A multi-output resonant gate-driver power supply for electric vehicle applications

Traction inverters for electric vehicle applications require galvanically isolated gate-driver power supplies with multiple outputs. These power supplies must offer low capacitive coupling, reduced complexity, as well as low material and manufacturing costs. A six-output resonant converter is proposed which consists of a single half bridge and six separated transformers with individual resonant capacitors to minimize the coupling capacitances. The converter is operated at a fixed switching frequency without pulse-frequency modulation or duty-cycle control. Thus, the need for controller and output-voltage feedback is eliminated which results in minimized component count, reduced complexity, and low manufacturing costs. The resonant tank is analyzed and designed for a load-independent output voltage at fixed-frequency operation which shows a good ruggedness against variations of the resonant-tank parameters. The concept is validated by measurements of a 45 W laboratory prototype for a HybridPACK™2 IGBT package.