Method of detecting metal oxide varistor (MOV) failure within a surge protection device

Patent metadata

Field	Value
Publication number	US-9784785-B2
Application number	US-201414564208-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Dec 9, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

An example method for monitoring the operation of a metal-oxide varistor (MOV) may involve monitoring an operating value of at least one parameter of the MOV using at least one sensor. Further, the method may involve determining, using one or more processors, that a difference between the operating value and a reference value corresponding to the at least one parameter satisfies a predetermined threshold condition corresponding to the at least one parameter. And the method may involve responsive to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition, transmitting a notification indicative of a potential failure of the MOV to at least one device.

First claim

What is claimed is:

1. A method for monitoring the operation of a metal-oxide varistor (MOV), comprising:
monitoring an operating value of at least one parameter of the MOV using at least one sensor;
determining, using one or more processors, that a difference between the operating value and a reference value corresponding to the at least one parameter satisfies a predetermined threshold condition corresponding to the at least one parameter;
determining, using the one or more processors, an estimated remaining useful life of the MOV based at least on an operating temperature of the MOV, and providing an indication of the estimated remaining useful life of the MOV; and
responsive to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition, transmitting a notification indicative of a potential failure of the MOV.

2. The method of claim 1 , wherein the MOV is a component of a surge protection device (SPD).

3. The method of claim 2 , further comprising, responsive to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition, triggering a predetermined safety-related action for a power system in which the SPD is installed.

4. The method of claim 1 , wherein the at least one parameter of the MOV comprises a parameter selected from the group consisting of: a temperature of the MOV; a current flow through the MOV; and a conduction voltage of the MOV.

5. The method of claim 1 :
wherein the at least one parameter of the MOV comprises a temperature of the MOV,
wherein the reference value corresponding to the temperature of the MOV comprises an ambient temperature, and
wherein the predetermined threshold condition corresponding to the temperature of the MOV comprises the difference between the operating value of the temperature of the MOV and the ambient temperature being greater than a predetermined threshold.

6. The method of claim 1 :
wherein the at least one parameter of the MOV comprises a current flow through the MOV,
wherein the reference value corresponding to the current flow through the MOV comprises a reference current flow through a reference MOV known to be operating in a desired manner, and
wherein the predetermined threshold condition corresponding to the current flow through the MOV comprises the difference between the operating value of the current flow through the MOV and the current flow through the reference MOV being greater than a predetermined threshold.

7. The method of claim 1 :
wherein the at least one parameter of the MOV comprises a current flow through the MOV,
wherein the reference value corresponding to the current flow through the MOV comprises a current threshold, and
wherein the predetermined threshold condition corresponding to the current flow through the MOV comprises the current flow through the MOV being greater than the current threshold.

8. The method of claim 1 :
wherein the at least one parameter of the MOV comprises a conduction voltage of the MOV,
wherein the reference value corresponding to the conduction voltage of the MOV comprises a reference conduction voltage through a reference MOV known to be operating in a desired manner, and
wherein the predetermined threshold condition corresponding to the conduction voltage of the MOV comprises the difference between the operating value of the conduction voltage of the MOV and the conduction voltage through the reference MOV being greater than a predetermined threshold.

9. The method of claim 1 :
wherein the at least one parameter of the MOV comprises a conduction voltage of the MOV,
wherein the reference value corresponding to the conduction voltage of the MOV comprises a nominal voltage of a power system of which the MOV is a component, and
wherein the predetermined threshold condition corresponding to the conduction voltage of the MOV comprises the conduction voltage of the MOV being less than the nominal voltage of the power system.

10. An apparatus for monitoring the operation of a metal-oxide varistor (MOV), comprising:
at least one sensor configured to monitor an operating value of at least one parameter of the MOV;
a communication interface through which the apparatus is configured to transmit notifications; and
a controller arranged to: (i) determine that a difference between the operating value and a reference value corresponding to the at least one parameter satisfies a predetermined threshold condition corresponding to the at least one parameter, (ii) determine an estimated remaining useful life of the MOV based at least on an operating temperature of the MOV, and providing an indication of the estimated remaining useful life of the MOV, and (iii) cause the apparatus to transmit a notification indicative of a potential failure of the MOV to at least one device in response to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition.

11. The apparatus of claim 10 , wherein the MOV is a component of a surge protection device (SPD).

12. The apparatus of claim 11 , wherein the controller is further arranged to trigger a predetermined safety-related action for a power system in which the SPD is installed in response to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition.

13. The apparatus of claim 10 , wherein the at least one parameter of the MOV comprises a parameter selected from the group consisting of: a temperature of the MOV; a current flow through the MOV; and a conduction voltage of the MOV.

14. The apparatus of claim 10 , wherein the at least one sensor comprises a sensor selected from the group consisting of: a thermocouple, an infrared temperature sensor, an electromechanical sensor, an optomechanical sensor, an electropnuematic sensor, and an electrical sensor.

15. A non-transitory computer-readable medium having stored therein instructions, that when executed by one or more processors of a computing device, cause the computing device to perform functions comprising:
monitoring an operating value of at least one parameter of a metal-oxide varistor (MOV) using at least one sensor;
determining that a difference between the operating value and a reference value corresponding to the at least one parameter satisfies a predetermined threshold condition corresponding to the at least one parameter;
determining, using one or more processors, an estimated remaining useful life of the MOV based at least on an operating temperature of the MOV, and providing an indication of the estimated remaining useful life of the MOV; and
responsive to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition, transmitting a notification indicative of a potential failure of the MOV.

16. The non-transitory computer-readable medium of claim 15 , wherein the at least one parameter of the MOV comprises a parameter selected from the group consisting of: a temperature of the MOV; a current flow through the MOV; and a conduction voltage of the MOV.

17. The non-transitory computer-readable medium of claim 15 :
wherein the at least one parameter of the MOV comprises a temperature of the MOV,
wherein the reference value corresponding to the temperature of the MOV comprises an ambient temperature, and
wherein the predetermined threshold condition corresponding to the temperature of the MOV comprises the differenc

Assignees

• Asco Power Technologies Lp

Inventors

• Farquhar Iii Louis A
• Gerlach Michael J

Classifications

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H02H9/042

  comprising means to limit the absorbed power or indicate damaged over-voltage protection device · CPC title

• G01R31/2827 Primary

  Testing of electronic protection circuits (testing switches G01R31/327; checking alarm systems G08B29/00; self test of summation current transformers H02H3/335) · CPC title

• G01R31/003 Primary

  Environmental or reliability tests (of individual semiconductors G01R31/2642; of PCB's G01R31/2817; of IC's G01R31/2855; of other circuits G01R31/2849) · CPC title