JP2011091340A - Inspection device of oil-immersed transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device capable of accurately detecting a state of an insulating oil of an oil-immersed transformer. <P>SOLUTION: An oil-immersed transformer 10 includes: a transformer body 14 containing an insulating oil 13 and a transformation section 12 in a tank 11; and a radiator 16 connected to the transformer body 14 via a communication pipe 15 and cooling the insulating oil 13 entering from the transformer body 14 through the communication pipe 15. An inspection device 18 includes a detector 19 to the communication pipe 15 wherein the detector detects a state of the insulating oil 13 flowing through the communication pipe 15. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an inspection apparatus for inspecting a state such as deterioration of insulating oil used in an oil-filled transformer.

  In general, an oil-filled transformer is configured by housing a transforming unit made of an iron core, a coil, or the like in a tank filled with insulating oil. In such oil-filled transformers, when an abnormality such as local overheating or partial discharge occurs in the tank, a specific decomposition gas is generated depending on the type of insulating material, the temperature of the abnormal part, etc., and this decomposition gas is insulated. Dissolves in oil. For this reason, if the state of the insulating oil is analyzed, it is possible to estimate the presence or absence of internal abnormality and the situation.

  Conventionally, in order to analyze the state of insulating oil, a method of collecting insulating oil from a tank and analyzing the collected insulating oil by a gas chromatograph has been employed. However, this method has a problem that it cannot be processed in a short time, requires a complicated operation, and requires labor and cost.

  As a technique for solving such a problem, in Patent Document 1 below, an oil sump is provided in the vicinity of a drain valve of a transformer filled with insulating oil, and an optical fiber is passed through the oil in the sump. A light-emitting device is coupled to one end of the optical fiber, and a light-receiving device is coupled to the other end, and an optical attenuation detection device that detects the attenuation of the received light amount and the optical attenuation detection device. A transformer diagnostic device has been proposed that includes a determination device that determines the degree of deterioration of insulating oil based on the amount of optical attenuation detected in the above.

Japanese Patent Laid-Open No. 9-7840

  The diagnostic device described in Patent Document 1 detects the attenuation amount of light passing through an optical fiber arranged so as to penetrate oil in an oil sump, so that the deterioration degree or abnormality of a transformer can be easily detected in a short time. There is an advantage that the presence or absence can be predicted. However, since there is a high possibility that the insulating oil stays in the oil sump, it is difficult to accurately determine the state of the entire insulating oil in the transformer. In addition, since the optical fiber penetrates the oil in the oil sump, it is necessary to remove at least the insulating oil in the sump during maintenance and inspection, which makes the work complicated, and in some cases, the transformer must be stopped. There is a disadvantage of having to. Another problem is that if the optical fiber breaks and enters the transformer tank, a large-scale removal operation is required.

  This invention is made | formed in view of such a situation, and makes it a main objective to provide the oil detection apparatus which can detect the state of the insulating oil of an oil-filled transformer correctly.

The present invention provides a transformer body containing insulating oil and a transformer in a tank, and the insulation connected to the transformer body via a communication pipe and flowing from the transformer body via the communication pipe. An oil-filled transformer inspection device comprising a radiator for cooling oil,
The communication pipe is provided with a detection unit that detects the state of the insulating oil flowing in the communication pipe.

  The inspection apparatus for an oil-filled transformer according to the present invention is provided with a detection unit that detects a state of insulating oil with respect to a communication pipe connecting the transformer main body and the radiator. Since the insulating oil circulates constantly with the radiator without stagnation, the state of the entire insulating oil can be accurately detected by the detection unit.

  In the above configuration, a light-transmitting light-transmitting window is formed on the tube wall of the communication tube, and the detection unit is connected to the insulating oil in the communication tube from the outside of the communication tube via the light-transmitting window. A light projecting unit that projects light, and light that has passed through the insulating oil is received outside the communication pipe via the light transmitting window, and can respond to a change in refractive index accompanying a change in state of the insulating oil. It is preferable to include a light receiving unit having a light receiving range and configured to be able to identify the light receiving position of the light within the light receiving range.

