三相四线制并网系统零序电流控制策略分析

Analysis of zero-sequence current control in three-phase four-wire grid-connected system

在三相并网系统数学模型的基础上,对正序和负序旋转坐标系下的电流环控制过程进行分析,给出了三相静止坐标系下的该模型的等效形式,提出一种零序电流的控制策略,其控制参数与正序、负序电流控制器可以共用,简化了参数的设计过程.并对该控制器进行稳定性分析,证明控制策略的可行性,最后利用仿真和实验证明了该零序电流控制策略的有效性.

Based on the three-phase grid-connected system mathematical model ,the control method of current circle under positive and negative sequence rotating coordinate systems was analyzed and the equivalent form of this system under three-phase static coordinate system was proposed .A control strategy of zero-sequence current was put forward out of the analysis and equivalent form above .The parameters of this controller are the same as the positive and negative sequence current controllers ’ which simplifies the parameter design .In addition ,the stability of this controller was analyzed and this zero-sequence current control strategy had been proved by simulations and experiments .