Grid-connected converters with voltage support using only local measurements

Abstract

This paper considers a single-phase grid-connected converter in the presence of non-linear loads. A local voltage support strategy is proposed to compensate the harmonics caused by the loads. This is an added feature implemented in parallel with a conventional current control method, and distinctively, it does not need measurements of the grid or load current. The converter output current consists of two components: a part at the fundamental frequency for power injection, and a part to compensate the harmonics introduced by the non-linear loads. As a result, the grid current harmonic distortion is minimized and the local voltage quality is enhanced. Simulation and experiments validate the effectiveness of the proposed voltage support strategy