JP2008064580A - Deterioration diagnosis method of electrical apparatus insulation material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To collect a sample easily without damaging the appearance of an electrical apparatus. <P>SOLUTION: Each integrated weight loss curve of a primary weight reduction quantity and a secondary weight reduction quantity of an integrated curve of a thermal weight reduction curve at a weight changing time of an insulation material acquired from TG-DTA is converted into a differential value to acquire a differential peak, and differential multiple peak dividing processing is performed, and a secondary weight reduction peak area value is divided by a primary weight reduction peak area value, to thereby calculate a weight reduction ratio, and correlation with a weight reduction rate acquired by a conventional method is taken by using the weight reduction ratio as an index value of TG-DTA, to thereby create a master curve, and the master curve is compared with a measurement/analysis result by TG-DTA of the sample collected from the electrical apparatus. Then, the insulation material 2 for sample collection is provided at an apparatus molding time on a measuring object portion near a primary conductor 1 by TG-DTA of the electrical apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for diagnosing deterioration of an insulating material of an electric device such as a current transformer (CT) which is a high voltage device using an insulating material such as an epoxy resin.

  In electrical devices such as current transformers, once a failure due to insulation deterioration occurs, it takes time and money to restore the device, and a huge loss occurs socially. Diagnosis of deterioration is performed. Epoxy resins typified by polymer insulation materials have good electrical properties, mechanical properties, and adhesiveness, and have long been used for large molded products such as coil insulation for rotating machines and insulation for stationary equipment such as transformers. As a result, it has been widely used as an electrical insulating material, up to small and high precision products represented by semiconductor packages. Among them, current transformers (CT), especially current transformers with integrated conductors, have a thermal effect on the epoxy resin that molds the current transformer due to heat generation because the conductor serves as the primary current path. become. Not only current transformers, but high-voltage equipment using epoxy resin deteriorates the mold resin that has been affected by heat for a long time, and its electrical characteristics (insulation characteristics) and mechanical characteristics are reduced. This may cause bad phenomena such as cracks in the mold. As a current insulation diagnosis method for electrical equipment, generally, a method based on an electrical characteristic test (various withstand voltage tests, partial discharge measurement, etc.) is mainly used as a diagnostic method, and a deterioration degree is measured.

Note that prior art document information relating to the invention of this application includes the following.
JP 2003-107075 A

  However, in the conventional electrical characteristic test, since the life prediction of the electrical equipment is predicted in units of about 10 years, the state at the time of the test can be grasped, but the life prediction is not reliable. Even when there is no problem in electrical characteristics, an excessive stress is applied to the insulating layer due to a decrease in the mechanical strength of the reinforcing member, and the insulating layer may be broken to cause an accident. In such a case, in the electrical property test, it was not possible to detect a decrease in mechanical strength due to the stress applied to the insulating layer of the electrical equipment or a change (deterioration) in the insulating material due to overheating or the like. For this reason, if a failure of an electrical device occurs due to the destruction of the insulating material, if the deterioration degree (remaining life) of the insulating material used in the electrical device can be appropriately evaluated and understood, It is possible to obtain a method for diagnosing deterioration of an insulating material that can be prevented.

  In view of this, the present applicant has proposed a method for diagnosing deterioration of an electrical equipment insulating material using a TG-DTA device in Japanese Patent Application Laid-Open No. 2005-338045 already filed. However, in this method, it is necessary to collect a sample from the measurement target site such as the vicinity of the primary conductor of the electrical equipment, which damages the external appearance of the device, such as mechanically scraping the measurement target site, resulting in cracks. There was a risk of causing this.

  The present invention has been made to solve the above-described problems, and does not cause damage to the external appearance of the electrical equipment during sample collection, does not cause cracks, and easily collects a sample. An object of the present invention is to obtain a method for diagnosing deterioration of insulating materials for electrical equipment.

  According to a first aspect of the present invention, there is provided a method for diagnosing deterioration of an electrical equipment insulating material, wherein the first weight reduction amount of the integral curve of the thermogravimetric reduction curve when the weight of the electrical equipment insulation material obtained from the TG-DTA device is changed. The integrated weight loss curve of the secondary weight loss is converted to a differential value to obtain a differential peak, and further differential multiple peak split processing is performed using a Gaussian function, and the obtained secondary weight loss peak area value is reduced to the primary weight. The weight loss ratio is calculated by dividing by the peak area value, and this weight loss ratio is used as an index value of the TG-DTA apparatus. pub. A master curve is created by correlating with the weight loss rate calculated in accordance with H.216, and the master curve is compared with the measurement and analysis results of the sample collected from the electric device by the TG-DTA device. In the method of diagnosing deterioration of an electrical equipment insulating material by determining the degree of thermal degradation, an insulating material for sampling is provided at the measurement target site near the primary conductor of the TG-DTA device of the electrical equipment when the equipment is molded.