  According to this configuration, the light projecting unit projects light onto the insulating oil in the communication pipe through the light transmitting window, and the light receiving unit receives light that has passed through the insulating oil through the light transmitting window. Further, the light emitted from the light projecting unit is refracted based on the difference in refractive index between the insulating oil and the light transmitting window before being received by the light receiving unit. Since the refractive index of the insulating oil changes depending on the state of deterioration or the like, the optical path passing through the insulating oil changes according to the state of the insulating oil, and the light receiving position in the light receiving portion also changes. Therefore, the state of the insulating oil can be detected by identifying the light receiving position.

  In addition, with the above configuration, it is possible to detect the state of the insulating oil without placing an optical fiber or other components inside the oil-filled transformer. There is no need to perform the extraction work, and the maintenance inspection work can be easily performed.

A pair of the translucent windows are provided opposite to each other in a direction crossing the communication tube, and the light projecting unit projects inspection light into the communication tube through one translucent window, and the light receiving unit. Can be configured to receive the inspection light through the other light-transmitting window.
With such a configuration, the light emitted from the light projecting unit is refracted between one light transmitting window and the insulating oil and between the insulating oil and the other light transmitting window and then received by the light receiving unit. Can do.

In the case of this configuration, it is preferable that the other light transmitting window is made of a material having a higher refractive index than the one light transmitting window.
In this case, after passing through the insulating oil, the light that reaches the other light transmission window can be refracted greatly and received by the light receiving unit, and the change in the refractive index accompanying the change in the state of the insulating oil is amplified, and the detection accuracy is increased. Can be increased.

The translucent window is provided on one side of the tube wall of the communication tube, the light projecting unit projects light into the communication tube through the translucent window, and the light receiving unit is The light reflected by the inner wall part of the communicating pipe facing the light transmitting window can be configured to be received through the light transmitting window.
With such a configuration, the light emitted from the light projecting unit can be received by the light receiving unit after being refracted between the light transmitting window and the insulating oil. The inner wall portion of the communicating tube that reflects light is preferably a mirror surface so that the light can be totally reflected.

  According to the inspection apparatus for an oil-filled transformer of the present invention, the state of insulating oil can be accurately detected.

It is a schematic block diagram of the oil-filled transformer which concerns on embodiment of this invention, and its inspection apparatus. It is a typical lineblock diagram of an inspection device. It is a flowchart which shows the operation | movement procedure of an inspection apparatus. It is a typical block diagram of the inspection apparatus of the oil-filled transformer which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an oil-filled transformer 10 and its inspection device 18 according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of the inspection device 18. The oil-filled transformer 10 includes a transformer body 14 configured by housing a transformer 12 and insulating oil 13 in a tank 11, and a radiator 16 connected to the transformer body 14 via a communication pipe 15. It has.

The transformer 12 is a part that performs voltage conversion, and includes an iron core, a winding wound around the core, and the like. In addition, the transformer 12 is provided with insulating paper used as a conductor covering of the winding, a press board used as a spacer between the windings (hereinafter simply referred to as “insulator”), and the like.
The insulating oil 13 is filled in the tank 11 in order to insulate the transformer 12 from the surroundings and absorb heat generated from the transformer 12. As this insulating oil 13, silicone oil or mineral oil can be used.

  The radiator 16 is for cooling the insulating oil 13 that has absorbed the heat of the transformer 12, and the insulating oil 13 is circulated between the transformer body 14 and the radiator 16 via the communication pipe 15. It has become. That is, the insulating oil 13 flows from the transformer main body 14 into the radiator 16 through the inflow communication pipe 15A, and is returned to the transformer main body 14 through the discharge communication pipe 15B after being radiated and cooled. It has become. The insulation oil 13 may be circulated by natural convection or forced circulation by a hydraulic pump or the like.

