Soft switching self-oscillating FET-based DC-DC converters

The authors introduce a family of topologies utilizing both zero voltage switching and self-oscillation. The Royer oscillator is modified to use MOSFETs as power switches. Thus insulated gate bipolar transistors (IGBTs) can also be used as power switches, enhancing the power capability for higher voltage and current ratings. A further advantage obtained by the use of FET-input switches, compared to the bipolar-transistor-based Royer and Jensen oscillators, is that stable operation can be obtained without the saturation of any core material. This enables very high efficiency of the power converter as well as a very high oscillation frequency. Typical applications of the family of topologies considered include DC-DC converters, high-frequency inverters, and high-frequency link converters. In high-power (>1 kW) applications, the use of IGBTs in the nonlinear resonant pole soft switching self-oscillating inverter will be advantageous to the efficiency, due to the reduced onstate voltage of a minority carrier device