  The degradation diagnosis method for electrical equipment insulating material according to claim 2 is the first weight reduction amount and the second weight of the integral curve of the thermogravimetric reduction curve when the weight of the electrical equipment insulation material obtained from the TG-DTA device changes. The integrated weight loss curve of the reduction amount is converted into a differential value to obtain a differential peak, and further, differential multiple peak split processing is performed using a Gaussian function, and the obtained secondary weight reduction peak area value is converted into the primary weight reduction peak area value. The weight loss ratio is calculated by dividing the weight loss ratio, and this weight loss ratio is used as an index value of the TG-DTA apparatus. pub. A master curve is created by correlating with the weight loss rate calculated in accordance with H.216, and the master curve is compared with the measurement and analysis results of the sample collected from the electric device by the TG-DTA device. In the method of diagnosing deterioration of an electrical equipment insulating material that determines the degree of thermal degradation by the above, an insulating material for sampling is provided at the time of equipment molding at a measurement target site of the TG-DTA device of the electrical equipment.

  According to a third aspect of the present invention, there is provided a method of diagnosing deterioration of an electrical equipment insulating material, wherein the integral weight reduction curve of the primary weight loss amount and the secondary weight loss amount of the integral curve of the line is converted into a differential value to obtain a differential peak. A differential multiple peak splitting process is performed using a function, and the weight loss ratio is calculated by dividing the obtained secondary weight loss peak area value by the primary weight loss peak area value, and this weight loss ratio is calculated as TG-DTA. As an index value of the device, IEC. pub. A master curve is created by correlating with the weight loss rate calculated in accordance with H.216, and the master curve is compared with the measurement and analysis results of the sample collected from the electric device by the TG-DTA device. In the method of diagnosing deterioration of an electrical equipment insulating material by judging the degree of thermal degradation by means of a sample of the same material as the member in place of a member not provided at the site to be measured in the vicinity of the primary conductor of the TG-DTA device of the electrical equipment An insulating material for collection is provided.

  As described above, according to the first aspect of the present invention, the insulating material for sampling is provided at the measurement target portion in the vicinity of the primary conductor of the TG-DTA device of the electric device at the time of device molding, which is most thermally affected. Since an insulating material for sampling is provided near the primary conductor that is easily received, the sample can be easily sampled without damaging the main body (winding and insulation), and the main body is nondestructively deteriorated. The degree and remaining life can be estimated.

  According to the second aspect of the present invention, the insulating material for sampling is provided at the measurement target portion of the TG-DTA device of the electric device when the device is molded without damaging the main body (winding portion or insulating portion). The sample can be easily collected, and the main body portion can be estimated nondestructively and the deterioration degree and remaining life.

  According to claim 3, since the insulating material for sampling of the same material as the member is provided in place of the member that is not provided in the portion to be measured in the vicinity of the primary conductor of the TG-DTA device of the electrical equipment, The sample can be easily collected without damaging the original member, and the original member can be estimated nondestructively and its deterioration degree and remaining life.

Best Embodiment 1
The best mode for carrying out the present invention will be described below with reference to the drawings. In Embodiment 1 of the present invention, a TG method (thermogravimetric differential thermal analyzer) using a TG-DTA (Thermogravimetric-differential thermal analyzer) device (thermogravimetric differential thermal analyzer) is used to reduce the thermogravimetric sample weight. It is a degradation diagnosis method that combines the weight loss rate of the conventional method using a thermal weight loss curve.

  In general, the TG method is a method for measuring the change in weight of a sample when the temperature is changed as a function of time or temperature, and is widely used for analysis of reaction mechanisms of inorganic and organic materials and evaluation of heat resistance of organic materials. It has been. When a polymer material such as an insulating material undergoes thermal degradation, it releases a low molecular weight component or an unstable end group and becomes apparently stable. As a result of this phenomenon, the decomposition start temperature of the polymer material shifts to the high temperature side, and the decomposition mechanism becomes the primary weight decrease on the low frequency side and the secondary weight decrease on the high temperature side. The degree of deterioration of the polymer material can be evaluated from the second weight ratio.

