Abnormality detection apparatus of vehicle AC generator

• US 20020193922A1
• Filed: 05/20/2002
• Published: 12/19/2002
• Est. Priority Date: 06/07/2001
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Muto, Katsuya, Taniguchi, Makoto
• Granted Patent: US 6,867,569 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle

Abstract

An abnormality detection apparatus of a vehicle AC generator that includes a rectifier for providing DC voltage is disclosed. The abnormality detection apparatus includes an abnormality judging unit and an alarm lamp. The abnormality judging unit judges abnormality of the vehicle AC generator if the number of ripples that is included in the output voltage of a rectifier is not equal to or more than a predetermined number for a predetermined period. The alarm lamp lights when the abnormality judging unit judges abnormality.

Claims

1. An abnormality detection apparatus of a vehicle AC generator including a rectifier, said abnormality detection apparatus comprising:

abnormality judging means for judging abnormality of said vehicle AC generator if the number of ripples that is detected is included in the output voltage of said rectifier for a predetermined period is not equal to or more than a predetermined number and

alarming means, connected to said abnormality judging means, for displaying an alarm when said abnormality detecting means judges said abnormality.

2. The abnormality detection apparatus of a vehicle AC generator according to claim 1, wherein

said abnormality judging means judges abnormality at every period that is in synchronism with output voltage of at least one phase-winding of a multiple phase armature winding as said predetermined period.

3. The abnormality detection apparatus of a vehicle AC generator according to claim 1, wherein

said abnormality judging means judges abnormality if the number of said ripples is equal to or more than a number defined by an expression km−

j for said predetermined period;

where m is the number of phases of said multiple phase armature winding, j is the number of said rectifiers, and k is an integer that is 1 or larger than 1.

4. The abnormality detection apparatus of a vehicle AC generator according to claim 1, characterized by further comprising conduction rate detecting means for detecting conduction rate of switching means for interrupting current supplied to a field coil of said vehicle AC generator, wherein

said alarming means stops displaying an alarm if said conduction rate is smaller than a value expressed by (2 km−

j)/2 km;

where m is the number of phases of said multiple phase armature winding, j is the number of said rectifiers and k is an integer that is 1 or larger than 1.

5. The abnormality detection apparatus of a vehicle AC generator according to claim 1, wherein at least one of elements of said rectifiers is a diode having a backward breakdown characteristic.

6. The abnormality detection apparatus of a vehicle AC generator according to claim 1, wherein

said vehicle AC generator comprises a plurality of multiple-phase windings insulated from each other and a plurality of rectifiers for respectively rectifying output voltages of said plurality of multiple phase windings.

7. The abnormality detection apparatus of a vehicle AC generator according to claim 1, wherein

said abnormality judging means judges abnormality by comparing a mean value of output voltage of said rectifiers after high harmonic frequency waves are removed therefrom with said output voltage.

8. The abnormality detection apparatus of a vehicle AC generator according to claim 1, further comprising an amplitude detecting means for detecting amplitude of said output voltage of said rectifiers, wherein

said alarming means stops displaying an alarm if said amplitude of said output voltage detected by said amplitude detecting means is equal to or smaller than a predetermined value.

9. The abnormality detection apparatus of a vehicle AC generator according to claim 1, further comprising voltage mean value detecting means, wherein

said alarming means stops displaying an alarm if said voltage mean value detected by said voltage mean value detecting means is equal to or larger than a predetermined value.

10. An abnormality detection apparatus of a vehicle AC generator including an armature winding having a plurality of phase windings, a voltage regulator and a rectifier, said abnormality detection apparatus comprising:

ripple detecting means for detecting the number of ripples included in output voltage of said rectifier for a predetermined period;

abnormality judging means for judging abnormality if said number of ripples is not equal to or more than a predetermined number; and

alarming means, connected to said abnormality judging means, for displaying an alarm when said abnormality detecting means judges abnormality.

11. The abnormality detection apparatus of a vehicle AC generator according to claim 10, wherein

said abnormality judging means judges abnormality at a timing in synchronism with output voltage of said armature winding.

12. The abnormality detection apparatus of a vehicle AC generator according to claim 11, wherein said rectifier is comprised of a plurality of Zener diodes.

13. The abnormality detection apparatus of a vehicle AC generator according to claim 12, wherein

said abnormality judging means comprises a voltage comparator and a filter, and wherein

said voltage comparator compares a mean value of output voltage of said rectifiers after high harmonic frequency waves are removed by said filter with said output voltage.

14. The abnormality detection apparatus of a vehicle AC generator according to claim 13, further comprising an amplitude detecting means for detecting amplitude of said output voltage of said rectifiers, wherein

said alarming means stops displaying an alarm if said amplitude of said output voltage detected by said amplitude detecting means is equal to or smaller than a predetermined value.