Control device for an electric motor, vehicle and method

Patent metadata

Field	Value
Publication number	US-9837947-B2
Application number	US-201515306874-A
Country	US
Kind code	B2
Filing date	Mar 5, 2015
Priority date	Apr 30, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

Embodiments relate to a control device for an electric motor having at least one phase. The control device includes a power unit having a first switching element and a first flyback element corresponding to the first switching element and a second switching element and a second flyback element corresponding to the second switching element. The first switching element is designed to couple a corresponding power connection of the motor with a positive supply voltage. The second switching element is designed to couple the corresponding power connection of the motor with a negative supply voltage; and a control unit designed to separately detect a first current flowing through the first switching element or second switching element corresponding to the phase, to detect a second current flowing through the flyback element corresponding to the respective second switching element or first switching element, and to control the switching elements of the power unit.

First claim

The invention claimed is:

1. A control device for an electric motor having at least one phase, said control device comprising:
a power unit which, for each phase of the electric motor, has a first switching element and a first flyback element corresponding to the first switching element as well as a second switching element and a second flyback element corresponding to the second switching element, wherein the respective first switching element is designed to couple a corresponding power connection of the electric motor with a positive supply voltage, and the respective second switching element is designed to couple the corresponding power connection of the electric motor with a negative supply voltage, and
a control unit which is designed to separately detect, in each of the phases, a first current flowing through the second switching element or first switching element corresponding to the phase and which is designed to detect a second current flowing through the flyback element corresponding to the respective second switching element or first switching element,
wherein the control unit is furthermore designed to control the switching elements of the power unit based on the detected currents,
wherein the second switching element, the first switching element, or both each have a first measuring tap coupled to the control unit and which is designed to transmit information about the current flowing through the second switching element, the first switching element, or both the first switching element and second switching element to the control unit, wherein the first measuring tap is directly integrated into the second switching element, the first switching element, or both the second switching element and the first switching element, and
wherein the flyback elements associated in each case with the second switching elements or first switching elements have in each case a second measuring tap coupled to the control unit and which is designed to transmit information about the current flowing through the respective flyback element to the control unit, wherein the second measuring tap is directly integrated into the flyback elements associated in each case with the second switching elements or first switching elements.

2. The control device according to claim 1 , wherein the second switching elements, the first switching elements, or both are designed as transistors and the first measuring taps are in each case formed in a substrate of one of the power connections of the transistors.

3. The control device according to claim 1 , wherein the flyback elements are designed as diodes and the second measuring taps are each formed in a substrate of an anode or a cathode of the diodes.

4. The control device according to claim 1 , wherein the control unit has a measuring input for each phase, wherein the corresponding first measuring tap and the corresponding second measuring tap are each coupled in a parallel circuit to the corresponding measuring input.

5. The control device according to claim 1 , wherein the electric motor has three phases and the power unit has three first switching elements and in each case a first flyback element corresponding to the first switching elements and three second switching elements and in each case a second flyback element corresponding to the second switching elements.

6. A vehicle comprising
an electric motor having at least one phase;
comprising an energy source; and
a control device including
a power unit which, for each phase of the electric motor, has a first switching element and a first flyback element corresponding to the first switching element as well as a second switching element and a second flyback element corresponding to the second switching element ( 7 - 1 - 7 - 3 ), wherein the respective first switching element is designed to couple a corresponding power connection of the electric motor with a positive supply voltage, and the respective second switching element is designed to couple the corresponding power connection of the electric motor with a negative supply voltage, and
a control unit which is designed to separately detect, in each of the phases, a first current flowing through the second switching element or first switching element corresponding to the phase and which is designed to detect a second current flowing through the flyback element corresponding to the respective second switching element or first switching element,
wherein the control unit is furthermore designed to control the switching elements of the power unit based on the detected currents,
wherein the second switching element, the first switching element, or both each have a first measuring tap coupled to the control unit and which is designed to transmit information about the current flowing through the second switching element, the first switching element, or both the first switching element and second switching element to the control unit, wherein the first measuring tap is directly integrated into the second switching element, the first switching element, or both the second switching element and the first switching element, and
wherein the flyback elements associated in each case with the second switching elements or first switching elements have in each case a second measuring tap coupled to the control unit and which is designed to transmit information about the current flowing through the respective flyback element to the control unit, wherein the second measuring tap is directly integrated into the flyback elements associated in each case with the second switching elements or first switching elements.

7. A method for controlling an electric motor having at least one phase, said electric motor comprising a control device a power unit which, for each phase of the electric motor, has a first switching element and a first flyback element corresponding to the first switching element as well as a second switching element and a second flyback element corresponding to the second switching element, wherein the respective first switching element is designed to couple a corresponding power connection of the electric motor with a positive supply voltage, and the respective second switching element is designed to couple the corresponding power connection of the electric motor with a negative supply voltage, the method comprising:
detecting for each phase a first current which flows through the second switching element or first switching element corresponding to the respective phase;
detecting for each phase a second current which flows through the flyback element corresponding to the respective second switching element or first switching element; and
controlling the switching elements of the power unit of the control device based on the detected currents,
wherein detecting the first current includes detecting the first current at the second switching element or the first switching element with a first measuring tap directly integrated into the second switching element, the first switching element, or both the second switching element and the first switching element, the first measuring tap coupled to the control unit, and
wherein detecting the second current includes detecting the second current at the flyback element corresponding to the respective second switching element or first switching element with a second measuring tap directly integrated into the flyback element corresponding to the respective second switching element, first switching element, or both the second switching element and the first switching element, the second measuring tap coupled to the control unit.

8. The method according to claim 7 , wherein the first currents and the second currents for each phase are in each case alternately measured via an individual measuring input for

Assignees

• Bosch Gmbh Robert

Inventors

• Wiecha Thomas
• Hirsch Michele
• Maur Marcel

Classifications

• H02P27/08 Primary

  with pulse width modulation · CPC title

• H01L27/0629

  Electricity · mapped topic

• H02M7/5387 Primary

  in a bridge configuration · CPC title

• G01R31/34

  Testing dynamo-electric machines · CPC title

• B60L11/1803

  Operations & Transport · mapped topic