METHOD AND APPARATUS FOR MANAGING POWER FLOW OF AN ELECTRIC POWER STORAGE DEVICE

• US 20090045815A1
• Filed: 08/14/2007
• Published: 02/19/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Salman, Mutasim A., Zhang, Xiaodong, Tang, Xidong, Walters, David W., Kapsokavathis, Nick S.
• Granted Patent: US 7,741,805 B2
• Time in Patent Office: Days
• US Class Current: 324/426
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 1/14 to electric lighting circuits
• CPC Class Codes: B60L 2240/34 Cabin temperature
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60R 16/033 characterised by the use of electrical cells or batteries for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: F02N 11/00 Starting of engines by means of electric motors
• CPC Class Codes: F02N 11/0862 characterised by the electrical power supply means, e.g. battery
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: F02N 2200/063 Battery voltage
• CPC Class Codes: F02N 2200/064 : Battery temperature
• CPC Class Codes: F02N 2200/122 : Atmospheric temperature
• CPC Class Codes: H02J 2310/46 : for ICE-powered road vehicles
• CPC Class Codes: H02J 9/002 : in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

An electrical power storage device provides power to crank an internal combustion engine. Thereafter available power from the electric power storage device to crank the engine again is continually updated. Remedial measures are invoked if the available power is less than a predetermined power threshold.

Claims

1. Method for managing electric power flow of an electric power storage device adapted to provide power through an electric circuit including an electric machine to crank an internal combustion engine, the method comprising:

cranking the engine a first time;

after cranking the engine the first time, substantially continually updating an available power from the electric power storage device to crank the engine again; and

if the available power is less than a predetermined power threshold, taking remedial measures including at least one of reducing power flow out of the electric power storage device and increasing power flow to the electric power storage device.

2. The method of claim 1 wherein substantially continually updating an available power from the electric power storage device to crank the engine again comprises:

estimating available power based on an initial estimate of internal resistance of the energy storage device updated substantially contemporaneously with cranking the engine the first time.

3. The method of claim 2 wherein substantially continually updating an available power from the electric power storage device to crank the engine again further comprises:

estimating available power based on a present estimate of internal resistance of the energy storage device updated substantially continuously subsequent to cranking the engine the first time.

4. The method of claim 3 wherein the initial estimate of internal resistance of the energy storage device is estimated as a function of resistance of said electric circuit.

5. The method of claim 3 wherein the initial estimate of the internal resistance of the energy storage device is estimated as a function of resistance of said electric circuit, and the present estimate of internal resistance of the energy storage device is estimated as a function of the initial estimate of the internal resistance, change in state of charge of the electric power storage device since cranking the engine the first time, and change in temperature of the electric power storage device since cranking the engine the first time.

6. Method for managing electric power flow of an electric power storage device, comprising:

electrically operatively coupling the electric power storage device to an electric circuit comprising an electric machine adapted to crank an engine;

determining initial states of the electric power storage device at a first engine crank event;

estimating future states of the electric circuit and the electric power storage device during operation subsequent to the first engine crank event;

predicting a maximum cranking power of the electric power storage device for a subsequent engine crank event based upon the initial and estimated future states of the electric power storage device and the future state of the electric circuit;

comparing the predicted maximum cranking power of the electric power storage device to a predetermined threshold power; and

,

controlling the electric power flow of the electric power storage device based upon said comparison.

7. The method of claim 6, wherein determining initial states of the electric power storage device at the engine cranking event comprises determining an initial open circuit voltage, an initial temperature, an initial state of charge, and an initial internal resistance at initiation of the engine crank event.

8. The method of claim 7, further comprising estimating a future state of charge of the electric power storage device at the subsequent cranking event based upon a present state of charge and a predicted parasitic load on the electric circuit.

9. The method of claim 8 further comprising estimating a future temperature of the electric power storage device at the subsequent cranking event and determining a future open circuit voltage of the electric power storage device at the subsequent cranking event based upon said predicted future state of charge at the subsequent cranking event and said estimated future temperature of the electric power storage device at the subsequent cranking event.

10. The method of claim 9, further comprising estimating a future internal resistance of the electric power storage device at the subsequent cranking event based upon said initial internal resistance, the difference between said initial and future states of charge of the electric power storage device, and the difference between said initial and future temperatures of the electric power storage device.

11. The method of claim 10, wherein predicting a maximum cranking power of the electric power storage device for a subsequent engine crank event is further based upon an initial state of the electric circuit at the first engine crank event.

12. The method of claim 10, wherein the initial and future states of the electric circuit comprise resistance of the electric circuit based upon an estimated initial electric circuit temperature and an estimated future electric circuit temperature, respectively.

13. The method of claim 6, wherein controlling the electric power flow from the electric power storage device comprises increasing engine idle speed to increase state of charge of the electric power storage device and decreasing electric power consumption when the predicted maximum cranking power is less than the threshold power.

14. The method of claim 6, wherein the electric power threshold comprises a power flow of the electric power storage device required to drive the electric machine to crank the engine.

15. The method of claim 6, further comprising controlling the electric power flow of the electric power storage device prior to the subsequent engine crank event.