Method and system for regulating a charge voltage delivered to a battery

• US 6,404,163 B1
• Filed: 06/25/2001
• Issued: 06/11/2002
• Est. Priority Date: 06/25/2001
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Matouka, Michael Frank, Walters, David William, Kapsokavathis, Nick S.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/887,959
• Time in Patent Office: 351 Days
• Field of Search: 320/104, 320/127, 320/128, 320/132, 320/134, 320/136, 320/147, 320/150, 429/51, 429/71, 429/75, 429/81, 429/83, 429/95, 324/426, 324/427, 324/432, 324/433
• US Class Current: 320/104
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/1469 Regulation of the charging current or voltage otherwise than by variation of field
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

A method of regulating a charge voltage delivered to a battery in an automobile, wherein the automobile has an engine and an ignition system capable of being activated with an ignition switch, is provided. The method includes the steps of periodically estimating the electrolyte temperature of the battery when the ignition switch is on, periodically sensing the voltage of the battery, using the estimated electrolyte temperature and the sensed voltage to estimate the electric current of the battery, using the estimated electric current to estimate the amp-hours into the battery, using the estimated amp-hours to estimate the state of charge of the battery when the engine is running, using the running state of charge and the estimated electrolyte temperature to determine an optimum charge voltage for the battery, using the sensed voltage to adjust the optimum charge voltage, communicating the optimum charge voltage to a generator, and using the generator to deliver a charge voltage to the battery wherein the charge voltage is regulated by the optimum charge voltage. Also, a system for implementing the method is provided. The system includes a generator, an engine control module, a sensor for sensing the temperature of air entering into the engine, an actuator capable of adjusting the idle speed of the engine, a data link, a body control module, a plurality of body controllers, and a plurality of electrical loads.

Claims

1. A method of regulating a charge voltage delivered to a battery in an automobile having an engine and an ignition system capable of being activated with an ignition switch, said method comprising the steps of:

(a) periodically estimating the electrolyte temperature of said battery when said ignition switch is on;

(b) periodically sensing the voltage of said battery when said ignition switch is on;

(c) estimating the electric current of said battery using said estimated electrolyte temperature and said sensed voltage;

(d) estimating the amp-hours into said battery using said estimated electric current;

(e) estimating the state of charge of said battery, when said engine is running, using said estimated amp-hours;

(f) determining an optimum charge voltage for said battery using said running state of charge and said estimated electrolyte temperature;

(g) adjusting said optimum charge voltage using said sensed voltage;

(h) communicating said optimum charge voltage to a generator; and

(i) delivering a charge voltage to said battery using said generator, wherein said charge voltage is regulated by said optimum charge voltage.

2. The method according to claim 1, said method further comprising the step (aa) of periodically sensing the open-circuit voltage of said battery when said ignition switch is off for helping estimate the state of charge of said battery when said ignition switch is later initially turned on for starting up said engine.

3. The method according to claim 2, wherein said step (aa) is accomplished with a voltage sensing circuit comprising an analog-to-digital converter.

4. The method according to claim 3, said method further comprising the step of adjusting said sensed open-circuit voltage with at least one correction factor relating to at least one of production variance, temperature sensitivity, and voltage range sensitivity of said voltage sensing circuit.

5. The method according to claim 2, said method further comprising the step (bb) of estimating the state of charge of said battery, when said ignition switch is initially turned on for starting up said engine, using said sensed open-circuit voltage and said estimated electrolyte temperature.

6. The method according to claim 5, said method further comprising the steps of:

determining the length of time that said ignition switch was off when said ignition switch is initially turned on; and

performing said step (bb) only when said length of time that said ignition switch was off is greater than a predetermined rest time for said battery.

7. The method according to claim 5, wherein said step (e) includes the step of estimating the state of charge of said battery when said engine is running by also using said estimated start-up state of charge.

8. The method according to claim 7, said method further comprising the step of saving recent voltage level values of said start-up state of charge and said running state of charge in at least one memory capable of being read for diagnostic testing.

