A DirectFET based high-frequency fuel-cell inverter

In this paper, the design guideline for a high-power-density inverter for fuel-cell applications is presented. Such an inverter can lead to savings in volume and weight due to high-frequency operation. Also, we present a guideline to determine the optimal size of the input filter. It is also illustrated that, for such a topology, an optimal choice of transformer leakage inductance is necessary to achieve low power loss and to establish a balance between efficiency and reliability. Transient load condition, which may degrade fuel-cell-stack reliability, is handled through a battery-sourced energy-buffering unit. Experimental results demonstrating the nominal operations of inverter and energy buffering unit are presented.