Patent ID: 11926377
Assignee: THYSSENKRUPP PRESTA AG
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC B  H | IPC B  H

Claim 0:
1. A method for disconnecting a multiphase electric motor of an electromechanical motor vehicle power steering system from a DC voltage source by way of a control unit for driving the multiphase electric motor, wherein the multiphase electric motor includes at least three phase windings with connection lines, which, for operating the multiphase electric motor by way of a motor controller and a driver circuit of the control unit, are configured to be alternately connected via high-side and low-side switching elements to a respective pole of the DC voltage source, wherein the connection lines each have a phase disconnection device for disconnecting the phase windings from the DC voltage source in an event of a fault, wherein the control unit performs the method comprising:
monitoring the low-side and high-side switching elements for short-circuit faults during operation of the multiphase electric motor;
switching off the low-side and high-side switching elements upon detection of a short-circuit fault;
determining whether one of the first high-side switching elements or one of the low-side switching elements is causing the short-circuit fault;
to brake the multiphase electric motor, switching on a second of the high-side switching elements or correspondingly a second of the low-side switching element in addition to the one of the first high-side switching elements or the one of the low-side switching elements causing the short-circuit fault;
switching off the low-side and high-side switching elements after a selectable braking period has elapsed; and
opening the respective phase disconnection devices.