基于复合电流调节的单相LCL并网逆变器控制方法

摘要

In order to suppress the resonance of the grid connected inverter LCL filter and to reduce the fundamental current tracking error together with the grid side current distortions of dual-mode converters caused by adopting the large output filter capacitor,a new weighted average current control strategy is proposed for single-phase microgrid converters.Firstly,a PIR controller is developed in a virtual two-axis synchronous rotating reference frame in order to improve the current control accuracy and dynamic response.Secondly,an improved current feed-forward control method is proposed considering that traditional method doesn't control the grid current and the error between grid current and weighted average current directly.By detecting the low frequency error of the output current and the grid side current,a current feed forward is constructed,which can effectively restrain the error of the network side current control.Simulation and experimental results are given to show the effectiveness of the proposed approach.%为了抑制并网逆变器LCL滤波器的谐振,减小双模式变流器因采用较大的输山滤波电容造成的基波电流跟踪误差和网侧电流畸变,提出了一种新型的加权电流控制方法用于单相微电网变流器的控制.首先,在虚拟坐标系下用比例积分谐振控制器提高加权电流的控制精度和动态响应.其次,考虑到传统的加权平均电流的控制不直接控制电网电流以及电网电流和加权平均电流之间的误差,提出了一种改进的电流前馈方法.该方法通过检测输出电流和网侧电流的低频误差构造出一个电流前馈项,从而有效地抑制了网侧电流控制的误差.仿真和实验验证了该控制方法的有效性.