Gate drive unit and method for short circuit protection for a power switch

摘要

A gate drive unit includes a measurement unit, a multi-resistive driving device, and a processing unit. The measurement unit measures a voltage across main terminals of a power switch. The driving device includes plural individually controllable resistive elements. The processing unit controls a control voltage applied to a control electrode of the power switch to activate the power switch. The processing unit individually activates or deactivates the resistive elements of the multi-resistive driving device to change which of the resistive elements at least partially conducts the control voltage to the power switch at different times responsive to the voltage across the main terminals representing a short circuit event. The processing unit changes which of the resistive elements are activated or deactivated to control a rate at which the control voltage decreases.

主权项

1. A gate drive unit for operation of a power switch in a converter, wherein the gate drive unit comprises:
a measurement unit configured to measure a first voltage across main terminals of a power switch; a multi-resistive driving device conductively coupled with a control electrode of the power switch, the multi-resistive driving device including plural individually controllable resistive elements conductively coupled between at least one voltage source and the control electrode of the power switch; and a processing unit configured to control a control voltage that is applied to the control electrode of the power switch by the voltage source to activate the power switch, the processing unit configured to individually activate or deactivate the resistive elements of the multi-resistive driving device to change which of the resistive elements at least partially conduct the control voltage from the voltage source to the control electrode of the power switch at different times responsive to the first voltage across the main terminals of the power switch representing a first type of short circuit event, the processing unit configured to change which of the resistive elements are activated or deactivated to control a rate at which the control voltage decreases during deactivation of the power switch responsive to a first type of a short circuit event occurring.