JP2005181235A - Method for diagnosing degradation of oil-filled electrical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for diagnosing the degradation of oil-filled electrical apparatuses capable of accurately measuring changes in the color of insulating oil and being adopted for an (existing) oil-filed electrical apparatuses in continuous use. <P>SOLUTION: The color of an insulating oil sample collected from an oil-filled electrical sample is measured through the use of a colorimetric means comprising both a colorimeter and a color difference meter. On the basis of the result of comparison between a measured value of the color of the sample and a previously set threshold value, the state of degradation of the insulating oil is determined. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a deterioration diagnosis method for determining a deterioration state or the like of insulating oil used in oil-filled electrical equipment such as a transformer.

  Generally, an oil-filled electrical device such as a transformer is configured by housing the contents of an electrical device including an iron core and a winding together with insulating oil in a case. The insulating oil is used for the purpose of cooling and insulating oil-filled electrical equipment. However, the oil-filled electrical equipment is affected by heat generated by energizing the windings during long-term operation of the oil-filled electrical equipment. Or deteriorated by contact with air entering from the outside. When the insulating oil is deteriorated, adverse effects such as deterioration of the electrical characteristics of the oil-filled electrical device occur. In the worst case, the oil-filled electrical device may become inoperable. Therefore, it was necessary to diagnose the deterioration situation so as not to hinder the operation of oil-filled electrical equipment.

  As a method of diagnosing the deterioration state of the insulating oil, for example, there is a method of measuring the color of the insulating oil. Since the color of the insulating oil changes (discolors) from a substantially colorless and transparent state to a darkened state as the deterioration progresses, the color of the insulating oil is periodically measured. It is possible to diagnose the deterioration situation. As a method for measuring the color of the insulating oil, for example, a measuring method using an ASTM color tester shown in JIS K2580 is generally adopted, and the color of the insulating oil (ASTM color) measured by the measuring method is used. ) Is represented by a numerical value of 16 steps in 0.5 increments from 0.5 to 8.0.

  However, the measurement of the ASTM color depends on human vision, and the display of the measurement result is not quantitative (if the sample oil color is between two ASTM color standard glasses, the darker one is used. This is because individual differences are likely to occur due to the fact that “L” is added in front of the numerical value of the ASTM color standard glass and the sample oil color is expressed as D8.0 when the color of the sample oil is higher than 8.0. was there. Moreover, the display in ASTM color is rough (0.5 step), so it is difficult to accurately grasp the subtle color change, and the color of the insulating oil does not always change along the ASTM color. There was also a problem of not being.

  For this reason, in recent years, a probe for colorimetry is installed in the case of an oil-filled electrical device in a state where it can be immersed in insulating oil, and is projected to the insulating oil from an external light source through an optical fiber and the probe for colorimetry. There has been proposed a method for detecting the discoloration of the insulating oil by measuring the transmittance of the insulating oil using the projected light (see, for example, Patent Document 1).

JP 2002-25839 A

  However, in the above method, since the color measurement probe is always immersed in the insulating oil in the case of the oil-filled electrical device, there is a concern about deterioration of the probe itself, and the probe is insulated for a long time. Due to contamination by immersion in oil, the transmittance of the insulating oil cannot be measured well, and it may be difficult to accurately detect the discoloration of the insulating oil. In addition, it is conceivable to insert the probe into the case of the oil-filled electrical device only when necessary, but in this case, when the probe is inserted or taken out, air does not enter the case. It is necessary to form the probe insertion portion with a structure, and as a result, there is a problem that the structure of the probe insertion portion is complicated.

  In addition, in the above method, when the probe for color measurement is previously installed in the case of the oil-filled electrical device, or when the probe is inserted into the case only when necessary, the probe is inserted into the case. The method for measuring the color of insulating oil using the probe in an oil-filled electrical apparatus of the type in which the probe has not been installed (existing), since the insertion portion must be formed in advance. It was difficult to adopt.

  In view of the above-mentioned various problems, the present invention can accurately measure a change in the color of insulating oil, and can also be used in (existing) oil-filled electrical equipment that has been used in the past. An object is to provide a method for diagnosing deterioration of oil-filled electrical equipment.

  In order to solve the above-mentioned problem, the invention according to claim 1 measures the color of a sample of insulating oil collected from an oil-filled electrical device using a colorimetric means comprising a colorimeter or a color difference meter, and the sample It is characterized in that the deterioration state of the insulating oil is determined based on the measured value of the color.

  According to a second aspect of the present invention, in the deterioration diagnosis method for an oil-filled electrical device according to the first aspect, the deterioration state of the insulating oil is determined based on a comparison result between the measured value of the color of the sample and a preset threshold value. It is characterized by doing.

