Optimized energy storage system design for a fuel cell vehicle using a novel phase shift and duty cycle control

This paper presented an optimized energy storage system (ESS) design for fuel cell (FC) vehicle system to interface battery unit (BU) and ultracapacitor (UC). A one-side asymmetrical phase shift and duty cycle control was developed for a current-fed three-port bidirectional DC/DC converter to achieve a wide range soft switching operation under varied input voltages. The proposed phase shift and duty cycle control is then integrated into the maximum fuel economy-oriented power management control strategy to optimize the ESS and system performance in a dynamic environment. The design was compared with other phase shift and duty cycle control in terms of system dynamic performance and power loss analysis. The simulation results from Real Time Digital Simulator (RTDS) and the experimental results from an emulated system test bed were provided to verify the optimized design.