A Compact Three-Port DC-DC Converter for Integrated PV-Battery System

In this paper, a new non-isolated three-port DC-DC converter (NITPC) to integrate a battery storage with a PV module is proposed. The intermittency of renewable energy and the unpredictable load demand are eliminated by firming a backup battery with the PV module to supply extra power when it is required. The proposed converter is reconfigurable and able to operate as a conventional boost converter, a buck-boost converter or a forward converter in different modes to support several power flow combinations and achieve power conditioning and regulation among the PV module, battery and an output port simultaneously. Nevertheless, the converter only consists of two switches, one coupled inductor, one diode and two capacitors. Thus, the system size and number of components are reduced compared with the traditional DC-DC converters. High output regulated voltage is achieved by using a coupled inductor and by combining the PV module and the battery in series. Simulation and experiment are carried out to verify the proposed circuit.