Method and control device for protection time setting in an electric drive system

摘要

The invention relates to a control device (12) for actuating a pulse-controlled converter of an electric drive system, having: an open-loop/closed-loop control circuit (12a) which is configured to generate pulse-width-modulated actuation signals for switching devices of the pulse-controlled converter; a fault logic circuit (12b) which can detect fault states in the drive system and which is configured to select a switching state or a sequence of switching states for the switching devices of the pulse-controlled converter which are assigned to the corresponding fault state; and a protection circuit (12c) which is embodied in hardware and which comprises a signal delay device (15), which is configured to delay the actuation signals in order to implement a minimum protection time, and a locking device (16a, 16b) which is configured to lock two complementary switching devices of a bridge branch of the pulse-controlled converter with respect to one another.

主权项

1. A control device (12) for controlling a pulse-controlled inverter (5) of an electric drive system, comprising:
an open-loop/closed-loop control circuit (12a) embodied as a microprocessor and configured to generate pulse-width-modulated control signals for switching devices of the pulse-controlled inverter (5) to dynamically adjust protection times for driving complementary switching devices in a bridge branch of the pulse-controlled inverter (5); a fault logic circuit (12b) , which can detect fault states in the drive system and configured to select a switching state or a sequence of switching states for the switching devices of the pulse-controlled inverter (5) which are assigned to the corresponding fault state; a protection circuit (12c), which is embodied in hardware and which comprises
a signal delay device (15), configured to delay the control signals in order to implement a minimum protection time, anda latching device (16a, 16b), configured to latch two complementary switching devices of a bridge branch of the pulse-controlled inverter (5) with respect to one another; and a driver circuit (12d), configured to drive the switching devices of the pulse-controlled inverter (5) depending on the control signals output by the protection circuit (12c); wherein the protection circuit (12c) is the last logic element upstream of the driver circuit (12d) and is independent of the open-loop/closed-loop control circuit (12a); and wherein the arrangement of the hardware protection circuit (12a) enables the setting of the minimum protection time and a failsafe latching of complementary power switching elements in the inverter (5) without adversely influencing open-loop/closed-loop control circuit software control of the switching times.