Primary Frequency Control with Flywheel Energy Storage Technologies

Over the last decade, concerns about greenhouse gas emissions have increased. Different strategies have been developed to minimize those effects, leading to the development of renewable energy sources worldwide. In recent years, the deployment of solar photovoltaic and wind energy-based renewable generation technologies have been growing at a fast pace. The penetration of these technologies into the power system network introduces new challenges for frequency and voltage stability because of the intermittency of these energy sources, and the increasing risk of significant voltage/frequency variations. The significant penetration of renewable sources requires fast regulation of the frequency deviations; hence, the implementation of primary frequency controls is necessary. There exists different techniques and strategies for primary frequency control, where governor regulation and under frequency load shedding are two of the best known, but these have several limitations regarding fast response. Thus, new control techniques based on energy storage systems, which are able to provide fast frequency control, are being studied. In this context, a flywheel energy storage (FES) system is studied and modeled in this thesis for frequency control in power systems, using the well-known software Dynamic Simulation Assessment Tool (DSATools)®, to allow researchers and practitioners to readily model FES in power system studies, particularly the Independent Electric System Operator (IESO) of Ontario. The proposed FES DSATools® model is tested and compared using a previously proposed test system with a large wind energy system (WES), which creates significant frequency and voltage fluctuations due to its characteristics. The FES stores and delivers energy to the power system, as required by the network, through a back-to-back power electronic converter system. A frequency/speed limiter controller is used, considering the network frequency deviation and the FES rotational speed in the active control of the flywheel-side converter for active power control of the flywheel. A static var compensator (SVC) for voltage control is also studied. The presented studies consider disturbances from sudden changes in the wind speed, which affect the WES output active power, creating considerable problems for the test system's stability. The simulation results suggest that the proposed FES model implemented on the system studied, provides effective primary frequency control, and it also improves the network voltage. Thus, the FES is shown to maintain system stability, increasing the operational efficiency of conventional and renewable generators

Transient analysis and modelling of multimachine systems with power electronics controllers for real-time application

Electricity usage has grown steadily ever since the first commercial generator came into operation more than one century ago. Power transmission networks too, have grown in size and in operational complexity to be able to handle the large blocks of electricity that travel from generator to consumers round-the-clock and with huge variations. At various stages of the development, state-of-the-art equipment, methods and techniques have been incorporated in the vast array of tools that power systems engineers have at their disposal to keep up with the demands imposed by the planning, management, operation and control of modern power systems. Transient stability has always been an issue of paramount importance in power system planning and operation. Arguably, most of the ideas and concepts associated with power system stability analysis were conceived many years ago. Nonetheless, continuous expansion of the network and the emergence of a new generation of fast acting, multi-purpose power system controllers have called for renewed research efforts in this all-important application area of power systems. In particular, there is growing concern that the power network is becoming more unbalanced, owing to higher operating voltages and a relentless drive for interconnection, and that unbalances may impair the effectiveness of power electronic-based loads and controllers. These are issues that may be difficult to address satisfactorily with conventional transient stability modelling approaches since they are based on the premise that the transmission network observes a perfect balance, even under faulted operating regimes. The study of a limited range of asymmetrical transient stability problems using conventional methods can be achieved, but only with great difficulty, which involves transforming the network into fictitious components (i. e. symmetrical components). This is significant since asymmetrical short-circuit faults constitute the largest percentage of faults that occur in the power network, and network designs based solely on the three-phase short-circuit-to-ground faults result in underengineered networks. Equally important issues are the widespread commissioning of modern power electronics controllers and the lack of suitable models and methods for assessing the impact of such controllers in network-wide operation with particular reference to transient stability and unbalanced operation. The research reported in this thesis addresses these issues and develops a direct time phasedomain model for conducting multimachine transient stability analysis where asymmetrical operating conditions and the impact of modem power electronics controllers are represented. In this simulation environment, AC synchronous and asynchronous generators are represented together with asynchronous motors. The set of non-linear equations describing the machines are solved using discretisation and the trapezoidal rule of integration. The proposed model is compared against an industry standard power system package for cases of symmetrical operation. The generality and versatility of the model is demonstrated when applied to the analysis of symmetrical and asymmetrical power system operations. An important aspect of this research is a drive towards the solution of transient stability in real-time, where the results produced are in actual world time. This is achieved by embedding the model into a commercially available multi-purpose real-time station. To this end, coherency-based synchronous generators equivalent has been developed to enable the solution of multimachine systems in real-time. The equivalent unit is obtained based on the aggregation of the coherent generators using phase-domain techniques. Dynamic loads in the form of asynchronous motors are implemented within the multimachine network. The adverse influences of motor operation on voltage problems in the network under symmetrical and asymmetrical conditions are analysed. Transient analysis of dispersed generation is also considered where the asynchronous machine is operated as a generator alongside synchronous generators. The behaviours of the two type of generators under various networks and operating conditions are presented. Models of power electronics controllers in the direct time phase-domain are also described in this thesis. The generalised models of the Static Var Compensator (SVC), Static Synchronous Compensator (STATCOM), Dynamic Voltage Restorer (DVR) and High Voltage Direct Current-Voltage Source Converter (HVDC-VSC) station are proposed. The SVC comprised of a fix capacitor and a thyristor controlled reactor (TCR) is developed. Here, switching functions are used to represent the operation of the thyristor. Models of STATCOM, DVR and HVDC-VSC station are developed based on the self-commutated voltage source converter (VSC) technology. The VSC is represented by the switching functions of its pulse width modulation (PWM) control, hence, providing a flexible model within the direct time phase-domain approach. The model of the VSC is implemented into the respective power electronics controllers enabling a convenient modular approach to be adopted. The power electronics controllers are incorporated into the multimachine environment for the analysis of transient and power quality related issues

