aplicação de redes neurais artificiais para ajuste de parâmetros de
um compensador estático de reativos, para controle de tensão e harmônicos. Devido à intensa
produção de correntes harmônicas e possíveis afundamentos de tensão em instalações
industriais como o forno a arco, é necessário um sistema de controle eficiente e robusto. Além
disso, os sistemas elétricos de potência se encontram em um cenário com a presença cada vez
maior de geração distribuída, cargas não-lineares e forte tendência à operação no contexto das
smartgrids e microgrids. Sendo assim, o suporte de reativos deve ser adequado a esses
sistemas, podendo atuar de forma rápida, precisa e confiável. Uma possível solução é a
utilização de um compensador estático de reativos (CER) com função adicional de filtragem
no ponto onde se deseja controlar a tensão e a distorção harmônica. Entretanto, para o correto
funcionamento, é necessário um sistema preciso para o ajuste dos parâmetros do CER, ou
seja, determinar os ângulos de disparo dos tiristores e o número de bancos de capacitores a
serem ligados. Neste trabalho é proposta uma estratégia de controle via redes neurais
artificiais, treinadas para o reconhecimento de padrões de operação em regime permanente e
definição da configuração do CER, conferindo inteligência ao equipamento.
Os desenvolvimentos propostos foram implementados no ambiente MatLab®. A validação do
método é feita através de simulações em sistemas-teste, presentes na literatura técnica,
utilizando o fluxo de potência pelo método de injeção de correntes trifásico harmônico. Os
resultados obtidos mostram as vantagens da utilização da estratégia proposta.<br>In this work, an artificial neural network-based static var compensator tuning is proposed for
voltage and harmonic distortion control. Due to intense harmonic current injection and
possible voltage sags produced by industrial facilities such as arc furnaces, an efficient robust
control system is needed. Besides, electrical power systems face a new scenario with high
penetration of distributed generation and non-linear loads and increased smart grid and
microgrid trends. Therefore, the available reactive power sources must be able to provide
system control in order to operate the system in a fast, accurate and reliable way. The
application of a static var compensator (SVC) with additional filtering function at the
controlled node is a possible solution. However, a precise SVC parameters tuning is needed,
in order to make the system to work properly. In this work, a control strategy based on
artificial neural networks is proposed. The neural networks are trained to recognize steadystate
operating patterns and give the SVC adjustment.
The proposed technique was implemented in the MatLab® environment. The methodology is
validated by simulations in test-systems available in technical literature, using the three-phase
harmonic current injection method power flow. Results show the advantages of the proposed
methodology.
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Гаврилюк, Ігор Миколайович, та Havryliuk Ihor. "Розробка проекту лінії електропередачі з вставкою постій¬ного струму". Master's thesis, ТНТУ імені Івана Пулюя, 2019. http://elartu.tntu.edu.ua/handle/lib/29562.
Full textAbstract:
В дипломній роботі виконано дослідження можливих варіантів об’єднання несинхронних електроенергетичних систем та систем з різними стандартами регулювання частоти.
Метою роботи є розробка лінії електропередачі «Ковель – Хелм» з вставкою постійного струму для продажу електроенергії з України у Польщу.
Об’єкти, аналогічні спроектованому у даному проекті, можна впровад¬жувати і в інших елек-тричних мережах, що дозволить значно зменшити розміри синхронних мереж змінного струму, запобігти або обмежити каскадні відключення, підвищити коефіцієнт корисної дії електромереж і надійність електроенергетичних систем.<br>In the diploma paper deals with the possibility of combining non-synchronous power systems and systems with different frequency control standards.
The purpose of the work is to develop a Kovel-Helm transmission line with a DC insert for the sale of electricity from Ukraine to Poland.
