Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho apresenta contribuições para algoritmos de controle utilizados em filtros ativos e híbridos conectados em redes elétricas trifásicas a 3 ou a 4 fios. Em relação aos algoritmos de controle para filtros ativos, a contribuição consiste em estender o conceito da filtragem harmônica seletiva para compensação de correntes harmônicas e desequilibradas em uma rede trifásica a 4 fios. Esses algoritmos derivam dos conceitos utilizados na teoria da potência instantânea (teoria pq), em conjunto com um circuito de sincronismo PLL. É importante ressaltar que estes algoritmos não utilizam as correntes consumidas pelas cargas, ou seja, apenas as tensões no ponto da rede onde o filtro está conectado são utilizadas para determinação das correntes harmônicas de referência. Apenas as correntes na saída do conversor são utilizadas como realimentação do controle PWM. Estes algoritmos também foram utilizados no filtro híbrido para compensação de correntes harmônicas em uma rede trifásica a 3 fios. Por fim foi feito uma alteração nesses algoritmos de controle que permite eliminar as correntes utilizadas na realimentação do controle PWM. Resultados de simulação são apresentados com objetivo de observar o comportamento desses algoritmos tanto no filtro ativo quanto no híbrido nas condições mencionadas. / This work presents some contributions involving control algorithms for active and hybrid filters connected in 3 or 4-wire three-phase electrical grids. In relation to the control algorithms for active filters, the contribution results from the extension involving the concepts of selective harmonic filtering to compensate unbalanced and harmonic currents in a 4-wire three-phase electrical grid. These algorithms derive from the instantaneous power theory (pq theory) together with a synchronizing PLL-circuit. It is important to mention that these algorithm do not use the currents consumed by the loads, i.e, only the voltages at the point common coupling (PCC) are used to determine the reference harmonic currents. Only the output converter currents were used as a feedback to the PWM control. These algorithms were also employed in a hybrid filter to compensate harmonic currents in a 3-wire three-phase electrical grid. Finally, some improvements on these control algorithms were done, such that the output converter currents used as a feedback of the PWM control were eliminated. Simulations results were provided in order to analyze the behavior of the active and hybrid filters in the aforementioned conditions.

Made available in DSpace on 2014-12-17T14:55:43Z (GMT). No. of bitstreams: 1 EricoCB_DISSERT.pdf: 1960043 bytes, checksum: 7c0ebefa8d09683721a890c3c7d00bbb (MD5) Previous issue date: 2010-03-26 / The Methods for compensation of harmonic currents and voltages have been widely used since these methods allow to reduce to acceptable levels the harmonic distortion in the voltages or currents in a power system, and also compensate reactive. The reduction of harmonics and reactive contributes to the reduction of losses in transmission lines and electrical machinery, increasing the power factor, reduce the occurrence of overvoltage and overcurrent. The active power filter is the most efficient method for compensation of harmonic currents and voltages. The active power filter is necessary to use current and voltage controllers loop. Conventionally, the current and voltage control loop of active filter has been done by proportional controllers integrative. This work, investigated the use of a robust adaptive control technique on the shunt active power filter current and voltage control loop to increase robustness and improve the performance of active filter to compensate for harmonics. The proposed control scheme is based on a combination of techniques for adaptive control pole placement and variable structure. The advantages of the proposed method over conventional ones are: lower total harmonic distortion, more flexibility, adaptability and robustness to the system. Moreover, the proposed control scheme improves the performance and improves the transient of active filter. The validation of the proposed technique was verified initially by a simulation program implemented in C++ language and then experimental results were obtained using a prototype three-phase active filter of 1 kVA / Os m?todos para compensa??o de correntes e tens?es harm?nicas v?m sendo bastante utilizados, visto que esses m?todos permitem reduzir a n?veis aceit?veis as distor??es harm?nicas nas tens?es ou correntes em um sistema el?trico de pot?ncia, e ainda, compensar reativos. A redu??o de harm?nicas e reativos contribuem para: a diminui??o das perdas nas linhas de transmiss?o e nas m?quinas el?tricas, o aumento do fator de pot?ncia e a redu??o de ocorr?ncias de sobretens?es e sobrecorrentes. O filtro ativo de pot?ncia ? o m?todo mais eficiente para compensa??o de correntes e tens?es harm?nicas. No filtro ativo de pot?ncia ? necess?ria a