Contributions of flywheel systems in wind power plants

The stepwise replacement of conventional power plants by renewable-based ones such as wind power plants could a ect the system behaviour and planning. First, the network stability may be compromised as it becomes less resilient against sudden changes in the loads or generator trips. This is because wind turbines are not synchronized with network frequency but they are usually connected to the grid through fast controllable electronic power converters. And second, due to the stochastic nature of wind, the electrical power generated by wind power plants is neither constant non controllable. This aff ects the network planning as the expected generation level depends on non reliable wind forecasts. Also it aff ects the power quality as the fast fluctuations of wind power can cause harmonics and flicker emissions. For these reasons, network operators gradually set up more stringent requirements for the grid integration of wind power. These regulations require wind power plants to behave in several aspects as conventional synchronized generating units. Among other requirements, it is set the provision of some ancillary services to the grid as frequency and voltage control, the capability of withstanding short-circuits and faults, and to respect some threshold level with regard to the quality of the power generated. Accordingly, energy storage systems may play an important role in wind power applications by enhancing the controllability of the output of wind power plants and providing ancillary services to the power system and thus, enabling an increased penetration of wind power in the system. This thesis focuses on the potential uses of flywheel energy storage systems in wind power. The thesis introduces the basis of several energy storage systems as well as identi es their applications in wind power based on an extensive literature review. It follows with the presentation of the design and setting up of a scale-lab flywheel-based energy storage system. From this work, research concentrates on the application of flywheel devices for power smoothing of wind power plants. The developed concepts are proved by simulations but also experimentally using the above mentioned scale-lab test bench. In particular, research focuses on the de nition of an optimization criteria for the operation of flywheel devices while smoothing the wind power, and the design and experimental validation of the proposed control algorithms of the storage device. The last chapters of the thesis research on the role of wind power plants in system frequency control support. In this sense, an extensive literature review on the network operator's requirements for the participation of wind power plants in system frequency control related-tasks is off ered. Also, this review covers the proposed control methods in the literature for enabling wind turbines to participate in system frequency control. The results of this work open the door to the design of control systems of wind turbines and wind power plants for primary frequency control. The contribution of flywheel devices is also considered. Results highlight the tremendous potential of energy storage systems in general for facilitating the grid integration of wind power plants. Regarding the uses of flywheel devices, it is worth noting that some of their characteristics as the high-ramp power rates can be exploited for reducing the variability of the power generated by wind turbines, and thus for improving the quality of the power injected to the grid by wind power plants. Also, they can support wind power plants to ful l the requirements for their participation in system frequency control support related tasks.El progressiu despla cament de plantes de generaci o convencionals per part de plantes de generaci o de tipus