Control apparatus for automotive alternator and automotive power generation system

• US 20080179890A1
• Filed: 01/28/2008
• Published: 07/31/2008
• Est. Priority Date: 01/30/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Asada, Tadatoshi, Maehara, Fuyuki
• Granted Patent: US 7,948,216 B2
• Time in Patent Office: Days
• US Class Current: 290/40B
• CPC Class Codes: H02P 9/30 using semiconductor devices

Abstract

A control apparatus controls power generation of an electric generator and communicates with an external control apparatus. The control apparatus includes: a control circuit that controls the power generation of the electric generator according to a command signal transmitted from the external control apparatus; means for reseting the control circuit; and means for informing the external control apparatus of a power generation condition of the electric generator by transmitting a condition signal, the condition signal indicating both the power generation condition of the electric generator and information on whether a reset of the control circuit is made by the reseting means. With such a configuration, when the control circuit is reset due to, for example, noises, the control apparatus can reliably inform the external control apparatus of the reset of the control circuit.

Claims

1. A control apparatus which controls power generation of an electric generator and communicates with an external control apparatus, the control apparatus comprising:

a control circuit that controls the power generation of the electric generator according to a command signal transmitted from the external control apparatus;

means for reseting the control circuit; and

means for informing the external control apparatus of a power generation condition of the electric generator by transmitting a condition signal, the condition signal indicating both the power generation condition of the electric generator and information on whether a reset of the control circuit is made by the reseting means.

2. The control apparatus as set forth in claim 1, wherein the informing means transmits the condition signal in a cycle of less than a half of a time consonant of field current supplied to the electric generator.

3. The control apparatus as set forth in claim 2, wherein when a reset of the control circuit is made by the resetting means, the informing means sets a reset flag to a first value, cyclically transmits for a predetermined time period the condition signal which represents the first value of the reset flag, and then sets the reset flag to a second value, the first value of the reset flag indicating that a reset of the control circuit is made, the second value of the reset flag indicating that no reset of the control circuit is made, the predetermined time period being longer than at least twice the cycle in which the condition signal is transmitted.

4. The control apparatus as set forth in claim 1, wherein the command signal represents command values for power generation control parameters, and the condition signal represents actual values of the power generation control parameters.

5. The control apparatus as set forth in claim 4, wherein the power generation control parameters include an output voltage of the electric generator, field current supplied to the electric generator, and a duty of a power transistor for controlling the field current.

6. The control apparatus as set forth in claim 1, wherein the electric generator is an automotive alternator, the control apparatus is a voltage regulator for regulating an output voltage of the automotive alternator, and the external control apparatus is an engine control unit.

7. An electric power generation system comprising:

an electric generator; and

first and second control apparatus that communicate with each other to control power generation of the electric generator,

wherein

the first control apparatus comprises;

a control circuit that controls the power generation of the electric generator according to a command signal transmitted from the second control apparatus;

means for reseting the control circuit; and

means for informing the second control apparatus of a power generation condition of the electric generator by transmitting a condition signal, the condition signal indicating both the power generation condition of the electric generator and information on whether a reset of the control circuit is made by the reseting means, and

wherein

the second control apparatus determines whether a reset of the control circuit of the first control apparatus is made on the basis of the condition signal transmitted from the first control apparatus.

8. The electric power generation system as set forth in claim 7, wherein when it is determined that a reset of the control circuit of the first control apparatus is made, the second control circuit transmits the command signal to the first control circuit.

9. The electric power generation system as set forth in claim 8, wherein when a reset of the control circuit is made by the resetting means, the informing means of the first control apparatus sets a reset flag to a first value, transmits to the second control apparatus the condition signal which represents the first value of the reset flag, and then sets the reset flag to a second value upon safe receipt of the command signal which is transmitted by the second control apparatus in response to the condition signal, the first value of the reset flag indicating that a reset of the control circuit is made, the second value of the reset flag indicating that no reset of the control circuit is made.

10. The electric power generation system as set forth in claim 7, wherein the command signal represents command values for power generation control parameters, and the condition signal represents actual values of the power generation control parameters.

11. The electric power generation system as set forth in claim 10, wherein the power generation control parameters include an output voltage of the electric generator, field current supplied to the electric generator, and a duty of a power transistor for controlling the field current.

12. The electric power generation system as set forth in claim 7, wherein the electric power generation system is for use in a motor vehicle with the electric generator being an automotive alternator, the first control apparatus being a voltage regulator for regulating an output voltage of the automotive alternator, and the second control apparatus being an engine control unit for controlling an engine of the vehicle.