Research on Leakage Current Suppression Mechanism and Control Strategy of Single-phase HERIC Inverter

With the development of photovoltaic energy storage inverter, the leakage current problem and control strategy become the research focus. HERIC (Highly Efficient and Reliable Inverter Concept) inverter is a topology that can effectively suppress leakage current. In this paper, SOGI-PLL (Second-order Generalized Integrator Phase-locked Loop) and repetitive control method are combined and innovatively applied to the grid-connected control of single-phase HERIC inverters. Under this topology and compound control strategy, the leakage current of the inverter is well suppressed, and the waveform of the grid-connected current is improved. The grid-connected simulation result and experimental prototype test waveforms are given to verify the feasibility and efficiency of the inverter system.