renovable, com els parcs e olics, pot afectar el comportament i la plani caci o del sistema el ectric. Primer, l'estabilitat pot ser compromesa ja que el sistema el ectric resulta m es vulnerable davant canvis abruptes provocats per les c arregues del sistema o desconnexions no programades de generadors. Aix o es degut a que les turbines e oliques no estan sincronitzades amb la freqü encia el ectrica del sistema ja que la seva connexi o es a trav es de convertidors electr onics de pot encia. Segon, degut a la gran variabilitat del vent, la pot encia el ectrica generada per les turbines e oliques no es constant ni controlable. En aquest sentit, la qualitat de la pot encia del parc e olic es pot veure compromesa, ja que es poden detectar nivells apreciables d'harm onics i emissions de "flicker" degudes a les r apides variacions de la pot encia generada pel parc e olic. Per aquests motius, els operadors dels sistemes el ectrics fan gradualment m es restrictius els requeriments de connexi o dels parcs e olics al sistema el ectric. Aquestes regulacions requereixen als parcs e olics que es comportin en molts aspectes com plantes de generaci o convencional. Entre d'altres requeriments, els parcs e olics han de proveir serveis auxiliars per a la operaci o del sistema el ectric com tamb e el suport en el control dels nivells de tensi o i freqü encia de la xarxa; oferir suport durant curtcircuits; i mantenir uns nivells m nims en la qualitat de la pot encia generada. Els sistemes d'emmagatzematge d'energia poden millorar la controlabilitat de la pot encia generada pels parcs e olics i ajudar a aquests a proveir serveis auxiliars al sistema el ectric, afavorint aix la seva integraci o a la xarxa. Aquesta tesi tracta l'aplicaci o en parcs e olics dels sistemes d'emmagatzematge d'energia basats en volants d'in ercia. La tesi introdueix les bases de diversos sistemes d'emmagatzematge i identi ca les seves potencials aplicacions en parcs e olics en base a una extensa revisi o bibliogr a ca. El treball continua amb la posta a punt d'un equipament de laboratori, que con gura un sistema d'emmagatzematge d'energia basat en un volant d'in ercia. Següents cap tols de la tesi estudien l'aplicaci o dels volants d'in ercia per a esmorteir el per l fluctuant de la pot encia generada pels parcs e olics. Els treballs es focalitzen en la de nici o dels criteris per a la operaci o optima dels volants d'in ercia per la seva aplicaci o d'esmorteir el per l fluctuant de potencia e olica, i tamb e en el disseny i validaci o experimental dels algoritmes de control desenvolupats per governar el sistema d'emmagatzematge. Els cap tols finals de la tesi tracten sobre el suport al control de freqü encia per part dels parcs e olics. S'ofereix una extensa revisi o bibliografica respecte els requeriments indicats pels operadors del sistema el ectric en aquest sentit. A m es, aquesta revisi o cobreix els m etodes de control dels parcs e olics i turbines e oliques per la seva participaci o en el suport al control de freqü encia. Les conclusions extretes serveixen per proposar sistemes de control de parcs e olics i de turbines e oliques per proveir el servei de control de freqüencia. Aquest treball, tamb e contempla la inclusi o de volants d'in ercia en els parcs e olics. Dels resultats de la tesi se'n dedueix l'important potencial dels sistemes d'emmagatzematge d'energia per a afavorir la integraci o a la xarxa dels parcs e olics. La controlabilitat de la pot encia dels volants d'in ercia, afavoreix el seu us per reduir la variabilitat de la pot encia generada pels parcs e olics, millorant aix la qualitat de pot encia del mateix. A m es, els volants d'in ercia poder ajudar als parcs e olics a complir amb els requeriments per a la seva integraci o a xarxa, com la participaci o en el control de freqüencia del sistema el ectric