9. The method according to claim 1, wherein said step (a) includes the step of sensing the temperature of the air entering into said engine.

10. The method according to claim 1, wherein said step (b) is accomplished with a voltage sensing circuit comprising an analog-to-digital converter.

11. The method according to claim 10, said method further comprising the step of adjusting said sensed voltage with at least one correction factor relating to at least one of production variance, temperature sensitivity, and voltage range sensitivity of said voltage sensing circuit.

12. The method according to claim 11, said method further comprising the step of adjusting said sensed voltage with at least one additional correction factor relating to at least one of various electrical loads electrically connected to at least one of said generator and said battery when said ignition switch is on and said engine is running.

13. The method according to claim 12, said method further comprising the step of filtering said sensed and corrected voltage.

14. The method according to claim 13, wherein estimating the electric current of said battery in said step (c) is particularly accomplished by using said estimated electrolyte temperature and said filtered voltage.

15. The method according to claim 13, said method further comprising the steps of:

monitoring said filtered voltage to determine whether the voltage level of said filtered voltage is outside of a predetermined voltage range; and

activating a visual warning indicator when said voltage level of said filtered voltage is outside of said predetermined voltage range.

16. The method according to claim 1, said method further comprising the step of determining a boost level of the idle speed of said engine using said running state of charge and said estimated amp-hours.

17. The method according to claim 16, wherein said boost level is one of a plurality of predefined idle speed boost levels.

18. The method according to claim 17, said method further comprising the steps of:

counting the number of entries into each upper boost level of said predefined idle speed boost levels; and

saving each said number of entries in a memory capable of being read for diagnostic testing.

19. The method according to claim 1, said method further comprising the step of determining a shed level of various electrical loads electrically connected to at least one of said generator and said battery using said running state of charge and said estimated amp-hours.

20. The method according to claim 19, wherein said shed level is one of a plurality of predefined electrical load shed levels.

21. The method according to claim 20, said method further comprising the steps of:

counting the number of entries into each upper shed level of said predefined electrical load shed levels; and

saving each said number of entries in a memory capable of being read for diagnostic testing.

22. The method according to claim 1, wherein said step (g) is accomplished with a proportional-integral controller comprising a comparator for comparing said sensed voltage with said optimum charge voltage.

23. The method according to claim 1, said method further comprising the steps of:

determining a line drop voltage between said generator and said battery; and

further adjusting said optimum charge voltage, before communicating said optimum charge voltage to said generator, using said line drop voltage.

24. The method according to claim 1, wherein said step (h) includes the steps of:

converting said optimum charge voltage into an electric pulse-width modulated duty cycle signal; and

communicating said duty cycle signal to said generator.

25. The method according to claim 24, wherein said charge voltage of said step (i) is particularly regulated by said duty cycle signal.

26. A method of regulating a charge voltage delivered to a battery in an automobile having an engine and an ignition system capable of being activated with an ignition switch, said method comprising the steps of:

(a) periodically estimating the electrolyte temperature of said battery when said ignition switch is on;

(b) periodically sensing the voltage of said battery;

(c) estimating the electric current of said battery using said estimated electrolyte temperature and said sensed voltage;

(d) estimating the amp-hours into said battery using said estimated electric current;

(e) estimating the state of charge of said battery, when said engine is running, using said estimated amp-hours;

(f) determining an optimum charge voltage for said battery using said running state of charge and said estimated electrolyte temperature;

(g) adjusting said optimum charge voltage using said sensed voltage;

(h) communicating said optimum charge voltage to a generator; and

(i) delivering a charge voltage to said battery using said generator, wherein said charge voltage is regulated by said optimum charge voltage.

