A new soft-switched DC-DC front-end converter for applications with wide-range input voltage from battery power sources

A technique which improves the performance of the two-inductor boost converter using a new active snubber circuit is described. The proposed snubber circuit consists of a small transformer, two diodes, and an auxiliary switch. This technique reduces reverse-recovery-related losses by controlling the di/dt rate of the rectifier current using a leakage inductance of the transformer. In addition, the energy stored in the leakage inductance is used to discharge the output capacitances of boost switches to zero voltage before they are turned on, thus eliminating their capacitive turn-on switching losses. Moreover, the reflected output voltage across the primary winding of the transformer resets the current in the leakage inductance and makes the auxiliary switch turn off using zero current switching. The performance of the proposed converter was evaluated on a 1.6-kW prototype circuit.