Analysis and Mitigation of Inductor Oscillation and Bridge Midpoint Voltage Imbalance in a GaN-Based Boost-HERIC Topology PV Inverter

With the rapid development of distributed photovoltaic (PV) systems, the boost-HERIC inverter topology has gained increasing adoption due to its superior voltage regulation and current control capability. In recent years, wide-bandgap devices such as GaN HEMTs have been extensively applied in PV inverters owing to their high switching speed and low conduction loss, thereby enabling higher power density and improved efficiency. However, in boost-HERIC systems, the fast switching operations of GaN HEMTs also introduce new challenges, including inductor current oscillation and bridge midpoint voltage imbalance. This paper investigates the underlying mechanisms of these issues and proposes corresponding mitigation strategies. A simulation model is developed to verify the effectiveness of the proposed methods, thereby providing theoretical guidance for the optimization of GaN-based PV grid-connected systems.