含有虚拟阻抗的微源逆变器微网小信号稳定性分析

Small-signal stability analysis of microgrid distributed generation converter with virtual impedance

微网渗透率升高使微网系统惯性减小,受到扰动之后微网易发生振荡失稳。文章引入虚拟阻抗,提出一种适用于低压微网的改进型下垂控制,减小线路阻抗的影响。在此基础上建立微网系统的小信号模型,通过计算系数矩阵特征根的形式判断系统的稳定性,并在Matlab/Simulink软件中搭建相应的模型,通过时域仿真图判断系统的稳定性。

With the development of the distributed generation, the system inertia decreases which may cause oscillation with small disturbance. The improved droop control is introduced in the paper with virtual impedance to decrease the impact of line impedance. Small signal module is established based on the mircogrid system. The characteristic roots of coefficient matrix are calculated to analyze the stability of the system. The simulation module is established in Matlab/Simulink. And the stability is also jugged by the time domain simulation diagrams.