A Novel Three-Port High-Gain DC–DC Converter for PV–Battery Stand-Alone System With Reduced Device Count

Abstract

Three-port converters are commonly used in solar photovoltaic (PV)-based applications catering stand-alone loads with energy storage. This article introduces a new partially isolated PV-battery-based three-port dc–dc converter (PBTPC) for the aforesaid application. The proposed converter has two input ports and one output port, which is isolated from the input ports using a high-frequency transformer. The two input ports are used to interface PV and battery, and the output port is regulated at 400 V. Compared with the existing solutions reported in the literature, the proposed converter has the advantages of reduced semiconductor device count, higher voltage gain, and better component sharing. The two inductors used in PBTPC are arranged such that both PV and battery ports are current-fed ports. Moreover, PBTPC eliminates the need for multiple high-frequency transformers and the requirement for additional converters for PV control. The operation of PBTPC under different modes is analyzed in detail, and the outcome is presented with equivalent circuit diagrams and waveforms. A 400 W prototype is built, and the performance of PBTPC is authenticated experimentally under load and insolation changes.