A soft-switching four-port DC-DC converter for segmented PEM fuel cell power management in vehicle application

In transport application, long high power PEM fuel cell stacks could suffer from voltage discrepancy between cells due to severe constraints or appearance of localized faults in case of bad water management, moreover the output power of the stack is limited by the weakest group of cells. This article proposes a three-part segmented fuel cell associated with an isolated four-source DC/DC converter which makes possible a power sharing between the fuel cell segments according to their state-of-health. This topology allows an enhanced utilization of the stack as well as fault tolerance. ZVS operation is achieved to improve global converter efficiency.