Interleaved boost converters with built-in voltage-doubler and current auto-balance characteristic

An interleaved boost converter with coupled inductors and switched capacitors is proposed in this paper. The switched capacitors are used to realize the inherent voltage-double function which increases the voltage gain and reduces the voltage stress of the switch greatly so that the low conduction resistance and low voltage rated switches can be applied. Moreover, according to capacitor charge balance, the load current can be auto-shared by each phase as a consequence of the switched capacitors adopted in the output stage. Active clamp circuits are applied for the interleaved two phases to recycle the leakage energy and absorb the voltage spikes caused by the leakage inductance. Both the main and the clamping switches are ZVT performances which reduce the switching losses during the whole switching transition. The current falling rate of the clamping and output diodes is controlled by the leakage inductance so that the diode reverse-recovery problem is alleviated. The experimental results based on a 48 V-to-380 V DC/DC prototype verify the effectiveness of the theoretical analysis.