A Modular Multiport Converter to Integrate Multiple Solar Photo-Voltaic (PV) Modules With a Battery Storage System and a DC Microgrid

A modular multiport converter (MMPC), which is capable of interfacing multiple solar Photo-Voltaic (PV) modules, a battery bank, and a dc microgrid, is proposed in this article. The number of solar PV modules that can be interfaced with the proposed MMPC is equal to the number of converter modules present in the system. Furthermore, all these solar PV modules can operate at their respective maximum power point, thus increasing the power extraction capability. A high-frequency transformer facilitates the interfacing of low-voltage solar PV modules and the battery bank with a 380-V microgrid. However, the power from the solar PV modules to the battery bank does not flow through this transformer. The variation in the transformer utilization with changes in operating voltages of the solar PV modules is analyzed. Detailed simulation studies are carried out on a system having five solar PV modules to verify the performance of the proposed MMPC. A laboratory prototype of the proposed MMPC consisting of four numbers of 400-W converter modules is fabricated. The performance of the MMPC is analyzed and the experimental results are presented.