不平衡电网电压下三相并网逆变器的控制策略分析

Control Strategy Analysis of Three-Phase Grid Connected Inverter Under Unbalanced Grid Voltage

本文使用仿真分析法,研究一种针对不平衡电网的光伏发电场三相并网逆变器的控制策略。通过对不平衡电网电压跌落过程进行建模并对模型进行量化分析,对仿真模型做出基础设计,并在仿真模型上对该策略进行验证。通过仿真,本文发现,通过引入陷波器及将多控制目标有效综合,在牺牲部分直流母线电压稳定性和输出功率稳定性的基础上,实现对输出电流波形畸变率的有效控制。该策略对提升逆变器工作效率,增加系统的综合稳定性和设备安全性,有积极意义。

In this paper,the simulation analysis method is used to study a control strategy of threephase grid connected inverter for unbalanced grid.Through the modeling and quantitative analysis of the unbalanced power grid voltage drop process,the basic design of the simulation model is made,and the strategy is verified on the simulation model.Through simulation,it is found that the effective control of the distortion rate of the output current waveform can be realized by introducing a notch filter and effectively synthesizing multiple control objectives,at the expense of the voltage stability and output power stability of some DC buses.This strategy has positive significance for improving the working efficiency of inverter,increasing the comprehensive stability of the system and the safety of the equipment.