Analysis, Control, and Design of a Hybrid Grid-Connected Inverter for Renewable Energy Generation With Power Quality Conditioning

This paper proposes a new type dc/ac inverter named: hybrid-coupling grid-connected inverter (HGCI) for photovoltaic active power generation with power quality conditioning, which consists of a full-bridge three-phase dc/ac inverter coupling to the power grid in series with a thyristor-controlled LC filter. Compared with the conventional inductive-coupling grid-connected inverter (IGCI) and capacitive-coupling grid-connected inverter (CGCI), the proposed HGCI has distinct characteristics of wide operational range and low dc-link operating voltage. Based on these prominent characteristics, the system cost and operational cost can be reduced. Moreover, it can transfer the active power and compensate reactive power, unbalanced power, and harmonic power simultaneously. In this paper, the analysis of the structure, parameter design, and control method of the HGCI is proposed and presented. Finally, simulation and experimental results are provided to verify the effectiveness and performance of the proposed HGCI in comparison with the IGCI and CGCI.