  According to a third aspect of the present invention, in the degradation diagnosis method for an oil-filled electrical device according to the first aspect, the difference between the measured value of the color of the sample and the measured value of the color of the sample measured last time, or the color of the sample The progress of the deterioration of the insulating oil is determined on the basis of the difference between the measured value and the measured value of the color of the insulating oil before use.

  According to a fourth aspect of the present invention, in the deterioration diagnosis method for an oil-filled electrical device according to the first aspect, the deterioration state of the insulating oil is determined based on a comparison result between the measured value of the color of the sample and a preset threshold value. And based on the difference between the measured color value of the sample and the measured color value of the sample previously measured, or the difference between the measured color value of the sample and the measured color value of the insulating oil before use. The present invention is characterized in that the progress of the deterioration of the insulating oil is determined.

  According to the first aspect of the invention, since the color of the sample of the insulating oil collected from the oil-filled electrical device is measured using the color measuring means comprising a colorimeter and a color difference meter, the color of the sample It is possible to accurately perform the measurement work without relying on human vision by mechanization. As a result, the color of the sample can be expressed as detailed and quantitative numerical data. Using numerical data on the color of the sample, it is possible to accurately grasp the subtle color change of the insulating oil, which was difficult to determine with the ASTM color, and to properly determine the deterioration status of the insulating oil. It becomes possible. In addition, since a sample of insulating oil is collected from an oil-filled electrical device, the probe may deteriorate or the probe may become soiled as in the case of installing a colorimetric probe in the oil-filled electrical device. It is possible to reliably prevent the occurrence of problems such as the inability to accurately detect the discoloration of insulating oil due to, etc., and the oil filling of the type in which the probe that has been used (existing) is not installed Also in an electric device, it has the outstanding effect that the deterioration condition etc. of insulating oil can be determined favorably.

  According to the second aspect of the present invention, it is easy to compare the measured value of the color of the sample of the insulating oil measured by using the colorimetric means including the colorimeter and the color difference meter with the preset threshold value. It is possible to determine the deterioration status (deterioration level) of the insulating oil. As a result, it is necessary to know beforehand whether or not the insulating oil needs to be replaced from the deterioration status of the insulating oil, and to operate the oil-filled electrical device. By exchanging the deteriorated insulating oil before causing trouble, the usable period (remaining life) of the oil-filled electrical device can be satisfactorily extended.

  According to the invention described in claim 3, the difference between the measured value of the color of the sample of the insulating oil measured using the color measuring means comprising a colorimeter and a color difference meter, and the measured value of the color of the sample measured last time, Or, based on the difference between the measured value of the color of the insulating oil sample measured using a colorimetric means comprising a colorimeter or color difference meter, and the measured value of the color of the insulating oil before use, the insulating oil can be easily It is possible to determine the progress of deterioration of the deterioration (whether the progress of deterioration is fast or slow). As a result, the remaining life of the insulating oil is grasped in advance from the progress of deterioration of the insulating oil, The usable period (remaining life) of the oil-filled electrical device can be satisfactorily extended by replacing the deteriorated insulating oil before the operation of the oil-filled electrical device is hindered.

  According to the invention described in claim 4, the insulating oil is measured by comparing the measured value of the color of the insulating oil sample measured using a colorimetric means including a colorimeter and a color difference meter with a preset threshold value. It is possible to determine the deterioration status (degradation level) of the sample, and the difference between the measured color value of the sample measured this time and the measured color value of the sample measured last time, or the measured color value of the sample measured this time It is possible to determine the progress of the deterioration of the insulating oil (whether the progress of deterioration is fast or slow) from the difference from the measured value of the color of the insulating oil before use. As a result, the deterioration of the insulating oil From the progress of deterioration and deterioration, it is necessary to grasp (predict) in advance how long it will be necessary to replace insulation oil in the future, and deteriorate before it interferes with the operation of oil-filled electrical equipment. The oil-filled electrical equipment can be used by replacing the insulation oil It can be satisfactorily extended (remaining life).

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram illustrating an example of an oil-filled electrical device (hereinafter referred to as a transformer) A such as a transformer. In FIG. 1, reference numeral 1 denotes a transformer body, which is configured by housing a transformer content 2 including an iron core 2 a and a winding 2 b in a case 4 together with an insulating oil 3. A conservator 5 is provided above the transformer body 1 and can communicate with the case 4 of the transformer body 1 through a communication pipe 5a. Further, the conservator 5 is shielded from the insulating layer 3 (common to the transformer main body 1) in the conservator 5 from the air layer 7 communicating with the atmosphere through the hygroscopic respirator 6 and the vent pipe 6a. Further, a diaphragm 8 made of a rubber member having excellent oil resistance that prevents the insulating oil 3 from deteriorating is provided, and the diaphragm 8 follows the expansion / contraction of the insulating oil 3 during the operation of the transformer A. Thus, the pressure in the transformer main body 1 communicating with the conservator 5 is adjusted by repeating the vertical movement.

