含分布式新能源和机电混合储能接入的微网协调控制策略

Microgrid-coordinated control strategy with distributed new energy and electro-mechanical hybrid energy storage

含分布式光伏等新能源接入的微网作为大电网的补充目前应用日趋广泛,但是随着新能源在微网系统中的占比比例不断增加,其出力的波动直接影响到微电网系统整体的稳定性。飞轮储能属于功率型储能系统,能够适应短时高频次充放电,相比于超级电容系统其环境适应性更好且全寿命周期内无污染。飞轮与电池储能系统相结合能够平滑分布式新能源出力波动,提升微网系统稳定性,但是飞轮储能和电池储能运行特性差别较大,控制难度较高,目前在微网系统内应用较少。本文设计了一种含分布式光伏、电池/飞轮机电混合储能系统接入的交直流混合微网运行拓扑,并在此基础上提出了基于电池/飞轮机电混合储能系统的微网系统协调控制策略,根据飞轮和电池剩余容量的不同,将混合储能系统划分为不同状态,以此为依据同时考虑不同类型储能系统输出额定功率和分布式新能源功率波动大小,对飞轮和电池的充放电电流进行调节,从而减小由于新能源接入引起的微网内功率波动。本文基于MATLAB/Simulink环境搭建了基于交直流混合母线的微网系统,仿真结果验证了所提微网协调控制策略的有效性。

Microgrid systems with distributed photovoltaic and other new energy sources are becoming widely used to supplement large power grids.However,with the increasing proportion of new energy in microgrid systems,the fluctuation in their output directly affects the overall stability of the microgrid systems.Flywheel is a powerful energy storage system that can adapt to short-term high-frequency charging and discharging and has better environmental adaptability and lesser pollution throughout the life cycle than the supercapacitor system.The combination of the flywheel and battery energy storage systems can smooth the fluctuations in the distributed new energy output and improve the stability of the microgrid system.However,the operating characteristics of flywheel and battery energy storage are quite different,and the control is difficult;thus,it is currently less used in microgrid systems.Herein,an AC and DC hybrid microgrid operation topology with distributed photovoltaic and battery-flywheel electromechanical hybrid energy storage system access is designed.Based on this,a coordinated control strategy of a microgrid system based on battery-flywheel electromechanical hybrid energy storage system is proposed.The control strategy divides the hybrid energy storage system into different states according to the remaining capacity of the flywheel and battery.It takes the output-rated power of different energy storage systems and the fluctuations in distributed new energy power simultaneously and adjusts the charging and discharging currents of the flywheel and battery to reduce the power fluctuations in the microgrid caused by new energy access.Herein,a microgrid system is built based on MATLAB/Simulink,and the simulation results verify the effectiveness of the proposed microgrid-coordinated control strategy.