Optimized Energy Management Strategy for Wind Plants with Storage in Energy and Reserve Markets

This paper addresses the joint operation of wind plants with energy storage systemsin multiple markets to increase the value of wind energy from an economic and technical point of view. The development of an optimized energy management allows scheduling the wind generation in energymarkets, as well as contributing to the system stability through the joint participation in frequency ancillary services. The market optimization maximizes market revenuesconsidering overallstoragecosts, while avoidingenergy imbalancesand market penalties. Moreover, wind power fluctuations, forecast errors and real-time reserverequirementsare controlledby the energy storagesystem and managed afterward through the participation in continuous intraday market. Furthermore, model predictive control approach enables a high compliance of reserve requirementsand a hugereduction of energy imbalancesin real-time operation. Different energy storagecapacities are selected in order to evaluate theircost-effectiveness enhancing the wind plant operation underthe considered study case.This work was partially supported by the Basque Government under Project Road2DC (ELKARTEK Research Program KK-2018/00083)

Development of optimal energy management and sizing strategies for large-scale electrical storage systems supporting renewable energy sources.

284 p.El desarrollo e integración de las fuentes de energía renovable (RES) conducirá a un futuro energético más sostenible. Las plantas renovables deberán mejorar su participación y operación a través de los mercados de electricidad de una manera más controlada y segura. Además, el diseño actual del mercado está cambiando para permitir una participación inclusiva en mercados de flexibilidad. En este contexto, los sistemas de almacenamiento de energía (ESS) se consideran una de las tecnologías flexibles clave que pueden apoyar la operación de las energías renovables, mediante servicios como: 1) control de la potencia generada, 2) mejora de los errores de predicción, y 3) provisión de servicios auxiliares de regulación de frecuencia. Sin embargo, el desarrollo del almacenamiento ha sido frenado también por sus altos costos. Por lo tanto, esta tesis doctoral aborda el tema del ¿Desarrollo de estrategias óptimas de gestión y dimensionamiento de los sistemas de almacenamiento eléctrico a gran escala como apoyo a fuentes de energía renovable¿, con el objetivo de desarrollar una metodología con una perspectiva global, mediante una estrategia de gestión de energía avanzada (EMS) que aborda la gestión de activos (RES + ESS) a largo plazo y por otro lado, el cálculo del dimensionamiento y operación del almacenamiento a corto plazo (en la operación en tiempo real), para asegurar un marco adecuado que permita evaluar la rentabilidad de la integración del almacenamiento en aplicaciones conectadas a la red. La estrategia de gestión de energía propuesta es validada a través de dos casos de estudio: una planta renovable individual (eólica o solar) con almacenamiento, y un porfolio de renovables y almacenamiento

Development of optimal energy management and sizing strategies for large-scale electrical storage systems supporting renewable energy sources.

284 p.El desarrollo e integración de las fuentes de energía renovable (RES) conducirá a un futuro energético más sostenible. Las plantas renovables deberán mejorar su participación y operación a través de los mercados de electricidad de una manera más controlada y segura. Además, el diseño actual del mercado está cambiando para permitir una participación inclusiva en mercados de flexibilidad. En este contexto, los sistemas de almacenamiento de energía (ESS) se consideran una de las tecnologías flexibles clave que pueden apoyar la operación de las energías renovables, mediante servicios como: 1) control de la potencia generada, 2) mejora de los errores de predicción, y 3) provisión de servicios auxiliares de regulación de frecuencia. Sin embargo, el desarrollo del almacenamiento ha sido frenado también por sus altos costos. Por lo tanto, esta tesis doctoral aborda el tema del ¿Desarrollo de estrategias óptimas de gestión y dimensionamiento de los sistemas de almacenamiento eléctrico a gran escala como apoyo a fuentes de energía renovable¿, con el objetivo de desarrollar una metodología con una perspectiva global, mediante una estrategia de gestión de energía avanzada (EMS) que aborda la gestión de activos (RES + ESS) a largo plazo y por otro lado, el cálculo del dimensionamiento y operación del almacenamiento a corto plazo (en la operación en tiempo real), para asegurar un marco adecuado que permita evaluar la rentabilidad de la integración del almacenamiento en aplicaciones conectadas a la red. La estrategia de gestión de energía propuesta es validada a través de dos casos de estudio: una planta renovable individual (eólica o solar) con almacenamiento, y un porfolio de renovables y almacenamiento

Energy storage systems comparison for the space station

An overview of the requirements, options, selection criteria and other considerations, and current status with regard to the energy storage subsystem (ESS) for the photovoltaic power system alternative for the space station is provided

