ZVT 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 that increases the voltage gain and reduces the voltage stress of the switch greatly. Therefore, the low-conduction resistance and low-voltage-rated switches can be applied to improve the efficiency of this topology. Moreover, the load current can automatically be equally 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 zero-voltage transition (ZVT) switches during the whole switching transition that reduce the switching losses. The current falling rates of the clamping diodes and output diodes are controlled by the leakage inductance so that the diode reverse-recovery problem is alleviated. The experimental results are shown to verify the effectiveness of the theoretical analysis based on a 48- to- 380-V dc/dc prototype.