  In the transformer A having the above-described configuration, the diaphragm 8 of the conservator 5 is damaged due to repeated vertical movement following the expansion / contraction of the insulating oil 3 while the transformer A is operated for a long period of time. Or when oil leaks from the case 4 or the conservator 5, air or the like enters from the outside and comes into contact with the insulating oil 3, so that the insulating oil 3 deteriorates or the transformer contents It is conceivable that the insulating oil 3 deteriorates due to the influence of heat generated by energization of the second winding 2b. When the insulating oil 3 is deteriorated, adverse effects such as deterioration of the electrical characteristics of the transformer A occur. In the worst case, the transformer A may become inoperable. Thus, it is necessary to diagnose the deterioration state so as not to hinder the operation of the transformer A.

  Therefore, in the present invention, the color of the insulating oil 3 changes sequentially as the insulating oil 3 deteriorates due to contact with air or the like during the operation of the transformer A, or the influence of heat, etc. Focusing on, for example, taking a sample of the insulating oil 3 during periodic inspection of the transformer A and measuring the color, and the deterioration status of the insulating oil 3 based on the measured value of the color of the sample Etc. are to be diagnosed.

In the present invention, a color system commonly used as a means for measuring the color of the insulating oil 3 (hereinafter referred to as color measuring means), such as L ^* a ^* b ^* color system, etc. It is assumed that a colorimeter or a color difference meter that can express colors is used. In the present invention, the case where the color of the insulating oil 3 measured using the colorimetric means is represented by an L ^* a ^* b ^* color system will be described as an example. For example, when the color of the insulating oil 3 measured using the colorimetric means including the colorimeter and the color difference meter is represented by the L ^* a ^* b ^* color system, the lightness index L ^* and the chromaticness index a ^* , B ^* can be expressed as a numerical value that is more detailed and quantitative than the ASTM color.

The L ^* a ^* b ^* color system includes an a ^* axis and a b ^* axis (indicating a chromaticness index) orthogonal to each other, and an L ^* axis (lightness) perpendicular to the intersection of the a ^* axis and b ^* axis. Represented by a color space stereoscopic image having an index). The lightness index L ^* represents a change in color in the black-white direction. The lightness increases as the numerical value increases, and the lightness decreases as the numerical value decreases (closes to 0). The chromaticness index a ^* represents a change in color in the green-red direction, and the chromaticness index b ^* represents a change in color in the yellow-blue direction. The larger the value, the brighter the color and the smaller the value. The color becomes duller as it approaches 0. The chromaticity (hue and saturation) of the measurement object (insulating oil 3 in the present invention) can be obtained from the intersection coordinates of the chromaticness indices a ^* and b ^* .

  Hereinafter, the degradation diagnosis method for the transformer A in the first embodiment of the present invention will be described with reference to the flowchart of FIG. The deterioration diagnosis method of the first embodiment is a colorimeter or a color difference meter for the color of a sample of insulating oil 3 (hereinafter referred to as sample oil) collected from the transformer body 1 during periodic inspection of the transformer A or the like. The deterioration of the insulating oil 3 is diagnosed by measuring using colorimetric means and comparing the measured value of the color of the sample oil with a preset threshold value.

In addition, since the insulating oil 3 changes color from a substantially colorless and transparent state to a darkened state as the deterioration progresses (that is, the brightness decreases), in this embodiment, for example, the colorimeter, Using the numerical value of the lightness index L ^* of the sample oil (insulating oil 3) measured by the colorimetric means comprising a color difference meter as a measured value, and comparing this with a preset threshold value, the deterioration status of the insulating oil 3 can be determined. Shall be diagnosed.

  First, in step S1 in FIG. 2, a predetermined amount of sample oil is sampled from the transformer main body 1 using a sampling pipe (not shown) provided in the transformer main body 1, and in step S2, the transformer main body 1 The color of the sample oil collected from 1 is measured using a colorimetric means comprising a portable colorimeter or a color difference meter, for example.

Subsequently, in step S3 of FIG. 2, the measured value of the color of the sample oil measured using the colorimetric means, for example, the numerical value of the lightness index L ^* is compared with a preset threshold value, and in step S4. The deterioration status (deterioration level) of the insulating oil 3 is determined based on the comparison result between the numerical value of the lightness index L ^* and the threshold value.

The deterioration state of the insulating oil 3 may be determined, for example, based on whether or not the numerical value of the brightness index L ^* exceeds a threshold value. That is, if the value of the lightness index L ^* exceeds the threshold value (that is, if the lightness of the insulating oil 3 is high), it is considered that the deterioration of the insulating oil 3 is not progressing so much. If the value of the lightness index L ^* is below the threshold value (that is, if the lightness of the insulating oil 3 is low) Since it is considered that the deterioration of the insulating oil 3 is considerably progressing, it may be determined that it is at a defective level that can be used continuously (that is, needs replacement). .