Objects similar to those projected in this project can be implemented in other power grids, which will significantly reduce the size of AC synchronous networks, prevent or limit cascade outages, increase the efficiency of grids and the reliability of power systems.<br>ПЕРЕЛІК УМОВНИХ СКОРОЧЕНЬ.................................................................... 7
ВСТУП .................................................................................................................…8
1 АНАЛІТИЧНА ЧАСТИНА ...............................................................................13
1.1 Призначення вставок постійного струму......................................................13
1.2 ВВППС – основні характеристики системи .................................................15
1.3 Варіанти застосування ВВППС .....................................................................16
1.4 Керування потужністю ...................................................................................17
1.5 Поведінка ВВППС в умовах виходу з ладу системи змінного струму......18
1.6 Вплив підключеної мережі змінного струму на ВПС .................................19
1.7 Споживання реактивної потужності .............................................................21
1.8 Висновки до розділу .......................................................................................23
2 НАУКОВО-ДОСЛІДНА ЧАСТИНА................................................................24
2.1 Пріоритетні напрями діяльності магістрального електромережевого
комплексу.........................................................................................................24
2.2 Заходи шодо зниження комерційних втрат електроенергії ........................28
2.3 Перспективи передачі електроенергії за допомогою постійного струму .30
2.4 Основні причини використання ППС в ОЕС України ................................32
2.5 Висновки до розділу .......................................................................................35
3 ТЕХНОЛОГІЧНА ЧАСТИНА ..........................................................................36
3.1 Вибір напруги ліній електропередач постійного струму............................36
3.2 Вибір схеми вставки постійного струму.......................................................40
3.3 Перетворення й регулювання струму конверторами ..................................41
3.4 Вибір тиристорів .............................................................................................44
3.5 Система захисту тиристорів від перенапруг та перевантажень .................48
3.6 Система охолодження тиристорних модулів ...............................................50
3.7 Визначення кількості тиристорів у вентильних групах перетворювача ...52
3.8 Висновки до розділу .......................................................................................54
4 ПРОЕКТНО-КОНСТРУКТОРСЬКА ЧАСТИНА ...........................................55
4.1 Вибір раціонального січення проводів .........................................................55
6
4.2 Розрахунок споживання реактивної енергії перетворювачами..................56
4.3 Усунення впливу вищих гармонік напруги й струму у схемі ВПС...........60
4.4 Розрахунок фільтрокомпенсуючого пристрою............................................65
4.5 Активні фільтри...............................................................................................71
4.6 Висновки до розділу .......................................................................................74
5 СПЕЦІАЛЬНА ЧАСТИНА................................................................................75
5.1 Вибір трансформатора ....................................................................................75
5.2 Компенсація реактивної потужності.............................................................78
5.3 Вибір місця під’єднання компенсаційних пристроїв ..................................81
5.4 Розрахунок потужності компенсаційних пристроїв ....................................81
5.5 Зменшення струму несиметрії у вставках постійного струму ...................84
5.6 Струм к.з. на шинах високої напруги трансформаторів .............................86
5.7 Вибір обладнання ............................................................................................87
5.8 Висновки до розділу .......................................................................................92
6 ОБГРУНТУВАННЯ ЕКОНОМІЧНОЇ ЕФЕКТИВНОСТІ..............................93
6.1 Критерії економічної ефективності енергетичного виробництва..............93
6.2 Визначення капітальних затрат .....................................................................94
6.3 Вартість електроенергії ..................................................................................95
6.4 Розрахунок економічної ефективності..........................................................98
7 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ...100
7.1 Заходи безпеки при обслуговуванні електроустановок ............................100
7.2 Захист персоналу від впливу електричних і електромагнітних полів .....103
7.3 Захист персоналу підстанції від наведених напруг ...................................106
8 ЕКОЛОГІЯ........................................................................................................108
8.1 Актуальність охорони навколишнього середовища..................................108
8.2 Вплив на людину електромагнітного забруднення довкілля ...................108
8.3 Вплив магнітного поля повітряних ліній постійного струму високої і
надвисокої напруги на навколишнє середовище.......................................110
ЗАГАЛЬНІ ВИСНОВКИ ДО ДИПЛОМНОЇ РОБОТИ ...................................112
ПЕРЕЛІК ПОСИЛАНЬ .......................................................................................113
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Lin, Pei-Hwang, and 林培煌. "Power Quality Compensation By Static Synchronous Compensator." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/09039273418921867807.
Full textAbstract:
碩士<br>國立雲林科技大學<br>電機工程系碩士班<br>93<br>With the rapid development of the Hi-Tech industry, the power quality is more and more important. When the electric perturbation phenomenon such as: voltage sag, voltage swell, voltage flicker ,load flicker and unbalance three-phases voltages is happen, the power system should be operated to supply users with stable and reliable electricity.
The system analysis and control scheme of static synchronous compensator are presented in the thesis, When the utility system is in the normal condition, the compensator is operated to improve the power factor at the source side. When the electric perturbation phenomenon is happen, the compensator can compensate the reactive power in order to obtain the constant RMS value at the load side.
In order to verify the feasibility of the control scheme proposed in this thesis, the software package MATLAB/SIMULINK is used to obtain the simulated waveforms.
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Chen, Ju-Yuan, and 陳如元. "Three-Phase Four-Wire Static Synchronous Compensator." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/92075329356386914449.
Full textAbstract:
碩士<br>國立臺灣大學<br>電機工程學研究所<br>93<br>Recently, because of advancement in science and technology, factory equipments require better power quality than before, especially in three phase electric machinery where the negative sequence voltage and zero sequence voltage must not exceed 1.5% of positive sequence voltage. Hence, in this thesis, a static synchronous compensator is designed in order to have better voltage profile on the customer side.
A symmetrical component algorithm will be proposed for the design of a static synchronous compensator which comprises a three phase four-arm voltage-sourced pulse width modulated inverter with a dc capacitor. The control kernel of the STATCOM is implemented by a PC-based digital system with advanced PCL-1800 data acquisition boards.
Finally, based on the results from simulations and experiments, it can be concluded that voltage unbalance and voltage sag can be effectively reduced by the proposed STATCOM.
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Weng, Yung-Tsai, and 翁永財. "Design of Static Synchronous Compensator for Voltage Regulation." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/33643477845714981008.
Full textAbstract:
碩士<br>國立臺灣大學<br>電機工程學研究所<br>90<br>In a distribution system, more and more manufacturing factories, especially in electronic industry, demand higher quality of supply voltage recently. In this thesis, a static synchronous compensator (STATCOM) is designed in order to have better voltage profile on the customer side.
