Mitigation of Circulating Current in Three Phase Quasi-Z-Source Parallel Inverters With PV and Battery Storage

This article presents an insightful analysis on parallel operation of three-phase quasi-Z-source inverters with photovoltaic (PV) and battery storage on input side. Coordinated operation of PV and battery during charging and discharging mode through self-tuned mechanism is also explained. The analysis also includes PV-battery source dynamics, which establishes an interlink between common-mode voltage (CMV), filter ground, and the load neutral currents. This has been utilized to propose a new controller, which reduces the circulating current in quasi-Z-source parallel inverters fed with PV-battery. The performance of proposed controller is verified through experimental validation under equal and unequal load-sharing conditions. Results establish the correctness of analysis and effectiveness of the proposed controller.