Alternator control with temperature-dependent safety feature

• US 9,735,718 B2
• Filed: 07/13/2015
• Issued: 08/15/2017
• Est. Priority Date: 06/29/2015
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Grafling, Martin, Seidl, Christoph
• Primary Examiner(s): Gonzalez Ramirez, Julio C
• Application Number:
  US14/797,814
• Publication Number:
  US 20160380567A1
• Time in Patent Office: 764 Days
• Field of Search: 322 17, 322 28, 322 59, 322 89, 322 33, 322 34, 290 40 R, 290 40 B, 320150, 323285
• CPC Class Codes: H02J 7/007192 in response to temperature
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: H02P 9/006 Means for protecting the generator by using control H02H7/06 takes precedence; control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P9/10
• 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
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method for controlling an alternator includes determining a temperature-dependent value associated with a battery coupled to an alternator and determining an excitation emergency threshold for the alternator based on the determined temperature-dependent value associated with the battery. The method further includes initiating, by a controller of an alternator, at least one safety measure upon a determination that a voltage associated with the battery exceeds the determined excitation emergency threshold.

Claims

1. A method for controlling an alternator, comprising:

determining a temperature-dependent first value associated with a battery, coupled to an alternator;

determining an excitation emergency threshold for the alternator based on the determined temperature-dependent first value associated with the battery, wherein the excitation emergency threshold comprises a temperature-dependent second value that indicates that a controller of the alternator is failing to regulate a voltage associated with the battery to a voltage set point; and

initiating, by the controller of the alternator, at least one safety measure upon a determination that a voltage associated with the battery exceeds the determined excitation emergency threshold.

2. The method of claim 1, further comprising:

receiving, by the controller of the alternator, the voltage set point; and

determining, based at least in part upon the received voltage set point, the temperature-dependent first value associated with the battery.

3. The method of claim 1, wherein the method further comprises:

receiving, via an interface to an engine control unit, the excitation emergency threshold.

4. The method of claim 1, wherein the at least one safety measure comprises disabling the voltage associated with the battery.

5. The method of claim 1, further comprising disabling the voltage associated with the battery by pulling a pulse width modulated signal to ground.

6. The method of claim 1, wherein the controller determines the excitation emergency threshold based at least in part upon one or more of a type of the battery, a size of the battery, a capacity of the battery, a manufacturer of the battery, and a product number of the battery.

7. The method of claim 6, wherein the controller determines the excitation emergency threshold based on one or more temperature profiles.

8. An apparatus comprising:

an output configured to provide a charging voltage as a feedback; and

a control circuit coupled to the output, the control circuit operable to;

determine a temperature-dependent first value associated with a battery coupled to an alternator;

determine an excitation emergency threshold for the alternator based on the determined temperature-dependent first value associated with the battery, wherein the excitation emergency threshold comprises a temperature-dependent second value that indicates that the control circuit is failing to regulate the charging voltage to a voltage set point; and

initiate at least one safety measure upon a determination that the charging voltage exceeds the determined excitation emergency threshold.

9. The apparatus of claim 8, wherein the temperature-dependent first value comprises the voltage set point.

10. The apparatus of claim 8, wherein the control circuit is further operable to receive, via an interface, the excitation emergency threshold.

11. The apparatus of claim 8, wherein the control circuit is further operable to:

based at least in part upon determining that the charging voltage exceeds the excitation emergency threshold, disable the charging voltage.

12. The apparatus of claim 11, wherein the control circuit is further operable to:

generate, based at least in part on the charging voltage and the voltage set point, an excitation current to be applied to an alternator load, wherein the excitation current is disabled by a signal that pulls a power switch to ground.

13. The apparatus of claim 8, wherein the control circuit determines the temperature-dependent first value based at least in part upon one or more of a type of the battery, a size of the battery, a capacity of the battery, a manufacturer of the battery, and a product number of the battery.

14. The apparatus of claim 13, wherein the control circuit determines the excitation emergency threshold based on one or more temperature profiles.

15. A system comprising:

an alternator configured to provide an output voltage to a vehicle battery;

an engine control unit coupled to the alternator via an interface;

wherein the alternator comprises a circuit to control the alternator and the circuit is configured to;

determine, based on information received from the engine control unit via the interface, a temperature-dependent first value associated with a battery coupled to the alternator;

determine an excitation emergency threshold for the alternator based on the determined temperature-dependent first value associated with the battery, wherein the excitation emergency threshold comprises a temperature-dependent second value that indicates that a controller of the alternator is failing to regulate a voltage associated with the battery to a voltage set point; and

initiate at least one safety measure upon a determination that the output voltage exceeds the determined excitation emergency threshold.

16. The system of claim 15, wherein the temperature-dependent first value comprises a voltage set point.

17. The system of claim 15, wherein the circuit to control the alternator is further operable to receive, via the interface, the excitation emergency threshold.

18. The system of claim 15, wherein the circuit to control the alternator is further operable to:

based at least in part upon determining that the output voltage exceeds the excitation emergency threshold, disable the charging voltage to the battery.

19. The system of claim 18, wherein the circuit to control the alternator is further operable to generate, based at least in part on the output voltage and a voltage set point, an excitation current to be applied to an alternator load, wherein the excitation current is disabled by a signal that pulls a power switch to ground.

20. The system of claim 15, wherein the circuit to control the alternator is further operable to determine the excitation emergency threshold based at least in part upon one or more of a type of the battery, a size of the battery, a capacity of the battery, a manufacturer of the battery, and a product number of the battery.