CONTROL SIGNAL-BASED REDUCTION OF GATE SWITCHING INSTABILITY FOR SEMICONDUCTOR POWER SWITCHES

Abstract

An electrical circuit (21) can be used as part of an electrical control system comprising a direct current (DC) power supply (18), an intermediate circuit capacitor (17), and an inverter circuit (11) for powering an electric machine (12). The electrical circuit (21) includes a driver circuit (15) connected to a gate terminal of a power switch (20), e.g., a silicon carbide power metal oxide semiconductor field-effect transistor (SiC power MOSFET). The power switch (20) has a gate-source voltage that responds to a drive voltage (VDR) and a degradation interval during which the gate-source voltage rises from a relatively low voltage level below a threshold voltage to a relatively high voltage level above the threshold voltage.The driver circuit (15) can be operated to form a trajectory of the drive voltage (VDR) over the degradation interval such that the drive voltage (VDR) is non-linear over the entire duration of the degradation interval.