Adaptive Energy Storage System Control for Microgrid Stability Enhancement

Microgrids are local power systems of different sizes located inside the distribution systems. Each microgrid contains a group of interconnected loads and distributed energy resources that acts as a single controllable entity with respect to the grid. Their islanding operation capabilities during emergencies improve the resiliency and reliability of the electric energy supply. Due to its low kinetic energy storage capacity, maintaining microgrid stability is challenging under system contingencies and unpredictable power generation from renewable resources. This dissertation highlights the potential benefits of flexibly utilizing the battery energy storage systems to enhance the stability of microgrids. The main contribution of this research consists in the development of a storage converter controller with an additional stability margin that enables it to improve microgrid frequency and voltage regulation as well as its induction motor post-fault speed recovery. This new autonomous control technique is implemented by adaptively setting the converter controller parameters based on its estimated phase-locked loop frequency deviation and terminal voltage magnitude measurement. This work also assists in the microgrid design process by determining the normalized minimum storage converter sizing under a wide range of microgrid motor inertia, loading and fault clearing time with both symmetrical and asymmetrical fault types. This study evaluates the expandability of the proposed control methodologies under an unbalanced meshed microgrid with fault-induced feeder switching and multiple contingencies in addition to random power output from renewable generators. The favorable results demonstrate the robust storage converter controller performance under a dynamic changing microgrid environment

Application of modern control techniques in AC speed drive system.

In the past, Direct Current (dc) machines have been commonly favoured in areas where a precise variable speed operation is highly required. This is due to the feasible linear control of flux and torque, which is accomplished by simply varying the field and armature currents. However, they are bulky, expensive and require periodic maintenance due to the existence of commutators and brushes. Alternating Current (ac) machines particularly the squirrel cage induction type have emerged as an alternative to those of dc machines in the application of speed drive systems. In general, however, they do require more complex control schemes than the dc motors, because of their highly non-linear dynamic structure with strong dynamic interactions. This situation has changed dramatically over the last few years with the advent of fast switching power converters along with high performance micro-controllers, which made a significant contribution to performance enhancement of modem speed drive systems. In addition, various control techniques have made possible the application of induction motors in high performance speed drive operations where traditionally only dc motors were previously available. On the other hand, in many speed drive applications which incorporate either scalar or vector control, the prime objective of the speed controller is the capability of achieving a good speed tracking performance and without sensitivity to parameters and operating condition changes. For these reasons, comprehensive investigation of state-of-the-art modem control schemes, which include fuzzy logic and sliding mode control are discussed. The main principles underlying fuzzy logic and sliding mode control schemes along with their basic theory and general mathematical representation are reviewed. In addition, the application of fuzzy logic concepts to reduce the chattering phenomenon typically inherited in the sliding mode control is successfully presented, which results in a new integrated fuzzy sliding mode control algorithms. Through extensive simulation studies, it is found that the fuzzy logic control scheme attained a good transient performance for the speed drive system in comparison to the conventional sliding mode control and the new integrated fuzzy sliding mode control. Furthermore, the design simplicity of the fuzzy logic control system has made it virtually attractive for the ease of practical implementation of the proposed drive system. Extensive practical testes of the proposed variable speed drive system have been carried out to verify the validity of the simulation analysis of the proposed fuzzy logic control system. Several tests are conducted in order to bring out the effectiveness of the designed control system upon step change in speed command and impact load disturbances. The digital implementation of the proposed fuzzy logic control algorithms is realised on a single chip, Intel 80C196KC 16-bit embedded microcontroller, a low cost derivative of the MCS-96 architecture. The main contribution of this thesis is the novel approach to design a sliding mode control system using concepts from fuzzy logic algorithms to alleviate the chattering problems and improve the dynamics of the induction motor drive

Application of Fuzzy Logic for Performance Enhancement of Drives

Fuzzy logic shows enormous potential for advancing power electronics technology. Its application to DC and AC drives control is discussed here. Initially, a phase-controlled bridge converter DC drive was considered. Analysis of converter performance at continuous and discontinuous conduction modes was first conducted. Fuzzy control was used to linearize the transfer characteristics of the converter in discontinuous conduction mode. It was then extended to current and speed loops, replacing the conventional proportional-integral controllers. The control algorithms were developed in detail, and verified by PC-SIMNON (developed by Lund Institute of Technology Sweden) digital simulation. Significant performance improvement was achieved over conventional control methods. Efficiency optimization of an indirect vector controlled induction motor drive was next considered. An accurate loss model of the converter induction machine system was first developed. Steady-state fundamental and harmonics loss characteristics, besides the dynamic of the machine were analyzed and incorporated in the model, resulting in a new synchronous frame dynamic De-Qe equivalent circuit. The converter system has been modeled accurately for conduction and switching losses. The lossy models were then used in the validation of the fuzzy logic based on-line efficiency optimization control. At steady-state, the fuzzy controller adaptively changes the excitation current on the basis of measured input power, until the maximum efficiency point is reached. The pulsating torque, due to flux reduction, has been compensated by an ingenious feedforward scheme. During transients, rated flux is established, to get the best transient response. After a comprehensive simulation study, an experimental 5 hp drive system was tested, with the proposed controller implemented on a Texas Instrument TMS320C25 digital signal processor, and the theoretical development was fully validated. Finally, fuzzy logic was applied in combination with model-reference adaptive control (MRAC) technique to slip gain tuning of an indirect vector controlled induction motor drive. The MRAC methods based on reactive power and D-axis voltage were combined through a weighting factor, generated by a fuzzy controller, that ensures the use of the best method for any point in the torque-speed plane. A second fuzzy controller tunes the slip gain based on combined detuning error and its slope. The drive performance was extensively investigated through simulations and experiments. The results confirmed the validity of the proposed method

