Comparative study of a bidirectional multi-phase multiinput converter for electric vehicles

Multiinput converters allow to create hybrid energy systems in electric vehicles with a reduced part count. In addition, interleaved structures help to build efficient converters with several possible benefits, such as low current ripple and high power density. This paper proposes utilizing a multiphase multiinput converter (MPMIC), which concentrates the aforementioned advantages and presents a comprehensive comparison with its single-phase version, called singlephase multiinput converter (SPMIC). After analysing their steady-state characteristics, SPMIC and MPMIC are designed considering same conditions. Then, two laboratory prototypes rated at 2.5kW output power are implemented to validate the analysis. Finally, these prototypes are compared in terms of voltage-gain, input current ripple, efficiency, complexity, cost, and power density. The results show that MPMIC surpasses SPMIC in efficiency and in input current ripple at the expense of increments in the complexity and cost. Besides, MPMIC results in comparatively high voltage gain in low power region thanks to the discontinuous current mode operation. On the other hand, it is explored that SPMIC can reach higher power density in the event of effective cooling.