HIGH-VOLTAGE BUSHING AND METHOD FOR MONITORING ITS OPERATION

Abstract

A high-voltage bushing has an insulator, which contains an insulating gas and an insulating solid, and an inner conductor which is led through the insulator. A mounting flange is employed for the mounting of the high-voltage bushing on a wall. A sensor, which is arranged on the mounting flange and is configured for the detection of at least one reaction product of the insulating gas and/or of the insulating solid. A corresponding method monitors an operating state of the high-voltage bushing.

Claims

1. A high-voltage bushing, comprising: an insulator having an insulating gas and an insulating solid; an inner conductor being led through said insulator; a mounting flange; and a sensor disposed on said mounting flange and configured for a detection of at least one reaction product of said insulating gas and/or of said insulating solid.

2. The high-voltage bushing according to claim 1, wherein said insulator has a resin-impregnated active part and a secondary insulation containing the insulating gas.

3. The high-voltage bushing according to claim 1, wherein said insulating gas is SF.sub.6.

4. The high-voltage bushing according to claim 1, wherein said at least one reaction product consists of at least one gas selected from the group consisting of: SO.sub.2, H.sub.2, CH.sub.4, CO and CO.sub.2.

5. The high-voltage bushing according to claim 1, wherein the high-voltage bushing is a DC voltage bushing for an insulation of a DC voltage.

6. A method for monitoring an operating state of a high-voltage bushing having an insulator with an insulating gas and an insulating solid, an inner conductor which is led through the insulator, a mounting flange, and a sensor, which comprises the steps of: detecting, by means of the sensor being disposed on the mounting flange, at least one reaction product of the insulating gas and/or of the insulating solid; and generating and evaluating a measuring signal.

7. The method according to claim 6, wherein, for a detection of the reaction product, extracting a gas sample from a gas compartment of the insulator and feeding the gas sample to the sensor.

8. The method according to claim 7, wherein the gas sample is repeatedly extracted at time intervals of at least 24 hours.

9. The method according to claim 6, wherein the evaluating step includes a comparison with predefined reference data.

10. The method according to claim 6, wherein the evaluating step includes a detection of a partial discharge in the high-voltage bushing.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0021] The figure of the drawing is an illustration of an exemplary embodiment of a high-voltage bushing according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022] Referring now to the single figure of the drawing in detail, there is shown a high-voltage bushing 1. The high-voltage bushing 1 contains an insulator 2. A tubular inner conductor 3 is led through the insulator 2.

[0023] The insulator 2 contains a housing 4 which, in the example represented in the figure, is formed of a porcelain body. The housing 4 extends between a head fitting 5 and a mounting flange 6. During the operation of the high-voltage bushing 1, the inner conductor 3 is at an electrical potential in excess of 100 kV, whereas the mounting flange 6 is essentially at ground potential. Alternatively, the housing can be comprised, for example, of a glass fiber-reinforced epoxy resin tube, onto which shields of silicone elastomer are vulcanized.

[0024] The insulator 2 contains an active part 7, which is comprised of insulating layers of paper or synthetic fabric which are impregnated with an epoxy resin. The active part 7 further contains coaxially arranged control inserts of aluminum foil, which are arranged in the region of the active part which is represented by a broken line 8, and are responsible for uniform voltage distribution on the insulator 2. Between the housing 4 and the active part, a gas compartment 9 is situated, which is at least partially filled with an insulating gas and a secondary insulation of dry foam. The insulator 2 thus contains a plurality of insulating solids, particularly resin, paper or fabric and dry foam.

[0025] On the mounting flange 4, a sensor 10 is arranged, which is connected to the gas compartment 9 by means of a feeder line 11. A sample of the insulating gas can be fed to the sensor by means of the feeder line 11. The sensor 10 is further connected by means of an electric cable connection 12 to an evaluation unit 13. The evaluation unit 13 is configured to evaluate a measuring signal which is delivered by means of the sensor 10, and to generate corresponding fault indicators.

[0026] The fundamental operating principle of a monitoring function of the high-voltage bushing 1 can be described as follows. At regular intervals (for example, once daily), a gas sample is fed to the sensor 10 via the feeder line 11. The sensor 10 can detect the reaction products of the insulating gas or the insulating solids associated with the occurrence of a fault in the gas compartment 9. Thereafter, the sensor 10 generates a measuring signal, which contains information on reaction products identified in the gas sample. The measuring signal is then relayed to the evaluation unit 13. The evaluation unit 13 executes an analysis of the measuring signal and, by way of an analysis result, for example, delivers a categorization of the operating state. Alternatively, the analysis is executed by means of the sensor 10 itself, wherein the result is routed to a superordinate monitoring unit. On the basis of the result, measures are optionally implemented, such as maintenance measures and/or a disconnection.