Inverter Design for SiC-based Electric Drive Systems with Optimal Redundant States Control of Space Vector Modulation

The need for inverters with ever increasing power density and efficiency has recently become the driving factor for research in various fields. Increasing the operating voltage of the whole drive system and utilizing newly developed SiC power switches can contribute towards this goal. Higher operating voltage allows the design of drives with lower current, which leads to lower copper losses in cables and machine, while SiC switches can drastically increase the inverter efficiency. Offshore renewable power generation, such as tidal power, is a typical application where the increase of operating voltage can be highly beneficial. The ongoing electrification of transportation calls also for high power electric powertrains with high power density,where SiC technology has key advantages.In the first part of the thesis, suitable control schemes for inverters in synchronous machine drive systems are derived. A properly designed Maximum Power Point Tracking algorithm for kite-based tidal power systems is presented. The speed and torque of this new tidal power generation system varies periodically and the inverter control needs to be able to handle this variable power profile. Experimental verification of the developed control is conducted on a 35 kVA laboratory emulator of the tidal power generation unit.Electric drives using multilevel inverters are studied afterwards. Multilevel inverters use multiple low-voltage-rated switches and can operate at higher voltage than standard two-level inverters. The Neutral Point Clamped (NPC) converter is a commonly used multilevel inverter topology for medium voltage machine drives. However, the voltage balancing of its dc-side capacitors and the complexity of its control are still issues that have not been effectively solved. A new method for the optimal utilization of the redundant states in Space Vector pulse-width-Modulation (SVM) is proposed in this thesis in order to control its dc-link voltages. Experimental verification on a 4-kV-rated prototype medium-voltage PMSM drive with 5-level NPC converters is conducted in order to validate the effectiveness of the proposed control technique.Low switching and conduction losses are typical characteristics of SiC switches that can be utilized to build inverters with high power density, due to the increased efficiency and smaller form-factor. Due to the above, SiC power modules have been particularly attractive for the automotive industry. The design approach of 2-level automotive inverters has been studied in this project. Moreover, a new design approach for the cooling system of automotive inverters has been developed in this thesis, which fine-tunes the inverter heatsink utilizing standard legislated test routines for electric vehicles. Multiple conjugate-heat-transfer (CHT) computation results showcase the iterative optimization procedure on a test-case 250 kW (450 A) automotive SiC inverter.Finally, the experimental testing of high power machine drives in order to verify the control and the hardware design is an important step of the development process. Thus, the performance of the prototype 450 A SiC 2-level inverter has been been experimentally validated in a power hardware-in-the-loop (P-HIL) set-up that emulates an automotive drive system. Several challenges have been addressed with respect to the accurate modelling of the motor and the control of the circulating power in the system. A new control technique utilizing the redundant states of the SVM has been developed for this set-up to effectively suppress the zero-sequence current to 3.3 % of the line current at rated power

