Converter device for an electrical machine, motor vehicle, and method for operating a converter device

Patent metadata

Field	Value
Publication number	US-2018294697-A1
Application number	US-201815945776-A
Country	US
Kind code	A1
Filing date	Apr 5, 2018
Priority date	Apr 11, 2017
Publication date	Oct 11, 2018
Grant date	—

Abstract

A converter device for an electrical machine, including a switch with a plurality of switching elements to generate a multiphase alternating current for the electrical machine and a plurality of phase conductors for conducting an alternating current generated in each case by the switch to the electrical machine, wherein a number of first phase conductors that is one less in number than the total number of phase conductors are coordinated with a current measuring means, and a control device is provided, which is designed to determine a calculated value describing a current along the second phase conductor from first measured values of the current measuring means, wherein the control device is designed to check the plausibility of the calculated value on the basis at least one second measured value of a short circuit detecting device coordinated with a switching element.

First claim

1 . A converter device for an electrical machine, comprising:
switching means with a plurality of switching elements to generate a multiphase alternating current for the electrical machine and a plurality of phase conductors for conducting an alternating current that is generated in each case by the switching means to the electrical machine, wherein a number of first phase conductors that is one less in number than the total number of phase conductors are coordinated with a current measuring means, and a control device is provided, which is designed to determine a calculated value describing a current along the second phase conductor from first measured values of the current measuring means, wherein the control device checks the plausibility of the calculated value on the basis of at least one second measured value of a short circuit detecting device coordinated with a switching element.

2 . The converter device according to claim 1 , wherein the control device determines a gain drift of a current measuring means for the checking of plausibility.

3 . The converter device according to claim 1 , wherein, for the checking of plausibility, the control device determines a deviation of a first measured value of a current measuring means from at least one second measured value in regard to one of the switching element of the switching means that generates the alternating current carried along the first phase conductor associated with the current measuring means.

4 . The converter device according to claim 1 , wherein, for the checking of plausibility, the control device determines a deviation of the calculated value from a second measured value in regard to one of the switching elements that generates the alternating current along the second phase conductor.

5 . The converter device according to claim 1 , wherein a temperature detecting device is provided to detect and/or model at least one temperature at one of the switching element or switching elements, wherein the control device takes account of the temperature in the plausibility check, especially for correcting the one or more second measured value(s).

6 . The converter device according to claim 1 , wherein the control device determines an error signal and/or to deactivate the converter device when the presence of an erroneous calculated value results from the plausibility check.

7 . The converter device according to claim 1 , wherein in each case, one of the switching means includes two IGBTs or two power MOSFETs as switching elements.

8 . The converter device according to claim 1 , wherein the short circuit detecting device for providing the second measured value includes a measurement means hooked up to an interconnected sense output of the switching element and/or an interconnected measurement means for detecting a voltage falling across the switching element, especially a collector-emitter voltage and/or a drain-source voltage.

9 . A motor vehicle, comprising an electrical machine for partial or total propulsion of the motor vehicle and a converter device according to claim 1 , wherein the phase conductors are connected to the electrical machine.

10 . A method for operating a converter device for an electrical machine, comprising:
switching means with a plurality of switching elements generating a multiphase alternating current for the electrical machine and a plurality of phase conductors, each conducting an alternating current that is generated by the switching means to the electrical machine, wherein a number of first phase conductors that is one less in number than the total number of phase conductors are coordinated with a current measuring means, and a calculated value describing a current along the second phase conductor is determined from first measured values of the current measuring means, wherein the calculated value is checked for plausibility on the basis of at least one second measured value of a short circuit detecting device coordinated with a switching element.

Assignees

• Audi Ag

Inventors

• Apelsmeier Andreas
• Brüske Stephan

Classifications

• H02K11/25

  Devices for sensing temperature, or actuated thereby · CPC title

• H02K11/33 Primary

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02K11/27

  Devices for sensing current, or actuated thereby (overcurrent protection responsive to temperature of the machines or parts thereof, e.g. windings, H02K11/25) · CPC title

• H02M1/32 Primary

  Means for protecting converters other than automatic disconnection · CPC title

• H02P29/0241

  the fault being an overvoltage · CPC title