Vehicle-generator control device

• US 20070085512A1
• Filed: 10/10/2006
• Published: 04/19/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Maehara, Fuyuki
• Granted Patent: US 7,423,351 B2
• Time in Patent Office: Days
• US Class Current: 322/28
• CPC Class Codes: H02J 7/243 with on/off action
• 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

The vehicle-generator control device for controlling an output voltage of a vehicle generator by on/off-controlling an excitation current flowing into an excitation winding of the vehicle generator, includes an excitation current detecting circuit detecting an excitation current flowing into the excitation winding, and a computation circuit having a first function of correcting the excitation current detected by the excitation current detecting circuit on the basis of a current flowing into an electrical load applied with the output voltage of the vehicle generator, and a second function of calculating an output current of the vehicle generator on the basis of the excitation current.

Claims

1. A vehicle-generator control device for controlling an output voltage of a vehicle generator by on/off-controlling an excitation current flowing into an excitation winding of said vehicle generator, comprising:

an excitation current detecting circuit detecting an excitation current flowing into said excitation winding; and

a computation circuit having a first function of correcting said excitation current detected by said excitation current detecting circuit on the basis of a current flowing into an electrical load applied with said output voltage of said vehicle generator, and a second function of calculating an output current of said vehicle generator on the basis of said excitation current.

2. The vehicle-generator control device according to claim 1, wherein said electric load is a vehicle battery charged by said vehicle generator, and said first function is configured to correct said excitation current detected by said excitation current detecting circuit on the basis of a variation of a battery current of said vehicle battery when said excitation current is varied by a predetermined amount.

3. The vehicle-generator control device according to claim 2, wherein said first function is configured to correct said excitation current detected by said excitation current detecting circuit on the basis of said variation of said battery current, and a variation of said output current calculated by said second function when said excitation current is varied by said predetermined amount.

4. The vehicle-generator control device according to claim 1, wherein a load current of said electric load is known, and said first function is configured to correct said excitation current detected by said excitation current detecting circuit on the basis of a variation of said output current calculated by said second function when said excitation current is varied by a predetermined amount, and said known load current of said electric load.

5. The vehicle-generator control device according to claim 1, wherein said second function is configured to calculate said output current of said vehicle generator on the basis of said excitation current corrected by said first function, a rotational speed of said vehicle generator, and said output voltage of said vehicle generator, and said computation circuit is configured to store a correction amount of said excitation current in a memory circuit.

6. The vehicle-generator control device according to claim 5, wherein said memory circuit includes a nonvolatile memory.

7. The vehicle-generator control device according to claim 1, wherein said computation circuit further includes a third function of calculating a power generation torque of said vehicle generator on the basis of said excitation current corrected by said first function, and is configured to limit said excitation current to such a value that an increasing rate of said calculated power generation torque does not exceed a predetermined value.