基于电感电流控制的单相Z源逆变器并网实现

Implementation of single-phase Z-source inverter grid-connected system based on inductor current control

常用的Z源逆变器电容电压控制中存在右半平面零点,致使系统阶跃响应出现负调,控制器的设计过程复杂化。针对上述问题,提出一种新的控制策略,通过控制Z源电感电流实现Z网络稳压输出。以单相Z源逆变并网系统为例,首先利用状态空间平均法建立小信号模型,分析得知控制至电感电流的传递函数中不含右半平面零点,因此电流控制器的设计相对简单。然后详细介绍了Z源电感电流控制器和并网电流控制器的设计,并通过Matlab/simulink仿真和RT-LAB实验验证了所提控制策略的有效性,具有一定的实用价值。

Capacitor voltage control of Z source inverter has an RHP zero, which results in the negative regulation of system step responses and makes the corresponding controller design complicated. In view of this problem, we propose a new control strategy by controlling the inductor current to steady the output of Z source inverter. Taking single-phase Z source inverter grid-connected system as an example, we establish a small signal model using state-space average method, analyze the transfer function from control to the inductor current and know that it does not contain RHP zero, thus the current controller design is simple. Then we detail the design of Z source inductor current controllers and grid-connected current controllers. Finally the validity of the controller is proved by the Matlab/simulink and RT-LAB experimental results. It shows a certain practical value.