Excitation current-limited power generator

• US 9,887,655 B2
• Filed: 05/31/2016
• Issued: 02/06/2018
• Est. Priority Date: 05/31/2016
• Status: Active Grant

• Current Assignee: Infineon Technologies AG, Valeo Equipements Electriques Moteur (Valeo SE)
• Original Assignee: Infineon Technologies AG, Valeo Equipements Electriques Moteur (Valeo SE)
• Inventors: Auer, Frank, Seidl, Christoph, Hartmann, Robert, Doffe, Ludovic, Agneray, Cdric
• Primary Examiner(s): Cuevas, Pedro J
• Application Number:
  US15/168,451
• Publication Number:
  US 20170346431A1
• Time in Patent Office: 616 Days
• Field of Search: 322 15, 322 29, 290 40 R, 700287
• CPC Class Codes: H02P 9/006 Means for protecting the generator by using control control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P9/10
• CPC Class Codes: H02P 9/10 Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load

Abstract

An excitation current-limited power generator includes a digital interface configured to be coupled to an engine control unit (ECU), a regulator coupled configured to be coupled to an excitation current input of an alternator, the excitation current controlling current generated by the alternator, a frequency sensor configured to measuring rotation speed of the alternator, and memory storing a communicated limit received by the digital interface and a first permanent limit, the regulator configured to limit the excitation current to the lesser of the first permanent limit and the communicated limit.

Claims

1. A device comprising:

a digital interface configured to be coupled to an engine control unit (ECU);

a regulator configured to be coupled to an excitation current input of an alternator, the excitation current controlling current generated by the alternator;

a frequency sensor configured to measure a rotation speed of the alternator; and

a memory configured to store a communicated limit received by the digital interface and a first permanent limit, the regulator configured to limit the excitation current to the lesser of the first permanent limit and the communicated limit.

2. The device of claim 1, wherein the regulator is further configured to periodically update the communicated limit with a value received from the ECU.

3. The device of claim 2, wherein the value received from the ECU is selected to limit the current generated by the alternator.

4. The device of claim 2, wherein the value received from the ECU is selected to limit counter-torque induced in the alternator.

5. The device of claim 1, wherein the memory is further configured to store a second permanent limit, and a rotation threshold associated with the second permanent limit, wherein the regulator is further configured to limit the excitation current to the lesser of the second permanent limit and the communicated limit when the rotation speed of the alternator is greater than the rotation threshold.

6. The device of claim 5, wherein the first permanent limit is greater than the second permanent limit.

7. The device of claim 5, wherein the first permanent limit is less than the second permanent limit.

8. The device of claim 1, wherein the regulator is further configured to limit the excitation current to the first permanent limit in response to the digital interface losing connection with the ECU.

9. The device of claim 1, further comprising the alternator.

10. The device of claim 9, wherein the alternator comprises a rotating coil in stator coils.

11. A method comprising:

receiving a communicated limit for an excitation current in an alternator over a digital interface;

determining a permanent limit for the excitation current in the alternator;

limiting the excitation current to the communicated limit in response to the communicated limit being less than the permanent limit; and

limiting the excitation current to the permanent limit in response to the communicated limit being greater than the permanent limit.

12. The method of claim 11, wherein determining the permanent limit comprises:

determining a rotation speed of the alternator; and

selecting a permanent limit from one or more permanent limits, the one or more permanent limits each corresponding to a lower and upper rotation speed threshold, the rotation speed of the alternator being between the lower and upper rotation speed threshold of the selected permanent limit.

13. The method of claim 12, wherein the one or more permanent limits comprise a first permanent limit and a second permanent limit, the upper rotation speed threshold of the first permanent limit being less than the upper rotation speed threshold of the second permanent limit.

14. The method of claim 13, wherein the first permanent limit is greater than the second permanent limit.

15. The method of claim 13, wherein the first permanent limit is less than the second permanent limit.

16. The method of claim 11, further comprising:

receiving an updated permanent limit over the digital interface; and

storing the updated permanent limit in memory.

17. A system comprising:

an engine control unit (ECU);

a digital interface coupled to the engine control unit;

an alternator coupled to the digital interface, the alternator comprising;

a memory configured to store a communicated limit received from the digital interface and a first permanent limit;

an excitation current input; and

a regulator coupled to the excitation current input, the regulator configured to control current output from the alternator by varying the excitation current, the regulator configured to limit the excitation current to the lesser of the first permanent limit and the communicated limit.

18. The system of claim 17, wherein the alternator further comprises a rotation sensor coupled to an output of the alternator, the rotation sensor configured to measure a rotation speed of the alternator.

19. The system of claim 18, wherein the memory is further configured to store a second permanent limit, the first permanent limit associated with a first rotation threshold and the second permanent limit associated with a second rotation threshold, the alternator configured to limit the excitation current to the first permanent limit when the rotation speed of the alternator is less than the first rotation threshold, the alternator configured to limit the excitation current to the second permanent limit when the rotation speed of the alternator is less than the second rotation threshold.

20. The system of claim 17, wherein the alternator is configured to update the first permanent limit stored in the memory with an updated permanent limit received from the ECU over the digital interface.