Electromagnetic relay diagnostic device

Patent metadata

Field	Value
Publication number	US-11488797-B2
Application number	US-201816957230-A
Country	US
Kind code	B2
Filing date	Feb 13, 2018
Priority date	Feb 13, 2018
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

An electromagnetic relay diagnostic device includes: an operation detection unit including a first light-emitting unit emitting light when a current flows through a wiring line connected to a coil of an electromagnetic relay; an operation detection unit including a second light-emitting unit emitting light when a current stops flowing through the wiring line; an operation detection unit including a third light-emitting unit emitting light when detecting a change in conductive state of a wiring line connected to a contact of the electromagnetic relay; an operation detection unit including a fourth light-emitting unit emitting light when detecting that the change in conductive state of the wiring line has disappeared; an imaging unit capturing a moving image of the operation detection units; and a diagnostic unit calculating a contact-on operation time and a contact-off operation time using the moving image, and diagnosing whether an abnormality has occurred in the electromagnetic relay.

First claim

The invention claimed is:

1. An electromagnetic relay diagnostic device, comprising:
a first operation detection unit including a first light-emitting unit to emit light when a current flows through a first wiring line connected to a coil of an electromagnetic relay;
a second operation detection unit including a second light-emitting unit to emit light when a current stops flowing through the first wiring line;
a third operation detection unit including a third light-emitting unit to emit light when detecting a change in conductive state of a second wiring line connected to a contact of the electromagnetic relay;
a fourth operation detection unit including a fourth light-emitting unit to emit light when detecting that the change in conductive state of the second wiring line has disappeared;
an imaging unit to capture a moving image of the first operation detection unit, the second operation detection unit, the third operation detection unit, and the fourth operation detection unit; and
a diagnostic unit to calculate, by using the moving image, a contact-on operation time that is a time from when a current starts flowing through the first wiring line until when a conductive state of the second wiring line changes and a contact-off operation time that is a time from when a current stops flowing through the first wiring line until when the change in conductive state of the second wiring line disappears, and to diagnose whether or not an abnormality has occurred in the electromagnetic relay on the basis of the contact-on operation time and the contact-off operation time calculated.

2. The electromagnetic relay diagnostic device according to claim 1 , wherein when at least one of the contact-on operation time and the contact-off operation time exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in the electromagnetic relay.

3. The electromagnetic relay diagnostic device according to claim 2 , comprising:
a storage unit to store measurement results of the contact-on operation time and the contact-off operation time, wherein
the diagnostic unit obtains the amount of increase with time in each of the contact-on operation time and the contact-off operation time from the contact-on operation time and the contact-off operation time at the time of previous measurement, which are stored in the storage unit and the contact-on operation time and the contact-off operation time at the time of current measurement, and when at least one of the amount of increase with time in the contact-on operation time and the amount of increase with time in the contact-off operation time exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in the electromagnetic relay.

4. The electromagnetic relay diagnostic device according to claim 2 , wherein when an operation time of a control sequence of a control circuit including two or more electromagnetic relays corresponding to the electromagnetic relay within an imaging range of the imaging unit exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in at least any one of the electromagnetic relays included in the control circuit.

5. The electromagnetic relay diagnostic device according to claim 1 , wherein
the diagnostic unit calculates the contact-on operation time from a difference between a frame number of the moving image at the time of light emission of the first light-emitting unit and a frame number of the moving image at the time of light emission of the third light-emitting unit, and a frame rate, and
calculates the contact-off operation time from a difference between a frame number of the moving image at the time of light emission of the second light-emitting unit and a frame number of the moving image at the time of light emission of the fourth light-emitting unit, and a frame rate.

6. The electromagnetic relay diagnostic device according to claim 5 , comprising:
a storage unit to store measurement results of the contact-on operation time and the contact-off operation time, wherein
the diagnostic unit obtains the amount of increase with time in each of the contact-on operation time and the contact-off operation time from the contact-on operation time and the contact-off operation time at the time of previous measurement, which are stored in the storage unit and the contact-on operation time and the contact-off operation time at the time of current measurement, and when at least one of the amount of increase with time in the contact-on operation time and the amount of increase with time in the contact-off operation time exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in the electromagnetic relay.

7. The electromagnetic relay diagnostic device according to claim 5 , wherein when an operation time of a control sequence of a control circuit including two or more electromagnetic relays corresponding to the electromagnetic relay within an imaging range of the imaging unit exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in at least any one of the electromagnetic relays included in the control circuit.

8. The electromagnetic relay diagnostic device according to claim 1 , wherein
the first operation detection unit includes a first Rogowski coil for detecting that a current has started flowing through the first wiring line,
the second operation detection unit includes a second Rogowski coil for detecting that a current has stopped flowing through the first wiring line,
the third operation detection unit includes a third Rogowski coil for detecting a change in conductive state of the second wiring line, and
the fourth operation detection unit includes a fourth Rogowski coil for detecting that the change in conductive state of the second wiring line has disappeared.

9. The electromagnetic relay diagnostic device according to claim 8 , comprising:
a storage unit to store measurement results of the contact-on operation time and the contact-off operation time, wherein
the diagnostic unit obtains the amount of increase with time in each of the contact-on operation time and the contact-off operation time from the contact-on operation time and the contact-off operation time at the time of previous measurement, which are stored in the storage unit and the contact-on operation time and the contact-off operation time at the time of current measurement, and when at least one of the amount of increase with time in the contact-on operation time and the amount of increase with time in the contact-off operation time exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in the electromagnetic relay.

10. The electromagnetic relay diagnostic device according to claim 8 , wherein when an operation time of a control sequence of a control circuit including two or more electromagnetic relays corresponding to the electromagnetic relay within an imaging range of the imaging unit exceeds a management value therefor, the diagnostic unit diagnoses that an abnormality has occurred in at least any one of the electromagnetic relays included in the control circuit.

11. The electromagnetic relay diagnostic device according to claim 1 , wherein
the first operation detection unit includes a first split-core current transformer to detect that a current has started flowing through the first wiring line,
the second operation detection unit includes a second split-core current transformer to detect that a current has stopped flowing through the first wiring line,
the third operation detection unit includes a third split-co

Assignees

• Mitsubishi Electric Corp

Inventors

• Fujioka Katsuhiko

Classifications

• H01H47/00

  Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current · CPC title

• H01H50/08

  Indicators; Distinguishing marks · CPC title

• H01H9/161

  comprising light emitting elements · CPC title

• H01H47/002 Primary

  Monitoring or fail-safe circuits · CPC title

• G01R31/3278

  of relays, solenoids or reed switches (measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002) · CPC title