Control device for vehicle AC generator

• US 8,704,497 B2
• Filed: 10/14/2010
• Issued: 04/22/2014
• Est. Priority Date: 04/23/2010
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Nishimura, Shinji, Wada, Noriyuki
• Primary Examiner(s): Patel, Tulsidas C
• Assistant Examiner(s): NGUYEN, VIET P
• Application Number:
  US12/904,784
• Publication Number:
  US 20110260697A1
• Time in Patent Office: 1,286 Days
• Field of Search: 322/28
• US Class Current: 322/28
• CPC Class Codes: H02P 9/006 Means for protecting the generator by using control control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P9/10
• CPC Class Codes: H02P 9/02 Details of the control
• 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 vehicle AC generator that comprises 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 control of a switching element connected in series to said field coil, the control device for the vehicle AC generator comprising:

a minimum value selector which compares on-duty of said switching element indicated by a power generation command inputted from a component located on the outside of a body of said control device to on-duty of said switching element calculated inside the body of said control device, selects a smaller on-duty of both on-duties to perform the ON/OFF control of said switching element, and transmits the selected on-duty to the component located on the outside,

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,

wherein said minimum value selector compares the on-duty of said switching element indicated 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 the smaller on-duty of both on-duties to perform the ON/OFF control of said switching element, and

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

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

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

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

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.

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

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

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

wherein a signal of the power generation command inputted from the component located on the outside of the body of said control device is a pulse width modulation (PWM) signal.

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

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

7. 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 vehicle AC generator comprising 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 control of a switching element connected in series to said field coil,

the control device for the vehicle AC generator comprising:

a minimum value selector which compares on-duty of said switching element indicated by a power generation command inputted from a component located on the outside of a body of said control device to on-duty of said switching element calculated inside the body of said control device, selects a smaller on-duty of both on-duties to perform the ON/OFF control of said switching element, and transmits a signal to the component located on the outside indicating whether the selected on-duty coincides with the power generation command from the component located on the outside,

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,

wherein said minimum value selector compares the on-duty of said switching element indicated 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 the smaller on-duty of both on-duties to perform the ON/OFF control of said switching element, and

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

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

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