The control kernel of the digital control system architecture for static synchronous compensators is based on a TI-DSP processor (TMS320C31) with Complex Programmable Logic Device IC (CPLD) and it’s peripheral circuit. The control rule is derived from the circuit prototype of the static synchronous compensator. The power stage is implemented using a voltage-sourced inverter (VSI) with sinusoidal pulse width modulation (SPWM) of external digital tri-wave circuit. With the derived control rules, the compensator can be used to control the system voltage effectively. Then from results of simulations and experiments, it is found that the system voltage can be compensated more effective by the proposed static synchronous compensator.
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Pradhan, Anil C. "Frequency domain analysis of the static synchronous series compensator." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=95038&T=F.
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Lin-jieJia and 賈林潔. "Suppression of Subsynchronous Resonance by Using Static Synchronous Series Compensator." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/66586729810433789677.
Full textAbstract:
碩士<br>國立成功大學<br>電機工程學系碩博士班<br>101<br>This thesis presents the damping of subsynchronous resonance (SSR) of the IEEE Second Benchmark Model, System #1 using a static synchronous series compensator (SSSC). The integrated system mathematical model is expressed in d-q reference frame under three-phase balanced condition. To achieve better damping performance on damping SSR of the studied system, a proper oscillation damping controller (ODC) is designed by using pole-assignment approach based on modal control theory. Steady-state analysis under different operating conditions is performed to verify the effectiveness of the SSSC joined with the designed ODC using eigenvalue analysis. Comparative time-domain simulations between the system without and with the proposed SSSC joined with the ODC reveals that the proposed SSSC with the designed ODC can suppress SSR of the studied system effectively. It can be concluded from the simulation results that the proposed SSSC coordinated with the designed ODC can significantly damp SSR under various operating conditions.
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Hsin, Wei-Lun, and 辛偉綸. "Design of Static Synchronous Compensator for a Grid-connected Induction Generator." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/67823313278222181526.
Full textAbstract:
碩士<br>國立臺灣大學<br>電機工程學研究所<br>94<br>As the issue of environmental protection receives increasing attention, renewable energy source, such as wind turbine-induction generator system, is getting more and more important. Three phase induction generators are the main source of the power. Induction machines are not commonly employed as generators except in the case of wind farms due to their unsatisfactory voltage regulation. Hence, in this thesis, a static synchronous compensator is designed to supply reactive power for the system and to regulate bus voltage, and to have better voltage profile on the customer side.
The static synchronous compensator employs a direct current capacitor to offer voltage source and use the pulse-width modulation technology to adjust the output voltage of the three phase voltage source inverter.
The effectiveness of the designed STATCOM is first investigated by digital simulations using the simulink of MATLAB software. Then, in the experiment, the control kernel of the STATCOM is based on a personal computer with Adventec PCL-1800 data acquisition cards. Finally, it is concluded from results of simulations and experiments that load bus voltage in a grid-connected induction generator can be effectively regulated by the STATCOM.
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Ting, Jui-Lin, and 丁瑞霖. "Application of Static Synchronous Compensator for a Grid-Connected Induction Generator." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/14424351783262333017.
Full textAbstract:
碩士<br>國立臺灣大學<br>電機工程學研究所<br>96<br>As the issue of environmental protection receives increasing attention and the price of fuel increases, renewable energy source, such as wind turbine generator system, is getting more and more important. Three phase induction generators are the main source of the power. Induction machines have unsatisfactory voltage regulation and the wind speed is variable. Hence, in this thesis, a static synchronous compensator is applied to supply reactive power for the system, to regulate bus voltage, and to achieve better voltage profile on the customer side.
The static synchronous compensator employs a direct current capacitor to offer voltage source and use the pulse-width modulation technique to adjust the output voltage of the three phase voltage source inverter.
The effectiveness of the STATCOM is investigated by simulations using the MATLAB/Simulink software and experiments. In the experiments, the controller of the STATCOM is based on a personal computer with Adventec PCL-1800 data acquisition cards. Digital control is implemented using C language. Finally, it is concluded from results of simulations and experiments the load bus voltage in a grid-connected induction generator can be effectively regulated by the STATCOM.
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Lai, Cheng-ying, and 賴正穎. "Dynamic Characteristic Analysis for a Static Synchronous Series Compensator Using Intelligent Controllers." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/7ka68f.
Full textAbstract:
碩士<br>國立中山大學<br>電機工程學系研究所<br>96<br>The static synchronous series compensator (SSSC) is a series controller of Flexible AC Transmission Systems (FACTS). It can be controlled by Thyristors, it also has the ability of fast control adjustments and high frequency operation. Through impedance compensation, it is able to control the magnitude and directions of the real power flow in the transmission system.
In order to achieve a fast and steady response for real power control in power systems, this thesis proposed a unified intelligent controller, which consists of RBFNN and GA for the SSSC to provide better control features for real power control in the dynamic operations of power systems. Finally, the simulation results of the proposed controllers is compared with the conventional proportional plus integral (PI) controllers to demonstrate the superiority and effectiveness of the unified intelligent controller.
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Liao, Ching Huan, and 廖京桓. "Development of Multi-Level Cascade Static Synchronous Compensator for Real-Time Load Compensation." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/788yav.
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Wang, Chiao-Hung, and 王喬弘. "Design of a Twelve Pulse Static Synchronous Compensator for Distribution System Voltage Regulation." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/07582646031305822568.
