Method for regulating the generator voltage in a motor vehicle

• US 20040021448A1
• Filed: 08/11/2003
• Published: 02/05/2004
• Est. Priority Date: 09/20/2000
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Dinser, Wolfgang, Kloepfer, Armin, Bluemel, Roland
• Granted Patent: US 7,091,626 B2
• Time in Patent Office: Days
• US Class Current: 322/44
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: H02J 7/1446 in response to parameters of a vehicle
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

The invention relates to a method for regulating a generator in a motor vehicle, in which the generator feeds a vehicle power supply system having loads and having at least one battery, with a regulator regulating the generator output voltage at the value of a nominal value voltage. In a recuperation readiness mode, the nominal value voltage is preset as a function of the driving state variables such that, during braking or when the vehicle is overrunning, electrical power is fed into the vehicle power supply system. According to the invention, switching takes place between the recuperation readiness mode and a recovery mode as a function of predetermined switching conditions, with the nominal value voltage in the recovery mode being preset such that the battery is regenerated.

Claims

1. Method for regulating a generator in a motor vehicle,

with the generator feeding a vehicle power supply system having loads and having at least one battery,

with a regulator regulating the generator output voltage at the value of a nominal value voltage,

with the nominal value voltage in a recuperation readiness mode being preset as a function of the driving state variables such that, during braking or when the vehicle is overrunning, electrical power is fed into the vehicle power supply system,

characterized

in that switching takes place between the recuperation readiness mode and a recovery mode as a function of predetermined switching conditions, with the nominal value voltage (U_nom) in the recovery mode being preset such that the battery (5) is regenerated.

2. Method according to claim 1, characterized in that, in the recovery mode, the nominal value voltage (U_nom) is set to the final charge voltage independently of the driving state variables.

3. Method according to claim 1, characterized in that, in the recovery mode, the nominal value voltage (U_nom) is regulated such that the battery (5) is discharged at least once down to a first predetermined state of charge SOC, and is then charged to a second predetermined state of charge SOC.

4. Method according to claims 1 to 3, characterized in that a recuperation characteristic variable, which is characteristic of the battery stress resulting from recuperation charging changes is used as a switching condition for switching from the recuperation readiness mode to the recovery mode.

5. Method according to claim 4, characterized in that the recuperation characteristic variable which is used as a switching condition is the charge throughput through the battery (5) which is detected after a specific start time.

6. Method according to claim 5, characterized

in that the start time from which the detected charge throughput through the battery 5 is considered is the time when switching last took place from the recovery mode to the recuperation readiness mode.

7. Method according to one of claims 1 to 6, characterized

in that the battery (5) is regulated at a predetermined partial state of charge in the recuperation readiness mode and in phases without recuperation operation.

8. Method according to one of claims 1 to 7, characterized

in that, in the recuperation readiness mode, an intermediate stage, in which the loads are supplied in a mixed manner from the battery 5 and from the generator 1, is provided during a change from a charging process for the battery 5 to charge being drawn from the battery 5.

9. Generator controller 7 for regulating the generator voltage in a motor vehicle having a generator which is driven by an internal combustion engine and having a vehicle power supply system, having

at least one battery and

a regulator which regulates the generator output voltage at the value of a nominal value voltage, with the generator controller

having a data input for driving state variables and battery characteristic variables, and

having a data output for the nominal value voltage, and in which case the nominal value voltage can be preset by the generator controller such that electrical power is fed into the vehicle power supply system as a function of the driving state variables in the recuperation readiness mode,

characterized

in that the generator controller 7 has an evaluation unit for determining the state of charge SOC of the battery and for evaluating driving state variables of the motor vehicle, and in that the generator controller 7 has a switching step for switching between the recuperation readiness mode and the recovery mode.