JP2012202695A - Deteriorated insulation diagnosing method and deteriorated insulation diagnosing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deteriorated insulation diagnosing method for estimating the advancing degree of deterioration of insulation by direct visual observation and preventing the insulation from breaking down.SOLUTION: By a method, deteriorated insulation is diagnosed by a direct visual observation step of checking the surface states of a plurality of insulators (st1), a faded color item selecting step of selecting insulators with faded color out of the checked insulators (st2), a color fading degree measurement step of measuring a degree of color fading selected out of glossiness, contact angle and hues of insulators with faded color (st3), and surface state determining steps of applying the degree of color fading to a characteristics formula configured into a database in advance and calculating the surface insulation resistance (st4 to st6).

Description

Embodiments described herein relate generally to an insulation deterioration diagnosis method and an insulation deterioration diagnosis device for diagnosing a secular change of an insulating material used in an electrical apparatus.

2. Description of the Related Art Insulators made of an insulating material such as an epoxy resin and a polyester resin that have been used in many electrical devices have been deteriorated in insulating properties after long-term use. For this reason, maintenance inspection is performed every predetermined period, the remaining life is calculated from insulation resistance measurement, partial discharge measurement, decomposition gas measurement, etc., and insulation breakdown is prevented (for example, refer to Patent Document 1).

In maintenance and inspection, it is very difficult and time-consuming to conduct the above-described characteristic investigation with all insulators. In general, an insulator is sampled and a characteristic survey is performed, and the characteristic is estimated for an unsampled sample. For this reason, an insulator that has not been sampled even though its characteristics are deteriorated is exposed to a risk of dielectric breakdown.

On the other hand, in the maintenance inspection, the visual inspection can be easily performed for all the insulators. Therefore, it is desirable to visually check the degree of fading such as color, dullness, and brightness on the surface of the insulator, select the one that seems to have the most advanced deterioration of insulation, and sample it to investigate its characteristics. It was.

JP 2005-61901 A

The problem to be solved by the present invention is to determine the degree of fading on the surface of the insulator from visual inspection, sample what seems to be the most advanced deterioration of insulation, and prevent dielectric breakdown in advance. An object of the present invention is to provide an insulation deterioration diagnosis method for an insulating material and an insulation deterioration diagnosis apparatus using the method.

In order to solve the above problems, the insulation deterioration diagnosis method for an insulating material according to an embodiment includes a visual inspection process for examining a surface state of a plurality of insulators, and a faded product selection process for selecting a faded insulator from the inspection. A fading degree measuring step for measuring the fading degree of the faded insulator, and a surface state determining step for calculating a surface insulation resistance by placing the fading degree on a characteristic formula previously stored in a database.

The flowchart which shows the insulation degradation diagnostic method of the insulating material which concerns on the Example of this invention. The figure which shows the measuring method of the surface insulation resistance which concerns on the Example of this invention. The figure which shows the relationship between the measurement item and measurement value which concern on the Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

An insulation deterioration diagnosis method according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a flowchart showing a method for diagnosing insulation deterioration of an insulating material according to an embodiment of the present invention, FIG. 2 is a diagram showing a method for measuring surface insulation resistance according to an embodiment of the present invention, and FIG. It is a figure which shows the relationship between the measurement item and measured value which concern on an Example.

As shown in FIG. 1, in the insulation deterioration diagnosis, first, the surface state of a plurality of insulators used in an electric room or an electric device is visually inspected (visual inspection step) (st1). From the visual inspection, faded or dull ones are sorted out (fading item sorting step) (st2).
Next, the fading degree of the most faded insulator is measured (fading degree measuring step) (st3). Here, the degree of fading refers to measured values of glossiness, contact angle, and hue described later. If the degree of fading has reached a predetermined value (st4), it is determined that the insulation has deteriorated (st5). If the specified value has not been reached (
st4), put on the characteristic formula stored in the database, and estimate the remaining life (st6). st4 ～ s
t6 is the surface state determination step of the insulator.

Such a diagnostic method will be described using an insulator of a vacuum switch made of polyester resin.

As shown in FIG. 2, first, the surface insulation resistance of the three-phase integral insulation barrier 1 is measured. A copper tape electrode 2 having a length of 50 mm was pasted on a predetermined surface at an interval of 10 mm, 1 kV was applied, and the value when 1 minute had elapsed was measured with an insulation resistance meter 3. The measurement environment is normal temperature and humidity.

