ACG OUTPUT VOLTAGE CONTROL

• US 20090184692A1
• Filed: 02/18/2009
• Published: 07/23/2009
• Est. Priority Date: 01/22/2008
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Company
• Inventors: Fujiwara, Tadashi, Owens, C. Richard JR.
• Granted Patent: US 8,217,631 B2
• Time in Patent Office: Days
• US Class Current: 322/23
• 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 2101/45 for motor vehicles, e.g. car alternators
• 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 system provides generator control for a power system within a vehicle. The system includes a battery, a generator that outputs power to charge the battery. A sensor detects a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery. A controller controls a voltage output mode of the generator in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

Claims

1. A system that provides generator control for a vehicle power system, comprising:

a battery;

a generator that outputs power to charge the battery;

a sensor that detects a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery; and

a controller that controls a voltage output mode of the generator in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

2. The generator control system of claim 1, wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

3. The generator control system of claim 2, wherein the controller provides a control signal to the generator based upon the SOC detected by the sensor, said control signal instructing the generator to operate in a selected one of the two modes when the SOC is outside a determined range.

4. The generator control system of claim 2, wherein the difference between the HI mode and the LO mode is approximately 1.7 volts.

5. The generator control system of claim 3, wherein the control signal instructs the generator to operate in the LO voltage output mode when the SOC is above a first determined threshold and instructs the generator to operate in the HI voltage output mode when the SOC is below a second determined threshold.

6. The generator control system of claim 3, wherein the mode selected is based at least in part upon a vehicle fuel economy value and an engine friction value.

7. The generator control system of claim 1, wherein the controller utilizes a charge/discharge algorithm and a charging voltage value to output a control signal the generator.

8. The generator control system of claim 1, wherein the output voltage of the generator is substantially inversely proportional to the temperature of the battery.

9. In a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a method for controlling a voltage output mode of the generator comprising:

(a) determining a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery; and

(b) controlling a voltage output mode of the generator in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

10. The method of claim 9, wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

11. The method of claim 9, step (b) comprises:

compelling the generator to operate in a selected one of the two modes when the SOC is outside a determined range.

12. The method of claim 9, wherein the controller utilizes a charge/discharge algorithm and a charging voltage value to output a control signal the generator.

13. The method of claim 9, wherein the mode selected is based at least in part upon a vehicle fuel economy value and an engine friction value.

14. The method of claim 9, wherein the difference between the HI mode and the LO mode is approximately 1.7 volts.

15. The method of claim 9, wherein the slew rate between the HI mode and the LO mode is about 2 volts/second.

16. The method of claim 9, wherein the output voltage of the generator is substantially inversely proportional to the temperature of the battery.

17. The method of claim 11, wherein the step of compelling comprises:

comparing the SOC to a threshold; and

compelling the generator to operate in the LO voltage output mode if the SOC is greater than the threshold, wherein the threshold is in an approximate range of between 98% to 110%.

18. A system that provides generator control for a vehicle power system, comprising:

a battery;

a generator that outputs power to charge the battery;

a sensor that detects a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery; and

a controller that controls a voltage output mode of the generator in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is linearly related to the SOC and the temperature of the battery.

19. The system according to claim 18, wherein the controller employs a control signal to select the voltage output mode of the generator from a plurality of finite voltage states.

20. The system according to claim 19, wherein the control signal instructs a voltage offset from a predetermined value based at least in part on the SOC value.

21. The system according to claim 19, wherein the system is employed in a vehicle, the voltage output mode is selected based at least in part upon fuel economy of the vehicle or friction of a vehicle engine.

22. The system according to claim 19, wherein the difference between a first mode and a second mode is about 1.7 volts.

23. The system according to claim 19, wherein the control signal instructs the selection of a predetermined voltage output mode value, the predetermined value is based at least in part upon a battery chemistry and/or a battery condition.

24. The system according to claim 18, wherein the voltage output of the generator is selected from a plurality of finite voltage states.

25. The system according to claim 18, wherein the controller employs a control signal to select the voltage output of the generator from a plurality of finite voltage states based on one or more of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor.

26. The system according to claim 18, wherein the controller determines a slew rate of changes to the voltage output of the generator.