ZVS Boost Converter for Grid connected Fuel Cell Systems

A new zero voltage switching current fed zero-voltage switching isolated boost converter topology for fuel cell applications is presented. L-type half-bridge is more suitable to low voltage, high current applications such as front-end dc–dc converters for the fuel cell applications. It has larger switch voltage rating and also suffers from high voltage across the switches. Clamping methods are needed to reduce the voltage spikes but they require additional components and losses. In this paper, an improved current-fed zero-voltage switching (ZVS) isolated boost converter is proposed for fuel cell applications. The voltage ratings of the primary switches and secondary diodes of the proposed converter are significantly reduced. It does not require any clamping circuits like conventional current fed converters. These advantages make the new converter promising for fuel cell applications. A simulation is carried out using MATLAB/Simulink to verify the proposed DC-DC converter. Keywords-Zero Voltage switching (ZVS), current fed , isolated boost converter , fuel cell.