Power generation controller for AC generator

• US 7,023,102 B2
• Filed: 03/05/2004
• Issued: 04/04/2006
• Est. Priority Date: 03/06/2003
• Status: Expired due to Fees

• Current Assignee: Suzuki Motor Corporation
• Original Assignee: Suzuki Motor Corporation
• Inventors: Itoh, Yasumitsu
• Primary Examiner(s): Schuberg, Darren
• Assistant Examiner(s): Cuevas, Pedro J.
• Application Number:
  US10/794,569
• Publication Number:
  US 20040174018A1
• Time in Patent Office: 760 Days
• Field of Search: 290/20, 290/40.C, 322/16, 322/20, 322 27- 29
• US Class Current: 290/40.00C
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A power generation controller for an AC generator detects the state of a battery and an electric load to control the output of the AC generator. A current detector detects a current to be used by an electric load on the vehicle. The controller includes a field current control section, a field current monitor section, and an output control section. The field current control section controls a field current of the AC generator. The field current monitor section monitors a field current duty value which is a controlled state of the field current of the AC generator. The output control section corrects the output of the AC generator according to the field current duty value, monitored by the field current monitor section, and/or the load current value, detected by the current detector.

Claims

1. A power generation controller for an alternator that is only capable of supplying power to a vehicle battery,

wherein the alternator is driven by rotation of a crank pulley of a crankshaft of an internal combustion engine mounted on a vehicle through a belt entrained around the crank pulley to charge the battery,

said power generation controller controls the output of the alternator according to a duty value which is determined by a ratio between the duration the alternator is deactivated and the duration the alternator is activated, the alternator being deactivated to stop power generation when an external input signal is received and being activated to generate power when the external input signal is not received and to a battery voltage, which change in accordance with a running state of the vehicle and/or a driving state of said engine, wherein

a current detector detects a current to be used by an electric load on the vehicle,

a control unit comprises a field current control section, a field current monitor section, and an output control section,

said field current control section controlling a field current of said alternator,

said field current monitor section monitoring a field current value which is a controlled state of the field current of said alternator, and

said output control section correcting the power output by said alternator according to the field current duty value monitored by said field current monitor section, and/or a load current value detected by said current detector.

2. The power generation controller for the alternator as defined in claim 1, wherein said control unit prevents said alternator from generating power by said output control section when a change-gear in a transmission in connection with said engine is shifted from first to second speed at startup, during acceleration of the vehicle, and when the load current value detected by said current detector is less than a predetermined value.

3. The power generation controller for the alternator as defined in claim 1, wherein said control unit, simultaneously with fuel cut of said engine of a hybrid vehicle, enables said alternator to start regenerative generation by said output control section during deceleration of the vehicle.

4. The power generation controller for the alternator as defined in claim 1, wherein said control unit sets said external input signal provided to said power generation controller of said alternator at a predetermined value when said current detector detects the electric load in the vehicle.

5. The power generation controller for the alternator of claim 1, wherein said alternator only selectively supplies power to said battery and provides no power to said crankshaft.

6. The power generation controller for the alternator of claim 1, wherein said power generation controller comprises a regulator circuit for said alternator, said regulator circuit preventing charging of said battery in all instances when the battery voltage is greater than a predetermined maximum value and said regulator circuit requiring charging of said battery in all instances when the battery voltage is less than a predetermined minimum value.

7. A method for controlling an alternator in a vehicle having an internal combustion engine comprising the steps of:

providing a belt entrained around a crank pulley of a crankshaft of the engine for driving the alternator by rotation of the crank pulley;

providing a regulator circuit for said alternator;

controlling the power output of the alternator in response to an external input signal to have a duty value which is determined by a ratio between a duration the alternator is deactivated and a duration the alternator is activated, deactivating of the alternator stopping power generation when the external input signal is received, and activating of the alternator generating a power output when the external input signal is not received, and controlling the power output in response to the battery voltage which changes in accordance with at least one of a running state of the vehicle and a driving state of the engine;

providing a control unit having a field current control section, a field current monitor section, and an output control section;

detecting a current used by an electric load of the vehicle with a current detector;

wherein said control unit sets the duty value provided to said alternator at a predetermined value when said current detector detects the electric load in the vehicle by at least one of;

monitoring a field current value which is a controlled state of the field current of the alternator with the field current monitor section and controlling a field current of the alternator with the field current control section; and

controlling the external input signal provided to the regulator circuit of said alternator.

8. The method of claim 7, including the step of allocating the output of power by the alternator during a time period based on an intended traveling distance and a predicted state of running operation determined by information from a navigation system and a traffic center.

9. The method of claim 7, including sensing the vehicle being driven up a slope so that power generation cut of the alternator is performed to reduce engine load, and including sensing the vehicle being driven down a slope so that regenerative power generation can be performed.

10. The method of claim 7, including the steps of:

comparing the voltage of said battery to a predetermined minimum value and a predetermined maximum value;

when the voltage of said battery is less than the minimum value, controlling the output of the alternator in all instances to charge the battery; and

when the voltage of said battery is greater than the maximum value, controlling the alternator in all instances to prevent any charging of the battery.

11. In a vehicle having an internal combustion engine, the combination of:

an alternator connected with a belt that is powered by a shaft driven by the internal combustion engine;

a battery connected to receive power from an output of the alternator;

a current sensor for sensing current from the battery to an electric load of the vehicle;

an acceleration switch;

an idle switch; and

a power generation controller for the alternator, the power generation controller for receiving an external output and in response thereto, providing power to the battery; and

a control unit for receiving inputs from the current sensor, the idle switch, and the acceleration switch to provide the external output to control the alternator, the control unit comprising;

a field current control section for limiting power from passing to the alternator when the voltage of the battery is greater than a large reference voltage;

a field current monitor section for monitoring a field current duty value of the alternator; and

an output control section for providing an external output preventing power generation by the alternator

     1) when a gear in a gear transmission is changed from low speed to a second speed or

     2) when the electric load current value detected by the current sensor is less than a predetermined value,

wherein the output control section provides the external output enabling power generation by the alternator during deceleration and the alternator only supplies power to the battery or provides no output to the battery.

12. The combination of claim 11, said power generation controller further comprising a fuel cut control section for cutting fuel to the engine simultaneously with the power generation of the alternator during deceleration of the vehicle.

13. The combination of claim 12, including a regulator circuit for said alternator, said regulator circuit enabling power to pass from the alternator to the battery in every instance when the voltage of the battery is less than a first predetermined value and said regulator circuit preventing the alternator from generating power and passing the power to the battery when the voltage of the battery is greater than a second predetermined value.

14. The combination of claim 13, wherein the first predetermined value comprises less than 12.8 volts and the second predetermined value comprises at or above 14.5 volts.

15. The combination of claim 11, wherein the external output of said output control section controls the amount of power output from alternator by a duty value that is determined by a ratio between a duration the alternator is deactivated and a duration that the alternator is activated.

16. The combination of claim 15, wherein the alternator is activated when the external output is not received and deactivated when the external output is received.