Sensorless temperature compensation for power switching devices

Abstract

An inverter for an electric vehicle drive has a bridge including a plurality of power switching devices having respective insulated gate terminals and emitter terminals. A PWM circuit determines switching commands for controlling the bridge. A plurality of gate drivers receive the switching commands and provide gate drive signals to respective gate terminals. A plurality of gate capacitors are each thermally coupled to a respective switching device and are electrically connected between the respective gate and emitter terminals. Each gate capacitor has a negative temperature coefficient adapted to counter changes in a switching speed of the switching devices over a predetermined range of temperature. As a result, a consistent switching speed is maintained so that power loss and switching device reliability are optimal across the full temperature range.

Dependencies are inferred from the claim text.