CONTROL DEVICE FOR VEHICLE AC GENERATOR

• US 20110260697A1
• Filed: 10/14/2010
• Published: 10/27/2011
• Est. Priority Date: 04/23/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: NISHIMURA, Shinji, WADA, Noriyuki
• Granted Patent: US 8,704,497 B2
• Time in Patent Office: Days
• US Class Current: 322/28
• CPC Class Codes: H02P 9/006 Means for protecting the generator by using control H02H7/06 takes precedence; control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P9/10
• CPC Class Codes: H02P 9/02 Details
• 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

In order to receive a power generation command from the outside of a body, to transmit power generation control condition with respect to the power generation command to the outside, and to enable a vehicle to drive properly depending on the condition; a minimum value selector by which on-duty of a switching element by the power generation command inputted from the outside of the body of a control device is compared to on-duty of the switching element calculated inside the body of the control device and smaller on-duty of both on-duties is selected to perform ON/OFF control of the switching element is included, and the selected on-duty is transmitted to the outside.

Claims

1. A control device for a vehicle AC generator, in which a DC voltage obtained by rectifying an AC output voltage of an armature coil in said AC generator that has said armature coil and a field coil with a rectifier is applied to said field coil to obtain a field current, and the field current is controlled by ON/OFF of a switching element connected in series to said field coil,

the control device for the vehicle AC generator, comprising a minimum value selector by which on-duty of said switching element by a power generation command inputted from the outside of a body of said control device is compared to on-duty of said switching element calculated inside the body of said control device, and smaller on-duty of both on-duties is selected to perform ON/OFF control of said switching element;

and

transmitting the selected on-duty to the outside.

2. The control device for the vehicle AC generator according to claim 1,

wherein the on-duty of said switching element calculated inside the body of said control device is an upper limit on-duty capable of continuing energization of said switching element, and

said minimum value selector compares the on-duty of said switching element by the power generation command to the upper limit on-duty of said switching element calculated inside the body of said control device, and selects smaller on-duty of both on-duties to perform ON/OFF control of said switching element.

3. The control device for the vehicle AC generator according to claim 2,

further comprising an upper limit restriction unit in which an upper limit of the on-duty of said switching element is a set voltage/the DC voltage.

4. The control device for the vehicle AC generator according to claim 3,

wherein the upper limit on-duty of said switching element is controlled to be zero when the DC voltage obtained by rectifying the AC output voltage with said rectifier exceeds a second set voltage that is larger than the set voltage.

5. The control device for the vehicle AC generator according to claim 3,

wherein the upper limit on-duty of said switching element is controlled to be zero when temperature of said AC generator is detected and the detected generator temperature exceeds a set temperature.

6. The control device for the vehicle AC generator according to claim 3,

wherein the upper limit on-duty of said switching element is controlled to be zero when rotational speed of said AC generator is detected and the DC voltage/the rotational speed is not lower than a set value.

7. The control device for the vehicle AC generator according to claim 1,

wherein a signal of the power generation command inputted from the outside of the body of said control device is a PWM signal.

8. The control device for the vehicle AC generator according to claim 1,

wherein a signal which transmits the selected on-duty to the outside is a PWM signal.

9. A control device for a vehicle AC generator, in which a DC voltage obtained by rectifying an AC output voltage of an armature coil in said AC generator that has said armature coil and a field coil with a rectifier is applied to said field coil to obtain a field current, and the field current is controlled by ON/OFF of a switching element connected in series to said field coil,

the control device for the vehicle AC generator, comprising a minimum value selector by which on-duty of said switching element by a power generation command inputted from the outside of a body of said control device is compared to on-duty of said switching element calculated inside the body of said control device, and smaller on-duty of both on-duties is selected to perform ON/OFF control of said switching element;

and

transmitting to the outside as to whether or not the selected on-duty coincides with the power generation command from the outside.

10. The control device for the vehicle AC generator according to claim 9,

wherein the on-duty of said switching element calculated inside the body of said control device is an upper limit on-duty capable of continuing energization of said switching element, and

said minimum value selector compares the on-duty of said switching element by the power generation command to the upper limit on-duty of said switching element calculated inside the body of said control device, and selects smaller on-duty of both on-duties to perform ON/OFF control of said switching element.

11. The control device for the vehicle AC generator according to claim 10,

further comprising an upper limit restriction unit in which an upper limit of the on-duty of said switching element is a set voltage/the DC voltage.