Comparison of Harmonics Mitigation Techniques for Grid-Connected PV System and Introduction of a Concept of Hybrid Filter

Nowadays, integrating photovoltaic (PV) generation into the conventional grid system has become a significant concern. As a consequence, the analysis of the impact of the PV system on the existing grid and the application of preventive methods to maintain the power quality of the system has joined paramount importance. In this paper, the authors have proposed a grid-connected PV ETAP Simulation Model to analyze the harmonics’ effect on the system in the presence of nonlinear loads. After analyzing, it is observed that different odd-order harmonics are generated in the system which can have a negative impact on the system. To take care of these odd-order harmonics the authors compare two basic mitigation techniques; one being the Single Tune Passive Filter (STPF) mitigation which is not applicable for multiple harmonics order reduction with system power loss and the other being the Phase sifting transform mitigation. As compared to the passive filter method, the phase-shifting transformer bears the advantage of minimal power loss and voltage fluctuations. However, the phase-shifting transformer method is effective for multiple harmonic order reduction but not applicable for higher odd harmonics. To overcome this problem authors introduced a hybrid concept of mitigation which reduces power loss by up to 52% and mitigates harmonics up to 85–90%.