Reconfigurable Step-Up/Down Series-Pass Partial Power Processing Converter for Electric Vehicle Charging Stations

This article proposes a systematic methodology to analyse series-pass Partial Power Processing (PPP) schemes for Electric Vehicle (EV) battery charging applications. All feasible Step-Up and Step-Down PPP schemes are evaluated and analysed. Suitable performance metrics are derived to compare the various schemes from the perspective of wide voltage variation seen in battery charging applications. A systematic methodology to derive Step-Up/Down-type PPP converters that facilitate bidirectional power flow is elucidated. A phase-shifted full-bridge converter (PSFBC) topology is selected to implement the PPP charging converter. The PPP approach improves the overall system efficiency, reduces switch stresses, and reduces the size of the power converter. The design and modelling considerations for the PSFBC topology for EV battery charging are elucidated. The designed topology is validated using switching circuit simulations and experimental results. Experimental results are provided to demonstrate that a PSFBC that is rated to handle an active power of 1.5 kW can be used to transfer 3.6 kW of power to charge the battery while achieving a system efficiency of 97.5%.