utiliza??o de controladores para as malhas de corrente e tens?o. Convencionalmente, o controle dessas malhas tem sido feito por controladores proporcionais integrativos. Neste trabalho, ? investigado o uso de uma t?cnica de controle adaptativo robusto nas malha de corrente e tens?o, do filtro ativo de pot?ncia em paralelo trif?sico, para aumentar a robustez e melhorar o desempenho desse filtro ativo na compensa??o de harm?nicos. A t?cnica de controle proposta ? baseada na combina??o das t?cnicas de controle adaptativo por posicionamento de p?los e de estrutura vari?vel. As vantagens do m?todo proposto sobre os convencionais s?o: menor taxa de distor??o harm?nica, maior flexibilidade, capacidade de adapta??o e robustez para o sistema. Al?m disso, a t?cnica de controle proposta aumenta o desempenho e melhora o transit?rio do filtro ativo. A valida??o da t?cnica proposta foi verificada inicialmente atrav?s de um programa de simula??o implementado em linguagem C ++ e em seguida foram obtidos resultados experimentais usando um prot?tipo de um filtro ativo trif?sico de 1 kVA

Neste trabalho propomos uma abordagem para a resolução do problema de Fluxo de Potência Ótimo (FPO) perturbado. A metodologia consiste na obtenção da solução ótima para o problema inicial via um programa de FPO, e na utilização de sensibilidade para estimar novas soluções depois de ocorridas algumas perturbações no problema. Essas perturbações são variações de carga em uma ou mais barras do sistema. A técnica de sensibilidade está baseada nas informações de segunda ordem e nas condições de otimalidade. A obtenção da solução após ocorrerem perturbações no sistema é direta e não necessita de parâmetros iniciais e de correção, como penalidade e barreira, utilizados nos programas de FPO convencionais. Os resultados numéricos apresentados evidenciam o potencial desta metodologia para resolução do problema de FPO perturbado. / An approach to solve the perturbated Optimal Power Flow (OPF) problem is proposed in this study. The methodology consists in obtaining the optimal solution for the initial problem via a program of OPF, and using sensitivity to estimate new solutions after the occurrence of some perturbations in the problem. These perturbations consist in load variations in some buses of the system. The sensitivity technique is based on both the information of second order and otimality conditions. The computation of the solutions after the occurrence of perturbations in the system does not depend of initial and correction parameters such as penalty and barrier used in the conventional OPF programs. The numerical results demonstrate the potential of this methodology for the solution of the perturbated OPF problem.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-26T12:14:24Z No. of bitstreams: 1 gabrielazevedofogli.pdf: 13619054 bytes, checksum: d260cb2571f242e43eab89132a03d62c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-26T12:26:45Z (GMT) No. of bitstreams: 1 gabrielazevedofogli.pdf: 13619054 bytes, checksum: d260cb2571f242e43eab89132a03d62c (MD5) / Made available in DSpace on 2017-04-26T12:26:45Z (GMT). No. of bitstreams: 1 gabrielazevedofogli.pdf: 13619054 bytes, checksum: d260cb2571f242e43eab89132a03d62c (MD5) Previous issue date: 2014-03-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação apresenta um estudo de conexão de um grupo gerador-diesel (GMG) trifásico em uma rede secundária de distribuição de energia elétrica. A integração do GMG é feita por uma unidade de processamento de energia (PPU) composta por um retificador trifásico não controlado conectado em série com um conversor fonte de tensão (VSC) modulado com uma estratégia de modulação por largura de pulso. O GMG pode operar de duas maneiras distintas: (i) modo standby (interligado) ou (ii) modo isolado. O conversor de saída da PPU pode ser controlado para injetar potência ativa na rede CA, ou como um filtro ativo de potência (FAP) compensando potência reativa e correntes harmônicas nos terminais das cargas. O VSC de interface é controlado no modo de corrente (CMC), sendo seus controladores projetados a partir de funções de transferência obtidas com o modelo matemático do sistema elétrico nas coordenadas dq0. Esses controladores são projetados com múltiplos integradores para garantir a qualidade da forma de onda da corrente injetada na rede CA. Dependendo do modo de operação é utilizada uma malha adicional para regular a tensão do barramento CC do conversor de interface. Para validar o modelo matemático e o algoritmo de controle são realizadas simulações digitais no programa PSIM. Resultados experimentais, obtidos com um protótipo de laboratório, cujos controladores foram implementados em um processador digital de sinais TMS320F28335 da Texas Instruments, são usados para validar as estratégias de controle propostas. / This dissertation presents a study about the connection of a three-phase Diesel Genset (DG) to a secondary distribution network. The integration of DG is done by a Power