Overview of storage energy systems for renewable energy system application

The integration of renewable energy system into modern power grids has significantly increased during the last decade. Solar and wind energy are the most popular renewable energy sources recently. Solar energy has reached about 17,3 GW in 2010 whilst about 340 TWh of wind energy source has been installed worldwide. In this paper, the overview of updated information regarding proposed storage energy systems for renewable energy is presented. It is useful information for practitioners in considering the possible options of storage energy technologies to be connected with renewable energy sources

Power Quality Improvement in Isolated Wind-Diesel Power System

Copyright © 2017 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution License 4.0Power quality related disturbances in electrical distribution networks have become a major concern for both network managers and operators associated with the continuous increase of renewable energy resources worldwide. Such disturbances can cause momentary voltage sags and spikes, current distortions and fluctuations in the frequency that directly impact on the efficiency and performance of the electric equipment. This paper proposes a control strategy of a shunt active power filter (SAPF) to enhance the power quality in terms of harmonics and reactive power compensation in a standalone wind-diesel power system. The control of the SAPF is based on the indirect current control (ICC) strategy combining two proportional-integral (PI) controllers with a fuzzy logic controller. The system model is developed under MATLAB/SIMULINK environment and the proposed control scheme is evaluated under varying wind dynamics, linear balanced, unbalanced and non-Linear balanced load conditions.Peer reviewe

Modeling, Simulation and Control of Wind Diesel Power Systems

Wind diesel power systems (WDPSs) are isolated microgrids that combine diesel generators (DGs) with wind turbine generators (WTGs). Often, WDPS are the result of adding WTGs to a previous existing diesel power plant located in a remote place where there is an available wind resource. By means of power supplied by WTGs, fuel consumption and CO2 emissions are reduced. WDPSs are isolated power systems with low inertia where important system frequency and voltage variations occur. WDPS dynamic modeling and simulation allows short-term simulations to be carried out to obtain detailed electrical variable transients so that WDPS stability and power quality can be tested. This book includes papers on several subjects regarding WDPSs: the main topic of interest is WDPS dynamic modeling and simulation, but related areas such as the sizing of the different WDPS components, studies concerning the control of WDPSs or the use of energy storage systems (ESSs) in WDPSs and the benefits that ESSs provide to WDPS are also discussed. The book also deals with related AC isolated microgrids, such as wind-hydro microgrids or wind-photovoltaic-diesel microgrids

A MPC Strategy for the Optimal Management of Microgrids Based on Evolutionary Optimization

In this paper, a novel model predictive control strategy, with a 24-h prediction horizon, is proposed to reduce the operational cost of microgrids. To overcome the complexity of the optimization problems arising from the operation of the microgrid at each step, an adaptive evolutionary strategy with a satisfactory trade-off between exploration and exploitation capabilities was added to the model predictive control. The proposed strategy was evaluated using a representative microgrid that includes a wind turbine, a photovoltaic plant, a microturbine, a diesel engine, and an energy storage system. The achieved results demonstrate the validity of the proposed approach, outperforming a global scheduling planner-based on a genetic algorithm by 14.2% in terms of operational cost. In addition, the proposed approach also better manages the use of the energy storage system.Ministerio de Economía y Competitividad DPI2016-75294-C2-2-RUnión Europea (Programa Horizonte 2020) 76409

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

Multi-objective energy storage power dispatching using plug-in vehicles in a smart-microgrid

This paper describes a multi-objective power dispatching problem that uses Plug-in Electric Vehicle (PEV) as storage units. We formulate the energy storage planning as a Mixed-Integer Linear Programming (MILP) problem, respecting PEV requirements, minimizing three different objectives and analyzing three different criteria. Two novel cost-to-variability indicators, based on Sharpe Ratio, are introduced for analyzing the volatility of the energy storage schedules. By adding these additional criteria, energy storage planning is optimized seeking to minimize the following: total Microgrid (MG) costs; PEVs batteries usage; maximum peak load; difference between extreme scenarios and two Sharpe Ratio indices. Different scenarios are considered, which are generated with the use of probabilistic forecasting, since prediction involves inherent uncertainty. Energy storage planning scenarios are scheduled according to information provided by lower and upper bounds extracted from probabilistic forecasts. A MicroGrid (MG) scenario composed of two renewable energy resources, a wind energy turbine and photovoltaic cells, a residential MG user and different PEVs is analyzed. Candidate non-dominated solutions are searched from the pool of feasible solutions obtained during different Branch and Bound optimizations. Pareto fronts are discussed and analyzed for different energy storage scenarios. Perhaps the most important conclusion from this study is that schedules that minimize the total system cost may increase maximum peak load and its volatility over different possible scenarios, therefore may be less robust