A Soft-Switched, Multiport Photovoltaic Power Optimizer With Integrated Storage Interface and Output Voltage Regulation

Abstract

This article proposed a multiport converter (MPC) configuration for a photovoltaic (PV) battery system. In the proposed design, the battery charging and discharging circuits are integrated with the PV power optimizer through high-frequency ac link. The proposed converter system is capable of regulating the output voltage, following battery charging profile and tracking the maximum power point (MPP) of each PV module. Variable switching frequency is used to achieve maximum power point tracking in this design. All the switches of the converter are able to achieve soft-switching turn-on and turn-off at different operating conditions. The operating principles and the control strategy of the proposed converter are presented. Simulation results and experimental results on a 175-W system are presented to validate the features of the proposed converter.