Processing Unit (PPU) composed of a three-phase rectifier connected in series with a Pulse Width Modulated Voltage Source Converter (VSC). The DG can operate in two distinct modes: (i) standby (interconnected) or (ii) islanding. The PPU’s output converter can be controlled to inject active power into AC electric grid, or as an Active Power Filter (APF), compensating the reactive power and harmonics currents at the load terminals. The VSC is controlled employing the current mode control (CMC), and its compensators are designed based on the electrical system transfer function in dq0 coordinates. Multiple rotating synchronous reference frame integrators (PI-MRI) are used to ensure the quality of the generated power. Depending on the operating mode, an additional loop is used to regulate the DC bus voltage. In order to validate the mathematical model and the control algorithm, digital simulations using PSIM are performed. Experimental results obtained with the prototype, which controllers were implemented in a TMS320F28335 of Texas Instruments are used to validate the proposed control strategies.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-07-03T11:17:42Z No. of bitstreams: 1 mateusfreitasbraga.pdf: 1732565 bytes, checksum: f8ebb1cc4fe4d9ecbd9cc50ba3eb3f2a (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-07T21:17:21Z (GMT) No. of bitstreams: 1 mateusfreitasbraga.pdf: 1732565 bytes, checksum: f8ebb1cc4fe4d9ecbd9cc50ba3eb3f2a (MD5) / Made available in DSpace on 2017-08-07T21:17:21Z (GMT). No. of bitstreams: 1 mateusfreitasbraga.pdf: 1732565 bytes, checksum: f8ebb1cc4fe4d9ecbd9cc50ba3eb3f2a (MD5) Previous issue date: 2017-03-20 / Cresce a cada dia o n úmero de cargas não lineares conectadas aos diversos sistemas el étricos, seja em ní vel de transmissão ou distribui ção. Como consequência desse crescimento, e possí vel encontrar casos de consumidores enfrentando problemas relacionados a desarmes de disjuntores e sobreaquecimento de condutores, entre outros efeitos indesejados. Tomando um desses casos como base para este estudo, esta disserta ção tem o objetivo de avaliar e propor uma solu ção para uma rede monof asica real, que possivelmente e comum a outros consumidores. A carga monof ásica composta por lumin árias a LED (t picas cargas não lineares) e cargas indutivas se apresenta aos terminais da fonte com um comportamento de elevado conte udo harmônico (THD) de corrente e baixo fator de potência. Essa condi ção adversa pode ser mitigada de diversas maneiras, como por exemplo pela a ção de um fi ltro passivo,fi ltro ativo ou ainda fi ltro h brido (o qual e composto por uma combina ção dos dois primeiros). Ser a proposto nesta disserta ção uma metodologia de projeto relacionada a aplica ção de um fi ltro hi brido monof ásico visando corrigir o fator de potência e reduzir o conte udo harmônico de corrente presente na fonte, tomando como base as caracterí sticas do sistema avaliado em uma ind ústria gr áfi ca t ípica. Serão investigadas algumas con gura ções de filtros com o objetivo de mitigar problemas de Qualidade de Energia El étrica. Como consequência, ser a desenvolvida a an álise matem atica da topologia adotada e o projeto do controlador, baseado em um controlador proporcional-ressonante e na Teoria p-q Monof asica. A veri ca ção da solu ção proposta e sustentada pelos resultados de simula ção obtidos via software PSIM. / The amount of non-linear loads connected to the various electrical systems grows on a daily basis, regardless those loads are tied to a transmission or distribution bar. As a consequence of this growth, it is possible to nd cases of consumers facing problems such as tripping of breakers and cables overheating, among other undesired e ects. Taking one of these cases as the focus of this study, this dissertation aims to evaluate and propose a solution to a real single-phase system, which could be considered similar to other consumers. The single-phase load composed of LED luminaires (typical non-linear load) and inductive loads presents high THD and low power factor behavior at source terminals. This condition can be mitigated by using some well-known techniques, such as passive lters, active lters or hybrid lters, (which are composed by the combination of the former two). This Master document Thesis proposes a design methodology of a single-phase hybrid lter aiming power factor correction and reduction of the harmonic content of the current delivered by the AC power supply when feeding a typical printing factory. It will be reviewed and discussed some possible lter con gurations aimed to solve the case under evaluation. It is also included the mathematical analysis of the proposed topology, along with the design of the control system of the inverter. The Single-Phase p-q Theory is reviewed in order to design the control. The closed-loop control is desinged by a proportional-resonant compensator. Simulation results, by employing the PSIM software, are provided aiming to validate the solution proposed.

