JPH0452567A - Method for diagnosing abnormality within oil-immersed electrical equipment and diagnosis diagram used for it - Google Patents

Abstract

PURPOSE:To enable presence or absence of abnormality to be judged at a glance without making comparison with abnormality reference values of each constituent by achieving an intensive display of one diagnosis diagram with analysis value of each constituent of gas remaining within oil which is extracted as a ratio. CONSTITUTION:At least three concentric circles, outer two circles of which have radii there are integral multiples of that of the center circle are provided. The circles are radially divided into, for example, 7 equal blocks according to the number of types of gas constituent by straight lines extending from the center of the center circle in radial directions. The regions of each block are a normal region A, a care-requiring region B, and an abnormal region C from the outer one for plotting the analysis values. Then, the reference values showing normal, care-requiring, and abnormal states of each gas constituent are previously set, it is plotted intensitively on one diagram by plotting at each block, and an abnormal state is readily diagnosed from the result.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for quickly diagnosing an abnormality inside oil-filled electrical equipment, and a diagnostic chart used therein.
In more detail, the analytical values of dissolved gases in oil extracted from oil-filled electrical equipment are displayed proportionally on a pattern diagram, and at a glance, it is possible to determine the amount of gas generated inside oil-filled electrical equipment. The present invention relates to a method for quickly diagnosing an abnormality caused by an abnormality, and a diagnostic chart used therein.

[Prior art and its problems] Large amounts of organic materials such as cellulose-based insulating materials and insulating oil are used in oil-filled electrical equipment such as transformers, rectifiers, capacitors, and cables. It is known that it decomposes when subjected to overheating or electric discharge, producing decomposition products such as gas. The rate of generation of decomposition products is greatly affected by the ambient temperature to which the insulating material is exposed; as the temperature increases, the rate of decomposition accelerates and a large amount of gas is released.

In particular, in recent years, as the scale of power systems has expanded, oil-filled electrical equipment has become increasingly high-voltage and large-capacity, and as a result, the impact of abnormalities has also tended to increase. be.

The gas produced when organic materials are decomposed due to local overheating or discharge inside oil-filled electrical equipment is C1.

Hydrocarbon gas such as C2H,, C2H,, C2H2,
or H2, GO, CO, etc., and these gases are dissolved in insulating oil inside oil-filled electrical equipment.

Therefore, by extracting the gas dissolved in the insulating oil, we can determine whether or not there is an abnormality inside the oil-filled electrical equipment based on its analytical values and composition.
Maintenance management technology is needed to accurately and early detect the type and extent of damage.

How to extract dissolved gas from insulating oil.

Dissolved gas is extracted by reducing the pressure in the insulating oil and utilizing the pressure difference between the oil and the space above the oil surface, such as methods using Torcherry vacuum, reciprocating motion of bellows, and Tebbler bomb. Alternatively, as shown in Japanese Unexamined Patent Publication No. 158943/1984, a device that integrates a sample measuring section, a sample gas extracting section, and a gas chromatograph is used, and the sample measuring section and sample gas extracting section are mounted on a carrier of gas chromatography glass. Incorporated into the gas flow path,
A method in which sample gas extraction and analysis are directly linked, and furthermore, as proposed in Japanese Patent Application No. 1-33521)9 by the applicant, a column filled with porous fine powder can be used. Examples include a method of extracting dissolved gas.

Dissolved gases extracted by these methods serve as indicators for diagnosing the presence or absence, type and degree of abnormalities inside oil-filled electrical equipment, depending on their analytical values and composition. The concentration that indicates the level is different, and the analysis value is recorded for each gas component by comparing with this abnormal level, and the abnormal state inside the oil-filled electrical equipment is diagnosed from the concentration result of each gas component. Not only is it complicated, but it also requires a considerable level of proficiency.

