JPS6095367A - Protecting and diagnostic device of transformer - Google Patents

Abstract

PURPOSE:To obtain a diagnostic device which is inexpensive and high in reliability extracting dissolved gas in the oil of plural transformers to analyze gas, comparing said each gas quantity, and detecting an abnormal state. CONSTITUTION:For instance, hydrogen gas in insulating oil is extracted by installing gas extracting devices 4A, 4B to the tank side walls of unit transformers 1A, 1B. This extracted gas quantity is compared by a comparing device 5, and when a special difference between both gas quantities is generated, a protecting countermeasure is taken beforehand by raising an alarm from an alarm device 6. In this case, the transformers 1A, 1B are operated under the same load, the same place and the same environment, and also the assembly, the installation in a job site, the period, etc. are brought to the same processing at the entirely same time, therefore, even if the gas quantity is varied only a little, it can be detected with high sensitivity, and the abnormality of the transformer can be detected in its early stage. Also, as for the comparing device and the alarm device, one set will do, and an inexpensive diagnostic device is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention particularly relates to a transformer insurance diagnosis system by analyzing dissolved gas in oil.

[Technical background of the invention and its problems] In recent years, new maintenance and diagnostic devices have been installed on equipment installed in power transmission systems, such as transformers, due to their importance in power transmission. Examples include methods for detecting partial discharges occurring inside oil-immersed transformers, and devices for extracting and analyzing gas stored in the oil of oil-immersed transformers. Such a diagnostic device is attached to a transformer to prevent electric shock from occurring and prevent the spread of accidents.

Conventional diagnostic equipment based on oil analysis for oil-immersed transformers extracts the dissolved gas inside the transformer, compares this extracted gas with a reference gas amount, and issues an alarm if an abnormal gas level is detected. It was a system that emitted.

In such a diagnostic device, the amount of extracted gas is compared with the amount of gas extracted in a previous step for diagnosis, and the change in pressure is determined from the increase or decrease in both. This is an attempt to find abnormalities in the equipment.

In this type of conventional gas analysis, which diagnoses abnormalities based on increases and decreases in the amount of gas, it is assumed that the amount of gas remains constant even if time elapses when there is no abnormality in the transformer. However, the gas in the insulating oil of the transformer is constantly changing. For example, at the beginning of operation, gas oozes out from insulating oil as well as water oozing out.For example, the number of months of operation of a transformer and hydrogen gas L1 shown in Figure 2 increase. As shown in the relationship, J may decrease by around 30 PPM in a month.The increase or decrease in this gas hill depends on the load situation during continuous rotation, L edge and a:f';
``A place of bad luck'' ko 1 Changes into plants depending on the situation.

Therefore, it is difficult to predict in advance the rate of decrease by 2. However, in the conventional method, the gas amount based on the previous analysis value is simply compared with the gas amount of 1.1 at D II'r x, and the judgment is made based on the comparison, so there is a high risk of misjudgment.

[Object of the Invention] An object of the present invention is to provide a transformer protection diagnosis device using gas analysis that does not cause erroneous judgments.

[Summary of the Invention] The transformer protection/diagnosis/damage treatment according to the present invention involves extracting gas dissolved in oil from two transformers out of a plurality of transformers that have been subjected to the same treatment at the same time, The present invention is characterized in that it is configured to detect abnormalities in the transformer by comparing the gas eaves.0 [Embodiments of the Invention] Hereinafter, regarding the embodiment ψ1 of the present invention shown in FIG. 1, 1. I will clarify. In FIG. 1, a multivalue transformer IA according to the invention is shown.
, IB indicates the -a portion of the transformer divided into two, and l and unit transformer. Inside each of the transformers IA and IB, a winding, an iron core, and an insulating oil are sealed. The lead wires from the windings are drawn out from the bushings 2 and 3, respectively. Then, semipermeable membrane type gas extraction devices 4A, 4B are attached to the side walls of the tanks of the unit transformers IA, IB to extract hydrogen gas, for example, from the insulating oil. This gas extraction device 4A
.

The gas M iJ extracted in 4B is compared with comparison device ft5, and if there is a difference in the amount of gas between the two, an alarm will be issued from the alarm device 6 and preventive measures will be taken. Become.

In the transformer protection/diagnosis device according to the present invention constructed as described above, transformers IA and IB carry the same load,
It is being operated at the same location and in the same location. Moreover, since the assembly, installation, period, termination, and treatment of the transformer are all carried out at the same time, IFI treatment is performed at exactly the same time, so the change in the amount of gas that naturally increases is caused by the change in the amount of gas in the transformer IA.

It will be the same in IB. Therefore, in the present invention, since 8Jl of gas is extracted from both transformers IA and IB and compared, even a slight change in the amount of gas in the bean paste can be detected with high sensitivity, and the drum-like shape of the transformer can be detected early. can be found in. Since the bath gas is extracted from the two unit transformers IA and IB at the same time, in the event of an abnormality, it is not only possible to determine which transformer is abnormal, but also to avoid erroneous judgments. There is no need to judge.Also, since the gas amount is compared between two unit transformers operating under the same operating conditions,
Only one comparison device or alarm device is required, and an inexpensive diagnostic device 6 is obtained. Even if one of the two gas extraction devices breaks down, the diagnosis of the other transformer is still possible. It becomes possible. Furthermore, since a semi-permeable membrane type gas extraction method is adopted, it is easy to handle and an inexpensive monitoring device can be obtained.

In addition, in the drawing, one phase is divided into two as unit transformers IA and IB.
Although the example is shown using a divided transformer, it may be divided into three or more transformers that are operated with the same load and perform the same processing, and it can also be applied to multiple transformers that are operated in parallel. Can be done.

[Effects of the Invention] As described above, the present invention has the advantage that a plurality of transformers 2. By extracting dissolved gas in oil, analyzing the gas, and comparing the mutual gas amounts to detect abnormalities, we have created an inexpensive and reliable commercial pressure gain insertion diagnostic device. Obtainable.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a transformer maintenance and diagnosis apparatus according to the present invention, and FIG. 2 is a characteristic diagram showing changes over time in hydrogen gas dissolved in oil. IA, IB... Unit transformer 2, 3... Bushing 4
A, 4B... Gas extraction device 5... Comparison device 6...
・Alarm device

Claims (1)

[Scope of Claims] (1) At least two unit transformers installed, a gas extractor for extracting dissolved gas in oil in each unit transformer, and gas detected by each gas extractor. A transformer protection diagnosis device (2) consisting of a comparison device that compares darkness, and a detection alarm that issues a detailed warning when the results compared by the comparison device are abnormal (2) multiple units The unit transformer is a unit transformer in which one phase of the transformer is divided into a plurality of units. The transformer is characterized in that it is a plurality of transformers operated in parallel [Claim 1]
4. The transformer protection diagnostic device (4) according to claim 1, wherein the gas extractor adopts a semi-permeable membrane type.
Maintenance of the transformer described in Section 1i11! ! diagnostic equipment