Systems and methods for controlling dynamic avalanche in switching devices

A method to mitigate occurrences of dynamic avalanche events in a semiconductor switching device, comprising:

• determining one or more values of system parameters in response to indicating the semiconductor switching device to enter a turn-off mode;
• determining whether to apply an intermediate gate voltage to the semiconductor switching device, wherein determining whether to apply the intermediate gate voltage comprises:
• determining a voltage applied to the semiconductor switching device prior to turn-off, a current propagating through the semiconductor switching device prior to turn-off, a differential peak voltage, or a combination thereof;
• and
• determining whether the voltage, the current, the differential peak voltage, or a combination thereof are within a respective threshold range;
• in response to determining to apply an intermediate gate voltage, determining an intermediate gate voltage based at least in part on the one or more values, wherein the intermediate gate voltage comprises a voltage between a turn-off threshold and a turn-off voltage;
• configuring a gate-drive unit coupled to the semiconductor switching device to a first configuration for applying the intermediate gate voltage;
• applying the intermediate gate voltage in response to configuring the gate-drive unit to the first configuration;
• configuring the gate-drive unit to a second configuration for applying the turn-off voltage;
• and
• applying the turn-off voltage in response to configuring the gate-drive unit to the second configuration.

An electrical system comprising:

• a gate-drive unit electrically coupled to a semiconductor switching device, wherein the gate-drive unit is configured to apply a voltage to a gate terminal of the semiconductor switching device, wherein the gate-drive unit comprises:
• one or more power sources configured to drive one or more power rails, wherein the one or more power sources comprises a voltage source, a current source, or a combination thereof;
• and
• one or more resistor stages, wherein each of the one or more resistor stages is coupled to the gate terminal and to the one or more power rails, wherein each of the one or more resistor stages comprises a positive bus gate resistor and a negative bus gate resistor coupled to the one or more power rails using a respective switch;
• and
• a controller configured to:
• indicate to the semiconductor switching device to turn-off;
• determine system parameters in response to indicating to the semiconductor switching device to turn-off;
• determine an intermediate gate voltage based at least in part on the system parameters, wherein the intermediate gate voltage is between a turn-off threshold and a turn-off voltage;
• configure the gate-drive unit to apply the intermediate gate voltage at the gate terminal;
• and
• configure the gate-drive unit to apply the turn-off voltage at the gate terminal subsequent to application of the intermediate gate voltage, wherein the turn-off voltage is applied in response to commutation of a current propagating through the semiconductor switching device.