[Objective of the Invention] Therefore, the purpose of the present invention is to summarize the analytical values of dissolved gas extracted from oil-filled electrical equipment into one graph, and simply by listing the results, it is possible to determine whether or not there is an abnormality inside the oil-filled electrical equipment. The object of the present invention is to provide a method for quickly diagnosing the type and degree of abnormality, and a diagnostic chart for quickly diagnosing abnormalities.

[Means for Solving the Problems] The present invention has been proposed to achieve the above-mentioned object, and includes a method for classifying extracted dissolved gas into at least a normal region, a caution region, and an abnormal region. This feature is characterized in that it is displayed as a ratio.

That is, according to the present invention, the abnormality determination reference value based on the concentration of dissolved gas in oil extracted from oil-filled electrical equipment is divided into at least three categories consisting of a normal area, a caution area, and an abnormal area, and Provided are a method for quickly diagnosing an abnormality inside an oil-filled electrical device, which is characterized by creating a single pattern diagram in which the analysis values of each gas component are displayed as ratios in a region, and a diagnostic diagram used therein.

[Preferred Embodiments of the Invention] A preferred embodiment of the method of quickly diagnosing an abnormality inside an oil-filled electrical device according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a pie chart for summarizing the analysis values of each component gas of the gas dissolved in oil and displaying them as a ratio.

In the present invention, the type of gas component refers to the unit of detected gas component and the TC expressed as the total amount thereof.
G (total amount of combustible gas) is also included.

This pie chart has at least three circles formed by concentric circles having a radius that is an integral multiple of the radius of the center circle, and the circumference of each day is divided into seven circles depending on the number of types of gas components. The areas of each block are divided into blocks divided by straight lines extending radially from the center of the circle, and the areas of each block are divided into normal area (A), caution area (B), and abnormal area from the outside of the circle. The area (C1) is an area for plotting the analysis values. Of course, this area can be divided into three or more in order to diagnose the abnormal state more precisely.

In Fig. 1, the analysis value of H2 is displayed as a ratio in (1) block, and the following (2) block CH, (3) block C2H, (4) block C, H4, (5) block C2H2 , (6) Block C05 (7) Block T
This shows an example in which CG (total combustible gas) is displayed.

At this time, the concentration of each gas has a different reference value indicating an abnormal state, and in the conventional method of displaying each analysis result as an absolute value, the absolute value is compared with the preset reference value each time. Abnormal conditions must be determined through comparison, and a considerable degree of skill is required to make quick and accurate decisions, making diagnosis inevitably complicated.

The most important technical feature of the present invention is the normality of each gas component,
Standard values indicating caution or abnormal conditions are set in advance, and the analysis values are plotted in each block according to the ratio to the standard value, aggregated and displayed on a single diagram, and abnormal conditions can be quickly diagnosed from the results. The point is that it made it possible to do so.

In other words, the concentration that indicates an abnormal state of a detected gas varies depending on the gas, and the concentrations (ppm) normally displayed in Tables 1 and 2 below are the reference values for caution and abnormality. If this standard value is exceeded, it will be diagnosed as requiring caution or abnormality.

Further, the concentration of the detected gas is determined from the viewpoint of the generation rate, and an abnormal state can be diagnosed in units of ppm/year.

That is, the generation rate is obtained by finding the difference in the amount of each gas component generated from the previous analysis value and the current analysis value, and dividing this by the unit time (year). The rate of occurrence of this indicates the degree of progress of the abnormality, and emergency measures can be taken for oil-filled electrical equipment. The generation rate (ppm/year) shown in Tables 3 and 4 below is usually the standard value for caution and abnormality.

Therefore, the abnormal reference value is displayed at the boundary between the abnormal area and the caution area of the pie chart, and the caution standard value is displayed at the boundary between the caution area and the normal area. For example, H, (rated voltage 275 kV or less, rated capacity 2000
kVA or less), the standard value that requires attention is 4.
Since it is 00 pp+m, the boundary between the normal area and the caution area is displayed as 400 pp■, which is the standard value for abnormality of 8 0
0 ppm is displayed at the boundary between the caution area and the abnormal area. That is, if it exceeds the 400 ppm boundary, it is diagnosed as requiring caution, and if it exceeds the 800 ppm boundary, it is diagnosed as indicating an abnormal state.

