单相LCL并网逆变器电流控制综述

Overview of Current Control Technique for Single-Phase Grid-Connected Inverter with LCL Filter

并网逆变器采用LCL滤波器方式的高频滤波效果优于单电感滤波器,但是由于电容支路的引入,将明显增加控制难度。就采用LCL滤波器的并网逆变器基本控制策略而言,可以大体分为三种:采用逆变器侧电感电流反馈的间接电流控制策略,采用电网侧电感电流反馈的直接电流控制策略,以及采用部分逆变器侧电感电流和部分电网侧电感电流反馈的混合控制策略。每一种控制策略可以采用不同的控制器来实现具体控制。文中以单相LCL并网逆变器为例,对当前文献报道的主要控制方案的性能进行了详细分析和比较。

A LCL filter＇s performance for attenuating high frequency harmonics of grid-connected inverter is better than that with single inductance filter. But the additional capacitor spur track makes the control of the inverter too complex. There are three basic control strategies for a grid-connected inverter with a LCL filter： the indirect current control with the inductor current tied to the inverter as feedback, the direct current control with the inductor current tied to the grid as feedback and the hybrid current control with partial inductor currents of both LCL filters as feedback. Several types of controller could be adopted for each strategy. The control for a single-phase grid-connected inverter is studied. The advantage and disadvantage of each method are analyzed and discussed in detail.