JPH0743414A - Aging diagnostic method of insulating paper for oil-filled electric equipment - Google Patents

Abstract

PURPOSE:To diagnose the aging of an insulating matter of a coil used in an oil-filled electric equipment without sampling the insulating matter from the coil. CONSTITUTION:Insulating paper of a wire lead 3 is sampled from a coil of an electric equipment to be diagnosed to measure an average polymerization residual rate of the insulating paper and an amount of CO2+CO generated of the insulating paper of the lead is determined from the average polymerization residual rate. A multiplying factor is determined between a generation speed of the CO2+CO of the insulating paper of the coil at a set temperature of the coil and that of CO2+CO of the insulating paper of a wire lead 3 at the temperature of the wire lead 3. The factor thus obtained is multiplied by the amount of the CO2+CO generated of the insulating paper of the coil determined previously to determine the amount of CO2+CO generated of the insulating paper of the coil. Average polymerization residual rate of an aging diagnosis element of the insulating paper of the coil is determined from the amount of the CO2+CO generated of the insulating paper of the coil determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing deterioration of insulating paper in oil-filled electrical equipment such as oil-filled transformers and oil-filled reactors.

[0002]

2. Description of the Related Art The life of an oil-filled electrical device is estimated from the degree of deterioration of the insulating material that insulates the coil used in the device. And the degree of deterioration of this insulator is
It can be known by measuring the tensile strength, the degree of polymerization and other physical properties of the insulator.

Such a measurement can be performed by taking out a coil from the oil-filled electric device and then taking an insulator from the coil. Therefore, the life diagnosis by such measurement can be performed only when the inside of the electromagnetic induction device is inspected, etc., when the inside is opened.If necessary, remove the insulator and measure it. , Cannot be diagnosed. Further, when the insulating paper is collected, it is extremely difficult to repair it, and it may become impossible to reuse it.

[0004]

SUMMARY OF THE INVENTION The present invention requires the collection of coil insulators when diagnosing the life of an oil-filled electrical device from the extent of deterioration of the coil insulator used in the device. The purpose is not to allow that diagnosis.

[0005]

According to the present invention, an insulating paper of a wiring lead from a coil of an electric device to be diagnosed is sampled and an average residual polymerization degree of the insulating paper is measured. First, obtain the amount of CO2 + CO produced from this insulating paper
Means, CO2 + CO generation rate of the insulating paper of the coil at the set coil temperature, and CO2 + of the insulating paper of the wiring lead at the measured temperature of the wiring lead.
Second means for obtaining a CO2 + CO production amount of the insulating paper of the coil by obtaining a multiplication factor with the CO production rate, and multiplying this multiplication factor by the CO2 + CO production amount obtained by the first means, coil insulation obtained by the second means It is characterized by comprising a third means for obtaining an average residual polymerization degree of the deterioration diagnosing element of the insulating paper of the coil from the CO2 + CO production amount of the paper.

[0006]

Since the heating temperature and the CO2 + CO production rate have a certain correlation, the production rate can be obtained by knowing the heating temperature. Therefore, the CO2 + CO generation rate with respect to the set coil temperature and the CO2 + CO generation rate with respect to the measured wiring lead temperature can be obtained. Since the temperature of the coil is higher than the temperature of the wiring lead, the magnification of both generation rates is obtained in advance.

The insulating paper of the wiring lead can be easily collected by opening the manhole of the tank. The average degree of polymerization residual ratio of the collected insulating paper is measured and determined. Since the average degree of polymerization remaining of the insulating paper and the amount of CO2 + CO produced have a certain correlation, if the average degree of polymerization remaining is known, the amount of CO2 + CO produced of the insulating paper of the wiring lead can be obtained.

By multiplying the obtained average degree of polymerization residual ratio by the previously obtained multiplying rate of both production rates, CO2 + C of the insulating paper of the coil is obtained.
The amount of O produced is obtained. As described above, since the average polymerization degree residual rate and the CO2 + CO production amount have a certain correlation, the average polymerization degree residual rate of the insulating paper of the coil is obtained using this relationship. Deterioration of the insulation paper of the coil can be diagnosed from the obtained average degree of polymerization residual ratio.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. In FIG. 1, reference numeral 1 is a tank of an oil-filled electric device in which a device body 2 is housed together with insulating oil. A wire lead 3 is led out from the coil of the device body 2, and is led out to the outside via a bushing 4. Reference numeral 5 is a manhole for the tank 1. According to the present invention, a part 6 of the insulating paper used for the wiring lead 3 is sampled. This collection is easy due to the opening of the manhole 5.

