Control device for power semiconductor switch

Abstract

The present invention relates to a control device for a power semiconductor switch. The control device for a power semiconductor switch comprises an actuation device for generating an actuation voltage for turning on the power semiconductor switch when a turn-on command is received at a third control device terminal, and generating an actuation voltage for turning off the power semiconductor switch when a turn-off command is received; current detection circuit, if the actuating voltage adopts a voltage value when the power semiconductor switch is switched on; the main voltage of the power semiconductor switch applied between the first control device terminal and the second control device terminal exceeds the main voltage value of the first power semiconductor switch; if so, generating a first high-current signal; the actuating device generates an actuating voltage for switching off the power semiconductor switch when receiving the switching-off command; and the actuation voltage is reduced so as to be greater in time interval elapsed between a first actuation voltage value taken by the actuation voltage upon receipt of the shut-off command in the presence of the first high currentsignal and a second actuation voltage value reaching an actuation voltage equal to 10% of the first actuation voltage value than in the absence of the first high current signal.

Description

technical field [0001] The invention relates to a control device for power semiconductor switches. Background technique [0002] When switching off a power semiconductor switch, an overvoltage can occur between the load current terminals of the power semiconductor switch due to stray inductance in the conductors electrically connected to it, especially in the case of high load currents flowing through the power semiconductor switch, which Damage or destruction of the power semiconductor switches may result. The higher the turn-off speed or the shorter the interruption time of the power semiconductor switches, the greater will be these overvoltages due to the increased relative rate of change of the load current. However, the reduction of the switch-off speed for switching off the power semiconductor switch has the disadvantage that when the power semiconductor switch is switched off, the energy loss on the power semiconductor switch increases, thereby reducing the electrica...

AI Technical Summary

Problems solved by technology

If the load current in the on-state of the power semiconductor switch (eg in the event of a short circuit) becomes very high, the voltage applied between the first and second load current terminals of the power semiconductor switch rises significantly, resulting in a control The voltage on the first input of the comparator of the device rises

If the voltage at the first input of the comparator exceeds the reference voltage applied to the second input, the comparator generates an overcurrent fault signal, which results in a continuous shutdown of the power semiconductor switch

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