In addition, C2H, whose respective reference values are different from H2 (rated voltage 275 kV or less, rated capacity 2000 kVA or less)
In this case, the boundary between the normal area and the caution area is 150
ppm is displayed, and 3 is displayed on the boundary between the caution area and the abnormal area.
00pp garden will be displayed.

In other words, even though the standard values for abnormalities or cautions specific to each gas component are different, the display plotted in each area of the graph is not an absolute value, but a ratio derived from each standard value.

800 pprm which is the abnormal standard value in case of H2,
The abnormality standard value of 300 ppm in the case of C1Hs is both plotted at the boundary between the abnormal area and the area requiring attention, and by just looking at this graph, it is possible to quickly diagnose abnormal conditions inside oil-filled electrical equipment. .

In this graph, it is preferable to display each area in a different color or to shade the area so that the abnormal state can be more clearly seen.

Moreover, by trackingly measuring each gas, changes in the gas concentration over time can be diagnosed at the same time. Furthermore, the plot in this case does not just show points; for example, if the rate of occurrence is normal, it is ○, if it is a little fast (careful), it is 0, if it is fast (abnormal).
By displaying different displays depending on the rate of occurrence, such as , it becomes possible to more accurately diagnose abnormal conditions inside oil-filled electrical equipment.

The method for displaying the gas concentration using a pie chart has been explained above, but the graph may also be a flat one as shown in Figure 2. In that case, either horizontal or vertical graphs can be used for quick diagnosis. It functions as a diagnostic diagram for carrying out.

[Effects of the Invention] According to the present invention, by collectively displaying the analysis values of each component of dissolved gas in oil extracted from oil-filled electrical equipment on a single diagnostic diagram as a ratio, abnormalities of each component can be detected. It becomes possible to immediately determine the presence or absence, type and degree of an abnormality just by looking at it, without having to compare it with reference values or cautionary reference values.

[Example] Hereinafter, the present invention will be described in detail based on Examples.

A sample taken from the drain valve of an oil-immersed transformer was extracted using the Torricley vacuum method and analyzed using a gas chromatograph.

The results are shown in Table 5.

FIG. 3 shows the results of this analysis plotted as a ratio derived from the reference value.

According to the graph displayed in Fig. 3, H,, CH, exceeds the caution standard value, and C, H,, C, H, and TCG
It can be determined at a glance that the abnormality exceeds the abnormality reference value, and it is recognized that the abnormality is progressing at a somewhat rapid rate in terms of the rate of occurrence, and the abnormality is also progressing over time. It is recognized that

[Brief explanation of drawings]

FIG. 1 is a pie chart showing an example of a pattern diagram used for diagnosing an abnormality inside the oil-filled electrical equipment according to the present invention. Figure 2 is a horizontal plane graph showing another example, and Figure 3 is a horizontal plane graph showing another example.
An abnormality diagnosis diagram showing the ratio of gas concentrations analyzed according to the example.

Claims (3)

[Claims] (1) Divide the abnormality judgment standard value based on the concentration of gas dissolved in oil extracted from oil-filled electrical equipment into at least three categories consisting of a normal area, a caution area, and an abnormal area, and divide each gas component into the area. A method for quickly diagnosing an abnormality inside oil-filled electrical equipment, the method comprising: creating a single pattern diagram that displays analysis values as ratios. (2) It has at least three circles formed by concentric circles with a radius that is an integral multiple of the radius of the center circle, and radiates from the center of the circle on the circumference of each circle according to the number of types of gas components. An abnormality diagnosis diagram characterized by being divided into equal parts by straight lines extending in the direction. (3) The diagnosing method according to claim (1), wherein the display on the pattern diagram is performed using different symbols representing the rate of abnormality occurrence.