JPS60210813A - Oil-immersed electric apparatus - Google Patents

Abstract

PURPOSE:To diagnose life expectation of oil-immersed electric apparatus without suspending the operation by loading a test piece of insulation material same as the determined insulation material into an oil tank and detecting failure of test piece from the outside if such test piece shows abnormal condition. CONSTITUTION:An oil tank 18 is provided at the internal upper part of reservoir 12 and a test apparatus 20 providing an insulation material test piece 20a immersed in the insulation oil 18a is housed at the inside of such oil tank 18. The insulation oil 18a of oil tank 18 can be adjusted a temperature almost equal to the maximum winding temperature of winding 11 of the transformer body 11. A test piece 20a is made of the insulation material which is also used for insulation material of the body 11. With such structure, a test piece 20a at the inside of oil tank 18 shows the aging deterioration which is equal to that of insulation material which reaches the maximum temperature of winding. Therefore, when the test piece 20a at the inside of oil tank 18 is mechanically destroyed, it can be estimated that the mechanical strength of insulation member of the part which reaches the maximum temperature of transformer 17 is lowered up to 60% of initial strength. Highly accurate diagnosis can be realized by judging deterioration degree from mechanical strength as described above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to oil-filled electrical equipment, and particularly to improvements in life expectancy diagnosis of insulating members used in this equipment.

[Technical background of the invention and its problems]

In recent years, increased demand for electric power has led to increased voltage-controlled, large-capacity power transmission, and as a result, oil-filled electrical equipment such as transformers and accelerators have been made dual-voltage and larger in capacity. Therefore, the reliability of oil-filled electrical equipment, which is the core equipment for large-capacity power transmission, is required more than ever.

As a response to this problem, the development of automatic internal partial discharge detection devices and technology for measuring dissolved decomposed gases in oil is progressing, and means to promptly detect internal abnormalities after they occur and prevent the abnormalities from expanding are being adopted. It has become so. However, all of these technologies detect and confirm the phenomenon after an internal abnormality occurs in oil-filled electrical equipment, and do not predict future abnormalities, so they are susceptible to deterioration over time. The lifespan due to this cannot be predicted.

``In other words, there is no way to predict the remaining life of insulating components of oil-filled electrical equipment that has been operated without problems, and the lifespan can only be determined when some abnormality or eventual accident occurs. Ta.

Insulating materials undergo various types of deterioration depending on the operating conditions of the device, so it has been extremely difficult to measure the remaining life of each device. The remaining life can be determined by measuring each characteristic.

However, in the past, it was impossible to use this method for all devices, and even if this method were used, the time, expense, and downtime required would be enormous, and furthermore, it would be difficult to consider the need for continuous use. Because the area that could be sampled was limited to only a few areas, the average degree of deterioration and remaining life assessment had stopped at 1g'iVc. In addition to this situation, overload operation is often carried out these days, so
It was desired to establish a technology to quantitatively measure the reduction in life due to overload.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and its purpose is to diagnose the remaining life of oil-filled electrical equipment during operation without stopping the operation, and to improve the reliability of operation. Our aim is to provide oil-filled electrical equipment that can

[Summary of the invention]

In order to achieve this object, according to the present invention, the main body of the electrical equipment is housed inside the container, the inside is filled with insulating oil, and the temperature can be adjusted so that the temperature at the highest point of the winding is reached inside the container. An oil chamber is provided, an insulating material specimen identical to that of the electrical equipment body is installed inside this oil tank, and a test device that applies a selected mechanical stress during a selected period is housed. 3. By detecting this abnormality from the outside of the oil tank when the edge column member takes on the shape of a specimen, the remaining life of this oil-filled electrical equipment can be diagnosed while it is in operation, and the reliability of operation can be improved. It is characterized by

[Embodiments of the invention]

An embodiment of the oil-filled electrical equipment of the present invention will be described below with reference to FIGS. 1 to 3. BACKGROUND OF THE INVENTION Among oil-filled electrical equipment such as transformers and reactors, an oil-filled transformer (hereinafter referred to as a transformer) will be described as a typical example. In the figure m1, an iron core 11a and a K winding 11b are wound through an insulating member to form a transformer body 11, and this transformer body 11'f
t storage and place the VCS together with the insulating oil 13 inside the container 12. Then, a conservator 15 is provided at the top of the container 12,
A transformer 17 is also constructed by providing a pusher plug 16 connected to the winding 11b via a lead wire 11C. In addition,
A type in which the insulating oil 13 is separated from the outside air via moisture and WX is used.

Further, an oil tank 18 is provided inside the upper part of the container 12, and the test device 20 attached to the insulating member specimen 20a' is housed inside the oil tank 18 so as to be immersed in the insulating oil 18a.

The insulating oil 18a of oil $18 can be adjusted to a temperature approximately equal to the highest point temperature of the winding 11b of the transformer body 11.

The insulating member sample 20a is made of the same insulating material as that used in the transformer body 11Vc. This insulating member is, for example, insulating paper or press board.

