光储柴独立微电网中的虚拟同步发电机控制策略

针对由可再生能源发电系统、常规柴油发电机组(DGS)和蓄电池储能系统组成的独立微网,提出一种适合微网在孤岛模式下稳定运行的虚拟同步发电机(VSG)控制策略。首先,建立DGS在同步旋转坐标系下的数学模型,并分析其输出电压和转速的阶跃响应特性;其次,在充分考虑DGS和VSG不同控制特性的基础上,提出一种适应独立微网分层协调控制的改进型VSG策略;然后,在基本VSG控制器中增加虚拟阻抗环节,灵活实现对微网谐波的抑制;最后,建立一套包含2台100 k V·A VSG及1台440 k W DGS并联的独立微网实验平台,实验结果验证了所述控制策略的正确性与有效性。

A Control Strategy for Islanded Photovoltaic-Battery-Diesel Microgrid Based on Virtual Synchronous Generator

This paper investigates a control strategy for islanded microgrid,including renewable energy,diesel generator set (DGS) and battery energy storage system based on virtual synchronous generator (VSG).Firstly,the DGS equivalent mathematical model is built to illustrate the step response characteristics of the DGS output voltage and rotating speed in a synchronous rotating reference frame.Besides,an improved VSG strategy adapted to the hierarchical coordinated control of islanded microgrid,which takes into full consideration the control characteristics of both the DGS and the VSG,is proposed.Furthermore,a virtual impedance control loop is added to the basic VSG controller to compensate for the system distorted voltage flexibly.Finally,the proposed strategy is demonstrated in detail and validated with a islanded mircogrid consisting of two 100 kV·A VSGs and a 440 kW DGS under various conditions.