Further, for example, the deterioration state of the insulating oil 3 may be determined based on the difference between the numerical value of the lightness index L ^* and the threshold value. In this case, for example, if a predetermined allowable range is set in advance with reference to the threshold value, and the difference between the numerical value of the lightness index L ^* and the threshold value exceeds the upper limit of the allowable range, the insulating oil 3 is deteriorated. Since it is considered that the situation has not progressed so much, it is determined that the level is a normal level that can be used continuously (that is, replacement is unnecessary), and the value of the lightness index L ^* and the threshold value are determined. If the difference is less than the lower limit of the allowable range, it is considered that the deterioration of the insulating oil 3 has progressed considerably, so there is no problem in continuing to use it (that is, replacement is necessary). If the difference between the numerical value of the lightness index L ^* and the threshold value is a numerical value within an allowable range, it is considered that the normal level is in transition to the defective level. Make sure you are at the level of caution Good.

  Then, as described above, when it is determined in step S4 in FIG. 2 that the deterioration state of the insulating oil 3 is at a defective level, the insulating oil 3 is replaced and the operation of the transformer A is hindered. You should be prepared not to come. In addition, when it is determined that the deterioration state of the insulating oil 3 is at a caution level, it is necessary that the deterioration of the insulating oil 3 progresses thereafter. May be performed.

As described above, in the first embodiment of the present invention, the color of the sample oil collected from the transformer main body 1 at the time of periodic inspection of the transformer A is measured using the color measuring means including the colorimeter and the color difference meter. As a result, it is possible to accurately capture the subtle color change of the sample oil that is difficult to determine by ASTM color, and to express this numerically. As a result, the sample measured using the colorimetric means By comparing the measured value of the color of the oil (the value of the lightness index L ^* ) with a preset threshold value, the deterioration status of the insulating oil 3 can be easily determined. In addition, since it is possible to easily grasp whether or not the current replacement of the insulating oil 3 is necessary from the deterioration state of the insulating oil 3, the insulating oil 3 can be replaced by replacing the insulating oil 3 as necessary. 3 can prevent the harmful effects that occur in the transformer A due to the deterioration of 3 and prolong the usable period (remaining life) of the transformer A.

  In the first embodiment of the present invention, sample oil is collected from the transformer body 1 and the color of the sample oil is measured using a colorimetric means comprising a colorimeter and a color difference meter. Therefore, there is no need to install a color measuring probe in the case 4 of the transformer body 1 as in the prior art. As a result, the color of the sample oil (insulating oil 3) can be measured well even in the transformer A of the type that has not been installed with the color measuring probe that has been used in the past (insulating oil 3). 3 can be diagnosed, and the problem that the probe deteriorates or the discoloration state of the insulating oil 3 cannot be accurately detected due to contamination of the probe or the like does not occur at all. In addition, since the probe for colorimetry is installed in the case 4, it is not necessary to form the probe insertion portion in the case 4.

In the first embodiment of the present invention, the deterioration state of the insulating oil 3 is determined based on the comparison result between the numerical value of the lightness index L ^* of the sample oil measured using the colorimetric means and a preset threshold value. However, for example, after determining the deterioration state of the insulating oil 3, the numerical value of the lightness index L ^* of the sample oil measured this time and the lightness index L of the sample oil (or insulating oil before use) measured last time ^The amount of change (difference) in the lightness index L ^* may be calculated from the numerical value ^* , and the progress of deterioration of the insulating oil 3 may be determined based on the amount of change (difference).

  Next, a degradation diagnosis method for the transformer A in the second embodiment of the present invention will be described with reference to the flowchart of FIG. The deterioration diagnosis method in the second embodiment compares the measured value of the sample oil color measured this time with the measured value of the color of the sample oil measured last time (or the measured value of the color of the insulating oil before use), The progress of deterioration of the insulating oil 3 is diagnosed based on the result.

  The color of the insulating oil 3 does not always change in the same manner depending on conditions such as deterioration factors (heat, oxidation, heat + oxidation, etc.) and the presence / absence of addition of an antioxidant (ie, almost the same as before use). In the second embodiment, for example, a trajectory (curve) indicating the discoloration process of the insulating oil 3 for each possible condition is preliminarily determined. The color (lightness, hue, saturation) of the insulating oil 3 is set (created) from the previous time (or the state before use) along the trajectory (curve) of the color changing process set (created) in advance. The progress of deterioration of the insulating oil 3 is determined depending on how much the change has occurred.

