Method for monitoring vacuum interrupter's condition and an electric switching device

Patent metadata

Field	Value
Publication number	US-12217922-B2
Application number	US-202017802115-A
Country	US
Kind code	B2
Filing date	Feb 24, 2020
Priority date	Feb 24, 2020
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

Embodiments relate to a method for monitoring the vacuum interrupter's condition of an electric device. The method comprises receiving a first voltage signal indicating a first voltage at a first contact of a switch inside the electric device. The first contact of the switch is coupled to a source line. The method further comprises receiving a second voltage signal indicating a second voltage at a second contact of the switch. The second contact of the switch is coupled to a reactive component. The method comprises receiving a current signal indicating a current at the second contact of the switch. The method comprises determining occurrence of a restrike in response to determining increasing amplitudes of the first voltage signal, the second voltage signal and the current signal in a time slot. The method further comprises determining the vacuum interrupter condition based on the determined occurrence of the restrike.

First claim

What is claimed is:

1. A method for monitoring a condition of a vacuum interrupter of an electric device, comprising:
receiving a first voltage signal indicating a first voltage between a source line and a first contact of a switch inside the electric device, the first contact of the switch coupled to the source line;
receiving a second voltage signal indicating a second voltage between a second contact of the switch and a reactive component, the second contact of the switch coupled to the reactive component;
receiving a current signal indicating a current at the second contact of the switch;
determining an occurrence of a restrike in response to determining a simultaneous increase in amplitudes of the first voltage signal, the second voltage signal, and the current signal; and
determining the condition of the vacuum interrupter based on the determined occurrence of the restrike, wherein determining the condition of the vacuum interrupter based on the determined occurrence of the restrike comprises either
counting a number of switching operations, between open and closed, performed by the switch in a time period, counting a number of determined occurrences of the restrike in the time period, computing a ratio of the counted number of the determined occurrences of the restrike to the counted number of the switching operation, and determining an unacceptable vacuum condition in response to determining that the computed ratio exceeds a predetermined ratio value, or
in response to determining the restrike, counting a number of switching operations, between open and closed, that are performed by the switch in a time period between the restrike and a subsequent determined restrike, and determining an unacceptable vacuum interrupter's condition in response to the number of the switching operations being below a predetermined number.

2. The method of claim 1 , wherein determining the occurrence of the restrike comprises:
determining, based on the first voltage signal, the first voltage exceeding a first predetermined voltage value;
determining, based on the second voltage signal, the second voltage exceeding a second predetermined voltage value; and
determining, based on the current signal, the current exceeding a predetermined current value.

3. The method of claim 1 , wherein the first contact is a fixed contact, and wherein the second contact is a movable contact.

4. The method of claim 3 , further comprising:
sending, prior to determining the occurrence of the restrike, an interruption signal to an actuator of the electric device to cause the movable contact to separate from the fixed contact.

5. The method of claim 1 , further comprising:
in response to determining the unacceptable condition of the vacuum interrupter, sending an alert signal via a transceiver of an electronic device to a remote center to indicate a requirement of replacement for the electric device.

6. The method of claim 1 , wherein the reactive component comprises a capacitor.

7. An electronic device comprising:
one or more processors; and
a computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by the one or more processors of the electronic device, cause the electronic device to
receive a first voltage signal indicating a first voltage between a source line and a first contact of a switch inside an electric device, the first contact of the switch coupled to the source line,
receive a second voltage signal indicating a second voltage between a second contact of the switch and a reactive component, the second contact of the switch coupled to the reactive component,
receive a current signal indicating a current at the second contact of the switch,
determine an occurrence of a restrike in response to determining a simultaneous increase in amplitudes of the first voltage signal, the second voltage signal, and the current signal, and
determine a condition of a vacuum interrupter based on the determined occurrence of the restrike, wherein determining the condition of the vacuum interrupter based on the determined occurrence of the restrike comprises either
counting a number of switching operations, between open and closed, performed by the switch in a time period, counting a number of determined occurrences of the restrike in the time period, computing a ratio of the counted number of the determined occurrences of the restrike to the counted number of the switching operation, and determining an unacceptable vacuum condition in response to determining that the computed ratio exceeds a predetermined ratio value, or
in response to determining the restrike, counting a number of switching operations, between open and closed, that are performed by the switch in a time period between the restrike and a subsequent determined restrike, and determining an unacceptable vacuum interrupter's condition in response to the number of the switching operations being below a predetermined number.

8. The electronic device of claim 7 , wherein determining the occurrence of the restrike comprises:
determining, based on the first voltage signal, the first voltage exceeding a first predetermined voltage value;
determining, based on the second voltage signal, the second voltage exceeding a second predetermined voltage value; and
determining, based on the current signal, the current exceeding a predetermined current value.

9. The electronic device of claim 7 , wherein the electronic device further comprises a transceiver, and wherein the instructions further cause the electronic device to:
in response to determining the unacceptable condition of the vacuum interrupter, send an alert signal via the transceiver to a remote center to indicate a requirement of replacement for the electric device.

10. The electronic device of claim 7 , wherein the first contact is a fixed contact, and wherein the second contact is a movable contact.

11. The electronic device of claim 10 , wherein the instructions further cause the electronic device to:
send, prior to determining the occurrence of the restrike, an interruption signal to an actuator of the electric device to cause the movable contact to separate from the fixed contact.

12. The electronic device of claim 7 , wherein the reactive component comprises a capacitor.

13. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by the one or more processors of an electronic device, cause the electronic device to:
receive a first voltage signal indicating a first voltage between a source line and a first contact of a switch inside an electric device, the first contact of the switch coupled to the source line;
receive a second voltage signal indicating a second voltage between a second contact of the switch and a reactive component, the second contact of the switch coupled to the reactive component;
receive a current signal indicating a current at the second contact of the switch;
determine an occurrence of a restrike in response to determining a simultaneous increase in amplitudes of the first voltage signal, the second voltage signal, and the current signal; and
determine a condition of a vacuum interrupter based on the determined occurrence of the restrike, wherein determining the condition of the vacuum interrupter based on the determined occurrence of the restrike comprises either
counting a number of switching operations, between open and closed, performed by the switch in a time period, counting a number of determined occurrences of the restrike in the time period, computing a

Assignees

• Hitachi Energy Ltd

Inventors

• Bachorz Lukasz
• Heemskerk Timothy John

Classifications

• G01R31/3275

  Fault detection or status indication · CPC title

• H01H33/668 Primary

  Means for obtaining or monitoring the vacuum · CPC title