No abstract

No abstract

No abstract

This paper presents a high efficiency 5-kW bidirectional DC-DC converter for use in electric vehicle super-capacitor systems. Super-junction MOSFETs are deployed in the power stage to minimize losses. This is achieved using a snubber inductor and by arranging the gate signal underlap delays in order to control charging current caused by the devices' highly non-linear output capacitance and to deactivate the intrinsic body drain diode respectively. The result is a 5-kW power converter with an estimated efficiency exceeding 99% in the power semiconductor stage and requiring no forced cooling. I.

Parasitic inductance in the gate path of a Silicon Carbide MOSFET places an upper limit upon the switching speeds achievable from these devices, resulting in unnecessarily high switching losses due to the introduction of damping resistance into the gate path. A method to reduce switching losses is proposed, using a resonant gate driver to absorb parasitic inductance in the gate path, enabling the gate resistor to be removed. The gate voltage is maintained at the desired level using a feedback loop. Experimental results for a 1200 V Silicon Carbide MOSFET gate driver are presented, demonstrating switching loss of 230 μJ at 800 V, 10 A. This represents a 20% reduction in switching losses in comparison to conventional gate drive methods