Next, the glossiness of the same surface as the measurement location of the surface insulation resistance is measured. Glossiness is JISZ8
It was measured at an incident angle of 60 ° according to 741. As a measuring instrument, a portable gloss meter PG-II manufactured by Nippon Denshoku Industries Co., Ltd. was used.

Next, as with the glossiness, the contact angle of the same surface as the measurement location of the surface insulation resistance is measured. 4m
The pure water of L was dripped with the syringe, the photograph was taken from the horizontal direction, and the angle of the tangent from the surface of an insulating material and the edge part of a water droplet was read.

Next, as with the glossiness, the hue of the same surface as the measurement location of the surface insulation resistance is measured. The hue was measured in accordance with JISZ8701, and the lightness L * indicating the degree of white to black was measured. As a measuring instrument, a portable color difference meter NF333 manufactured by Nippon Denshoku Industries Co., Ltd. was used.

These results are shown in FIG. New, deteriorated product used for 22 years in domestic A area, domestic B
About the deteriorated product 2 used for 28 years in a district, 3-5 places were measured, respectively, and the average value was calculated | required. Here, when the surface insulation resistance is reduced to 10 ⁹ Ω as in the case of the deteriorated product 2, the insulation deterioration proceeds rapidly, so the threshold value for dielectric breakdown was used.

As a result, the new product has a surface insulation resistance of 10 ¹⁴ Ω, but tends to decrease as the insulation deterioration progresses. And when surface insulation resistance falls, glossiness falls rapidly and a contact angle and a hue increase slightly. When the change rate of each measurement item when the surface insulation resistance changes by one digit, the glossiness was 19.2%, the contact angle was 3.5%, and the hue was 1.7%. For this reason, as the degree of fading, the glossiness reacts most and is easy to measure.

When the glossiness is 2.6 or less and the surface insulation resistance falls below the threshold value, it can be determined that the insulation is deteriorated. When the glossiness exceeds 2.6, the remaining life is calculated from the characteristic formula stored in the database. The glossiness varies depending on the measurement method such as the type of insulating material and the incident angle of the measurement light. Therefore, the relationship between the glossiness and surface insulation resistance for each condition is obtained and stored in the database device. And

Further, the surface insulation resistance can be obtained by calculating the characteristic of the contact angle and hue characteristics, and the remaining life can be calculated. The measurement of the surface insulation resistance is easily influenced by the environment such as temperature and humidity, but the contact angle and hue including the glossiness are relatively unaffected and easy to measure. These glossiness, contact angle, and hue were selected to quantify the degree of fading.

The color and dullness of the insulator can be easily selected by visual inspection, and it is easy to find the fading color, that is, the material with the most advanced insulation deterioration. By sampling this and obtaining the glossiness, the surface insulation resistance can be grasped.

According to the insulation deterioration diagnosis method of the above embodiment, the progress of insulation deterioration can be easily grasped by visual inspection, the surface insulation resistance can be obtained from the measurement of fading, and insulation breakdown can be prevented in advance. be able to.

In addition, this invention is not limited to the said Example, In the range which does not deviate from the summary of invention, it can implement in various deformation | transformation. In the above embodiment, the insulating material has been described as a polyester resin. However, insulation deterioration can be diagnosed by visual inspection even in an insulator manufactured from an epoxy resin or a bushing manufactured from a phenol resin.

Although the embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and the like can be made without departing from the spirit of the invention.
Changes can be made. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 Insulation barrier 2 Copper tape electrode 3 Insulation resistance meter

Claims (4)

A visual inspection process for examining the surface condition of a plurality of insulators;
A fading product selection process for selecting a fading insulator from the inspection;
A fading degree measuring step of measuring a fading degree of the faded insulator;
A surface state determination step of calculating a surface insulation resistance by putting the color fading degree on a characteristic formula that has been databased in advance;
An insulation deterioration diagnosis method for diagnosing insulation deterioration provided with   The insulation deterioration diagnosis method according to claim 1, wherein the color fading degree is a glossiness. The insulation deterioration diagnosis method according to claim 2, wherein the insulator is made of a polyester resin, the incident angle is set to 60 ° in the measurement of the glossiness, and the insulation deterioration is determined when the glossiness is 2.6 or less. A gloss meter to measure the gloss of the insulator surface;
A database device storing the relationship between the gloss level and the surface insulation resistance;
An insulation deterioration diagnosis apparatus that calculates surface insulation resistance from the gloss measured by the gloss meter and diagnoses insulation deterioration.

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