Harmonic rejection using Multi-Synchronous Reference Frame technique for CSI-based distributed generation with grid voltage distortion

In the midst of the growing penetration of renewable energy resources and Distributed Generation (DG), power quality is one of the main concerns. Achieving low total harmonic distortion (THD) of exported current using low switching frequency inverters is a challenge, especially under conditions of severe utility voltage distortion. Previous work depended on the wide bandwidth of passive filters accompanying high switching frequency inverters, which enables controlling fast tracking of pure sinusoid reference current. This paper presents a control structure for current source inverter-based distributed generation based on Multi-Synchronous Reference Frame, to reject the effect of utility distortion and attain high quality output current. This solution is applicable for low switching frequency inverters, with limited passive filter bandwidth. Experimental results validate the proposed technique.