The oil-filled transformer 10 according to the present embodiment is provided with an inspection device 18 for inspecting a state such as deterioration of the insulating oil 13. The inspection device 18 includes a detection unit 19 provided in the discharge communication pipe 15, and the detection unit 19 includes a pair of translucent windows 20A and 20B, a light projecting unit E, as shown in FIG. The light receiving units R _{1 to} R _n and the control unit 21 for controlling the light projecting unit E and the light receiving units R _{1 to} R _n are provided. The detection unit 19 may be provided in the inflow communication tube 15A, or may be provided in both the inflow communication tube 15A and the discharge communication tube 15B.

The light projecting unit E includes, for example, a laser oscillator that emits visible light laser light or infrared laser light.
The translucent windows 20A and 20B are formed of a member capable of transmitting the laser beam LB projected from the light projecting unit E, for example, transparent glass or plastic, and are provided so as to face in a direction crossing the communication tube 15B. The entrance side translucent window 20A and the exit side translucent window 20B are comprised. Moreover, the exit side light transmission window 20B is formed of a material having a higher refractive index than the entrance side light transmission window 20A.

  The light projecting unit E projects laser light LB obliquely from the outside of the communication pipe 15B to the entrance-side light transmission window 20A, and the laser light LB is separated from the insulating oil 13 in the communication pipe 15B and the outgoing side light transmission. It arrange | positions so that the optical window 20B may be passed. The laser beam LB travels while being refracted based on the difference in refractive index between the entrance-side light transmitting window 20A and the insulating oil 13 and between the insulating oil 13 and the exit-side light transmitting window 20B.

The light receiving parts R _{1 to} R _n are a photodiode that can receive the laser light LB emitted from the light projecting part E and passed through the entrance side transparent window 20A, the insulating oil 13, and the exit side transparent window 20B. It has a light receiving element such as a transistor or a phototube. In the present embodiment, the light receiving range is set by the plurality of light receiving portions R _{1 to} R _n so as to cover the entire range in which the laser beam LB can pass in the insulating oil 13, and which light receiving portions R _{1 to} R _n receive light. Depending on whether or not, the light receiving position of the laser beam LB within the light receiving range can be identified. In FIG. 2, the plurality of light receiving portions R _{1 to} R _n are illustrated as being spaced apart from each other. However, in practice, a plurality of light receiving portions R _{1 to} R _n are provided so that a portion that cannot receive the laser beam LB does not occur. The light receiving parts R _{1 to} R _n are arranged without gaps.

  The insulating oil 13 in the transformer body 14 has an acid value that increases due to deterioration due to use, and the generation of sludge is promoted. This sludge adheres to an insulator, an iron core or the like, thereby causing a reduction in cooling effect and thermal deterioration of the insulator, causing local heating and partial discharge. Further, when local heating or partial discharge occurs in the tank 11 of the transformer body 14, the surrounding insulator is thermally decomposed to generate decomposition gas, which is dissolved in the insulating oil. Since there is a correlation between the abnormality occurring in the transformer and the cracked gas dissolved in the insulating oil 13, in the conventional gas analysis in oil, the abnormality of the transformer is analyzed by analyzing the components of the cracked gas. Judging.

For example, as a decomposition gas in insulating oil, H2 (hydrogen), CH ₄ (methane), C ₂ H ₆ (ethane), if C ₂ H ₄ (ethylene), C ₂ H ₂ to (acetylene) has occurred In this case, it can be determined that the insulating oil 13 is overheated. In addition, when CO (carbon monoxide) and CO ₂ (carbon dioxide) are generated, the insulating oil 13 is immersed in the insulating oil 13. It can be determined that the insulating material is overheated. Moreover, H2 (hydrogen), CH ₄ (methane), C ₂ H ₄ (ethylene), that when C ₂ H ₂ to (acetylene) has occurred is determined to be occurring discharge in the insulating oil In addition to these, when CO (carbon monoxide) and CO ₂ (carbon dioxide) are generated, it can be determined that the insulator immersed in the insulating oil 13 is discharged. it can.

