A multiple input dc-dc converter for interfacing of battery/ultracapacitor in EVs/HEVs/FCVs

Electrification of vehicles is seen to be a promising technology for transportation system. In vehicle electrification, hybridization of energy systems plays a crucial role for its sustainable development. Therefore, suitable integration of different energy sources and their better utilization demand appropriate interfacing circuitry. In this paper, a non-isolated bidirectional multiple input dc-dc converter is presented to interface a battery and an ultracapacitor for vehicular applications. The proposed converter is capable of drawing power from multiple energy sources to supply the demand of vehicle loads. The presented converter has bidirectional capability and operates in buck, boost or buck-boost modes of operation. It offers simplicity in structure, flexibility in control scheme and reliability in operation. A fixed frequency PWM switching strategy has been demonstrated. The proposed converter along with inverter-motor drive is analyzed through detailed device level simulation in open loop modes.