Power converter optimal control for wind energy conversion systems

L'energia eòlica ha incrementat la seva presència a molts països i s'espera que tingui encara un pes més gran en la generació elèctrica amb la implantació de la tecnologia eòlica marina. En aquest context el desenvolupament de models dels Sistemes de Generació per Turbina de Vent (SGTV) precisos és important pels operadors de xarxa per tal d'avaluar-ne el comportament. Els codis de xarxa ofereixen un seguit de normes per validar models amb dades obtingudes de proves de camp. A la primera part d'aquesta tesi un model de SGTV amb màquina d'inducció doblement alimentada (DFIG) és validat d'acord amb les normatives espanyola i alemanya. Avui dia molts parc eòlics utilitzen DFIG i, en conseqüència, les dades de camp disponibles son per aquesta tecnologia. Per a la indústria eòlica marina un avanç prometedor son els SGTV amb generadors síncrons d'imants permanents (PMSG). Per aquesta raó la segona part d'aquesta tesi es centra en SGTV basats en PMSG amb convertidor back-to-back de plena potència. Aquest convertidor es pot dividir en dues parts: el costat de xarxa (GSC) que interactua amb la xarxa elèctrica i el costat de màquina (MSC) que controla el generador. En general, el sistema de control del convertidor recau en els tradicionals controladors PI i, en ocasions, incorpora desacoblaments per reduir les influencies creuades entre les variables. Aquest controlador pot ser sintonitzat i implementat fàcilment donat que la seva estructura és simple, però, no presenta una resposta ideal donat que no aprofita tots els graus de llibertat disponibles en el sistema. És important desenvolupar controladors fiables que puguin oferir una resposta previsible del sistema i proveir robustesa i estabilitat. En especial per zones on la presència eòlica és gran i per parcs eòlics connectats a xarxes dèbils. En aquest treball es proposa un sistema de control pel convertidor basat en teoria de control H-infinit i en controladors Lineals amb Paràmetres Variants (LPV). La teoria de control òptim proveeix un marc de treball on més opcions es poden tenir en consideració a l'hora de dissenyar el controlador. En concret la teoria de control H-inifinit permet crear controladors multivariables per tal d'obtenir una òptima resposta del sistema, proveir certa robustesa i assegurar l'estabilitat. Amb aquesta tècnica durant la síntesi del controlador el pitjor cas de senyals de pertorbació és contemplat, d'aquesta manera el controlador resultant robustifica l'operació del sistema. Es proposa aquest control per al GSC posant especial èmfasi en obtenir un control de baixa complexitat que mantingui els beneficis d'aplicar la teoria de control òptim i faciliti la seva implementació en computadors industrials. Pel MSC es proposa una estratègia diferent basada en control LPV donat que el punt d'operació del generador canvia constantment. El sistema de control basat en LPV és capaç d'adaptar-se dinàmicament al punt d'operació del sistema, així s'obté en tot moment la resposta definida durant el procés de disseny. Amb aquesta tècnica l'estabilitat del sistema sobre tot el rang d'operació queda garantida i, a més, s'obté una resposta predictible i uniforme. El controlador està dissenyat per tenir una estructura simple, com a resultat s'obté un control que no és computacionalment exigent i es proveeix una solució que pot ser utilitzada amb equips industrials. S'utilitza una bancada de proves que inclou el PMSG i el convertidor back-to-back per tal d'avaluar experimentalment l'estratègia de control dissenyada al llarg d'aquest treball. L'enfoc orientat a la implementació dels controls proposats facilita el seu ús amb el processador de senyals digitals inclòs a la placa de control de la bancada. Els experiments realitzats verifiquen en un ambient realista els beneficis teòrics i els resultats de simulació obtinguts prèviament. Aquestes proves han ajudat a valorar el funcionament dels controls en un sistema discret i la seva tolerància al soroll de senyals i mesuresWind energy has increased its presence in many countries and it is expected to have even a higher weight in the electrical generation share with the implantation of offshore wind farms. Consequently, the wind energy industry has to take greater responsibility towards the integration and stability of the power grid. In this sense, there are proposed in the present work control systems that aim to improve the response and robustness of the wind energy conversion systems without increasing their complexity in order to facilitate their applicability. In the grid-side converter it is proposed to implement an optimal controller with its design based on H-infinity control theory in order to ensure the stability, obtain an optimal response of the system and also provide robustness. In the machine-side converter the use of a Linear Parameter-Varying controller is selected, this choice provides a controller that dynamically adapts itself to the operating point of the system, in this way the response obtained is always the desired one, the one defined during the design process. Preliminary analysis of the controllers are performed using models validated with field test data obtained from operational wind turbines, the validation process followed the set of rules included in the official regulations of the electric sector or grid codes. In the last stage an experimental test bench has been developed in order to test and evaluate the proposed controllers and verify its correct performance

