A Single-Stage Capacitor-Bridge Boost Converter Topology for PV-Battery Series Integration in Regulated DC Microgrids

Abstract

Integration of a solar photovoltaic (PV) generation and a battery energy storage (BES) is a suitable solution for sustainable energy production and management for the next energy grid model, such as DC microgrids. Although this PV-battery integration has been widely studied in DC microgrid applications, many integrations still use legacy power electronics converter topologies such as DC-DC boost converters. This paper proposes a novel DC-DC power electronics converter topology that allows seamless integration of a solar PV array and a BES and interfaces them to a regulated DC microgrid. In the proposed topology, a single power converter stage is designed with the PV-battery DC-series integration approach. To be interfaced with the regulated DC microgrid, the PV-battery DC-series network equips a capacitor-bridge. Operation modes and switching principles are described in detail, and the asymmetrical PWM switching strategy is proposed to satisfy the inductor volt-second balance under asymmetrical system operating conditions. The feasibility and effectiveness of the proposed topology have been verified through simulation and experimental results.