Investigation of grid voltage sampling distortion effects on feedforward control in LCL grid-connected inverters

This paper proposed an inner current loop control method for a grid-connected inverter with a LCL filter, which used the inverter side current as feedback parameter. Due to the sensitivity of grid current to grid voltage distortion, the grid voltage feedforward schemes were utilized to solve this problem. Nevertheless, the sampling distortion of grid voltage will bring about the distortion of grid current. The distortions in the three-phase grid currents caused by the zero-sequence components in the grid voltage feedforward control were analyzed. Furthermore, two different approaches converting line voltages to phase voltages were investigated. In the end simulation and experiment results verify that the analysis is valid.