  The life criterion as an actual deterioration diagnosis method is IEC. pub. In 216 “Guidelines for determining the heat resistance characteristics of electrical insulating materials”, the recommended life reference point of materials is described as a weight reduction rate of 5%. Accordingly, as the life criterion, since the weight reduction rate of 5% or more is the life region classification, the safety region is determined to be less than 2.5% of 1/2 the safety factor from the life region, and the warning region is 2. Temporary life criteria were set within 5% to 5% and with a life region category of 5% or more. However, in the operation in the heat resistance evaluation of the winding of the insulation material of the actual machine, the direct evaluation cannot be applied due to the weight reduction due to the destructive test. Therefore, the weight obtained by incorporating the TG-DTA apparatus for equipment analysis in advance by grasping in advance the correlation with the weight loss rate characteristics by simulating thermal degradation of the insulating material of the electrical equipment to be evaluated. A master curve was created from the correlation with the weight loss rate characteristic using the weight loss ratio as an index value. By conducting device analysis on the winding of the insulating material of the actual machine to be evaluated, the characteristics of the insulating material could be estimated, and the degree of deterioration could be grasped from the provisional life criterion for the degree of deterioration.

  Deterioration degree estimation (transmission measurement method) of a bisphenol-based epoxy resin, which is one of insulating materials of electrical equipment to be evaluated, by a TG-DTA apparatus is used as a technique for determining the deterioration degree and estimating the remaining life. In this method, an exothermic peak associated with an exothermic reaction is detected, and the peak shifts to a lower temperature side as the thermal deterioration time increases. A master curve is created from the correlation between the heat deterioration time and the exothermic peak temperature.

  In the conventional instrumental analysis method, the boundary layer of the integrated thermogravimetric decrease curve of the “primary weight loss” and “secondary weight loss” of the integral curve of the thermogravimetric decrease curve is determined by visual judgment, The weight loss ratio is calculated by dividing the primary weight loss by the primary weight loss. Therefore, in the conventional method, the reproducibility is poor with the visual judgment of the boundary layer, and the analysis accuracy is very poor.

  On the other hand, in Embodiment 1, the sample-adjusted specimen is analyzed and measured by the TG-DTA apparatus, and the “primary weight loss amount” and “secondary weight loss” of the integral curve of the thermogravimetric weight loss curve are obtained. The integral reduction curve of “amount” is converted into a differential value by a commercially available general-purpose statistical software to obtain a differential peak. Furthermore, a differential multiple peak splitting process was performed using a Gaussian function. Next, the weight loss ratio is calculated by dividing the separated secondary weight reduction peak area value by the primary weight reduction peak area value. The weight loss ratio obtained here is used as an index value for analysis of the TG-DTA apparatus, and a master curve is created by correlating with the weight loss rate result of the conventional method (IEC.pub.216). Perform deterioration diagnosis and life expectancy estimation using.

  The above method is applied to actual machines by collecting data necessary for measurement from the insulating mold part of the bisphenol-based epoxy resin of the used product or each mold electric device in use (periodic or single-shot sampling), master curve and TG -The deterioration degree of the mold resin part is estimated by collating the analysis and measurement results of the sample collected by the DTA apparatus. However, as described above, if the sample is collected by mechanically scraping the target portion in the vicinity of the primary conductor, the appearance of the electrical equipment may be damaged, resulting in cracks and the like. . 1A to 1C are a plan view, a front view, and a side view of a current transformer for a wound mold instrument according to Embodiment 1 of the present invention, and a primary conductor 1 of the current transformer for the wound mold instrument. An insulating material 2 for sampling, which is made of a bisphenol-based epoxy resin, is provided at the measurement target site of the TG-DTA apparatus in the adjacent portion at the time of device molding.

  In the first embodiment described above, in a wound-type molded instrument current transformer that is a high-voltage device molded with an epoxy resin, a sample is molded at the measurement target site near the primary conductor 1 that is most susceptible to heat. Insulating material 2 for collection is provided, and it is possible to easily collect samples without damaging the main body (winding part or insulating part), and the main body is non-destructive and the degree of deterioration and remaining life can be estimated. can do.

Embodiment 2
2 (a) to 2 (c) show a front view, a plan view, and a side view of a current transformer for a bar primary mold instrument according to Embodiment 2 of the present invention, and the primary current transformer for a bar primary mold instrument. An insulating material 4 for sampling is provided at the measurement target portion of the TG-DTA apparatus adjacent to the conductor 3 when the epoxy resin is molded.

