JPH0216473B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an abnormality detection device for oil-filled electrical equipment,
In particular, the present invention relates to an abnormality detection device for oil-filled electrical equipment that can automate the extraction and detection of gas generated in insulating oil and display an alarm.

As an example of a method for detecting abnormalities in oil-filled electrical equipment, such as transformers, when the insulation of a transformer, mainly organic insulation materials such as mineral oil and cellulose insulation, thermally decomposes, a decomposition gas peculiar to the material is generated. There is a method in which a protective relay is activated and an alarm is displayed when the decomposed gas amount exceeds a specified amount. However, in order to prevent deterioration of the insulating oil, recent transformers have adopted a pressureless sealed structure, and sufficient deaeration is performed when filling the transformer with insulating oil. In the above method, even if cracked gas is generated due to a malfunction inside the transformer, the initially generated cracked gas is absorbed into the insulating oil, and after the absorption is saturated, the subsequently generated cracked gas becomes bubbles. Only when it escapes from the insulating oil will it be detected by the protective relay and an alarm will be displayed. Therefore, there is a drawback that there is a considerable time delay after the initial malfunction occurs until the protective relay detects it and an alarm is displayed.

On the other hand, various devices have been developed and widely used for detecting gases generated in insulating oil, but these detection devices are capable of collecting sample oil for gas detection, degassing the sample oil, and degassing gases generated from the sample oil. Operations at each stage of detection must be performed manually. Moreover, for each operation, the sample oil must be returned to the laboratory or testing room, which has drawbacks such as the inability to detect abnormalities quickly and is extremely difficult to use as a continuous abnormality detection device. There are drawbacks such as:

In particular, as devices for extracting generated gas from insulating oil, there are gas extraction devices using a Trithier vacuum, gas extraction devices using a combination of a mercury diffusion pump and a Teppler pump, and gas extraction devices using a vacuum pump and a moving valve. Due to the use of glass containers or the use of mercury, there are problems with various dangers such as damage to the glass container and the escape of mercury vapor.

The present invention has been made in view of these points, and is capable of automatically extracting and detecting gas generated in insulating oil, as well as continuously detecting it, quickly and reliably detecting abnormalities in electrical equipment, and detecting damage. There is no need to use a glass device that can be dangerous, and the risk of mercury vapor escaping can be eliminated. It is an object of the present invention to provide an abnormality detection device for oil-filled electrical equipment, which can sufficiently transfer and charge generated gas into a gas sample tube and reliably detect even initial abnormalities in the electrical equipment.

An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes an oil tank of an oil-filled electric device, such as a nitrogen-filled transformer, and 2 is a gas diffusion permeation device housed within the oil tank 1. In FIG. This gas diffusion permeation device 2 is formed of a polymeric material with good gas permeability into a cylindrical shape with a bottom, and its open end is a lid 2.
It is sealed with a. This gas diffusion permeation device 2 has its bottomed side inserted into the insulating oil of the oil tank 1, and the lid 2a is fixed to the outside of the side wall of the oil tank 1. This gas diffusion permeation device 2 is connected to a cylinder chamber 6a of a reciprocating piston device 6 via a valve 5, and a vacuum pump 9 is connected to the cylinder chamber 6a via a valve 7 and a three-way valve 8. The cylinder chamber 6a of the reciprocating piston device 6 has a small diameter and has a piston 6b inside. The piston 6b of the reciprocating piston device 6 is connected to the piston 13b of the differential pressure piston 13, and is driven thereby. That is, the differential pressure piston device 13 is connected to the cylinder chamber 6 of the reciprocating piston device 6.
The cylinder chamber 13a has a diameter larger than the cylinder chamber 13a, and has a piston 13b connected to the piston 6b by a rod 16 inside the cylinder chamber 13a. Also, the cylinder chamber 2 on the piston 6b side of the cylinder chamber 13a
3a and the other cylinder chamber 33a are connected to the vacuum pump 9 via three-way valves 14 and 15, respectively. Therefore, the three-way valve 15 is switched to connect the cylinder chamber 33a to the vacuum pump 9, and the three-way valve 14 is connected to the vacuum pump 9.
When the cylinder chamber 23a is opened to the atmosphere, the piston 13b moves downward in the figure due to the pressure difference on both sides thereof, and the piston 6b moves downward accordingly. Conversely, if the three-way valve 14 is switched to connect the cylinder chamber 23a to the vacuum pump 9, and the three-way valve 15 is switched to open the cylinder chamber 33a to the atmosphere, the piston 13b and the piston
b can be moved upwards. On the other hand, a switching valve 11 is connected to a conduit 10 connected to the three-way valve 8, and a gas sampling pipe 1 is connected to this switching valve 11.
2 are connected, and a gas analyzer 17 and an alarm display device 18 are also connected via a conduit 16.
Furthermore, a carrier gas conduit 19 is connected. Therefore, when the switching valve 11 is rotated by a predetermined angle, the gas in the gas sampling pipe 12 is transferred to the switching valve 1 by the carrier gas from the conduit 19 connected to the switching valve 11.
1, the gas is led to a gas analyzer 17 via a conduit 16, and as a result of gas analysis here, if the amount of combustible gas such as hydrogen gas exceeds a specified amount, an alarm display device 18 is activated. It is now possible to display a warning.