  First, in step S11 of FIG. 3, a predetermined amount of sample oil is sampled from the transformer main body 1 using a sampling pipe (not shown) provided in the transformer main body 1, and in step S12, the transformer main body 1 The color of the sample oil collected from 1 is measured using a colorimetric means comprising a portable colorimeter or a color difference meter, for example.

Subsequently, in step S13 of FIG. 3, the numerical values of the lightness index L ^* and chromaticness indices a ^* , b ^* of the sample oil measured using the colorimetric means, and the lightness index L ^* of the sample oil measured last time ^. And the change amount (difference) of the numerical values of the respective indices L ^* , a ^* , b ^* is calculated from the numerical values of the chromaticness indices a ^* , b ^* . Note that first sample oil color current (psychometric lightness L ^* and chromaticness indices a ^*, b ^*) in the case of measuring the brightness index of the insulating oil before use L ^* and chromaticness indices a ^*, b ^* and From the lightness index L ^* and the chromaticness index a ^* , b ^{* of the} sample oil, the amount of change (difference) in the numerical values of the indices L ^* , a ^* , b ^* is calculated.

Next, in step S14 of FIG. 3, the progress of deterioration of the insulating oil 3 is determined based on the amount of change (difference) in the numerical values of the lightness index L ^* and chromaticness index a ^* , b ^* . In this case, for example, the amount of change in chromaticity (hue and saturation) obtained from the intersection of the lightness index L ^* and the chromaticness index a ^* , b ^* , that is, the color of the sample oil measured this time. each index showing L ^*, a ^*, and b ^* coordinates, the index indicating the color of the sample oils was previously measured (or color of insulating oil before use) L ^*, from a ^*, b ^* coordinates, insulating oil It can be seen how much the three colors (that is, lightness, hue, saturation) have changed along a trajectory (curve) indicating a previously set (created) discoloration process. What is necessary is just to judge the progress of deterioration of the.

That is, the smaller the change amount of the lightness index L ^* and the chromaticness index a ^* , b ^* (chromaticity), the less the deterioration of the insulating oil 3 has progressed from the previous time (or the state before use). Therefore, it is determined that the progress of the deterioration of the insulating oil 3 is slow, and the larger the change amount of the lightness index L ^* and the chromaticness index a ^* , b ^* (chromaticity), the larger the insulating oil. 3 is considered to be a situation that has progressed considerably since the last time (or the state before use), and therefore it is sufficient to determine that the progress of the deterioration of the insulating oil 3 is fast.

  As described above, when it is determined in step S14 of FIG. 3 that the progress of deterioration of the insulating oil 3 is fast, it is considered that the remaining life of the insulating oil 3 is shortened. It is only necessary to replace the oil 3 so that it does not hinder the operation of the transformer A.

As described above, in the second embodiment of the present invention, the color of the sample oil collected from the transformer main body 1 during the periodic inspection of the transformer A is measured using a colorimetric means including a colorimeter and a color difference meter. As a result, it is possible to accurately capture the subtle color change of the sample oil that is difficult to determine by ASTM color, and to express this numerically. As a result, the sample measured using the colorimetric means calculating oil lightness index L ^* and chromaticness indices a ^*, and numbers of b ^*, the lightness index L ^* and chromaticness indices a sample oil was previously measured (or insulating oil before use) ^*, the b ^* numbers In addition, the progress of deterioration of the insulating oil 3 (whether the progress of deterioration is fast or slow) is easily determined based on the amount of change (difference) in the numerical values of the indices L ^* , a ^* , b ^*. Can do. In addition, the period (remaining life) until the insulation oil 3 needs to be replaced can be easily predicted from the progress of the deterioration of the insulation oil 3, so that the insulation oil 3 is replaced when necessary. As a result, it is possible to prevent the adverse effects that occur in the transformer A due to the deterioration of the insulating oil 3, and it is possible to satisfactorily extend the usable period (remaining life) of the transformer A. .

  In the second embodiment of the present invention, sample oil is collected from the transformer body 1 and the color of the sample oil is measured using a colorimetric means comprising a colorimeter and a color difference meter. Therefore, there is no need to install a color measuring probe in the case 4 of the transformer body 1 as in the prior art. As a result, the color of the sample oil (insulating oil 3) can be measured well even in the transformer A of the type that has not been installed with the color measuring probe that has been used in the past (insulating oil 3). 3 can be determined, and the problem that the probe deteriorates or the discoloration state of the insulating oil 3 cannot be accurately grasped due to contamination of the probe or the like does not occur at all. In addition, since the probe for colorimetry is installed in the case 4, it is not necessary to form the probe insertion portion in the case 4.

