High step-up soft switching interleaved boost converters with cross-winding-coupled inductors and reduced auxiliary switch number

An interleaved boost converter is proposed to extend the voltage gain and to reduce the switch voltage stress compared with the conventional interleaved boost converter in high step-up applications. With the topology variation, 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 of the winding-coupled inductors. Both the main switches and the clamp switch of the proposed converter are ZVT soft switching performances during the whole switching transition, which minimises the switching losses. The output diode turn-off current falling rate is controlled by the leakage inductance, which alleviates the output diode reverse-recovery problem and reduces the relative reverse-recovery losses. The experimental results based on a 40-380-V DC/DC prototype verify the effectiveness of the theoretical analysis.