Next, the operation of the apparatus of the present invention configured as described above will be explained.

First, we will discuss the components of the gas produced by thermal decomposition of the insulators used inside the transformer. When cellulose-based insulators are thermally decomposed, carbon monoxide and carbon dioxide gas are generated, and when insulating oil (mineral oil) is thermally decomposed, gases such as methane, ethane, ethylene, and hydrogen are generated. In particular, when insulating oil (mineral oil) is thermally decomposed by arc or corona discharge, organic gases such as hydrogen, acetylene, and ethylene are generated. These generated gases continuously permeate into the gas diffusion permeation device 2 due to the gas permeation effect of the cylindrical tube made of a polymeric material with good gas permeability, so that the generated gases are extracted. This system detects abnormalities in equipment caused by thermal decomposition of insulating oil, etc., and displays an alarm.

In the apparatus of the present invention, first, the vacuum pump 9 is driven, the three-way valve 8 is switched, and the gas analyzer 17 and the gas sampling pipe 12 are connected via the conduit 10 and the switching valve 11.
communicate with. On the other hand, the valve 7 is switched to communicate with the cylinder chamber 6a, and the valve 5 is further switched to communicate with the gas diffusion permeation device 2. On the other hand, the cylinder chamber 23a is connected to the vacuum pump 9 through the three-way valve 14, and the cylinder chamber 3 is connected through the three-way valve 15.
By opening 3a to the atmosphere, the piston 1
3b and the piston 6b connected via the rod 16 are moved upward together. By continuing to drive the vacuum pump 9, the interiors of the gas analyzer 17, gas sampling tube 12, conduit 10, cylinder chamber 6a, cylinder chamber 23a, gas diffusion permeation device 2, etc. are brought into a predetermined vacuum state.
In this way, after the inside of the gas diffusion permeation device 2, etc. reaches a predetermined vacuum state, the three-way valve 8 is switched to cut off the communication between the cylinder chamber 6a, the gas diffusion permeation device 2, etc., and the vacuum pump 9, and the valve 5 is closed, the valve 7 is closed, the vacuum pump 9 is stopped, and the gas is left for a certain period of time to allow the generated gas to permeate into the gas diffusion permeation device 2 and accumulate therein.

Next, the gas diffusion permeation device 2 is connected to the cylinder chamber 6a by opening the valve 5, opening the three-way valve 14 to the atmosphere, and switching the three-way valve 15 to communicate with the cylinder chamber 6a.
By communicating with the vacuum pump 9 and driving the vacuum pump 9, the piston 13b moves downward due to the differential pressure on both sides, and the piston 6b descends accordingly, causing the inside of the cylinder chamber 6a to further rise. A vacuum state is created, and the generated gas accumulated inside the gas diffusion permeation device 2 is extracted into the cylinder chamber 6a. Then, the valve 5 is closed and the cylinder chamber 6 is closed.
The three-way valve 8 is placed in a state where the switching valve 11 and the switching valve 11 communicate with each other.
While maintaining this, the differential pressure piston device 13 is operated to move the piston 6b of the reciprocating piston device 6 upward. Therefore, by the movement of the piston 6b, the generated gas extracted in the cylinder chamber 6a is forcibly transferred through the switching valve 11 into the gas sampling pipe 12.