Les travaux de thèse s’intéressent au réglage de la puissance active injectée dans le réseau, ce qui représente aujourd'hui l'une des problématiques principales du pilotage des parcs éoliens participant à la gestion du réseau. Dans le même temps, l'un des buts reste de maximiser la puissance extraite du vent en considérant les effets de couplage aérodynamique entre les éoliennes.La structure du contrôle-commande choisie est de type hiérarchisée et distribuée. Dans la première partie de la thèse, les travaux portent sur la commande de la turbine d'une éolienne autour des points de fonctionnement classiques mais également autour des points à puissance extraite réduite. En fait, cela relève d’une condition de fonctionnement nécessaire pour l'atteinte des objectifs imposés au pilotage d'un parc éolien.Dans la deuxième partie, le problème du contrôle à l'échelle d'un parc est posé sous la forme d'une optimisation distribuée parmi les turbines. Deux nouveaux algorithmes d'optimisation métaheuristique sont proposés et leur performance testée sur différents exemples de parcs éoliens. Les deux algorithmes s'appuient sur la méthode d'optimisation par essaim particulaire, qui est ici modifiée et adaptée pour les cas d'application aux systèmes multi agents. L'architecture de contrôlecommande globale est enfin évaluée en considérant les dynamiques des turbines contrôlées. Les simulations effectuées montrent des gains potentiels significatifs en puissance.Finalement, dans la troisième partie de la thèse, l'introduction d'une nouvelle étape de coopération au niveau des contrôleurs locaux des turbines, par l'utilisation de la technique de contrôle par consensus, permet d'améliorer les performances du système global. / In this PhD work we focus on the wind farm (WF) active power control since some of the new set grid requirements of interest can be expressed as specifications on its injection in the electric grid. Besides, one of our main objectives is related to the wind farm power maximization problem under the presence on non-negligible wake effect. The chosen WF control architecture has a two-layer hierarchical distributed structure. First of all, the wind turbine (WT) control is addressed. Here, a nonlinear controller lets a WT work in classic zones of functioning as well as track general deloaded power references. This last feature is a necessary condition to accomplish the WF control specifications. Secondly, the high level WF control problem is formulated as an optimization problem distributed among the WTs. Two novel distributed optimization algorithms are proposed, and their performance tested on different WF examples. Both are based on the well-known particle swarm optimization algorithm, which we modify and extend to be applicable in the multi-agent system framework. Finally, the overall WF control is evaluated by taking into account the WTs controlled dynamics. Simulations show potential significant power gains. Eventually, the introduction of a new control level in the hierarchical structure between the WF optimization and the WTs controllers is proposed. The idea is to let further cooperation among the WT local controllers, via a consensusbased technique, to enhance the overall system performance.