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碩士<br>國立臺灣大學<br>電機工程學研究所<br>94<br>The proliferation of voltage-sensitive load equipment has made the industrial processes much more vulnerable to degradation in the quality of power supply. Voltage deviations can cause severe process disruptions and result in substantial economic losses. Therefore, there are many studies on how to recover the original voltage immediately and keep it steady when voltage deviations are detected.
The purpose of the thesis is to analyze and design the Static Synchronous Compensator （STATCOM）. The proposed STATCOM comprises a 12-pulse Voltage Source Inverter（VSI） and a DC capacitor. Proportional-Integral（PI） controller are designed in order to regulate ac bus voltage and stabilize DC capacitor voltage. Both computer simulations and experiments are conducted in order to demonstrate the effectiveness of the proposed controller. MATLAB-Simulink is employed as the simulation tools in order to design proper parameters for the controller. In the experiments, PC-based Adventec PCL-1800 data acquisition cards with C language are used to achieve voltage compensation.
Results from computer simulations and experiments indicate that ac bus voltage can be regulated effectively by the proposed 12-pulse STATCOM.
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Lin, Yi-Liang, and 林羿良. "Design of Distribution Static Synchronous Compensator Based on Adaptive Recursive Least Square Algorithm." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/c5s28x.
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碩士<br>國立中央大學<br>電機工程學系<br>105<br>The goal of this thesis is to show the improvement of the power quality which sometimes distorted by various load with DSTATCOM (Distribution Static Synchronous Compensator). We use different control strategies to analyze load current and calculate the ideal reference current. Once we calculate the reference current, we use PWM Technique to generate compensation current which generated by three phase two-level inverter.
Instaneous Power Theory is a traditional control strategy which is uncapable of dealing with the unbalance current situation. ADALINE theorem is a ideal way to solve this problem. LMS algorithm is traditionaly used for updating weight of Adaline theorem. However we discover that there is unstable steady stae by using LMS algorithm. As a result, another algorithm presented in this thesis is applied to deal with. After doing lots of experiement we discover the algorithm presented in ths paper has better performane in both transient state and steady state.
Finally, we do all kinds of experiement to see the the performance based on aboved-mentioned three different strategies mentioned above. Beside we work hard to show the adavantage of the algorithm presented in this thesis.
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Mishra, Soumya. "Performance Analysis of Photovoltaic Fed Distributed Static Compensator for Power Quality Improvement." Thesis, 2017. http://ethesis.nitrkl.ac.in/8710/1/2017_PhD_512EE1013_SMishra.pdf.
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Owing to rising demand for electricity, shortage of fossil fuels, reliability issues, high transmission and distribution losses, presently many countries are looking forward to integrate the renewable energy sources into existing electricity grid. This kind of distributed generation provides power at a location close to the residential or commercial consumers with low transmission and distribution costs. Among other micro sources, solar photovoltaic (PV) systems are penetrating rapidly due to its ability to provide necessary dc voltage and decreasing capital cost. On the other hand, the distribution systems are confronting serious power quality issues because of various nonlinear loads and impromptu expansion. The power quality issues incorporate harmonic currents, high reactive power burden, and load unbalance and so on. The custom power device widely used to improve these power quality issues is the distributed static compensator (DSTATCOM). For continuous and effective compensation of power quality issues in a grid connected solar photovoltaic distribution system, the solar inverters are designed to operate as a DSTATCOM thus by increasing the efficiency and reducing the cost of the system.
The solar inverters are interfaced with grid through an L-type or LCL-type ac passive filters. Due to the voltage drop across these passive filters a high amount of voltage is maintained across the dc-link of the solar inverter so that the power can flow from PV source to grid and an effective compensation can be achieved. So in the thesis a new topology has been proposed for PV-DSTATCOM to reduce the dc-link voltage which inherently reduces the cost and rating of the solar inverter. The new LCLC-type PV-DSTATCOM is implemented both in simulation and hardware for extensive study. From the obtained results, the LCLC-type PV-DSTATCOM found to be more effective than L-type and LCL-type PV-DSTATCOM.
Selection of proper reference compensation current extraction scheme plays the most crucial role in DSTATCOM performance. This thesis describes three time-domain schemes viz. Instantaneous active and reactive power (p-q), modified p-q, and IcosΦ schemes. The objective is to bring down the source current THD below 5%, to satisfy the IEEE-519 Standard recommendations on harmonic limits. Comparative evaluation shows that, IcosΦ scheme is the best PV-DSTATCOM control scheme irrespective of supply and load conditions.
In the view of the fact that the filtering parameters of the PV-DSTATCOM and gains of the PI controller are designed using a linearized mathematical model of the system. Such a design may not yield satisfactory results under changing operating conditions due to the complex, nonlinear and time-varying nature of power system networks. To overcome this, evolutionary algorithms have been adopted and an algorithm-specific control parameter independent optimization tool (JAYA) is proposed. The JAYA optimization algorithm overcomes the drawbacks of both grenade explosion method (GEM) and teaching learning based optimization (TLBO), and accelerate the convergence of optimization problem. Extensive simulation studies and real-time investigations are performed for comparative assessment of proposed implementation of GEM, TLBO and JAYA optimization on PV-DSTATCOM. This validates that, the PV-DSTATCOM employing JAYA offers superior harmonic compensation compared to other alternatives, by lowering down the source current THD to drastically small values.