ELECTRICAL POWER TAKE-OFF SYSTEM DESIGN AND PERFORMANCE ASSESSMENT FOR POINT ABSORBER WAVE ENERGY CONVERTER

Wave energy has great potential but has a high levelized energy cost compared to other renewable energy sources (e.g., solar and wind). Improving the buoy control performance in the wave-to-wire energy conversion would be a straightforward way to increase the wave energy conversion efficiency and decrease the wave energy levelized cost. To improve the buoy control schemes design, the assessment of the state of the art controls and the study of the power take-off (PTO) power loss model are demanded. This dissertation starts with the basic dynamics of the wave energy converter (WEC) buoy and electrical PTO, introduces essential mechanics of the WEC wave-to-wire model composing. Furthermore, the details of the electrical machine control methodologies and the state-of-the-art buoy control schemes are included as well to generate the WEC wave-to-wire control frame. According to the wave-to-wire dynamic model, one fast evaluation methodology for energy extraction potential assessment is introduced. The sea-state-output-power matrices are generated while considering various electrical PTO effects and constraints to obtain electrical output power directly instead of relying on dynamic models propagation. Based upon the fast evaluation methodology, 16-years ground truth ocean wave data is analyzed for solving energy storage system (ESS) sizing problems for off-shore applications. To improve the ESS design reliability, the statistical study is applied as well. To further study the electrical PTO power loss model, the PTO dynamic model is implemented xxxi to the WEC buoy dynamic model. Several state-of-the-art WEC buoy control schemes are applied to the device and the performance is assessed. While considering the PTO copper losses, operation constraints, and the PTO nonlinear power loss model, the results show that the buoy control schemes will be affected significantly by the actual PTO dynamics. By studying the PTO operation efficiency, the possible solutions for improving the WEC energy extraction performance are provided. Designing the control for the wave-to-wire from a global point of view is demanded. So in the last chapter, the machine reinforcement learning (RL) control for the WEC wave-to-wire modeling is proposed, and the results are compared to other model-based controls, which turns out that the RL control can achieve much higher output power with better power qualities and it is robust for various wave conditions. According to the research results, a future study plan is discussed as well in the last

A Methodology for Sizing Subsea Energy Storage Devices for Offshore Wind-Powered Oil and Gas Platforms

This thesis presents a methodology for sizing subsea energy storage devices for offshore wind-powered oil and gas platforms. This study examines the literature on hybrid energy systems (HES) and subsea energy storage systems (ESS). A subsea energy storage system is proposed as an environmentally friendly and economically feasible solution for power backup. It could be integrated into the power grid of a HES consisting of the ESS, renewable and non-renewable energy sources. It requires an appropriate ESS sizing approach. Two methods of subsea energy storage sizing are presented in this thesis. The first method uses the wind speed expected value. The second method relies on the weather window analysis. Both methods aim to estimate the ESS size capable of working within a chosen period in the power grid of a HES consisting of the wind farm and non-renewable energy source. Correspondingly, the sizing results of an ESS comparing both methods are presented in this work. Finally, initial charging of the device, additional power supply from the shore, and recommendations on future work are discussed. As a result, this study is expected to serve as a guide for planned and existing projects regarding sizing subsea energy storage

Smart management strategies of utility-scale energy storage systems in power networks

Power systems are presently experiencing a period of rapid change driven by various interrelated issues, e.g., integration of renewables, demand management, power congestion, power quality requirements, and frequency regulation. Although the deployment of Energy Storage Systems (ESSs) has been shown to provide effective solutions to many of these issues, misplacement or non-optimal sizing of these systems can adversely affect network performance. This present research has revealed some novel working strategies for optimal allocation and sizing of utility-scale ESSs to address some important issues of power networks at both distribution and transmission levels. The optimization strategies employed for ESS placement and sizing successfully improved the following aspects of power systems: performance and power quality of the distribution networks investigated, the frequency response of the transmission networks studied, and facilitation of the integration of renewable generation (wind and solar). This present research provides effective solutions to some real power industry problems including minimizationof voltage deviation, power losses, peak demand, flickering, and frequency deviation as well as rate of change of frequency (ROCOF). Detailed simulation results suggest that ESS allocation using both uniform and non-uniform ESS sizing approaches is useful for improving distribution network performance as well as power quality. Regarding performance parameters, voltage profile improvement, real and reactive power losses, and line loading are considered, while voltage deviation and flickers are taken into account as power quality parameters. Further, the study shows that the PQ injection-based ESS placement strategy performs better than the P injection-based approach (in relation to performance improvement), providing more reactive power compensations. The simulation results also demonstrate that obtaining the power size of a battery ESS (MVA) is a sensible approach for frequency support. Hence, an appropriate sizing of grid-scale ESSs including tuning of parameters Kp and Tip (active part of the PQ controller) assist in improving the frequency response by providing necessary active power. Overall, the proposed ESS allocation and sizing approaches can underpin a transition plan from the current power grid to a future one