The current model for electricity generation is based on power plants connected to the transmission network. This provides electricity to the distribution network and after that to the consumers. To ensure the security of the electrical network and prevent a blackout, the performance of every electricity generation unit connected to the network is quantified in grid codes. In the case of the French transmission system, the requirements regarding the performance are written in a document produced by the French Transmission System Operator (TSO). Various events with various configurations of connection to the network have to be simulated and the corresponding performance has to be evaluated. The aim of these simulations is to determine the stability of the generators and key elements, including the response time on the active power after events such as a short circuit.Taking into account the amount of generators connected to the transmission network, the need for optimization appears and is the purpose of this Master Thesis. To perform those simulations in an efficient way on all the generators owned by the main French electricity producer, EDF, this Master Thesis contributes with a tool called AuDySim coded with the softwares MATLAB and EUROSTAG. The implemented tool allows the user to configure an electricity generation unit before realizing all the simulations specified by the TSO and produces a report containing the results by means of curves and data. The simulations and the production of the report are achieved automatically to create a gain of time and resources.In order to validate the performance of the tool, two case studies are performed on different types of power plants. The two case studies analyzed present a hydraulic and a nuclear power plant. In the results the performance of each type of power plant is assessed focusing on the rotor angle stability of the machine and key elements, such as the voltage and the active power. These results lead to the conclusion that AuDySim fulfills its mission, by achieving automatically an analysis of the performance of an electrical generation unit and producing it in a report. / Den nuvarande elproduktionsmodellen baseras på kraftverk som är direktkopplade till stamnätet. Stamnätet i sin tur matar distributionsnätet som därefter levererar el till slutkonsumenterna. För att säkerställa stamnätets integritet samt säkerhet och undvika strömavbrott kvantifieras prestandan hos varje generator som är ansluten till det med hjälp av nätkoder. När det gäller det franska stamnätet skrivs prestandakraven i ett dokument som utfärdas av den franska transmissionssystemoperatören (TSO). Olika händelser med olika anslutningskonfigurationer måste simuleras där dess prestanda ska utvärderats. Syftet med dessa simuleringar är att identifiera stabiliteten vid varje elproduktionsenhet med bl. a. dess reaktionstid för den aktiva effekten efter kortslutningar.Med tanke på antalet generatorer som är anslutna till stamnätet framträder ett behov för överföringsoptimering vilket är syftet med detta examensarbete. För att utföra dessa simuleringar på ett effektivt sätt på alla generatorer som ägs av den ledande franska elproducenten, EDF, bidrar denna avhandling med ett verktyg som heter AuDySim kodat i mjukvarorna MATLAB och EUROSTAG. Verktyget gör det möjligt för användaren att konfigurera en elproduktionsenhet innan man utför alla simuleringar som specificeras av TSO:n och samtidigt producerar en rapport som innehåller grafisk- och data resultat. Både simuleringar och rapporten produceras automatiskt för att optimera en bearbetningstid och resursanvändning.För att validera verktygets prestanda utförs två fallstudier på olika typer av kraftverk. De två fallstudierna fokuserar på ett hydraulisk- respektive ett kärnkraftverk. I resultaten utvärderas prestanda för varje typ av kraftverk, med fokus på maskinens rotorvinkelstabilitet och andra viktiga faktorer, såsom spänning och aktiv effekt. Resultat leder till slutsatsen att AuDySim uppfyller sitt uppdrag genom att automatiskt analysera prestanda hos en elektrisk generationsenhet och presentera analysen i en rapport.

In an electric power system, there will always be an electric balance. Nevertheless, System Operators (SOs) often uses the term imbalance. Here, the term imbalance refers to the difference between trades and real-time measurements. This thesis defines the term imbalance and develops a framework helping SOs in finding better decisions controlling these imbalances.  Imbalances are controlled by many decisions made at various stages before real-time. A decision can be to increase the flexibility in production and consumption. However, this is not the only decision affecting real-time balancing operation. Other decisions are grid code requirements, such as ramp rates of HVDC and generation; balancing market structure, such as imbalance fees and trading period lengths; and the strategies used in the system-operational dispatch. The purpose of this thesis is to create a new possibility for SO to find decisions improving the balancing operation.  In order to find and compare decisions, the thesis develops a framework that evaluates many different decisions made at various stages before real-time. The framework consists of the following. First, it develops an intra-hour model using multi-bidding zone data from a historical time-period; able to capture the normal state frequency and active power dynamics. The model creates high-resolution data from low-resolution measurements using several data-processing methods. The uncertainty from the historical time-period is re-created using many sub-models with different input data, time-scales and activation times of reserves. Secondly, the framework validates the model and identifies system parameters based on simulated frequencies and frequency measurements in the normal state operation. Finally; new decisions' are modelled, tested, and evaluated on their impact on selected targets supporting corporate missions of the SOs. The goal of the framework is that it should be able to find better decisions for balancing operation but also that it should be applicable for real and large power systems. To verify this, the framework is tested on a synchronous area containing 11 bidding zones in northern Europe. Results show that the framework can be validated and trusted. Three new decisions, made at various stages before real time, have been modelled, tested and evaluated. The modelled decisions were (i) lower ramp rates for generation, (ii) increased capacities for automatic reserves, and (iii) a new strategy for the system-operational dispatch. One implication of applying the balancing evaluation framework on data from July 2015 is that all tested decisions improve several selected targets supporting the corporate missions of the SOs.  The conclusion is that the balancing framework is useful as a simulation tool in helping SOs in finding more efficient decisions for transmission system balancing operation. / <p>QC 20180116</p>

