Energy Management Strategies in hydrogen Smart-Grids: A laboratory experience

As microgrids gain reputation, nations are making decisions towards a new energetic paradigm where the centralized model is being abandoned in favor of a more sophisticated, reliable, environmentally friendly and decentralized one. The implementation of such sophisticated systems drive to find out new control techniques that make the system “smart”, bringing the Smart-Grid concept. This paper studies the role of Energy Management Strategies (EMSs) in hydrogen microgrids, covering both theoretical and experimental sides. It first describes the commissioning of a new labscale microgrid system to analyze a set of different EMS performance in real-life. This is followed by a summary of the approach used towards obtaining dynamic models to study and refine the different controllers implemented within this work. Then the implementation and validation of the developed EMSs using the new labscale microgrid are discussed. Experimental results are shown comparing the response of simple strategies (hysteresis band) against complex on-line optimization techniques, such as the Model Predictive Control. The difference between both approaches is extensively discussed. Results evidence how different control techniques can greatly influence the plant performance and finally we provide a set of guidelines for designing and operating Smart Grids.Ministerio de Economía y Competitividad DPI2013-46912-C2-1-

Economic and Energetic Assessment of a Hybrid Vanadium Redox Flow and Lithium-ion batteries considering different Energy Management Strategies

Hybrid energy storage systems (HESS) combine different energy storage technologies aiming at overall system performance and lifetime improvement compared to a single technology system. In this work, control combinations for a vanadium redox flow battery (VRFB, 5/60 kW/kWh) and a lithium-ion battery (LIB, 3.3/9.8 kW/kWh) are investigated for the design of a HESS. Four real-time energy management/power allocation scenarios are considered for the operation of the hybrid storage solution through a 15-year economic and energetic analysis. The results obtained for each scenario are compared with a single technology battery performance. In the definition of the scenarios, real electricity generation is considered from two solar photovoltaic installations (3.2 kWp and 6.7 kWp) and an estimated representative load of a services building. HESS performance is evaluated through specific energy and economic key performance indicators. The results obtained indicate that the use of customized energy management strategies (EMSs) renders the VRFB and LIB characteristics complementary, besides enhancing the competitiveness of VRFB, as a single technology. Moreover, the HESS management impacts the seasonality factor, contributing to the overall electric system smart management.Comment: 19 pages, 7 figures, research pape

Optimal Planning of Microgrid-Integrated Battery Energy Storage

Battery energy storage (BES) is a core component in reliable, resilient, and cost-effective operation of microgrids. When appropriately sized, BES can provide the microgrid with both economic and technical benefits. Besides the BES size, it is found that there are mainly three planning parameters that impact the BES performance, including the BES integration configuration, technology, and depth of discharge. In this dissertation, the impact of each one of these parameters on the microgrid-integrated BES planning problem is investigated. Three microgrid-integrated BES planning models are developed to individually find the optimal values for the aforementioned parameters. These three microgrid-integrated BES planning models are then combined and extended, by including the impact of microgrid islanding incidents on the BES planning solution, to develop a comprehensive planning model that can be used by microgrid planners to simultaneously determine the installed BES optimal size, integration configuration, technology, and maximum depth of discharge. Besides applications in microgrids, this dissertation investigates the integration of BES to provide other types of support in distribution networks such as load management of commercial and industrial customers, distribution network expansion, and solar PV ramp rate control

Microgrid design, control, and performance evaluation for sustainable energy management in manufacturing

This research studies the capacity sizing, control strategies, and performance evaluation of the microgrids with hybrid renewable sources for manufacturing end use customers towards a distributed sustainable energy system paradigm. Microgrid technology has been widely investigated and applied in commercial and residential sector, while for manufacturers, it has been less explored and utilized. To fill the gap, the dissertation first proposes a cost-effective sizing model to identify the capacities as well as control strategies of the components in microgrids considering a commonly used energy tariff, i.e., Time of Use (TOU). Then, the sizing model is extended by integrating control strategies for both microgrid components and manufacturing systems considering a typical demand response program, i.e., Critical Peak Pricing (CPP), where customer side load adjustment is highly encouraged. After that, the control strategy of the manufacturers in an overgeneration mitigation-oriented demand response program is further investigated based on the identified optimal size of onsite microgrid to minimize the energy cost. Later, the system is analyzed from its higher level of abstraction where a prosumer community is developed by aggregating such manufacturers with onsite microgrid system. To enhance the reliable energy operation in the community, the performance of the microgrid is investigated through the estimation of the lifetime of Battery Energy Storage System (BESS), a critical design parameter the architecture. Finally, conclusions are presented and future research on real-time joint control strategy for both microgrids and manufacturing systems and identification as well as optimal energy management of the controllable loads in manufacturing system are discussed --Abstract, page iii