A Coupled Inductors Based High Gain Non-Isolated Three-Port DC-DC Converter

A novel high gain non-isolated three-port DC-DC converter (TPC) based on coupled inductors is proposed in this paper, which interfaces with one photovoltaic (PV) port, one bidirectional battery port and one load port. Coupled inductor technique is applied to obtain high voltage gain. The use of diode-capacitor technique also enables the converter to obtain an additional double voltage gain while reducing the voltage stress of the switches. The steady state of the converter is divided into three operation modes, and the output voltage analytical expressions under each mode is derived in this paper. The control strategy for the topology is also proposed to realize constant output voltage, battery protection, and maximum power point tracking (MPPT) at the same time. Simulation and experimental results verify the performance of the proposed converter and the feasibility of the control strategy.