针对微电网孤岛运行时配有储能装置的分布式电源,提出了一种虚拟惯性频率控制策略,使微电网电源具有下垂特性的同时,还具有类似于同步发电机转子的惯性。在扰动发生时,该策略能够支撑微电网的频率,从而提高微电网频率的稳定性。以一个2机系统为例,分析了在微电网中采用这种控制策略时可能引起的功率振荡问题,通过优化主电路和控制器参数抑制了这种振荡。PSCAD/EMTDC的仿真结果验证了该控制策略的有效性。
Given that the distributed generations(DGs) are normally equipped with energy storage devices when a microgrid is in isolated island operation state,a frequency control strategy based on virtual inertia method is developed.This method enables the DGs not only to maintain the droop characteristics,but also to have proper inertia as synchronous generator rotors have.This strategy can support the frequency of a microgrid and thus improve its frequency stability.The problem of power oscillations between DGs when applying this control strategy in microgrid is analyzed through a two-DG system.The oscillations are restrained by optimizing the main circuit and controller parameters.Simulation results from PSCAD/EMTDC verify the effectiveness of this control strategy.