Output current control for grid-connected VSI with LCL filter

Abstract

This paper presents an output current control method for grid-connected voltage-source inverter (VSI) with LCL output filter. LCL filter has been shown to provide a high attenuation to high-frequency harmonics with small physical size than other types of filters, like L and LC filters. However, filter oscillation is the major concern in this type of filter. Different passive and active damping methods have been proposed to tackle this issue, but they have their respective limitations, like slow dynamic response, power dissipation, etc. The control method proposed in this paper utilizes the natural oscillation, but without sustained oscillations, to achieve fast dynamic response.