The following operations exemplify specific numbers and will be described with reference to the flow chart shown in FIG. The operating temperature of the coil used in the device body 2 is set to 95 ° C. This temperature is the temperature defined by the standard. FIG. 2 is a characteristic curve diagram showing the relationship between the heating temperature and the CO2 + CO generation rate of insulating paper, which is a known one. From FIG. 2, the CO2 + CO production rate 1 × 10 −5 (ml / g · h) of the insulating paper at 95 ° C. is obtained.

Separately, the temperature of the wiring lead 3 is calculated. As a specific example, when the rated current (line current) is 87.5 A and the wiring lead has a cross-sectional area of 38 mm2 (allowable current 145 A), the current density is 2.3 A / mm2. Becomes The temperature rise for this current density is 6 ° C. Therefore, if the oil temperature rise value is 40 ° C. and the outside air temperature is 20 ° C., the wiring lead temperature becomes 66 ° C.

The CO 2 + CO generation rate of the insulating paper at this temperature is required to be 5 × 10 −7 (ml / g · h) from FIG. 2. These results indicate that the rate of formation of the coil insulation paper is 20 times higher than that of the wiring lead insulation paper. On the other hand, the average residual rate of the degree of polymerization of the insulating paper of the collected wiring lead is measured and obtained. This measured value is, for example, 5
It is assumed to be 4.5%.

FIG. 3 is a characteristic curve diagram showing the relationship between the average residual polymerization degree of the insulating paper and the amount of CO2 + CO produced per unit weight of the insulating paper when the insulating paper is heated and deteriorated in insulating oil.
This is a known one. From FIG. 3, the average degree of polymerization residual rate is 5
CO2 + CO production at 4.5% 1.1 (ml
/ G) is required. The amount of CO2 + CO produced at 95 ° C is 20 times that at 66 ° C.
The production amount of CO2 + CO at the temperature of ° C is 22 (ml / g), which is 20 times the value of 1.1 (ml / g).

When the average degree of polymerization residual rate when the amount of CO2 + CO produced is 22 (ml / g) is obtained from FIG. 3, it is 18%. That is, the average residual degree of polymerization of the insulating paper of the coil at 95 ° C. is calculated to be 18%. It is possible to diagnose deterioration of the insulating paper of the coil from the average residual degree of polymerization.

The average degree of polymerization remaining of the insulating paper of the coil of the above-mentioned actual electric equipment was measured and found to be 18.5%. Therefore, it is found that the value obtained as described above and the value obtained by actual measurement substantially match.

[0016]

As described above in detail, according to the present invention, when diagnosing the deterioration of the insulating paper of the coil of the oil-filled electrical equipment from the average residual rate of the polymerization degree, it is diagnosed without disassembling the target electrical equipment. In addition, the average residual degree of polymerization of the obtained insulating paper substantially matches the actually measured value, so that the reliable diagnosis can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a characteristic curve diagram showing a relationship between a heating temperature and a CO 2 + CO generation rate of insulating paper.

FIG. 3 is an average residual polymerization degree of the insulating paper and CO2 per unit weight of the insulating paper when the insulating paper is heated and deteriorated in insulating oil.
It is a characteristic curve figure which shows the relationship with + CO production amount.

FIG. 4 is a flow chart for explaining the method of the present invention.

[Explanation of symbols]

 1 Tank 2 Equipment body 3 Wiring lead 5 Manhole 6 Wiring lead sampling area

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Nomura 47 Umezu Takaunecho, Ukyo-ku, Kyoto City Nissin Electric Co., Ltd.

Claims (1)

[Claims] 1. An insulating paper of a wiring lead from a coil of an electric device to be diagnosed is sampled, an average residual polymerization degree of the insulating paper is measured, and the insulating paper C02 is obtained from the average residual polymerization degree.
First means for obtaining + CO production, CO2 + C of the insulating paper of the coil at the set temperature of the coil
A ratio between the O generation rate and the CO2 + CO generation rate of the insulating paper of the wiring lead at the measured temperature of the wiring lead is calculated, and the C is calculated by the first means.
Insulating paper of the coil CO2 +
Second means for obtaining the CO production amount, and third means for obtaining the average residual polymerization degree of the deterioration diagnosing element of the insulating paper of the coil from the CO2 + CO production amount of the insulating paper of the coil obtained by the second means. A method for diagnosing deterioration of insulating paper for oil-filled electrical equipment, comprising: