Pulsed charge power delivery circuit for a vehicle having a combined starter/alternator

• US 6,304,056 B1
• Filed: 09/21/2000
• Issued: 10/16/2001
• Est. Priority Date: 09/21/2000
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gale, Allan Roy, Tamor, Michael Alan, Degner, Michael W
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/667,187
• Time in Patent Office: 390 Days
• Field of Search: 320/103, 320/104, 320/110, 320/127, 320/128
• US Class Current: 320/104
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A method of charging a primary energy storage device in a vehicle including a secondary energy storage device and an engine coupled to a combined starter/alternator. The method comprises the steps of operating the starter/alternator as a generator at approximately a peak efficiency value, and electrically connecting the starter/alternator and the secondary energy storage device for a first predetermined period of time such that the starter/alternator charges the secondary energy storage device. Once the secondary energy storage device reaches a desired charge value, the starter/alternator and the secondary energy storage device are disconnected. The method also electrically connects the primary and secondary energy storage devices such that the secondary energy storage device charges the primary energy storage device. This continues until the charge on the secondary energy storage device reaches a minimum charge value, at which time, the starter/alternator is again operated at a peak efficiency value and connected to the secondary energy storage device. In this way, the starter/alternator pulse-charges the secondary energy storage device which, in turn, maintains the desired charge on the primary energy storage device.

Claims

1. A method of charging a primary energy storage device in a vehicle including a secondary energy storage device and an engine coupled to a combined starter/alternator, the method comprising the steps of:

operating said starter/alternator as a generator at approximately a peak efficiency value;

electrically coupling said starter/alternator and said secondary energy storage device for a first predetermined period of time such that said starter/alternator charges said secondary energy storage device;

disconnecting said starter/alternator and said secondary energy storage device; and

,

electrically connecting said primary and secondary energy storage devices for a second predetermined period of time such that said secondary energy storage device charges said primary energy storage device.

2. The method of claim 1, further comprising the steps of:

monitoring a charge value on said secondary energy storage device;

electrically coupling said starter/alternator and said secondary energy storage when said charge value is less than a minimum charge value;

disconnecting said starter/alternator and said secondary energy storage device when said charge value is greater than a maximum charge value.

3. The method of claim 2 further comprising the step of disconnecting said primary and secondary energy storage devices when said charge value is less than a minimum charge value.

4. The method of claim 2 wherein the step of disconnecting said starter/alternator and said secondary energy storage device includes the step of de-activating said inverter switching circuit.

5. The method of claim 3 wherein the step of disconnecting said primary and secondary energy storage devices includes the step of de-activating a converter switching circuit.

6. The method of claim 1 wherein the step of electrically connecting said starter/alternator and said secondary energy storage device includes the step of activating an inverter switching circuit.

7. The method of claim 1 wherein the step of electrically connecting said primary and secondary energy storage devices includes the step of activating a converter switching circuit.

8. The method of claim 1 further comprising the steps of:

monitoring a charge value on said primary energy storage device;

electrically connecting said starter/alternator and said secondary energy storage when said charge value is less than a minimum charge value;

disconnecting said starter/alternator and said secondary energy storage device when said charge value is greater than a maximum charge value.

9. A power delivery system for a vehicle including an engine and combined starter/alternator, the system comprising:

a primary energy storage device;

a secondary energy storage device;

a converter for electrically connecting said primary and secondary energy storage devices;

an inverter switching circuit for electrically connecting said starter/alternator and said secondary energy storage device; and

a controller programmed to perform the following steps;

monitor a charge value on said secondary energy storage device;

electrically connect said starter/alternator operating at approximately a peak efficiency value and said secondary energy storage when said charge value is less than a minimum charge value;

disconnect said starter/alternator and said secondary energy storage device when said charge value is greater than a maximum charge value; and

,

electrically connect said primary and secondary energy storage devices for a predetermined period of time such that said secondary energy storage device charges said primary energy storage device.

10. The system of claim 9 wherein said controller is further programmed to disconnect said primary and secondary energy storage devices when said charge value is less than a minimum charge value.

11. The system of claim 9 wherein said primary energy storage device is a battery and said secondary energy storage device is a capacitor.