为了抑制孤岛模式下光伏微电网逆变器之间由于输电线路阻抗差异所引起的环流问题,文章提出了一种用于多逆变器并联系统的改进的虚拟同步发电机(VirtualSynchronousGenerator,VSG)控制策略。首先,基于传统的VSG控制框图,通过引入线路功率反馈环节,使每台逆变器分别抵消其输电线路上的功率损耗,以提高有功、无功功率均分精度,并降低输出电压跌落,改善电能质量;然后,通过引入同步控制器,减小逆变器并联瞬间的电流冲击,降低多逆变器并联系统之间的瞬时环流;最后,通过仿真与实验验证了所提控制策略的有效性。

An improved virtual synchronous generator ( VSG ) control strategy for multi-inverterparallel system is proposed in this paper to suppress the circulating current caused by the impedancedifference of transmission lines between PV microgrid inverters in islanded mode. Firstly, based on thetraditional VSG control block diagram, each inverter counteracts the power loss on the transmissionline by introducing the line power feedback, so as to improve the active and reactive power sharingaccuracy, reduce the output voltage drop, and improve power quality. Then, the synchronouscontroller is introduced to reduce the instantaneous current and suppress the instantaneous circulatingcurrent between the multi-inverter parallel system. Finally, the effectiveness of the proposed controlstrategy is verified by simulation and experiment.