CONTROL DEVICE FOR AN ELECTRIC MACHINE, A VEHICLE, AND A METHOD

• US 20170302205A1
• Filed: 08/13/2015
• Published: 10/19/2017
• Est. Priority Date: 10/07/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Goetting, Gunther, Chouk, Lanouar
• Granted Patent: US 10,148,208 B2
• Time in Patent Office: Days
• CPC Class Codes: H02P 21/14 Estimation or adaptation of machine parameters, e.g. flux, current or voltage
• CPC Class Codes: H02P 29/66 Controlling or determining the temperature of the rotor
• CPC Class Codes: H02P 29/68 based on the temperature of a drive component or a semiconductor component

Abstract

The invention relates to a control device for an electric machine with a stator and a rotor, comprising a temperature detection device which is designed to detect the temperature of the stator and the temperature of the rotor, as well as a calculation device which is designed to adjust the operating point of said electric machine on the basis of a specified torque, the detected temperature of the stator, the detected temperature of the rotor, and a predefined thermal load distribution of said stator and rotor. The invention also relates to a vehicle and to a corresponding method for controlling an electric machine.

Claims

1. A control device (1) for an electric machine (2) including a stator (3) and a rotor (4), the control device comprising:

a temperature detection device (5) which is configured to detect the temperature (6-1) of the stator (3) and the temperature (6-2) of the rotor (4); and

including a computing device (7) which is configured to set the operating point (8) of the electric machine (2) based on a torque specification (9) and the detected temperature (6-1) of the stator (3) and the detected temperature (6-2) of the rotor (4) and a predefined distribution (10) for the thermal load of the stator (3) and the rotor (4).

2. The control device as claimed in claim 1,

wherein the computing device (7) is configured to set the operating point (8) by calculating a d-axis component (11) of a current vector (13-1 to 13-3) and a q-axis component (12) of the current vector (13-1 to 13-3) in a field-oriented coordinate system.

3. The control device as claimed in claim 2,

including a memory (14) which is configured to store a machine-specific characteristic curve field (15) for the electric machine (2), which specifies the resulting motor current (16) and the resulting torque (17) and the resulting magnetic flux (30) in the electric machine (2) for predefined values of the d-axis component (11) and the q-axis component (12) of the current vector (13-1 to 13-3).

4. The control device as claimed in claim 2,

wherein the computing device (7) is configured to adjust the d-axis component (11) of the current vector (13-1 to 13-3) with respect to the q-axis component (12) of the current vector (13-1 to 13-3), and to adjust the q-axis component (12) of the current vector (13-1 to 13-3) in such a way that the torque predefined by the torque specification (9) is reached in the electric machine (2) if the thermal load of the rotor (4) is to be decreased with respect to the thermal load of the stator (3);

wherein the computing device (7) is configured to increase the d-axis component (11) of the current vector (13-1 to 13-3) with respect to the q-axis component (12) of the current vector (13-1 to 13-3), to decrease the q-axis component (12) of the current vector (13-1 to 13-3) with respect to the d-axis component (11) of the current vector (13-1 to 13-3), or both when the thermal load of the rotor (4) is decreased with respect to the thermal load of the stator (3).

5. The control device as claimed in claim 4,

wherein the computing device (7) is configured to increase the d-axis component (11) of the current vector (13-1 to 13-3) and to decreased the q-axis component (12) of the current vector (13-1 to 13-3), so that the resulting current vector (13-1 to 13-3) is shifted to a characteristic curve having a constant torque (17).

6. The control device as claimed in claim 2,

wherein the computing device (7) is configured to decrease the magnitude of the current vector (13-1 to 13-3) if the thermal load of the stator (3) is to be decreased.

7. The control device as claimed in claim 1,

wherein the computing device (7) is configured to calculate the operating point (8) based on an intermediate circuit voltage (18) of the control device (1), a stator frequency (19) or both.

8. The control device as claimed in claim 1,

wherein the temperature detection device (5) is configured to calculate the temperature (6-1) of the stator (3), the temperature (6-2) of the rotor (4), or both;

and

wherein the temperature detection device (5) includes at least one temperature sensor (20) for detecting the temperature (6-1) of the stator (3), the temperature (6-2) of the rotor (4), or both.

9. The control device as claimed in claim 1,

including a current controller (21) which is coupled to the computing device (7) and is configured to calculate control voltages (22-1 to 22-3) for the phases (23-1 to 23-3) of the electric machine (2) based on the operating point (8) set by the computing device (7).

10. A vehicle (26)

including an electric machine (2) which includes a stator (3) and a rotor (4);

and

including a control device (1) which is coupled to the electric machine (2) and is configured to control the electric machine (2), the control device including

a temperature detection device (5) which is configured to detect the temperature (6-1) of the stator (3) and the temperature (6-2) of the rotor (4); and

including a computing device (7) which is configured to set the operating point (8) of the electric machine (2) based on a torque specification (9) and the detected temperature (6-1) of the stator (3) and the detected temperature (6-2) of the rotor (4) and a predefined distribution (10) for the thermal load of the stator (3) and the rotor (4).

11. The vehicle as claimed in claim 10,

wherein the electric machine (2) is coupled to a drive train (24) of the vehicle (26) and is configured to drive the vehicle (26).

12. The vehicle as claimed in claim 11,

including an internal combustion engine (25) which is mechanically coupled to the drive train (24) and is configured to drive the vehicle (26) alone or in connection with the electric machine (2).

13. A method for controlling an electric machine (2) including a stator (3) and a rotor (4), including:

detecting (S1) a temperature (6-1) of the stator (3) and a temperature (6-2) of the rotor (4); and

setting (S2) an operating point (8) of the electric machine (2) based on a torque specification (9) and the detected temperature (6-1) of the stator (3) and the detected temperature (6-2) of the rotor (4) and a predefined distribution (10) for the thermal load of the stator (3) and the rotor (4).

14. The method as claimed in claim 13,

wherein the setting of the operating point (8) takes place by calculating a d-axis component (11) of a current vector (13-1 to 13-3) and a q-axis component (12) of the current vector (13-1 to 13-3) in a field-oriented coordinate system.

15. The method as claimed in claim 14,

wherein when setting, the d-axis component (11) of the current vector (13-1 to 13-3) is increased with respect to the q-axis component (12) of the current vector (13-1 to 13-3), and wherein the q-axis component (12) of the current vector (13-1 to 13-3) is decreased with respect to the d-axis component (11) of the current vector (13-1 to 13-3), if the thermal load of the rotor (4) is to be decreased with respect to the thermal load of the stator (3);

and

wherein when setting, the magnitude of the current vector (13-1 to 13-3) is decreased if the thermal load of the stator (3) is to be decreased.