  Next, a deterioration diagnosis method for the transformer A in the third embodiment of the present invention will be described with reference to the flowchart of FIG. The deterioration diagnosis method of the third embodiment compares the measured value of the sample oil color with a preset threshold value to determine the deterioration state of the insulating oil 3, and the measured value of the sample oil color measured this time and the previous time The progress of deterioration of the insulating oil 3 is determined by comparing the measured value of the color of the sample oil (or the measured value of the color of the insulating oil before use). In the third embodiment, similarly to the second embodiment, in order to determine the progress of the deterioration of the insulating oil 3, a trajectory (curve) indicating the discoloration process of the insulating oil 3 for each possible condition is previously set. Set (create).

  First, in step S21 of FIG. 4, a predetermined amount of sample oil is collected from the transformer body 1 using a sampling pipe (not shown) provided in the transformer body 1, and in step S22, the transformer body 1 The color of the sample oil collected from 1 is measured using a colorimetric means comprising a portable colorimeter or a color difference meter, for example.

Subsequently, in step S23 of FIG. 4, the measured value of the color of the sample oil measured using the colorimetric means, for example, the numerical value of the lightness index L ^* is compared with a preset threshold value, and in step S24. The deterioration status (deterioration level) of the insulating oil 3 is determined based on the comparison result between the numerical value of the lightness index L ^* and the threshold value.

The deterioration state of the insulating oil 3 may be determined, for example, based on whether or not the numerical value of the brightness index L ^* exceeds a threshold value. That is, if the value of the lightness index L ^* exceeds the threshold value (that is, if the lightness of the insulating oil 3 is high), it is considered that the deterioration of the insulating oil 3 is not progressing so much. If the value of the lightness index L ^* is below the threshold value (that is, if the lightness of the insulating oil 3 is low) Since it is considered that the deterioration of the insulating oil 3 is considerably progressing, it may be determined that it is at a defective level that can be used continuously (that is, needs replacement). .

Further, for example, the deterioration state of the insulating oil 3 may be determined based on the difference between the numerical value of the lightness index L ^* and the threshold value. In this case, for example, if a predetermined allowable range is set in advance with reference to the threshold value, and the difference between the numerical value of the lightness index L ^* and the threshold value exceeds the upper limit of the allowable range, the insulating oil 3 is deteriorated. Since it is considered that the situation has not progressed so much, it is determined that the level is a normal level that can be used continuously (that is, replacement is unnecessary), and the value of the lightness index L ^* and the threshold value are determined. If the difference is less than the lower limit of the allowable range, it is considered that the deterioration of the insulating oil 3 has progressed considerably, so there is no problem in continuing to use it (that is, replacement is necessary). If the difference between the numerical value of the lightness index L ^* and the threshold value is a numerical value within an allowable range, it is considered that the normal level is in transition to the defective level. Make sure you are at the level of caution Good.

  Then, as described above, when it is determined in step S24 of FIG. 4 that the deterioration state of the insulating oil 3 is at a defective level, the insulating oil 3 is exchanged and the operation of the transformer A is hindered. You just have to be prepared not to come. If it is determined that the deterioration state of the insulating oil 3 is at a normal level or a level requiring attention, the process proceeds to step S25. When it is determined that the deterioration state of the insulating oil 3 is at a caution level, it is necessary that the deterioration of the insulating oil 3 progresses thereafter, so that the insulating oil 3 is replaced at this stage. May be performed.

Next, in step S25 in FIG. 4, this time measured lightness of the sample oil L ^* and chromaticness indices a ^*, b ^* numbers and, lightness index of the sample oils was previously measured L ^* and chromaticness indices a ^*, from b ^* numbers, each index L ^*, a ^*, calculates the amount of change in numerical value of b ^* (difference). Note that first sample oil color current (psychometric lightness L ^* and chromaticness indices a ^*, b ^*) in the case of measuring the brightness index of the insulating oil before use L ^* and chromaticness indices a ^*, b ^* of From the numerical value and the numerical value of the lightness index L ^* and the chromaticness index a ^* , b ^* of the sample oil, the amount of change (difference) in the numerical values of each index L ^* , a ^* , b ^* is calculated.

Subsequently, in step S26 of FIG. 4, the progress of deterioration of the insulating oil 3 is determined based on the amount of change (difference) in the values of the lightness index L ^* and the chromaticness indices a ^* , b ^* . In this case, for example, the amount of change in chromaticity (hue and saturation) obtained from the intersection of the lightness index L ^* and the chromaticness index a ^* , b ^* , that is, the color of the sample oil measured this time. each index showing L ^*, a ^*, and b ^* coordinates, the index indicating the color of the sample oils was previously measured (or color of insulating oil before use) L ^*, from a ^*, b ^* coordinates, insulating oil It can be seen how much the three colors (that is, lightness, hue, saturation) have changed along a trajectory (curve) indicating a previously set (created) discoloration process. What is necessary is just to judge the progress of deterioration of the.

