Single Stage Transformerless Microinverter with Time Sharing Operation for PEM Fuel Cell Applications

In this paper, a single stage transformerless microinverter topology is proposed for proton exchange membrane (PEM) fuel cell applications. PEM Fuel Cell is characterizes with low voltage, large current which imposes limitation in microinverters designs. In order to maximize the boosting ratio and achieve high power conversion efficiency, the proposed circuit architecture eliminates the bulky electrolytic DC link capacitor employing a bypass diode and boost converter with integrated coupled inductor. The proposed topology facilitates the time-sharing operation where the inverter uses high switching PWM control only in small portion of the line frequency. Therefore, the proposed microinverter realizes high power conversion efficiency. The proposed transformerless microinverter is simulated and analyzed to validate the principle of operation.