Research Of Energy Storage Device Application In Microgrid

With the development of global energy and environment, micro-grid technologyhas become a hot research topic. and It began to be considered an importantsupplement to the big grid. Micro-grid is an independent power supply system whichcombined distributed power load, energy storage device and control device together, itcan provide electricity as well as heat, and it can not only grid-connected operationbut also isolated operation. As a powerful complement to the power system, themicro-grid can better solve grid-connected operation problems between the big gridand distributed power. Micro-grid with a combination of big grid can better improvethe reliability of power supply, which can effectively solve the drawbacks of thetraditional power supply. As an effective complement to big grid, Micro-grid has abright future.As one of core technology of micro-grid, energy storage can improve the qualityof micro-grid’s power supply, increase the stability of system and the economicefficiency of micro-grid, reduce the peak valley difference of load, and inhibitoscillation of power system, etc. The energy storage is the key to the safe and reliableoperation of the micro-grid. This paper references uses hybrid energy storage ofbattery and superconducting magnetic as research object, and the energy storage inmicro-grid as research purpose, to study the energy storage system and the controlstrategy of charge and discharge.Firstly, this paper summarizes the definition, structure, operation characteristicsand development of micro power grid, and elaborates the key technology o f micropower grid from the micro grid control, relay protection and its economy, andespecially introduces the control strategy of micro-grid. Then several main distributedgenerations, including photovoltaic cells, wind motor, and fuel cells, are researc hedon its working theory, system structure, the mathematical model, simulation analysisand so on. For photovoltaic cell, the simulation obtains the output characteristics ofphotovoltaic cells at the condition of different temperature and illumination in tensity,shows the MPPT model achieved by used the perturbation method, which can trackthe maximum power very well. For wind turbine, the fan model in MATLAB/simulinkis used to establish the wind power system simulation for simulation analysis. Aboutfuel cell, simulation analysis is used PEMFC as model to study the characteristics ofthe polarization and efficiency, and the dynamic response of the voltage and power. Further, this paper establishes the simulation model of battery andsuperconducting energy storage, researches its control strategy, analyzes threeformation the battery and superconducting magnetic in parallel, and establishes theequivalent model of hybrid energy storage. Finally, simulation analyzes themicro-grid that include different distributed generator and energy storage, researchesthe energy storage’s compensation effect on voltage sag when the micro grid happenthree-phase short-circuit fault. The energy storage can balance power of frequency inmicro grid when casting or cutting load from micro grid. Based on the idea of peakload shaving, the economic benefit evaluation is considered, and the effect of energystorage to the micro grid’s economic optimization operation is researched, to verifyeconomic optimization operation in the energy storage.