A high performance ZVS full-bridge DC-DC 0-50 V/0-10 A power supply with phase-shift control

This paper presents a high performance DC-DC switching mode power supply designed to deliver a regulated 0-50 V/0-10 A output. The proposed power supply is based on a modified version of the zero voltage switching full-bridge phase-shift DC-DC converter, which incorporates commutation auxiliary inductors to provide zero voltage switching for the entire full load range, as well as a commutation aid circuit to clamp the output diode voltage. The control strategy is based on two control loops operating in cascade mode. The inner loop maintains the regulated output current, whereas the external voltage loop keeps the regulated output voltage, independently of load changes and input voltage variations. To obtain a high reliability converter, the control circuit has been implemented using just two ICs. The phase-shift regulator UC3875 IC generates the gate drive signal to the MOSFETs. The control loop regulators are implemented using the TL074 IC. Theoretical analysis and experimental results have been obtained for a 0-50 V/0-10 A power supply operating at 100 kHz.