This project deals with voltage source converters with energy storage capability. The main objective is to study the possible benefits of energy storage to a power system with a VSC as the interface between them. First of all, a converter control system is proposed for a two level VSC. In the conventional converter control, the control system usually takes the voltage measured at the point where the converter is connected and calculates the reference voltage for the converter; with a modulation system the converter then produces the required 'average voltage'. In this project, a novel flux modulation scheme, combined with the deadbeat current control strategy, is proposed. The current controller is capable of controlling both positive and negative sequence current components. With flux modulation, the control system measures the bus flux and commands the converter to generate the required flux. Based on the proposed control strategies, several application studies have been carried out. The first application study investigates the effect of energy storage on the power quality at the point of common coupling when a system is subject to load disturbances. The voltage at PCC in a weak network is very sensitive to load changes. A sudden change in active load will cause both a phase jump and a magnitude fluctuation in the bus voltage, whereas reactive load changes mainly affect the voltage magnitude. With the addition of energy storage to a StatCom, it is possible to compensate for the active power change as well as providing reactive power support. In this thesis, some effective active power compensation schemes are proposed. Simulations and experiments have been performed to verify the compensation schemes. The results show that a StatCom with energy storage can significantly reduce phase jumps and magnitude deviations of the bus voltage. pact of the energy storage on the performance of weak systems under fault conditions has been investigated. The investigation was done by studying an example system. The system model was established based on a real system, in which some induction motors driving pumps along a pipeline are fed from a radial transmission line. Studies show that for a weak system with induction motor loads, a StatCom with certain energy storage capacity will effectively improve the system recovery after faults. Although this incurs extra cost for the increasing dc voltage rating and size of the dc side capacitor, the overall rating of the converter can be reduced by utilization of the proposed active power compensation scheme. The last case study investigates the possible use of a StatCom with energy storage to improve the power quality at the point of common coupling where a cyclic load is connected. Studies show that by providing both fast reactive and fast active power support to the network, not only the voltage magnitude can be well controlled, but also the voltage phase jump can be reduced significantly. / QC 20101124

The electric power supply industry has evolved into one of the largest industries. Even though secure and reliable operation of the electric power system is fundamental to economy, social security and quality of modern life, the complicated power grid is now facing severe challenges to meet the high-level secure and reliable operation requirements. New technologies will play a major role in helping today's electric power industry to meet the above challenges. This dissertation has focused on some key technologies among them, including the emerging technologies of energy storage, controlled power electronics and wide area measurement technologies. Those technologies offer an opportunity to develop the appropriate objectives for power system control. The use of power electronics based devices with energy storage system integrated into them, such as FACTS/ESS, can provide valuable added benefits to improve stability, power quality, and reliability of power systems. The study in this dissertation has provided several guidelines for the implementation of FACTS/ESS in bulk power systems. The interest of this study lies in a wide range of FACTS/ESS technology applications in bulk power system to solve some special problems that were not solved well without the application of FACTS/ESS. The special problems we select to solve by using FACTS/ESS technology in this study include power quality problem solution by active power compensation, electrical arc furnace (EAF) induced problems solution, inter-area mode low frequency oscillation suppression, coordination of under frequency load shedding (UFLS) and under frequency governor control (UFGC), wide area voltage control. From this study, the author of this dissertation reveals the unique role that FACTS/ESS technology can play in the bulk power system stability control and power quality enhancement in power system. In this dissertation, almost all the studies are based on the real system problems, which means that the study results are special valuable to certain utilities that have those problems. The study in this dissertation can assist power industry choose the right FACTS/ESS technology for their intended functions, which will improve the survivability, minimize blackouts, and reduce interruption costs through the use of energy storage systems. / Ph. D.