Another indispensable aspect of PV-DSTATCOM is that due to parameter variation and nonlinearity present in the system, the reference current generated by the reference compensation current extraction scheme get altered for a changing operating conditions. So a sliding mode controller (SMC) based p-q theory is proposed in the dissertation to reduce these effects. To validate the efficacy of the implemented sliding mode controller for the power quality improvement, the performance of the proposed system with both linear and non-linear controller are observed and compared by taking total harmonic distortion as performance index. From the obtained simulation and experimentation results it is concluded that the SMC based LCLC-type PV-DSTATCOM performs better in all critical operating conditions.
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Pien, Chun-Hao, and 卞均浩. "Design of a Current Sensorless and Harmonic Elimination Pulse-Width-Modulated Static Synchronous Compensator." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/62286444215888664918.
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碩士<br>長庚大學<br>電機工程學研究所<br>97<br>Power systems compensated by static synchronous compensator (STATCOM) is superior to the conventional fixed capacitor because of dynamic reactive power compensation and smaller volume/weight due to high integration of semiconductor structure. This thesis presents a FPGA-based harmonic elimination pulse-width modulated STATCOM to suppress lower order harmonics and to limit switching losses for high power applications. In the developed approach, the off-line computations of switching patterns based on harmonic elimination strategy are stored in EPROM, thereby allowing a microprocessor-free design. Furthermore, in order to simplify the control system and to reduce the system cost, the ac and dc voltage regulators were proposed in place of the current regulators. A droop control strategy was adopted to minimize the error bound caused by uncertainty in source impedance and therefore large change in control output due to small deviation in load voltage can be avoided. The validity of the proposed control algorithm has been verified by laboratory experiments on a 2.5kVA DSP-based controlled prototype. The experimental results for the steady-state operating condition and transient operating condition for the system subjected to various step load changes, which include inductive load and capacitive load, are presented to demonstrate the effectiveness of the proposed controller.
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Sher, Wen-Tan, and 施文堂. "Design of Static Synchronous Compensator under different loads in a Grid-connected Induction Generator." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/32596902332734524508.
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碩士<br>國立臺灣大學<br>電機工程學研究所<br>95<br>Due to the rise in oil price and the need to reduce carbon dioxide in order to alleviate the greenhouse effect, green energy such as wind-power electricity generation received much attention in recent years. Because the speed of the wind is not regular in wind-power electricity generation, induction machines are often used.
The purpose of this thesis is to design and analyze the static synchronous compensator (STATCOM) which regulates the voltage of an induction generator system. With a direct current capacitor to offer the voltage source, a three-phase voltage source type converter is designed using a pulse-width modulation (PWM) technique in order to reach voltage compensation and control. Simulations are conducted using the software of Matlab_simulink. Both the steady-state performance and the transient characteristic of the system subject to the disturbances of step load change, and induction motor starting, and continuous load fluctuations are investigated in the thesis. Simulation and experimental results reveal that the system voltage can really be stabilized by the proposed static synchronous compensator. It is a very efficient manner when the system is subjected to various disturbances.
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Aduragba, Adebiyi Abayomi. "Investigating the application of Static Synchronous Compensator (STATCOM) for mitigating power transmission line losses." Thesis, 2017. http://hdl.handle.net/10321/2459.
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Submitted in fulfillment of the requirements for the degree of Master of Engineering in Electrical Power Engineering, Durban University of Technology, Durban, South Africa, 2017.<br>Voltage instability and increased power loss on transmission lines are major challenges in power transmission due to ever increasing load growth. This work investigates the effect of Static Synchronous Compensator (STATCOM) to mitigate power losses and enhance the voltage stability of a transmission system. STATCOM, a shunt-connected power electronic device, operate as a Voltage Source Converter (VSC) to improve power transfer capacity of transmission lines by injecting a set of three-phase balanced sinusoidal current with controllable magnitude and phase angle into the transmission lines to regulate the line voltage and compensate for reactive power at the Point of Common Coupling (PCC).
To validate the capacity of STATCOM in this light, a modified model of IEEE 14 bus test system was simulated using DIgSILENT PowerFactory v15. Four different load profiles were included by increasing the base load in a step of 10%. In each case, power flow was run with and without STATCOM incorporated in the network with a view to determine the impact of STATCOM on bus voltage and transmission line losses.
The simulation results are obtained were recorded and analyzed. It is noted that there was sufficient improvement in the new voltage profile obtained for the weak buses of the system, the active and reactive power losses were mitigated by 17.73% and 24.80% respectively when STATCOM was incorporated at normal load.
The results showed that STATCOM could give quick voltage support to reduce the likelihood of voltage collapse and mitigate power losses along the transmission lines. Reduction of reactive power losses along the lines is higher than the active power losses resulting in the improvement of the voltage profile as the device is connected to the system.<br>M
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Xiu-YuLu and 盧修宇. "Improvement of Three-phase Voltage Unbalance in Distribution Systems Using a Multilevel Static Synchronous Compensator." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7g4fas.
