Design of high step-up conversion circuit for fuel cell power supply system

This paper presents a high step-up conversion circuitry for fuel cell power-generation system, which utilizes three-winding coupled inductors and rectified-voltage doubler circuit to get high step-up gain. In addition, the circuitry functions as an active-clamped circuit, which alleviates the voltage stress across the power switch and conduction loss on the power switch. When the power switch is turned off, energy stored in the leakage inductor is recycled to output terminal, which efficiently limits voltage spike across the power switch and increases the conversion efficiency. Finally, the prototype circuit controlled by an analog IC: UC3845 with 60~100-V input voltage, 380-V output, and 1000-W output power was implemented as a fuel cell powergeneration system to verify its performance.