ZVT interleaved boost converter with intrinsic voltage-doubler characteristic

This paper introduces a novel interleaved boost converter. By applying winding coupled inductors and switched capacitors in the output stage, the voltage gain of this topology is significantly increased and the voltage stress of the switch is greatly reduced so that the low conduction resistance and low voltage rated switches can be applied. Because of part of the output energy storing in the switched capacitors, the size of magnetic components can be reduced. The load current can be auto-shared by each phase of the converter as a result of charge-balance of the switched capacitor. Only one active clamp circuit is needed for the interleaved two phases to recycle the leakage energy and absorb the voltage spikes caused by the leakage inductance, which reduces the circuit complexity. Both the main and the auxiliary switches are ZVT performances during the whole switching transition which reduce the switching losses. The diode reverse-recovery problem is alleviated due to the current falling rate of the clamping and output diode is controlled by the leakage inductance. The experimental results based on a 1 kW 48 V to 380 V DC/DC prototype verify the significant improvements in efficiency.