Integration of distributed generation using energy storage systems

New challenges in grid reliability are coming up with the increasing penetration of renewable energies and distributed generation (DG). The use of Energy Storage Systems (ESS) is proposed in this thesis as solution for different problems related to these new challenges. The development and current state of ESS are described in this thesis. This description permits to choose the best solution for the different scenarios that are analyzed. The analysis of electrical grids is carried out by means of simulation tools. For this purpose a dynamic power calculation is proposed. The modeling of electrical components and their implementation in the proposed simulation tool permits to analyze the frequency and voltage stability of power systems. These two are the most important parameters for grid operation and therefore the most important parameters to analyze the integration of DG. Some applications related to the use of ESS as a solution for a certain problem related to the high penetration of DG are analyzed in the present work. Voltage regulation, restoration of large frequency deviations, primary frequency regulation and the control of the power dispatch of a wind farm are proposed as applications for ESS. The design of an application combining these functionalities is discussed. Hybrid ESS that combines different ESS technologies is proposed as a single solution for all the applications analyzed during the course of this thesis.Energia berriztagarrien eta Sorkuntza Barreiatuaren (SB) erabilera azkorrak erronkau berriak aurkezten ditu sare elektrikoen sinesgarritasunari begira. Tesi honetan Energia Metatzeko Sistemen (EMS) erabilera eztabaidatzen da aipatutako erronketatik eratorritako zenbait arazo konpontzeari begira. EMSen garapena eta egungo egoera azaltzen dira tesi honetan. Deskribapen honek tesi honetan aztertzen diren egoera desberdinentzat konponbide egokiena hautatzea ahalbideratzen du. Sare elektrikoen azterketa simulaziorako tresnen bidez egiten da. Helburu hau betetzeko potentzia fluxuen kalkulu dinamikoa proposatzen da. Osagai elektrikoen modelatzeak eta beren inplementazioak proposaturiko simulazio tresnan potentziako sistemen tentsio eta frekuentziaren azterketa egitea ahalbideratzen du. Bi parametro hauek dira garrantzitsuenak sare elektrikoaren operazioaren ikuspegitik eta honenbestez parametro garrantzitsuenak dira SBren integrazioa aztertzeko orduan. Lan honetan EMSen erabileraren inguruko hainbat aplikazio aztertzen dira, SBren sarrera handiarekin erlazionatutako zenbait arazori konponbidea bilatzeko. Tentsioaren erregulazioa, frekuentziaren desbideratze handien berreskurapena, frekuentziaren erregulazio primarioa eta parke eolikoen despatxu kontrolatua EMSentzako aplikazio bezala proposatzen dira. Funtzio guzti hauek beteko lituzken aplikazio baten diseinua eztabaidatzen da. EMS Hibrido bat proposatzen da EMS teknologia desberdinak konbinatuko dituena, lan honetan aztertu diren aplikazio desberdinentzako soluzio bezala.La creciente penetración de energías renovables y Generación Distribuida (GD) presentan nuevos retos en la fiabilidad de las redes eléctricas. El uso de Sistemas de Almacenamiento de Energía (SAE) se propone en esta tesis como solución a diferentes problemas derivados de los mencionados retos. El desarrollo y el actual estado de los SAE se describen en esta tesis. Esta descripción permite elegir la mejor solución ante los diferentes escenarios que se analizan. El análisis de las redes eléctricas se realiza mediante herramientas de simulación. Con este objetivo se propone el cálculo dinámico de los flujos de carga. El modelado de componentes eléctricos y su implementación en la herramienta de simulación propuesta permite analizar la estabilidad del voltaje y la frecuencia en los sistemas de potencia. Estos dos parámetros son los más importantes para operación de la red eléctrica y por consiguiente son los parámetros más importantes para analizar la integración de la GD. En este trabajo se analizan varias aplicaciones relacionadas con el uso de los SAE como solución a ciertos problemas relacionados con la alta penetración de la GD. Regulación de voltaje, restitución de grandes desviaciones de frecuencia, regulación primaria de frecuencia y el despacho controlado de los parques eólicos se proponen como aplicaciones para SAE. Se debate el diseño de una aplicación que combine estas funcionalidades. Se propone un SAE Híbrido que combine diferentes tecnologías de SAE como solución única para todas las aplicaciones analizadas durante el curso de esta tesis