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HE, ZHAO-JUN, and 何肇濬. "Improving the Voltage Stability of a Power System by Optimized Parameters of Static Synchronous Compensator." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/xfe2ug.
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碩士<br>明志科技大學<br>電機工程系碩士班<br>108<br>The interconnected system of New England/NewYork is used to inspect whether the voltage stability of all load buses conform transmission system planning criteria of the Taiwan Power Company. Various FACTS devices have been widely used to solve the problems of transmission system at present. The STATCOM is used in this study to improve the problem of lacking voltage stability . A novel optimized algorithm for alternating GAPSO and PSODE, called AGPD, is developed to determine the optimal positions and capacities for STATCOMs under various operating conditions to increase the voltage stability of all load buses in the test system. The AGPD algorithms are used to verify the performances of other algorithms. The final results show that HDE, PSODE and AGPD can find out the optimal solution of meeting the transmission system planning criteria of the Taiwan Power Company. Therefore, the optimization of STATCOM controller parameters will only use the HDE, PSODE and AGPD algorithms and Small Signal Analysis software in the frequency domain to find out a set of the optimal control parameter of STATCOMs for increasing the stability of a small signal stability.
The simulation results show that the AGPD algorithm can find minimum amount and capacity of STATCOMs in steady state that can conform the transmission system planning criteria of the Taiwan Power Company, and decrease the cost. The STATCOM controller parameters searched by AGPD can get the best damping ratio compare with other algorithms. Finally, the curves of line power flow, reactive power and bus voltage on time domain simulation by PSSTME are observed to verify the results of the frequency-domain analysis. STATCOM parameters of AGPD can converge faster and stable than HDE and PSODE.
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Chou, Ying-Chun, and 周映君. "Voltage Stability Improvement Research of Wind Farm Equipped Micro-Grid with Switched-Capacitor and Static Synchronous Compensator." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/44313494471025397430.
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碩士<br>國立臺灣大學<br>電機工程學研究所<br>102<br>Renewable energy generation system and micro-grids received much attention in recent years.In Taiwan,wind farms are usually installed in coastal areas faraway from existing subtations.If micro-grids equipped with wind farms are connected to power systems,substantial variations in generator terminal voltages will be observed when there is a fault in the power system. Severe faults in the system may ever cause voltage collapse and generator instability.
The purpose of this thesis is to investigate terminal voltage stability of wind generators when the power system is subjected to disturbances. MATLAB/Simulink/SimPowerSystems was used to perform digital simulations on the wind generator system subjected to disturbances. The grid-connected micro-grid simulation model included the area loads and the wind farm composed of squirrel-cage induction generators.
Results from theoretical analyses and digital simulations indicate that ,as the transmission line impedence increases,the load limit for the wind farms will decrease.Shunt-capacitors(SCs) can be used to improve the terminal voltage stability of wind farms.In addition,thyristor switched capacitors(TSC) can be used to effectively control the voltage magnitude within the range from 0.9 to 1.1p.u. when the area load change with time.On the other hand,when there is a disturbance such as system fault or motor starting,SCs and static synchronous compensators(STATCOMs) are useful for the enhancement of generator terminal voltages. Therefore, SCs ,which are simple and inexpensive,and STATCOMs ,which are capable of provide rapid and smooth compensation can be employed to provide voltage regulations and reactive power compensations for a remote micro grid with wind farms in Taiwan.
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Freire, Diogo Filipe Martins. "Multi-Level Converter with Predictive Control for Power Conditioning." Master's thesis, 2018. http://hdl.handle.net/10316/86563.
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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia<br>A estabilidade de tensão e o controlo do factor de potência são dois pontos-chave na operação em regime permanente dos sistemas eléctricos. O static synchronous compensator e o seu sistema de controlo podem ser usados para melhorar o desempenho do sistema energia. Neste trabalho é usado um controlador preditivo com uma nova abordagem de geração de referências e que permite compensar a potência reactiva necessária para manter um fator de potência escolhido no final da linha de transmissão. Os resultados da simulação demonstram que a estratégia de controlo proposta melhora o fator de potência e estabiliza a tensão no final da linha de transmissão. Para avaliar o desempenho do método de controlo proposto, foi simulada uma rede de distribuição de 10kV. Para testar experimentalmente o desempenho do método de controlo proposto, foi construído um protótipo de um conversor trifásico Neutral-Point-Clamped de cinco níveis. O teste experimental foi realizado num nível de tensão inferior, com 130V. Para se ter uma melhor base de comparação foi simulado um sistema mais próximo do realizado experimentalmente. Os resultados obtidos são muito semelhantes, mas não tão perfeitos como nos testes feitos no primeiro sistema simulado (rede de distribuição de 10kV). Isto pode ser justificado pelo elevado tempo de amostragem que teve de ser usado para que o processador de sinal digital pudesse computar toda a informação, mas também pode ser justificado pelas baixas correntes com que o sistema foi testado.<br>Voltage stability and power factor control are two key points in the steady-state operation of electrical systems. The static synchronous compensator and its control system can be used to improve the performance of the energy system. In this work, a predictive controller model with a new reference generation approach is used. It compensates the reactive power required to maintain a chosen power factor at the end of the transmission line. To evaluate the performance of the proposed control method, a 10kV distribution network was examined in simulation. Simulation results demonstrate that the proposed control strategy improves the power factor and stabilize the voltage at the Point of Common Coupling. The results of the simulation also demonstrate that the proposed control strategy improves the power factor and stabilizes the voltage at the end of the transmission line. To evaluate the performance of the proposed control method, a 10kV distribution network was simulated. In order to experimentally test the performance of the proposed control method, a prototype of a five-phase three-phase Neutral-Point-Clamped converter was constructed. The experimental test was performed at a voltage level of less than 130V. In order to have a better basis of comparison, a simulation system was simulated that was closer to the experimental one. The results are very similar, but not as perfect as in the tests done in the first simulated system (10 kV network). This can be justified by the high sampling time that had to be used so that the digital signal processor could compute all the information but could also be substantiated by the low currents that the system was tested.<br>FCT
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Deng-YauWu and 吳登耀. "Improvement of Three-phase Voltage Unbalance in Distribution Systems Using a Multilevel Cascaded H-bridge Static Synchronous Compensator." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/yzvw7n.