Further, the test apparatus 20 is configured to apply a tensile stress or a compression stress to the insulating member specimen 20aVC as a mechanical stress. Now let's use the analogy of mechanical stress as tension. Also, from the test device 20 to the oil tank 18 and container 1
The display section 21 and the information device 22 are connected to the outside of the device 2 via a lead wire 21a indicated by a dot. Then, the insulating member sample 20a is applied with a tensile strength of the insulating member to a selected value, for example, 60% of the initial value, for a selected period of time, for example, continuously or periodically. Configure it so that it adds to the target.

Next, the operation of the present invention will be explained. ? 3. At operating temperatures, insulating materials such as insulating paper soaked in heat deteriorate due to a bonding reaction with oxygen in oil. However, this bonding reaction is temperature-related, and it is known that the higher the temperature, the shorter the lifetime.

In Fig. 2, the vertical axis shows the initial value of mechanical customization such as tensile strength or compressive strength as 100, and the horizontal axis shows time, for example, the mechanical strength of the insulating member as it ages. The characteristics deteriorate with aging, and the higher the operating temperature, the higher the curve 1. jl, IIl, f
As shown in the order of f, the state of decrease when each temperature is increased is shown.

As can be seen, the higher the operating temperature, the more significant the mechanical stress, that is, the decrease in mechanical properties.

Since the temperature of the insulating oil 18a inside the oil tank 18 is adjusted to reach the maximum temperature of the winding of the transformer body 11, the insulating member specimen 20a inside the oil tank 18 is adjusted to reach the highest temperature of the winding. It shows the same aging deterioration as insulating members. Therefore, when the mechanical strength of the insulating member specimen 20a inside the oil tank 18 decreases and an abnormality occurs, that is, when it mechanically breaks, the insulating member at the highest point temperature part of the transformer 17 also loses its mechanical strength. It is estimated that the mechanical strength has decreased to 60% of its initial value.

Further, in FIG. 3, if the initial value of the mechanical properties of the sound insulating member on the vertical axis is taken as 100chi, and time (years) is plotted on the horizontal axis, the secular change becomes as shown by the concave line ■.

For example, the life of an insulating member is 6% compared to the initial value of mechanical strength.
When the mechanical percentage becomes 0%, as shown by the dotted line by extrapolation, the time (year) of the intersection with the curve ■ is 50 cm.
The remaining life can be determined by

In general, the insulating member 1Ilj1. Although the electrical characteristics hardly deteriorate over time, the mechanical strength does decrease, so by determining the degree of deterioration based on the mechanical strength, a highly accurate lifespan diagnosis can be made. Note that the mechanical stress 1 applied to the plurality of insulating member specimens 20a by a testing device 20 that applies mechanical stress housed inside the oil tank 18 is
By changing K, it is possible to cope with rapid deterioration caused by overload operation, etc., and more accurate life prediction can be made.

Furthermore, since the display device 21 and the alarm device 22 are provided, at the time when an abnormality, for example, breakage occurs in the insulating member specimen 20a of the test device 20, the outside of the oil tank 18 and the container 12,
In other words, from the outside of the transformer d17, the mechanical characteristics of the insulating member are determined without stopping the %VC transformer 17,
For example, it can be seen that it has reached 60% of the initial value, so if we assume that the life span is 50 cm, then this! ? It is possible to estimate the remaining life until reaching 0chi.

〔Effect of the invention〕

In this way, according to the present invention, in order to reduce the mechanical strength of the insulating member, the degree of deterioration of the insulating member corresponding to the operating conditions of the oil-filled electrical equipment is determined, and the remaining life, that is, the remaining life, is determined. The lifespan can be determined, and although this remaining life changes little by little due to overload operation and subsequent operation, the remaining life can be diagnosed successively from regular or continuous measurements.
It is possible to issue a warning before an abnormality occurs or the end of the lifespan is reached, and the remaining life of oil-filled electrical equipment during operation can be diagnosed, improving the reliability of operation of oil-filled electrical equipment. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the oil-filled electrical equipment of the present invention, and FIGS. 2 and 3 are lines showing the relationship between the mechanical percent property of the insulating member used in the 7-in/out electrical equipment of the present invention and elapsed time. It is a diagram. 11...Transformer 4 body, lla...iron core, llb...winding, 12...container, 13...insulating oil, 17...transformer, 18...oil tank, 18a...insulating oil, 20... ...Testing device, 20a...Insulating member specimen, 21...Display device, 2
2... Reporting device. Figure 1

Claims (1)

[Claims] In an oil-filled electrical device, in which a main body of an electrical device consisting of a winding wire wound around an iron core via an insulating member is housed inside a container, and insulating oil is sealed inside the container, the highest point temperature of the winding occurs. An oil tank whose temperature has been adjusted as described above is placed inside the container, an insulating material specimen identical to that used in the main body of the electrical equipment is mounted inside this oil tank, and a selected mechanical stress is applied to the insulating material specimen during a selected period. A test device applied to the specimen is immersed in insulating oil and stored, and when the insulation member specimen exhibits an abnormality due to a selected mechanical stress of the insulation member specimen, this abnormality is detected from outside the oil tank. Characteristic oil-filled electrical equipment.