CIRCUIT INTERRUPTER EMPLOYING A LINEAR TRANSDUCER TO MONITOR CONTACT EROSION

• US 20140090965A1
• Filed: 10/03/2012
• Published: 04/03/2014
• Est. Priority Date: 10/03/2012
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Leccia, Brad R., Yanniello, Robert, Castelein, Steven, De Jong, Johan
• Granted Patent: US 8,952,826 B2
• Time in Patent Office: Days
• US Class Current: 200/308
• CPC Class Codes: G01R 31/3274 Details related to measuring, e.g. sensing, displaying or computing; Measuring of variables related to the contact pieces, e.g. wear, position or resistance measuring contact resistance G01R27/205
• CPC Class Codes: H01H 1/0015 Means for testing or for inspecting contacts, e.g. wear indicator measuring circuits G01R31/3274
• CPC Class Codes: H01H 11/0062 Testing or measuring non-electrical properties of switches, e.g. contact velocity monitoring contacts H01H1/0015; monitoring gas density H01H33/563; monitoring vacuum H01H33/668; calibrating H01H69/01; adjusting H01H71/74; testing of electrical properties G01R31/333
• CPC Class Codes: H01H 33/6662 using bistable electromagnetic actuators, e.g. linear polarised electromagnetic actuators

Abstract

A circuit interrupter includes, a first contact and a second contact, the second contact being moveable relative to the first contact, a drive assembly structured to move the second contact relative to the first contact, and an erosion monitoring device including a linear transducer coupled to a portion of the drive assembly. The liner transducer is structured to generate an output signal representative of an amount of linear displacement of the portion of the drive assembly, wherein the erosion monitoring device is structured to monitor a degree of erosion of at least one of the first contact and the second contact based on the output signal.

Claims

1. A circuit interrupter, comprising:

a first contact and a second contact, the second contact being moveable relative to the first contact;

a drive assembly structured to move the second contact relative to the first contact; and

an erosion monitoring device including a linear transducer coupled to a portion of the drive assembly, the liner transducer being structured to generate an output signal representative of an amount of linear displacement of the portion of the drive assembly, wherein the erosion monitoring device is structured to monitor a degree of erosion of at least one of the first contact and the second contact based on the output signal.

2. The circuit interrupter according to claim 1, wherein the portion of the drive assembly includes a rod member, and wherein the drive assembly also includes a spring coupled to the rod member and the second contact.

3. The circuit interrupter according to claim 2, wherein a push rod is proved between the spring and the second contact.

4. The circuit interrupter according to claim 3, wherein the spring is provided within a housing coupled to the rod member.

5. The circuit interrupter according to claim 2, wherein the first contact and the second contact are provided as part of a vacuum interrupter within a vacuum chamber.

6. The circuit interrupter according to claim 5, wherein at least the vacuum interrupter and the drive assembly are provided within a main housing, and wherein the first contact is fixed relative to the main housing.

7. The circuit interrupter according to claim 2, wherein the erosion monitoring device includes a control unit (36) coupled to the linear transducer, the control unit being structured to receive the output signal and monitor the degree of erosion of at least one of the first contact and the second contact based on the output signal.

8. The circuit interrupter according to claim 7, wherein the control unit is structured to determine a velocity or an acceleration of the portion of the drive assembly based on the output signal responsive to the circuit interrupter moving from a closed condition in which the first contact engages the second contact to an open condition in which the first contact does not engage the second contact and monitor the degree of erosion of at least one of the first contact and the second contact based on the velocity or the acceleration.

9. The circuit interrupter according to claim 1, wherein the linear transducer is a linear variable differential transformer (LVDT).

10. A method of monitoring a degree of erosion of at least one of a first contact and a second contact of a circuit interrupter having a drive assembly structured to move the second contact relative to the first contact, the method comprising:

measuring an amount of linear displacement of a portion of the drive assembly responsive to the circuit interrupter moving from a closed condition in which the first contact engages the second contact to an open condition in which the first contact does not engage the second contact; and

determining that the degree of erosion has at least reached a predetermined level based on the measured amount of linear displacement.

11. The method according to claim 10, wherein the determining step includes determining a velocity or an acceleration of the portion of the drive assembly based on the measured amount of linear displacement and determining that the degree of erosion has at least reached a predetermined level based on the velocity or the acceleration.

12. The method according to claim 11, wherein the portion of the drive assembly includes a rod member, and wherein the drive assembly also includes a spring coupled to the rod member and the second contact.

13. The method according to claim 12, wherein a push rod is proved between the spring and the second contact.

14. The method according to claim 13, wherein the spring is provided within a housing coupled to the rod member.

15. The method according to claim 12, wherein the first contact and the second contact are provided as part of a vacuum interrupter within a vacuum chamber.

16. The method according to claim 15, wherein at least the vacuum interrupter and the drive assembly are provided within a main housing, and wherein the first contact is fixed relative to the main housing.

17. The method according to claim 10, wherein the measuring an amount of linear displacement of a portion of the drive assembly employs a linear transducer coupled the portion of the drive assembly and structured to generate an output signal representative of the amount of linear displacement of the portion of the drive assembly.

18. The method according to claim 17, wherein the linear transducer is a linear variable differential transformer (LVDT).