A Smart Three-Port Converter for Interconnecting Grid, EV, and Solar-PV for Enhancing System Performance

Multiport converters have gained immense importance due to their compact size and cost-effectiveness, particularly when interfacing multiple sources/loads in a single converter. A smart multiport converter for the interconnecting grid, solar-PV, and electric vehicle (EV) is presented in this paper. This single converter is partially isolated, bidirectional and can operate along with smart modes of control, depending upon the user's requirement. Considering EV and rectified AC grid as source/sink and solar-PV as the source, there are seven valid operating modes possible with this converter. To achieve two control freedoms, pulse width modulation at the primary side & phase shift control strategies at the secondary side are used. The reduction in current and voltage ripples at the PV port is obtained. Furthermore, zero voltage switching (ZVS) is also realized for some modes. This paper presents reverse power operation modes (i.e. when the grid is fed), the controller design and validation using PSIM. A 500-W prototype is built for experimental verification, where Mode 3 (solar to EV and grid) is implemented in an open loop and EV to Grid(V2G) mode is implemented in a closed loop.