As described above, when the state of the insulating oil 13 changes due to various reasons such as deterioration of the insulating oil 13 and dissolution of decomposition gas, the refractive index of the insulating oil 13 also changes. 2, the optical paths of the laser beams LB _{1 to} LB _n projected from the light projecting unit E change. For example, the silicone oil as the insulating oil 13 has a refractive index of about 1.4. However, when the state changes due to deterioration or the like, the refractive index increases or decreases.

In FIG. 2, the laser beam that has passed through the normal insulating oil 13 without deterioration or the like is indicated by a solid line together with the reference LB ₁ , and this laser beam LB ₁ is received by the light receiving unit R ₁ . The laser light that has passed through the insulating oil 13 having an abnormality such as deterioration is indicated by two-dot chain lines together with the symbols LB _{2 to} LB _n . The laser light LB _{2 to} LB _n is received by the light receiving portions R _{2 to} R _n . Received light. Therefore, when the light receiving unit R ₁ receives the laser beam LB ₁ , it can be determined that there is no abnormality in the insulating oil 13 or the transformer main body 14, and the other light receiving units R _{2 to} R _n receive the laser beam. When LB is received, it can be determined that an abnormality has occurred in the insulating oil 13 or the transformer.

In addition, since a plurality of light receiving portions R _{1 to} R _n that receive the laser light are provided, abnormalities such as deterioration of the insulating oil 13 are caused by the light receiving portions R _{1 to} R _n that receive the laser beams LB _{1 to} LB _n . The degree can be determined. Further, since the other light receiving portions R _{2 to} R _n are arranged on both sides of the light receiving portion R ₁ , not only when the refractive index of the insulating oil 13 is increased due to an abnormality such as deterioration, but also when it is decreased. Can be detected.

As shown in FIG. 2, the control unit 21 includes a control unit 25, an alarm generation unit 26, a transmission unit 27, and the like. The control unit 25 drives and controls the light projecting unit E so as to emit the laser beam LB, and light reception signals are input from the light receiving units R _{1 to} R _n . The alarm generation unit 26 generates an alarm signal according to the light reception signal input to the control unit 25. Moreover, the transmission part 27 has a function which transmits the alarm signal produced | generated in the alarm generation part 26 to the monitoring center 28 (refer FIG. 1) etc. which were installed in the place away from the oil-filled transformer 10, for example. ing.

Hereinafter, the operation flow of the inspection device 18 of the oil-filled transformer 10 of the present embodiment will be described with reference to FIG.
First, in step S1, the control unit 25 of the control unit 21 drives and controls the light projecting unit E so as to project the laser light LB. When the light projecting part E projects the laser light LB toward the communication tube 15, the laser light LB passes through the entrance side light transmission window 20A, the insulating oil 13, and the exit side light transmission window 20B while being refracted.

Next, in step S2, the control unit 25 determines whether or not the laser beam LB is received by any of the light receiving units R _{1 to} R _n . If the laser beam LB is received by any of the light receiving units R _{1 to} R _n , the process proceeds to step S3, and if not received, the process proceeds to step S8.

In step S3, the control unit 25 further laser beam LB is determined whether or not received by the light receiving unit R _1. If the laser beam LB by the light receiving portion R ₁ is received, in step S4, the control unit 25 determines that the normal state of the insulating oil 13 to repeat the above operation returns to step S1.

When the laser beam LB is not received by the light receiving unit R _{1, that} is, when the laser beam LB is received by the light receiving units R _{2 to} R _n , the control unit 25 determines that the state of the insulating oil 13 has deteriorated in step S5. Judge that there is an abnormality. In step S6, the alarm generation unit 26 generates an alarm signal indicating that the insulating oil 13 is not normal (step S6). In step S7, the alarm signal is transmitted to the remote monitoring center 28 by the transmission unit 27.

