JPS6056365B2 - Abnormality detection method for electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention primarily relates to an abnormality detection method for detecting the presence of abnormal discharge inside SF6 gas equipment.

Traditionally, SF.

Among the methods for detecting abnormal discharges that occur inside gas appliances, methods for detecting micro discharges such as corona discharge include methods that detect light generated accompanying micro discharges, methods that detect sound or vibration, and methods that detect micro discharges such as corona discharges. There is a method of gas analysis of an insulating medium containing decomposed gas generated by electric discharge. The method of detecting light has drawbacks, such as the need to incorporate a detection element into the device and the need for finger tips. With methods of detecting sound or vibration, if the detection element is installed outside the device, the detection sensitivity will be affected by the surrounding noise conditions, and if the detection element is installed inside the device, the sensitivity will increase, but This method has disadvantages in that it is necessary to modify the main body of the device, and measures must be taken to prevent gas leakage. Methods based on gas analysis have the disadvantage that the increase in decomposed gas concentration is suppressed due to the influence of the adsorbent normally placed inside, so the smaller the discharge, the more difficult it is to detect.

In addition, if there is a steady microdischarge, it can be detected by occasional observation using any of the above methods, but intermittent discharges in the early stage cannot necessarily be detected by occasional observation;・Constant observation requires a large amount of money. This invention was made in order to solve the above problems, and is an adsorption/desorption method that adsorbs and desorbs a medium by temperature change in the vicinity of a detection substance that accumulates or misleads decomposition products generated by abnormal discharge. place the substance,
An object of the present invention is to provide an abnormality detection method for electrical equipment that causes a flow of a medium due to a temperature change and allows a detection substance to detect decomposition products in a high range. Hereinafter, the present invention will be specifically explained based on an illustrated embodiment.

In the figure, numeral 1 is a metal container of an electrical device (hereinafter referred to as equipment) for sealing SF6 gas, which is an insulating medium, 2 is SF6 gas (insulating medium) filled in this container 1, and 3 is High voltage conductor housed in container 1, 42,4
2 is a gas distribution pipe for circulating SF6 gas, 5 is an on-off valve,
6 is a detection section connected to the gas flow pipe 42. Also the second
The figure and FIG. 3 are enlarged views of the container of the detection unit 6. In the figure, 61 is a main container, 62 is a blank lid of the main container 61, 63 is a packing for gas-sealing the main container 61 and the blank lid 62, 641 and 642 are wire meshes through which SF6 gas can pass, and 65 is an SF6 Decomposition gas (decomposition products)
For example, silica gel is used as a gas accumulating substance (sensing substance) made of a porous material for accumulating gas.
Then, this gas accumulation substance (detection substance) 65 is transferred to the communication hole 42 of the gas circulation pipe 42 by the wire mesh 641, 642.
Inside the detection part 6 (see Figure 2) near a or the communication hole 4
2a (see FIG. 3). 66 is a synthetic zeolite (adsorption/desorption substance) that causes significant adsorption/desorption of SF6 gas due to temperature changes.

Next, the operation of the abnormality detection method J in the apparatus having such a configuration will be explained.

SF4 (sulfur tetrafluoride) generated inside SF6 gas equipment
Active fluorine-containing SF6 decomposition gases (decomposition products) such as SOF2 (thionyl fluoride) and HF (hydrogen fluoride) undergo diffusion,
It diverges into the surrounding gas space by convection.

Operating equipment not only generates heat when electricity is turned on, but also rises in temperature due to direct sunlight. That is, at night, the detection section 6 cools down faster than the main body of the device, and therefore SF6 gas flows in from the device side. At this time, the SF6 decomposition gas (decomposition product) contained in the SF6 gas is adsorbed by the gas accumulation substance (sensing substance) near the communication hole 42a of the gas circulation pipe 42. The synthetic zeolite (adsorbent material) 66 of the detection unit 6, which has been exposed to direct sunlight again, releases the adsorbed SF6 gas as the temperature rises.

In this way, the adsorption/desorption material 66 which performs a significant adsorption/desorption action on SF6 gas due to temperature changes is arranged in the main body container 61 together with the gas accumulating material 65. Because of the flow, the SF6 separation gas (decomposition products) can accumulate in the gas accumulating material (sensing material) 65 at a high concentration.

Although the concentration of SF6 decomposed gas inside the equipment is reduced by adsorbents such as synthetic zeolite that are normally installed inside the equipment, by using a large amount of synthetic zeolite compared to the adsorbents inside these equipment, A high concentration of SF6 decomposition gas can be accumulated.

Samples are taken once every six months or one year during the operating period of the device, and the presence or absence of discharge is determined by measuring the amount of F in the accumulated portion. In the above example, a silica gel-based porous material was used as an example of the gas accumulating material (detection material) 65, but it has a good adsorption ability for SF6 decomposed gas and does not release interfering ions to the extract side during measurement. The more difficult the substance is, the higher the detection sensitivity becomes.

Furthermore, instead of the decomposed gas-accumulating substance, a detection substance such as a substance or reagent that changes color upon reaction with the SF6 decomposed gas can also be used. As described above, according to the present invention, the following effects can be obtained.

(1) Even in minute discharges or intermittent initial discharges, decomposition gas (decomposition products) can be accumulated by the detection substance, so highly sensitive detection is possible.

(2) Since an adsorbing/desorbing substance that significantly adsorbs/desorbs SF6 gas due to temperature changes is arranged together with a detection substance such as a gas accumulating substance, a flow of SF6 gas is generated due to temperature changes.

In other words, since no external driving force is required to move the insulating medium, there are almost no defects caused by installing the detection section. (3) The SF6 decomposed gas component (F- ion) can be easily extracted from the accumulated material using pure water, etc., and does not require complicated analysis operations.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an embodiment of an abnormality detection method according to the present invention, Fig. 2 is a detailed structural diagram of the detection section, and Fig. 3 is an SF6
FIG. 2 is a detailed structural diagram showing an example of a case where an SF6 decomposed gas accumulation substance is arranged in a gas flow pipe. 1... Metal container, 2... SF6 gas (insulating medium), 3... High voltage conductor, 41, 42...
...Pipe, 5...Opening/closing valve, 6...Detection part,
61... Main container, 62... Blind lid, 63...
... Backing, 641, 642 ... Wire mesh, 65 ... Detection substance, 66 ... Adsorption/desorption substance.

Claims (1)

[Scope of Claims] 1. Electrical equipment in which a high voltage conductor is housed in an interior filled with an insulating medium such as SF_6 gas, and the above-mentioned electrical equipment that is connected to this electrical equipment and occurs when abnormal discharge occurs in the electrical equipment. a detection unit that detects the abnormal discharge by accumulating and sensing decomposition products of the medium; and a detection unit that is disposed within or near the detection unit and that accumulates or senses the decomposition products and detects the presence of the abnormal discharge. A substance and an absorbent disposed near the sensing substance, which adsorbs and desorbs the insulating medium according to temperature changes, causes a flow of the insulating medium, and allows the sensing substance to perform detection in a high range.・Anomaly detection method for electrical equipment equipped with desorbable substances. 2. An abnormality detection method for an electrical device according to claim 1, characterized in that the detection substance is disposed within the detection section or at a connection between the electrical device and the detection section. 3. An abnormality detection system for electrical equipment according to claim 1 or 2, characterized in that a silica gel-based porous substance is used as the detection substance. 4. An abnormality detection system for electrical equipment according to claim 1, characterized in that a substance that adsorbs a large amount of SF_6 gas, such as synthetic zeolite or activated carbon, is used as the adsorption/desorption substance.