一种改进的光伏并网逆变器双闭环控制策略

An improved double closed loop control strategy for photovoltaic grid-connected inverter

文章提出了一种改进的光伏并网逆变器双闭环控制策略。外环为直流电压环,维持直流母线电压恒定,并始终跟随参考值;内环采用电感电流实时反馈与电网电压前馈补偿的复合控制方式,抑制电网电压波动对系统带来的扰动,实现光伏逆变器的并网功率控制。以两级式并网光伏发电系统为控制对象,验证所提出控制策略的正确性与有效性。实验结果表明,当外界光照条件发生变化时,系统具有良好的动态性能。

This paper presents an improved dual-loop control strategy for photovoltaic grid-connected inverter.The extenal loop realizes DC voltage control function.It is ensure that the DC bus voltage remains constant and always follows the reference value.In the inner loop,a compound control based on inductor current feed-back and grid voltage feed-forward compensation is adopted to suppress the disturbance caused by grid voltage fluctuation.This article takes two stages grid-connected photovoltaic system as control object to verify the correctness and effectiveness of the proposed control strategy.The control results show that the system has good dynamic performance when external light condition changes.