Device with overvoltage protection and method for its testing

Patent metadata

Field	Value
Publication number	US-9396848-B2
Application number	US-201113326942-A
Country	US
Kind code	B2
Filing date	Dec 15, 2011
Priority date	Dec 16, 2010
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

Exemplary embodiments are directed to a device with overvoltage protection that includes a varistor which can be connected by a first connection via a first line to high-voltage potential in a circuit arrangement, while a second connection is connected to ground via a second line. Furthermore, an additional impedance is provided, which can be connected between the second connection and ground or the first connection and the high voltage, or is mounted fixed in this position. The corresponding line can be interrupted by a switching arrangement. In order to test the withstand voltage of the circuit arrangement, at least one of the first and second line is interrupted and an additional impedance is inserted. A test voltage is applied to the circuit arrangement. After the overvoltage test, the interruption in at least one of the first and second lines is removed again.

First claim

What is claimed is:

1. A device having overvoltage protection for carrying out an overvoltage test in a circuit arrangement to which at least one surge arrestor is connected, comprising:
a varistor which can be connected to high voltage potential at a first connection and can be connected to ground at a second connection;
a first line, via which the first connection can be connected to the high voltage potential;
a second line, via which the second connection can be connected to ground;
at least one additional impedance, which has a higher impedance than the first or second line and which can be arranged between the first connection and the high voltage, and/or between the second connection and ground;
a mechanical switching arrangement for interrupting the first or second line during the overvoltage test; and
an encapsulation that encloses an insulating gas or an insulating liquid, wherein the varistor and the additional impedance are arranged in the encapsulation,
wherein the switching arrangement has a switch which is arranged in the encapsulation and is operated through the encapsulation, and
wherein the switch has a moving element which extends through the encapsulation and is held movably in a gas tight bushing.

2. The device as claimed in claim 1 , wherein the movable element is electrically conductive and forms part of the first or second line.

3. A device having overvoltage protection for carrying out an overvoltage test in a circuit arrangement to which at least one surge arrestor is connected, comprising:
a varistor which can be connected to high voltage potential at a first connection and can be connected to ground at a second connection;
a first line, via which the first connection can be connected to the high voltage potential;
a second line, via which the second connection can be connected to ground;
at least one additional impedance, which has a higher impedance than the first or second line and which can be arranged between the first connection and the high voltage, and/or between the second connection and ground;
a mechanical switching arrangement for interrupting the first or second line during the overvoltage test; and
an encapsulation that encloses an insulating gas or an insulating liquid, wherein the varistor and the additional impedance are arranged in the encapsulation,
wherein the switching arrangement has a switch which is arranged in the encapsulation and is operated through the encapsulation, and
wherein the switch has a movable element which is operated by a magnet arrangement.

4. The device as claimed in claim 1 , comprising:
an encapsulation that encloses an insulating gas or an insulating liquid in a sealed manner, wherein the varistor is arranged in the encapsulation, and wherein the switching arrangement is arranged outside the encapsulation.

5. A device having overvoltage protection for carrying out an overvoltage test in a circuit arrangement to which at least one surge arrestor is connected, comprising:
a varistor which can be connected to high voltage potential at a first connection and can be connected to ground at a second connection;
a first line, via which the first connection can be connected to the high voltage potential;
a second line, via which the second connection can be connected to ground;
at least one additional impedance, which has a higher impedance than the first or second line and which can be arranged between the first connection and the high voltage, and/or between the second connection and ground;
an encapsulation that encloses an insulating gas or an insulating liquid in a sealed manner, wherein the varistor is arranged in the encapsulation, and wherein the switching arrangement is arranged outside the encapsulation; and
an electrically conductive, removable grounding element, arranged between the second connection and ground, or having an electrically conductive, removable bridging element arranged between the first connection and high voltage potential.

6. The device as claimed in claim 5 , wherein the grounding element is disposed into a depression or an external contour of the device.

7. The device as claimed in claim 1 , comprising:
an encapsulation that encloses an insulating gas or an insulating liquid in a sealed manner, wherein the varistor is arranged in the encapsulation, and wherein the additional impedance is arranged outside the encapsulation.

8. The device as claimed in claim 7 , wherein the additional impedance is arranged in an additional module, and wherein the grounding element and/or the bridging element and the additional module are alternatively fitted to the encapsulation.

9. The device as claimed in claim 1 , wherein the additional impedance is arranged between the second connection and ground.

10. The device as claimed in claim 1 , wherein the additional impedance has a capacitive and/or resistive impedance value.

11. The device as claimed in claim 1 , wherein the additional impedance has an impedance value which decreases as the voltage increases.

12. The device as claimed in claim 1 , wherein the device is a surge arrester or a bushing.

Assignees

• Fuechsle Dieter
• Neeser Daniel
• Doser Bernhard
• Müller Daniel
• Ljuslinder Marlene
• Greuter Felix
• Abb Research Ltd

Inventors

• Fuechsle Dieter
• Neeser Daniel
• Doser Bernhard
• Müller Daniel
• Ljuslinder Marlene
• Greuter Felix

Classifications

• H02H3/048

  Checking overvoltage diverters · CPC title

• H02G13/80

  Discharge by conduction or dissipation, e.g. rods, arresters, spark gaps · CPC title

• H01C7/12 Primary

  Overvoltage protection resistors; Arresters · CPC title

• H01C1/024

  the housing or enclosure being hermetically sealed (H01C1/028, H01C1/032, H01C1/034 take precedence) · CPC title

• G01R31/58

  Testing of lines, cables or conductors (testing of electric windings G01R31/72) · CPC title