METHOD AND DEVICE FOR OPERATING AN ELECTRICAL MACHINE HAVING SEPARATE EXCITATION

• US 20140125268A1
• Filed: 09/30/2011
• Published: 05/08/2014
• Est. Priority Date: 12/02/2010
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kolmorgen, Stefan, Spannhake, Stefan, Raichle, Daniel, Mikulec, Dragan, Goetting, Gunther, Herranz Gracia, Mercedes, Challand, Yves, Beyer, Mario, Scheidle, Alexander
• Granted Patent: US 9,531,304 B2
• Time in Patent Office: Days
• US Class Current: 318/473
• CPC Class Codes: G05D 23/20 with sensing elements having variation of electric or magnetic properties with change of temperature G05D23/13 takes precedence
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 29/666 by rotor current detection
• CPC Class Codes: H02P 9/30 using semiconductor devices
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence

Abstract

A method and a device for operating an electrical machine having separate excitation, especially a synchronous machine. With the aid of a sensor system, a variable characterizing a rotor temperature and/or a stator temperature are/is determined, and an excitation current and stator currents for the electrical machine are specified by a control unit as a function of the variable characterizing the rotor temperature and/or the stator temperature, at least in specifiable operating ranges.

Claims

1-10. -10. (canceled)

11. A method for operating an electrical machine having separate excitation, the method comprising:

determining a variable that characterizes at least one of a rotor temperature) and a stator temperature; and

specifying an excitation current and stator currents for the electrical machine at least in specifiable operating ranges, as a function of the variable characterizing the at least one of the rotor temperature and the stator temperature.

12. The method of claim 11, wherein at least three operating ranges are formed as a function of the variable characterizing the at least one of the rotor temperature and the stator temperature.

13. The method of claim 12, wherein in a first operating range, in which the at least one of the rotor temperature and the stator temperature lie(s) below a specifiable first limit value, the excitation current and the stator currents for a specified working point of the electrical machine, which is defined by a torque and an engine speed, are specified in efficiency-optimized manner independently of the at least one of the rotor temperature and the stator temperature.

14. The method of claim 12, wherein in a second operating range, in which the at least one of the rotor temperature and the stator temperature lie(s) above the first limit value but below a predefinable second limit value, the excitation current and the stator currents of the electrical machine are specified as a function of the variable characterizing the at least one of the rotor temperature and the stator temperature, without reducing a maximally allowed power of the electrical machine in the process.

15. The method of claim 12, wherein in a third operating range, in which the at least one of the rotor temperature and the stator temperature lie(s) above the second limit value, the maximally permitted power of the electrical machine is reduced.

16. The method of claim 15, wherein the excitation current and the stator currents in the third operating range may be specified in efficiency-optimized manner independently of the variable characterizing the at least one of the rotor temperature and the stator temperature.

17. The method of claim 15, wherein the excitation current and the stator currents in the third operating range are specified as a function of the variable characterizing the at least one of the rotor temperature and the stator temperature.

18. The method of claim 11, wherein the electrical machine is used as drive unit for a vehicle, and the excitation current and the stator currents for the electrical machine in the specifiable operating ranges are specified as a function of additional operating parameters of the vehicle.

19. The method of claim 13, wherein the electrical machine serves as drive unit of a vehicle, and at least one of the first limit value and the second limit value is specified as a function of additional operating parameters of the vehicle.

22. The method of claim 11, wherein the electrical machine is a synchronous machine.

20. A device for operating an electrical machine having separate excitation, comprising:

a sensor system for detecting at least one variable characterizing at least one of a rotor temperature and a stator temperature; and

a control unit, which specifies an excitation current and stator currents for the electrical machine as a function of the variable characterizing the at least one of the rotor temperature and the stator temperature, at least in specifiable operating ranges.

21. The device of claim 20, wherein the electrical machine is a synchronous machine.