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Quang-SonVo and 武光山. "Dynamic Stability Improvement of a Large-Scale Power System with a DFIG-Based Wind Farm Using a Static Synchronous Series Compensator (SSSC)." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/81326718491169259330.
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Saikumar, H. V. "Investigations On Small Signal Stability Of Power Systems Affected By FACTS Supplementary Modulation Controllers." Thesis, 2004. https://etd.iisc.ac.in/handle/2005/1168.
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Saikumar, H. V. "Investigations On Small Signal Stability Of Power Systems Affected By FACTS Supplementary Modulation Controllers." Thesis, 2004. http://etd.iisc.ernet.in/handle/2005/1168.
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Marks, Nathan. "Control and performance of a cascaded H-bridge photovoltaic power system." Thesis, 2016. http://hdl.handle.net/1959.13/1322404.
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Research Doctorate - Doctor of Philosophy (PhD)<br>This thesis presents the control and performance of a Cascaded H-Bridge photovoltaic power system. The cascaded H-Bridge multilevel converter offers a number of attractive features for use in photovoltaic power systems. They provide opportunities for increases in efficiency, superior tracking of the maximum available power and direct connection to higher voltages. This system topology is a relatively immature technology and a number of key areas exist for research. In particular, the individual maximum power point tracking performance requires further analysis and development, the operation of the system in the presence of variable power generation in the photovoltaic arrays requires further investigation and the ability of the system to maintain operation under different array configurations is an interesting area for investigation. The details and the performance of a heuristic model predictive control scheme are presented, as well as the control techniques used to compensate for the power variability. The operation of the system when some arrays have zero power is also investigated. Two new maximum power point tracking techniques are proposed and the performance relative to the established Perturb and Observe technique is evaluated. A photovoltaic array current sensorless technique is also developed to exploit the switching characteristics produced by the model predictive control scheme. Finally, simulation and experimental results are presented that evaluate and validate the performance of the proposed control techniques. The results show that the proposed control techniques offer excellent performance.
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Maturu, Suresh. "Performance Evaluation Of Distance Relays For FACTS Compensated Transmission Lines." Thesis, 2011. https://etd.iisc.ac.in/handle/2005/2084.
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With limited enhancement or expansion of the transmission infrastructure, the contemporary power systems are operating under more stressed conditions. It becomes important to fully utilize the existing transmission system to supply load demand as much as possible, thus eliminating or reducing the need for new transmission investment.
Flexible AC Transmission System (FACTS) technology provides an alternative to fully utilize the existing transmission lines as well as new and upgraded lines, by controlling power and also enhancing the power transfer capability of transmission lines. However, the implementation of FACTS controllers in the transmission system has introduced new power system dynamics that must be addressed in the area of power system protection, such as rapid changes in line impedance, power angle, line currents, transients introduced by the occurrence of fault and associated control action of the FACTS controller. Therefore, the performance of the protection system must be carefully analyzed in the presence of FACTS controllers.
The thesis aims at evaluating the performance of distance relays when different types of FACTS controllers, in particular Voltage Source Converter (VSC) based FACTS controllers, are incorporated at the midpoint of the transmission system to achieve voltage profile improvement and power transfer capability. The detailed models of these controllers and their control strategies are described. The presence of FACTS controllers in the loop affects both steady state and transient components of voltage and current signals. The rapid response of FACTS controllers to different power system configurations significantly affects the apparent impedance seen by distance relays. The apparent impedance seen by distance relays would be different from that of the system without FACTS controller. Due to this, the distance relay may malfunction, resulting in unreliable operation of the power system during faults. Furthermore, the effect of FACTS controllers on distance relay operation depends on the type of FACTS controller used, the application for which it has been installed and its location in the power system. The distance relay is evaluated for different loading conditions and for various fault conditions. Simulation studies are carried out using PSCAD/EMTDC based transient simulation package.
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Maturu, Suresh. "Performance Evaluation Of Distance Relays For FACTS Compensated Transmission Lines." Thesis, 2011. http://etd.iisc.ernet.in/handle/2005/2084.
