Single-stage low-cost and energy-efficient isolated phase-shifted high-frequency inverter followed by a forced cycloconverter for universal residential fuel cell power system

We describe a single-stage low-cost and efficient fuel-cell (FC) power-electronics system (PES), which comprises a front end phase-shifted high-frequency (HF) full-bridge inverter followed by a step-up high-frequency transformer and a forced cycloconverter for universal residential FC power system (i.e., 110 V/240 V and 60/50 Hz). This single-stage dc/ac converter approach meets the higher energy efficiency requirement without exceeding the U.S. Department of Energy (DOE) cost constraint of $40/kW. The described topology achieves a direct power conversion and does not require any intermediate energy storage components. The FC PES increases the reliability by precluding the need for front-end dc/dc converter and also provides a low-cost viable alternative to high power density.