Stabilized electric distribution system for use with a vehicle having electric assist

• US 7,258,183 B2
• Filed: 09/24/2003
• Issued: 08/21/2007
• Est. Priority Date: 09/24/2003
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Leonardi, Franco, Thomas, Steven G., Miller, John M., Brost, Ronald D., Berels, David J.
• Primary Examiner(s): VANAMAN, FRANK BENNETT
• Application Number:
  US10/605,350
• Publication Number:
  US 20050061561A1
• Time in Patent Office: 1,427 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.4, 701/22, 903/930, 903/942, 903/943, 903/948
• US Class Current: 180/65.1
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2300/10 Buses
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• 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: Y10S 903/93 Conjoint control of different elements

Abstract

A stabilized electric distribution system for use in a vehicle having electric assist. The system electrically couples an electric assist bus to an accessory load bus while protecting the first electrical bus from electric assist and regenerative braking induced voltage variations. An energy management controller selectively controls each of a electric motor/generator, a DC/DC converter, and an alternator to affect electric energy distribution within the system. Preferably, the electric energy distribution is controlled to maintain the first electrical bus voltage within a predefined voltage range.

Claims

1. A method for operating a vehicle having a first electrical bus for providing power to accessory loads and a second electrical bus electrically coupled to the first electrical bus, the second electrical bus including an ultracapacitor and at least one electric motor/generator for providing electric motor traction assist to wheels of the vehicle, the method comprising:

providing electric motor assist by powering the electric motor/generator with energy from the ultracapacitor;

regulating a voltage of the first electrical bus within a predefined voltage range while the electric motor provides the electric motor traction assist;

wherein regulating the first electrical bus within the predefined voltage range includes controlling a DC/DC converter electrically coupled between the first and second electrical buses to prevent electric energy to flow from the second to the first bus during the electric motor traction assist; and

providing energy from the first to the second electrical bus if an ultracapacitor voltage of the ultracapacitor is below a predefined voltage limit by controlling the DC/DC converter such that electric energy flows from the first to the second electric bus while still regulating the first electric bus within the predefined voltage range, the electric motor traction assist provided based on the electric energy flow from the first to the second electric bus.

2. The method of claim 1, further comprising permitting energy to flow from a battery electrically coupled to the first electrical bus to the second electrical bus to permit the electric energy to flow from the first to the second electric bus.

3. The method of claim 2, further comprising controlling an alternator set-point to increase energy flow to the first electrical bus from an alternator electrically coupled to the first electrical bus based on the energy flow from the battery to the second electric bus if the battery voltage of the battery is below a predefined battery voltage range.

4. The method of claim 2, further comprising regeneratively braking the electric motor/generator for charging the ultracapacitor and for providing energy to the first electrical bus by regulating the flow of energy from the second to the first electrical bus while still regulating the first electric bus within the predefined voltage range by controlling energy flow through the DC/DC converter.

5. The method of claim 4, further comprising lowering an alternator set-point based on the energy flow produced by the regenerative braking to limit energy provided by the alternator to the first electrical bus for regulating the first electric bus within the predefined voltage range.

6. The method of claim 1, wherein regulating the voltage of the first electrical bus includes executing a start-up energy management mode.

7. The method of claim 1, wherein regulating the voltage of the first electrical bus includes executing an electric traction assist energy management mode.

8. The method of claim 1, wherein regulating the voltage of the first electrical bus includes executing a running energy management mode.