Low-pass filter design of a current-source 1-ph grid-connected PV inverter

This paper addresses one of the critical sections of the current-source inverter, the output filter. Firstly, the background of low-pass output line filters for voltage-source inverters (VSI) and current-source inverters (CSI) are provided. Important factors such as filter resonance and damping are explained. Then four different damped CL filter circuits are discussed and the performance of the filter with a grid-connected CSI inverter is analysed. The filter normalisations for the design process are also provided. Finally, the selection of the filter parameters is examined.