This is a prototype of power converters for high-temperature applications such as automobile and aircraft engines.

A DC-to-DC power converter, nominally rated for a power of 180 W, an input potential of 28 V, an output potential of 270 V, and a maximum operating temperature of 200°C has been designed, built, and tested. This power converter serves as a prototype for further development of power converters required to be capable of operating in high-temperature environments in diverse settings, including automobile, aircraft, and spacecraft engines, and oil and gas wells.

The Power Stage of the DC-to-DC power converter contains high-temperature-rated components. The circuit topology is chosen in conjunction with the switching cycle so that transformer leakage inductance energy is fed back to the input capacitor and the maximum voltage stress on S1, S2, RD1, and RD2 is limited to the input voltage.

During each switching cycle, the power converter proceeds through three successive modes of operation:

• An energy-transfer mode in which S₁ and S₂ are on and D₁ conducts;
• A transformer-reset mode in which (1) RD₁ and RD₂ conduct, applying reverse input potential to the primary winding of the transformer and (2) the output inductor current freewheels through D₂; and
• A dead-time mode in which S₁ and S₂ are off and RD₁ and RD₂ are not conducting while the output inductor current is freewheeling through D₂.