Harmonic mitigation through advanced control methods for grid-connected renewable energy sources

Abstract

With increasing renewable distributed generation (DG) units connected to utility power grids, deterioration of power quality at the point of common coupling (PCC) becomes a major concern. Power electronic devices in DG units generate harmonics, these harmonics along with harmonics from other nonlinear load in the system might cause excessive harmonic distortion at the PCC. In this paper, an extensive literature review is conducted focusing on harmonic mitigation techniques through advanced control methods for grid-interfacing inverter. Harmonics generated by solar photovoltaic (PV) system are firstly reviewed, potential resonance due to LCL filter is discussed. Then various control methods for harmonics mitigation are reviewed and summarized. This systematic review can facilitate better understanding of harmonics and develop more advanced control schemes to mitigate harmonics in renewable energy system.