An Interleaved Winding-Coupled Boost Converter With Passive Lossless Clamp Circuits

An interleaved winding-coupled boost converter is proposed in order to realize ZCS turn-on condition and to achieve high step-up gain. The voltage gain is extended easily and the voltage stress on the switches is reduced with different turns ratios of the coupled inductors. The output diode reverse-recovery problem is alleviated due to the inherent leakage inductor of the winding-coupled inductors. The simple but effective passive lossless clamp circuits are introduced to limit the voltage stress on the switches when they turn off so that the low-voltage, high-performance devices with low conduction resistor can be used in the proposed converter to reduce the relative losses. The leakage energy is ultimately recovered to the load. The high efficiency of 90.7% at full load and the maximum efficiency of 92.6% are achieved in a 1-kW 40-V-input-to-380-V-output prototype for front-end application. There is more than 10% efficiency improvement with the passive lossless clamp circuits compared to the case with RCD dissipated snubbers. The efficiency of 5% improvement at full load is achieved with the proposed converter with passive lossless circuits compared to the conventional interleaved boost converter.