  In Embodiment 2 as well, a correlation between the weight reduction ratio and the weight reduction rate is made to create a master curve, and the measurement and analysis results of the master curve and the sample collected from the electrical equipment by the TG-DTA apparatus are obtained. By comparing, the degree of thermal degradation is judged, and the deterioration of the electrical equipment insulating material is diagnosed. In a current transformer for a bar primary type mold instrument, which is a high voltage device molded with an epoxy resin, an insulating material 4 for sampling at the time of molding at a measurement target portion near the primary conductor 3 that is most susceptible to heat. Therefore, the sample can be easily collected without damaging the main body (winding portion or insulating portion), and the main body can be estimated nondestructively and the deterioration degree and remaining life.

Embodiment 3
3 (a) to 3 (c) show a front view, a left side view, and a right side view of a bushing mold instrument current transformer according to Embodiment 3 of the present invention, and the primary of the bushing mold instrument current transformer. An insulating material 6 for sampling, which is made of epoxy resin, is provided at the measurement target site of the TG-DTA apparatus adjacent to the conductor 5 at the time of molding.

  Also in the third embodiment, a correlation between the weight reduction ratio and the weight reduction rate is taken to create a master curve, and the master curve and the sample collected from the electrical equipment are measured and analyzed by the TG-DTA apparatus. By comparing, the degree of thermal degradation is judged, and the deterioration of the electrical equipment insulating material is diagnosed. In the current transformer for bushing type mold instrument, which is a high voltage device molded with epoxy resin, the insulating material 6 for sampling at the time of molding is applied to the measurement target part near the primary conductor 5 that is most susceptible to heat. The sample can be easily collected without damaging the main body (winding portion or insulating portion), and the main body can be estimated nondestructively and the deterioration degree and remaining life.

Embodiment 4
4 (a) to 4 (d) are a front view, a longitudinal side view, a partially enlarged front view of a part A (bushing part), and a side view of a current transformer according to Embodiment 4 of the present invention. An insulating material 8 for sampling, which is made of an epoxy resin, is provided at the measurement target portion of the TG-DTA apparatus adjacent to the primary conductor 7 of the fluency bushing at the time of molding.

  Also in the fourth embodiment, a correlation between the weight reduction ratio and the weight reduction rate is made to create a master curve, and the measurement and analysis results of the master curve and the sample collected from the electrical equipment by the TG-DTA apparatus are obtained. By comparing, the degree of thermal degradation is judged, and the deterioration of the electrical equipment insulating material is diagnosed. In a current transformer bushing, which is a high voltage device molded with an epoxy resin, an insulating material 8 is provided at the time of molding near a primary conductor 7 that is most susceptible to heat, and a main body (winding) The sample can be easily collected without damaging the wire portion or the insulating portion, and the main body portion can be estimated nondestructively and the deterioration degree and remaining life.

Embodiment 5
5 (a) and 5 (b) are a front view and a side view of a molded instrument transformer according to the fifth embodiment of the present invention, and an epoxy at the time of molding is applied to a measurement target portion of the TG-DTA device of the molded instrument transformer. An insulating material 9 for collecting a sample made of resin is provided.

  Also in the fifth embodiment, a correlation between the weight reduction ratio and the weight reduction rate is taken to create a master curve, and the master curve and a sample collected from the electrical equipment are measured and analyzed by the TG-DTA apparatus. By comparing, the degree of thermal degradation is judged, and the deterioration of the electrical equipment insulating material is diagnosed. And, in a transformer for molded instrument which is a high voltage device molded with epoxy resin, an insulating material 9 for sampling is provided at the measurement target part at the time of molding, and the main body part (winding part and insulating part) is damaged. Therefore, the sample can be easily collected, and the main body portion can be estimated nondestructively and the deterioration degree and the remaining life.

Embodiment 6
6 (a) and 6 (b) are a front view and a side view of a molded grounded instrument transformer according to a sixth preferred embodiment of the present invention, and a measurement target portion of a TG-DTA device of the molded grounded instrument transformer. An insulating material 10 for collecting a sample made of an epoxy resin is provided at the time of molding.

  Also in the sixth embodiment, a master curve is created by correlating the weight reduction ratio and the weight reduction rate, and the measurement and analysis results of the master curve and the sample collected from the electrical equipment by the TG-DTA apparatus are used. By comparing, the degree of thermal degradation is judged, and the deterioration of the electrical equipment insulating material is diagnosed. In a molded grounded instrument transformer, which is a high-voltage device molded with an epoxy resin, an insulating material 10 for sampling is provided at a measurement target part at the time of molding, and a main body (winding part or insulating part) The sample can be easily collected without damaging the main body, and the main body portion can be estimated nondestructively and the deterioration degree and remaining life.

