三相光伏并网逆变器电流控制器研究与设计

电网对馈入其中的电流谐波含量有严格的要求.带有隔离变压器的并网逆变器运行时,逆变器输出电流中常含有谐波成分,必须对电流波形质量进行控制.分析了变压器影响逆变器输出电流波形质量的主要原因,建立了含变压器的三相并网逆变器输出电流数学模型,在此基础上提出了同步旋转坐标系下PI控制与重复控制相结合的三相光伏并网逆变器电流控制器设计方案并研制出一台实验样机.实验结果表明,采用该控制方案的逆变器输出电流谐波含量低,电流波形质量较好.

Research on the Current Controller of Three Phase Photovoltaic Grid-connected Inverter

The harmonic component of output current of grid-connected inverter,which will feed into grid,is limited by some criterions.This paper analyzes some factors that will affect the quality of inverter's output current and develops mathematics model of output current.A novel current control scheme,which is the combination of PI controller and repeti-tive controller,is presented.Finally,a laboratory prototype has been designed to verify the discussion and analysis.The ex-perimental results show that the proposed scheme can work well.Highly accurate steady output and less harmonic distur-bance is gained.