That is, the smaller the change amount of the lightness index L ^* and the chromaticness index a ^* , b ^* (chromaticity), the less the deterioration of the insulating oil 3 has progressed from the previous time (or the state before use). Therefore, it is determined that the progress of the deterioration of the insulating oil 3 is slow, and the larger the change amount of the lightness index L ^* and the chromaticness index a ^* , b ^* (chromaticity), the larger the insulating oil. 3 is considered to be a situation that has progressed considerably since the last time (or the state before use), and therefore it is sufficient to determine that the progress of the deterioration of the insulating oil 3 is fast.

  As described above, if it is determined in step S26 in FIG. 4 that the progress of deterioration of the insulating oil 3 is fast, it is considered that the remaining life of the insulating oil 3 is shortened. It is only necessary to replace the oil 3 so that it does not hinder the operation of the transformer A.

As described above, in the third embodiment of the present invention, the color of the sample oil collected from the transformer body 1 during the periodic inspection of the transformer A is measured using a colorimetric means including a colorimeter and a color difference meter. As a result, it is possible to accurately capture the subtle color change of the sample oil that is difficult to determine by ASTM color, and to express this numerically. As a result, the sample measured using the colorimetric means By comparing the numerical value of the lightness index L ^* of the oil with a preset threshold value, the deterioration status of the insulating oil 3 can be easily determined, and the lightness index L ^* and the chromaticness index of the sample oil measured this time a ^*, b ^* numbers and, lightness index L ^* and chromaticness indices a sample oil was previously measured (or insulating oil before use) ^* was calculated from b ^* numbers, each index L ^*, a ^* , the amount of change in b ^* of the numerical value Based on the difference), it is possible to easily determine the progress of deterioration of insulating oil 3 (whether advances how degradation is fast slow). In addition, from the deterioration state of the insulating oil 3 and the progress state of the deterioration, for example, even if the deterioration state of the insulating oil 3 is at a normal level or a caution level, the progress state of deterioration (how the deterioration proceeds) is determined in advance. By grasping, it is possible to easily predict whether or not to replace the insulating oil 3 in the future, the timing of replacement, etc., so that the deterioration of the insulating oil 3 can be performed by replacing the insulating oil 3 when necessary. As a result, it is possible to prevent the adverse effects that occur in the transformer A and to prolong the usable period (remaining life) of the transformer A.

  In the third embodiment of the present invention, sample oil is collected from the transformer body 1 and the color of the sample oil is measured using a colorimetric means comprising a colorimeter and a color difference meter. Therefore, there is no need to install a color measuring probe in the case 4 of the transformer body 1 as in the prior art. As a result, the color of the sample oil (insulating oil 3) can be measured well even in the transformer A of the type that has not been installed with the color measuring probe that has been used in the past (insulating oil 3). The deterioration status (degradation level) 3 and the progress of the degradation can be determined, and the probe is deteriorated, or the discoloration status of the insulating oil 3 cannot be accurately grasped due to contamination of the probe. Does not occur at all. In addition, since the probe for colorimetry is installed in the case 4, it is not necessary to form the probe insertion portion in the case 4.

In the first and third embodiments of the present invention, the deterioration state of the insulating oil 3 based on the comparison result between the numerical value of the lightness index L ^* of the sample oil measured using the colorimetric means and a preset threshold value. (Deterioration level) is determined, but instead, for example, the value of the lightness index L ^* of the sample oil measured this time and the lightness index L of the sample oil (or insulating oil before use) measured last time You may make it determine the deterioration condition of the insulating oil 3 based on the comparison result of the difference with the numerical value of ^* , and the preset threshold value.

In the first and third embodiments of the present invention, the deterioration state (deterioration level) of the insulating oil 3 is determined using the numerical value of the lightness index L ^* of the sample oil measured by the colorimetric means. Instead, the deterioration state of the insulating oil 3 may be determined using numerical values of the chromaticness indices a ^* and b ^* of the sample oil measured by the colorimetric means simultaneously with the lightness index L ^* .

Further, as described above, the deterioration condition (deterioration level) of the insulating oil 3 using only the numerical value of the lightness index L ^* of the sample oil measured by the colorimetric means or the numerical values of the chromaticness indices a ^* and b ^*. ) instead determines, for example, lightness of this brightness index of the measured sample oil L ^* and chromaticness indices a ^*, b ^* numbers and, sample oils were previously measured (or insulating oil before use) L ^* And the color difference calculated from the numerical values of the chromaticness index a ^* , b ^* (color difference = [(difference of numerical value of the lightness index L ^* ) ² + (difference of numerical value of the chromaticness index a ^* ) ² + (chromaticness index b The difference between the numerical values of ^* ) ² ] ^1/2 ) may be used to determine the deterioration status of the insulating oil 3.

