Method for fault recognition in an electric machine controlled by an inverter in a motor vehicle and device for monitoring an operation of the electric machine

摘要

A method for fault recognition in an electric machine controlled by an inverter in a motor vehicle, in which the phase currents of the electric machine are ascertained, in particular ascertained by measuring, and a fault is recognized if at least one of the phase currents or a variable derived therefrom, exceeds a predefined upper threshold value, the upper threshold value being established as a function of operating parameters of the motor vehicle, in particular of the electric machine and/or of the inverter.

主权项

1. A method for providing fault recognition in an electric machine, controlled by an inverter in a motor vehicle, the method comprising:
ascertaining the phase currents of the electric machine by measuring; and recognizing a fault, via a control unit, if at least one of the phase currents or a variable derived therefrom exceeds a predefined upper threshold value; wherein the upper threshold value is established as a function of operating parameters of the motor vehicle, including at least one of the electric machine and the inverter, and wherein a control signal is applied to a base terminal of a first transistor, the collector terminal of which is connected to a gate terminal of a second transistor via a pull-up resistor, a potential divider which is formed from a series connection of three resistors being connected downstream of the second transistor, wherein a drain terminal of the second transistor is connected to a first center tap between the first resistor and the second resistor of the potential divider, wherein the upper threshold value for a voltage corresponding to the phase current is tapped at the first center tap.