A new fixed-frequency zero-voltage switching PWM DC-DC power converter using multi-stage inverter and reactor

The authors describe novel constant-frequency phase-shifted-mode PWM (pulse-width-modulated) DC-DC power converters that incorporate two-stage inverters with high-frequency transformer links and reactors (either saturable reactors or linear reactors). The proposed converters can perform efficient zero-voltage switching over a large load range and a wide voltage regulation range. The steady-state characteristics of the two types of converter, using either saturable or linear reactors, are compared. The steady-state characteristics are evaluated and discussed through computer-aided simulation and experimental results. The experiments were carried out with a 0.5 kW 500 kHz breadboard. It is shown that the converter using saturable reactors has more desirable characteristics