When the transfer of gas to the gas sampling pipe 12 is completed as described above, the switching valve 11 is switched at that point.
The piston 6b of the reciprocating piston device 6 is moved again.
Move it downward. As a result, the inside of the cylinder chamber 6a is changed to a high vacuum again, so that a small amount of generated gas that has permeated into the gas diffusion permeation device 2 by opening the valve 5 is extracted and accumulated in the cylinder chamber 6a. Ru. The accumulated generated gas is sequentially transferred into the gas sampling tube 12 by repeating the above-described operations. By repeating the extraction, transfer, and charging operations in this manner, trace amounts of generated gas that have penetrated can be efficiently extracted. Then, the gas accumulated in the gas sampling pipe 12 or by switching the switching valve 11 and supplying the carrier gas from the conduit 19 to the gas sampling pipe 12 is sent to the gas analyzer 17 via the switching valve 11 and the conduit 16. .

An alarm display device 18 is connected to the gas analyzer 17, and if the amount of combustible gas such as hydrogen exceeds a specified amount as a result of analyzing the generated gas, the alarm display device 18 is activated and the transformer is An alarm will be displayed indicating that there is an abnormality.

Since the present invention is configured as described above, it is possible to repeatedly extract by reciprocating the piston 6b of the reciprocating piston device 6, so that even a small amount of generated gas can be sufficiently extracted and transferred, and gas permeation is possible. The gas generated in the insulating oil is continuously separated and extracted by the diffusion and permeation action of the cylindrical gas diffusion permeation device 2 made of a polymeric material with good properties.
There is no difference between the time when an abnormality occurs and the time when an alarm is displayed, and if each valve is a solenoid valve and the opening/closing operation of the solenoid valve and the operation of the vacuum pump 9 are performed by a combination of a relay and a timer, the work timing can be adjusted.
Since the operation sequence is automatically performed, the equipment maintenance manager only has to give a command to start operation, and everything from extraction of generated gas to analysis and alarm display can be done automatically on the spot, and the equipment can be quickly and reliably operated. It is possible to provide an abnormality detection device for oil-filled electrical equipment that can detect abnormalities in oil-filled electrical equipment.

In the above embodiment, a case has been described in which the gas diffusion permeation device 2 is configured in a cylindrical shape, but as shown in FIG. The lid 22b
The gas diffusion permeation device 22 can also be configured by connecting it to a container 22c provided in the container 22c.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of an abnormality detection device for oil-filled electrical equipment according to the present invention, and FIG. 2 is a block diagram showing another embodiment of the present invention. 1... Oil tank of oil-filled electrical equipment, 2, 22... Gas diffusion permeation device, 5... Valve, 6... Reciprocating piston device,
6a, 13a, 23a, 33a... cylinder chamber,
6b, 13b... Piston, 8, 14, 15... Three-way valve, 9... Vacuum pump, 11... Switching valve, 12... Gas sampling tube, 13... Differential pressure piston device, 17... Gas analyzer, 18... Alarm display device.

Claims (1)

[Claims] 1. Inserted into insulating oil of an oil tank of oil-filled electrical equipment,
A gas diffusion permeation device made of a polymeric material with good gas permeability is used to extract the generated gas from the insulating oil that has diffused and permeated through the insulating oil, and the generated gas is collected via a switching valve. A reciprocating piston device that transfers the gas to the pipe, a differential pressure piston device that reciprocates due to a pressure difference between a vacuum generated by a vacuum pump and atmospheric pressure, and drives the reciprocating piston device, and is connected to the gas sampling pipe. Oil-filled electrical equipment consisting of a gas analyzer that analyzes the gas accumulated in the gas sampling pipe, and an alarm display device that is connected to the gas analyzer and displays an alarm when a specified gas exceeds a specified concentration. Anomaly detection device. 2. An abnormality detection device for oil-filled electrical equipment according to claim 1, wherein the gas diffusion permeation device has a cylindrical shape. 3. An abnormality detection device for oil-filled electrical equipment according to claim 1, wherein the gas diffusion permeation device is constructed by bending a pipe into a spiral shape.