逆变型微网下垂控制器参数选择和稳定性分析

摘要

Eigen-analysis is widely used in dynamic stability analysis of power system.And droop control method is used to stabilize the voltage and frequency under islanding modes of microgrid.The selection of droop gain of droop controller will have great influence on system stability.This paper analyzes the stability of the state matrix containing uncertain parameters of the linear system, and establishes the small-signal model of microgrid under droop control mode.With the proposed method, the small-signal stability of micro-grid is analyzed.In such context, the dropping gain range is given when the system is asymptotically stable.Finally, the relationship between system stability and droop gain is analyzed through modal participating factor method.The numerical example demonstrates the validity of the method.%微网的动态稳定分析广泛采用特征分析法.微网孤岛运行时,多使用下垂控制方法来稳定其电压和频率.下垂控制器中下垂增益的选取会对微网系统的稳定性产生重要的影响.本文研究了状态矩阵中含有不确定参数的线性系统的稳定性分析方法,建立了微网采用下垂控制的小信号模型.利用提出的方法,分析了微网的小信号稳定性,并给出了系统为渐进稳定时下垂控制器下垂增益的范围.最后,通过模态相关因子的方法分析了系统稳定性与下垂增益的关系.算例结果验证了该方法的正确性.