An Isolated High Step‐Up Interleaved DC‐DC Converter With Coupled Inductors and Active Clamp for Fuel Cell Power Conversion System

ABSTRACT In this paper, a high conversion gain, isolated high step‐up interleaved converter for fuel cell systems is presented. By employing the interleaved technique, a pair of coupled inductors is used to store energy and reduce input current ripple. Reducing current ripple can effectively prolong fuel cell life. The series connection of coupled inductors and transformer enables a higher voltage conversion ratio and achieves galvanic isolation. In addition, the energy from leakage inductance is recycled into the active clamp capacitor, reducing voltage spikes on the main switches. On the secondary side, a voltage‐doubler circuit is employed to achieve a higher voltage gain. The proposed topology features low‐current ripple, high conversion efficiency, high‐power level, and wide input voltage. Finally, the prototype circuit with a fuel cell stacks voltage of 40–80 V, an output voltage of 800 V, and a rated power of 1.5 kW is implemented for fuel cells, thus validating the feasibility of the proposed topology. The experimental results show that the maximum efficiency is 97.76%, and the full‐load 1.5 kW efficiency is 97.51%.