27. A method of regulating a charge voltage delivered to a battery in an automobile having an engine and an ignition system capable of being activated with an ignition switch, said method comprising the steps of:

(a) periodically sensing the open-circuit voltage of said battery when said ignition switch is off;

(b) periodically estimating the electrolyte temperature of said battery when said ignition switch is on;

(c) estimating the state of charge of said battery when said ignition switch is initially turned on for starting up said engine using said sensed open-circuit voltage and said estimated electrolyte temperature;

(d) periodically sensing the voltage of said battery when said ignition switch is on and said engine is running;

(e) estimating the electric current of said battery using said estimated electrolyte temperature and said sensed voltage;

(f) estimating the amp-hours into said battery using said estimated electric current;

(g) estimating the state of charge of said battery when said engine is running using said estimated start-up state of charge and said estimated amp-hours;

(h) determining an optimum charge voltage for said battery using said running state of charge and said estimated electrolyte temperature;

(i) adjusting said optimum charge voltage using said sensed voltage;

(j) converting said optimum charge voltage into an electric pulse-width modulated duty cycle signal;

(k) communicating said duty cycle signal to a generator; and

(l) delivering a charge voltage to said battery using said generator, wherein said charge voltage is regulated by said duty cycle signal.

28. A system for regulating a charge voltage delivered to a battery in an automobile having an engine, said system comprising:

a generator having an output terminal capable of being electrically connected to said battery for delivering a charge voltage to said battery;

an engine control module, electrically connected to said generator, capable of sensing an electric feedback signal from said generator;

a sensor, electrically connected to said engine control module, capable of sensing the temperature of the air entering into said engine;

an actuator, electrically connected to said engine control module, capable of adjusting the idle speed of said engine;

a data link electrically connected to said engine control module;

a body control module, electrically connected to said data link, capable of being electrically connected to said battery and having means for sensing the voltage of said battery;

a plurality of body controllers electrically connected to said data link; and

a plurality of electrical loads electrically connected to said body controllers and capable of being powered by at least one of said generator and said battery;

wherein said body control module is capable of determining an optimum charge voltage for said battery, adjusting said idle speed of said engine, and selectively shedding said electrical loads using said sensed electric feedback signal, said sensed air temperature, and said sensed battery voltage; and

wherein said engine control module is capable of communicating said optimum charge voltage to said generator such that said generator is capable of delivering a charge voltage to said battery which is regulated by said optimum charge voltage.

29. The system according to claim 28, wherein said generator has a first terminal electrically connected to said engine control module, wherein said engine control module is capable of communicating said optimum charge voltage to said first terminal of said generator.

30. The system according to claim 29, wherein said engine control module has a detection circuit electrically connected to said first terminal of said generator, wherein said detection circuit is capable of detecting a fault in said generator.

31. The system according to claim 29, wherein said generator has a second terminal electrically connected to said engine control module, wherein said engine control module is capable of sensing said electric feedback signal from said second terminal of said generator.

32. The system according to claim 28, said system comprising a data link connector electrically connected to said data link, wherein said data link connector is capable of providing electrical access to said data link for diagnostic testing.

33. A system for regulating a charge voltage delivered to a battery in an automobile having an engine, said system comprising:

a generator having a first terminal, a second terminal, and an output terminal, wherein said output terminal is capable of being electrically connected to said battery for delivering a charge voltage to said battery;

an ignition system capable of being electrically connected to said battery;

an engine control module electrically connected to said first terminal, said second terminal, and said ignition system, wherein said engine control module is capable of sensing an electric feedback signal from said second terminal;

a sensor, electrically connected to said engine control module, capable of sensing the temperature of the air entering into said engine;

an actuator, electrically connected to said engine control module, capable of adjusting the idle speed of said engine;

a data link electrically connected to said engine control module;

a body control module, electrically connected to said data link, capable of being electrically connected to said battery and having means for sensing the voltage of said battery;

a plurality of body controllers electrically connected to said data link; and

a plurality of electrical loads electrically connected to said body controllers and capable of being powered by at least one of said generator and said battery;

wherein said body control module is capable of determining an optimum charge voltage for said battery, adjusting said idle speed of said engine, and selectively shedding said electrical loads using said sensed electric feedback signal, said sensed air temperature, and said sensed battery voltage; and

wherein said engine control module is capable of communicating said optimum charge voltage to said first terminal of said generator such that said generator is capable of delivering a charge voltage to said battery which is regulated by said optimum charge voltage.