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With limited enhancement or expansion of the transmission infrastructure, the contemporary power systems are operating under more stressed conditions. It becomes important to fully utilize the existing transmission system to supply load demand as much as possible, thus eliminating or reducing the need for new transmission investment.
Flexible AC Transmission System (FACTS) technology provides an alternative to fully utilize the existing transmission lines as well as new and upgraded lines, by controlling power and also enhancing the power transfer capability of transmission lines. However, the implementation of FACTS controllers in the transmission system has introduced new power system dynamics that must be addressed in the area of power system protection, such as rapid changes in line impedance, power angle, line currents, transients introduced by the occurrence of fault and associated control action of the FACTS controller. Therefore, the performance of the protection system must be carefully analyzed in the presence of FACTS controllers.
The thesis aims at evaluating the performance of distance relays when different types of FACTS controllers, in particular Voltage Source Converter (VSC) based FACTS controllers, are incorporated at the midpoint of the transmission system to achieve voltage profile improvement and power transfer capability. The detailed models of these controllers and their control strategies are described. The presence of FACTS controllers in the loop affects both steady state and transient components of voltage and current signals. The rapid response of FACTS controllers to different power system configurations significantly affects the apparent impedance seen by distance relays. The apparent impedance seen by distance relays would be different from that of the system without FACTS controller. Due to this, the distance relay may malfunction, resulting in unreliable operation of the power system during faults. Furthermore, the effect of FACTS controllers on distance relay operation depends on the type of FACTS controller used, the application for which it has been installed and its location in the power system. The distance relay is evaluated for different loading conditions and for various fault conditions. Simulation studies are carried out using PSCAD/EMTDC based transient simulation package.
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Mahmoodianfard, Forough. "Investigation and Model Development for Operational Modes of a Unified Power Flow Controller." 2012. http://hdl.handle.net/1993/12343.
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The focus of this research is on deriving small signal stability models for different Flexible AC Transmission Systems devices by introducing a simple systematic method that is applicable to any dynamic device.
Two different small signal models for Unified Power Flow Controllers are introduced. One model is called the power control mode and the other model is the voltage control mode. The two models are compared from transient stability point of view to show the necessity of developing both models for UPFC.
The thesis also shows how to derive the small signal stability model of Static Synchronous Compensator, as the shunt branch of UPFC. The small signal stability models of both devices are then validated to ensure the accuracy of the derived models. STATCOM and UPFC power control mode are validated against PSCAD. The UPFC voltage control mode is validated against nonlinear solution of system equations.
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Balibani, Siva Kumar. "Small Signal Stability Analysis of a Power System with a Grid Connected Wind Powered Permanent Magnet Synchronous Generator (PMSG)." Thesis, 2015. http://etd.iisc.ac.in/handle/2005/3835.
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Small signal oscillation has been always a major concern in the operation of power systems. In a generator, the electromechanical coupling between the rotor and the rest of the system causes it to behave in a manner similar to a spring mass damper system. Following any disturbance, such as sudden change in loads, actuations in the output of turbine and faults etc. it exhibits an oscillatory behaviour around the equilibrium state. The use of fast acting high gain AVRs and evolution of large interconnected power systems with transfer of bulk power across weak transmission links have further aggravated the problem of these low frequency oscillations. Small oscillations in the range of about 0.1Hz to 3.5Hz can persist for long periods, limiting the power transfer capability of the transmission lines. These oscillations can be reduced by incorporating auxiliary controllers on generator excitation system.
Power System Stabilizers (PSSs) were developed to produce additional damping by modulating the generator excitation voltage. Designing effective PSS for all operating conditions especially in large interconnected power systems still remains a difficult and challenging task.
More and more power electronic based controllers have been and will be used in power systems. Many of these controllers such as Static Var Compensators (SVCs), Static Synchronous Compensators (STATCOMs) and Unified Power Flow Controllers (UPFCs) etc., are incorporated in power transmission networks to improve its operational capability. In addition, some of the energy storage systems such as Battery Energy Storage systems (BESS), Super conducting Magnetic Energy Storage System (SMES) as well large non-conventional energy sources are also increasingly being integrated with the power grid. With large integration of these devices, there is a significant impact on system stability, more importantly on small signal oscillatory instability of the power system.
This thesis primarily focuses on impact of such devices on small signal oscillatory stability of the power systems. More specifically in this thesis small signal stability analysis of a Single Machine Infinite Bus (SMIB) system with a grid connected wind powered Permanent Magnet Synchronous Generator (PMSG) has been presented. A SMIB system has been purposely chosen so that general conclusions can be obtained on the behaviour of the embedded STATCOM/Energy Source (ES) system on system stability. With a better understanding of the impact of such a system it would be probably possible to analyze more complicated multimachine power system and their impact on system stability. Small signal model of the complete system which comprises the generator, transmission network, inter connecting STATCOM, the wind power generator and all associated controllers has been developed. The performances of the system following a small disturbance at various operating conditions have been analyzed.
To obtain quantitative estimates of the damping and synchronizing torques generated in the system, expressions for damping and synchronizing torque clients have been developed.
With these analyses, the relative impact of the STATCOM and STATCOM with ES on system performance have been assessed. It is shown that with active and reactive power modulation capabilities effective and efficient control of small signal oscillations in power systems can be achieved.