Embodiment 7
FIGS. 7A and 7B show a longitudinal side view of the current transformer and an enlarged view of the B portion thereof. The primary conductor 13 is supported on the board surface 11 via a support insulator 12. Unlike the molding material, the supporting insulator 12 cannot be provided in the vicinity of the primary conductor 13. Therefore, in the seventh embodiment, an insulating material 14 made of the same material as that of the support insulator 12 is provided adjacent to the primary conductor 13.

  Also in the seventh embodiment, a correlation between the weight reduction ratio and the weight reduction rate is taken to create a master curve, and this master curve and a sample collected from the electrical equipment are measured and analyzed by the TG-DTA apparatus. By comparing, the degree of thermal degradation is judged, and the deterioration of the electrical equipment insulating material is diagnosed. And in the current transformer which is a high voltage device molded by epoxy resin, a sample of the same material as the supporting insulator 12 is placed on the measurement target portion of the adjacent portion of the primary conductor 13 which is most thermally affected by the TG-DTA device. The insulating material 14 for collection is provided, the sample can be easily collected without damaging the original member, and the original member can be estimated nondestructively and the deterioration degree and the remaining life.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view, a front view, and a side view of a wound-type molded instrument current transformer according to Embodiment 1 of the present invention. It is a front view, a top view, and a side view of a current transformer for a bar primary mold instrument according to the second embodiment. It is a front view, a left side view, and a right side view of a bushing type mold instrument current transformer according to the third embodiment. It is the front view of a current transformer by Embodiment 4, a vertical side view, the partial front view of the A section (bushing part), and its side view. It is the front view and side view of the transformer for mold instruments by Embodiment 5. It is the front view and side view of a mold grounding type instrument transformer according to the sixth embodiment. It is the vertical side view of the current transformer by Embodiment 7, and the B section enlarged view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,3,5,7,13 ... Primary conductor 2,4,6,8,9,10,14 ... Insulation material 12 ... Support insulator

Claims (3)

  The differential peak is obtained by converting the integral weight loss curve of the integral weight curve of the thermogravimetric weight loss curve at the time of weight change of the electrical equipment insulation material obtained from the TG-DTA device into the differential value. Further, a differential multiple peak splitting process is performed using a Gaussian function, and the weight loss ratio is calculated by dividing the obtained secondary weight reduction peak area value by the primary weight reduction peak area value. As an index value of the TG-DTA apparatus. pub. A master curve is created by correlating with the weight loss rate calculated in accordance with H.216, and the master curve is compared with the measurement and analysis results of the sample collected from the electric device by the TG-DTA device. In the method for diagnosing deterioration of an electrical equipment insulating material that determines the degree of thermal degradation by using an insulating material for sampling at the time of equipment molding, a measurement target site near the primary conductor of the TG-DTA device of the electrical equipment is provided. Degradation diagnosis method for electrical equipment insulation materials.   The differential peak is obtained by converting the integral weight loss curve of the integral weight curve of the thermogravimetric weight loss curve at the time of weight change of the electrical equipment insulation material obtained from the TG-DTA device into the differential value. Further, a differential multiple peak splitting process is performed using a Gaussian function, and the weight loss ratio is calculated by dividing the obtained secondary weight reduction peak area value by the primary weight reduction peak area value. As an index value of the TG-DTA apparatus. pub. A master curve is created by correlating with the weight loss rate calculated in accordance with H.216, and the master curve is compared with the measurement and analysis results of the sample collected from the electric device by the TG-DTA device. In the method for diagnosing deterioration of an electrical equipment insulating material by judging the degree of thermal degradation by using the electrical equipment insulation material, an insulating material for sampling is provided at the time of equipment molding at a measurement target part of the TG-DTA device of the electrical equipment Deterioration diagnosis method of   The differential peak is obtained by converting the integral weight loss curve of the integral weight curve of the thermogravimetric weight loss curve at the time of weight change of the electrical equipment insulation material obtained from the TG-DTA device into the differential value. Further, a differential multiple peak splitting process is performed using a Gaussian function, and the weight loss ratio is calculated by dividing the obtained secondary weight reduction peak area value by the primary weight reduction peak area value. As an index value of the TG-DTA apparatus. pub. A master curve is created by correlating with the weight loss rate calculated in accordance with H.216, and the master curve is compared with the measurement and analysis results of the sample collected from the electric device by the TG-DTA device. In the method of diagnosing deterioration of an electrical equipment insulating material by judging the degree of thermal degradation by means of a sample of the same material as the member in place of a member not provided at the site to be measured in the vicinity of the primary conductor of the TG-DTA device of the electrical equipment A method for diagnosing deterioration of insulating material for electrical equipment, characterized by providing an insulating material for collection.

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