In the second and third embodiments of the present invention, the value of the lightness index L ^* and the chromaticness index a ^* , b ^* of the sample oil measured this time and the sample oil (or insulating oil before use) measured last time ) Of the lightness index L ^* and the chromaticness index a ^* , b ^* , the change amount (difference) of the numerical values of the respective indexes L ^* , a ^* , b ^* is calculated and based on the change amount (difference). Thus, the progress of deterioration of the insulating oil 3 is determined, but instead, for example, the amount of change (difference) in the numerical values of the lightness index L ^* and the chromaticness indices a ^* , b ^* calculated this time Further, the progress of deterioration of the insulating oil 3 may be determined from the amount of change (difference) in the numerical values of the lightness index L ^* and chromaticness index a ^* , b ^* calculated last time. Furthermore, the progress of the deterioration of the insulating oil 3 is determined based on the comparison result between the change amount (difference) in the numerical values of the lightness index L ^* and the chromaticness index a ^* , b ^* and a preset threshold value. calculated lightness index L ^* and chromaticness indices a ^*, b ^* of the lightness index previously calculated change amount (difference) numbers L ^* and chromaticness indices a ^*, the amount of change in value of b ^* of the (difference) The progress of deterioration of the insulating oil 3 may be determined based on a comparison result between the difference and a preset threshold value.

Further, in the first to third embodiments of the present invention, the case where the color of the sample oil is expressed by the L ^* a ^* b ^* color system is described as an example, but the present invention is not limited to this, and the XYZ ( Yxy) may be represented by another color system that can be measured and displayed by a color measuring means such as a colorimeter or a color difference meter, such as a color system or an L ^* C ^* h color system.

  In the first to third embodiments of the present invention, sample oil is collected from the transformer main body 1 during periodic inspection of the transformer A. Instead, the sample oil is supplied to the transformer A. You may make it extract | collect sample oil from the conservator 5 at the time of an energization stop (at the time of an operation stop).

  Furthermore, in the first to third embodiments of the present invention, the transformer A having the conservator 5 has been described as an example. However, the transformer A having no conservator 5 (small and medium) is not limited thereto. Similarly, the deterioration state of the insulating oil 3 and the progress of deterioration can be determined.

  Further, in the first to third embodiments of the present invention, the transformer A has been described as an example of the oil-filled electrical device. However, the present invention is not limited to this, and in oil-filled electrical devices other than the transformer, The deterioration status of the insulating oil 3 and the progress status of the deterioration can be determined.

  Furthermore, the present invention can determine the deterioration state (deterioration level) and the progress of deterioration of the insulating oil 3 based on the measured value of the color of the sample oil measured using a colorimetric means comprising a colorimeter and a color difference meter. By determining, not only the necessity of replacement of the insulating oil 3, the period until replacement is necessary (remaining life), etc., but also abnormalities in the transformer A (for example, the diaphragm of the conservator 5) Needless to say, the present invention can also be applied to detection or the like of 8 that is damaged and air has entered.

It is a schematic block diagram which shows an example of an oil-filled electrical apparatus. It is a flowchart which shows the deterioration diagnostic method of the oil-filled electrical equipment in 1st Example of this invention. It is a flowchart which shows the deterioration diagnostic method of the oil-filled electrical equipment in 2nd Example of this invention. It is a flowchart which shows the deterioration diagnostic method of the oil-filled electrical equipment in 3rd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transformer body 2 Transformer content 2a Iron core 2b Winding 3 Insulating oil 4 Case 5 Conservator 8 Diaphragm A Transformer (oil-filled electrical equipment)

Claims (4)

  Measure the color of the sample of insulating oil collected from oil-filled electrical equipment using colorimetric means consisting of a colorimeter or color difference meter, and determine the deterioration status of the insulating oil based on the measured value of the color of the sample A method for diagnosing deterioration of oil-filled electrical equipment.   The deterioration diagnosis method for oil-filled electrical equipment according to claim 1, wherein the deterioration state of the insulating oil is determined based on a comparison result between the measured value of the color of the sample and a preset threshold value.   Based on the difference between the measured value of the color of the sample and the measured value of the color of the sample measured last time, or the difference between the measured value of the color of the sample and the measured value of the color of the insulating oil before use, the insulating oil The deterioration diagnosis method for oil-filled electrical equipment according to claim 1, wherein the progress of deterioration of the oil is determined.   Based on the comparison result between the measured value of the color of the sample and a preset threshold value, the deterioration state of the insulating oil is determined, and the difference between the measured value of the color of the sample and the measured value of the color of the sample measured last time 2. The oil filling according to claim 1, wherein the progress of deterioration of the insulating oil is determined based on a difference between the measured value of the color of the sample and the measured value of the color of the insulating oil before use. Degradation diagnosis method for electrical equipment.

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