基于改进虚拟同步发电机控制技术的低压微电网功率分配策略

低压微电网中，采用虚拟同步发电机（virtual synchronous generator，VSG）策略控制多台逆变器并联运行时，由于线路阻抗差异较大，无法实现输出功率的按容量精确分配。针对这一问题，文章提出一种改进的VSG控制技术，在无功电压控制环中引入公共点电压反馈和积分环节，消除线路阻抗对无功分配的影响；并在虚拟阻抗环引入无功功率反馈，根据系统运行情况实时调整虚拟阻抗的阻值。在Matlab/Simulink环境下搭建了仿真模型，仿真结果表明，所提改进控制策略实现了有功和无功功率的精确分配，降低了逆变器输出电压幅值跌落，并且具有较强的鲁棒性。

Microgrid Power Distribution Strategy Based on Improved Control Strategy of Virtual Synchronous Generator

In a low-voltage microgrid， the virtual synchronous generator （VSG） strategy is adopted to control the parallel operation of multiple inverters. Due to the difference in line impedance， the accurate allocation of output power according to capacity cannot be realized. In view of this problem， this paper proposes an improved VSG control strategy， in which feedback and integration of voltage of common coupling point are introduced into the reactive voltage control loop to eliminate the influence of line impedance on reactive power distribution. The reactive power feedback is introduced into the virtual impedance loop to adjust the resistance value of the virtual impedance in real time according to the operation of the system. The simulation which results in Matlab/Simulink show that， the improved control strategy can realize the accurate distribution of active and reactive power， also can reduce the amplitude drop of inverter output voltage， and has strong robustness.