Interleaved ZVT Boost Converters with Winding-Coupled Inductors and Built-In LC Low Pass Output Filter Suitable for Distributed Fuel Cell Generation System

Abstract

An interleaved boost converter with winding-coupled inductors is proposed in this paper to extend the voltage gain and to reduce the voltage stress of the switch compared with the conventional interleaved boost converter for high step-up distributed fuel cell generation system. Only one set of active clamp circuit is necessary for the interleaved two phases to recycle the leakage energy and to absorb the voltage spikes caused by the leakage inductance. Both the main and the clamp switches are ZVT soft switching performances during the whole switching transition. The output diode turn-off current falling rate is controlled by the leakage inductance to alleviate the reverse-recovery problem. By some topology modifications and adding another two small capacitors, the voltage ringing on the output diode is clamped and a built-in LC low pass output filter is formed by the leakage inductance and the additional capacitors. So the output current ripple is cancelled. The experimental results based on a 40 V-to-380 V DC/DC prototype verify the effectiveness of the theoretical analysis.