On the other hand, in step S2, when the laser beam LB is determined not to be received by any of the light-receiving portion R ₁ to R _n, the failure of the light projecting portion E or the light receiving unit R ₁ to R _n, laser light It is probable that there was a problem such as the occurrence of an obstacle that interrupts. Therefore, the control unit 25 determines that a detection error has occurred (step S8). In step S6, the alarm generation unit 26 generates an alarm signal indicating the detection error, and the transmission unit 27 transmits this alarm signal to the monitoring center. Transmit (step S7).

  In the monitoring center 28, an alarm signal at the time of abnormality detection is transmitted from the inspection device 18 in real time. Based on this alarm signal, it is possible to take quick measures such as stopping the use of the transformer. In addition, the transformer in which the abnormality is detected by the inspection device 18 can diagnose the cause of the abnormality by a detailed inspection such as gas analysis in oil or perform maintenance such as replacement of the insulating oil 13. .

The inspection device 18 of the oil-filled transformer 10 having the above configuration includes the detection unit 19 in the communication pipe 15 in which the insulating oil 13 is always circulated between the transformer body 14 and the radiator 16. The state of the entire oil 13 can be accurately detected.
In addition, since the inspection device 18 detects the state of the insulating oil 13 depending on which light receiving portions R _{1 to} R _n receive the laser light LB that has passed through the insulating oil 13, it is possible to determine abnormality such as deterioration. It is extremely simple, and false detection can be reduced.

Further, when an abnormality in the insulating oil is detected in the inspection device 18, an alarm signal is transmitted to a remote location such as the monitoring center 28, so that it is sent to the installation location of the oil-filled transformer 10 or the installation location of the inspection device 18. Abnormality can be monitored without it.
Moreover, since the exit side light transmission window 20B is formed of a material having a higher refractive index than the entrance side light transmission window 20A, the amount of refraction of the laser light LB between the insulating oil 13 and the exit side light transmission window 20B. And the change in the optical path of the laser beam LB can be detected with high accuracy.

  Since the inspection device 18 is configured to receive the laser beam LB projected from the outside of the communication tube 15 outside the communication tube 15, the inspection device 18 is provided inside the communication tube 15 where the insulating oil 13 exists. There is no need to place any parts. Therefore, when performing maintenance and inspection of the inspection device 18, the work of extracting the insulating oil 13 is not necessary, and the work can be performed easily and in a short time. Further, even if a part of the inspection device 18 is damaged, it does not enter the transformer main body 14, so that removal work or the like is not required.

FIG. 4 is a schematic configuration diagram of the inspection device 18 of the oil-filled transformer 10 according to another embodiment of the present invention.
In the present embodiment, a translucent window 20 is provided on one side of the discharge communication tube 15B, and a reflecting mirror 30 is provided on the inner wall of the other side of the discharge communication tube 15B so as to face the translucent window 20. Is provided. Then, the laser beam LB projected from the light projecting unit E passes through the insulating oil 13 and is totally reflected by the reflecting mirror 30, and again passes through the insulating oil 13 and proceeds to the outside from the light transmitting window 20. The light receiving parts R _{1 to} R _n are arranged in parallel with the light projecting part E, and are provided so as to receive the laser light LB reflected by the reflecting mirror 30 through the light transmitting window 20. Similarly to the above-described embodiment, a predetermined light receiving range is set by the plurality of light receiving portions R _{1 to} R _n so as to correspond to the refraction of the laser light LB.
Therefore, also in this embodiment, there exists an effect similar to 1st Embodiment. The detection unit 19 of the present embodiment, it is possible to arrange the light projecting portion E and the light-receiving portion R ₁ to R _n are juxtaposed on the same side of the communicating pipe 15, compact device It becomes possible.

The present invention is not limited to the above-described embodiment, and can be appropriately changed in design. For example, in the above embodiment, a plurality of light receiving portions (light receiving elements) R _{1 to} R _n are arranged in parallel to set a light receiving range that can cope with a change in refraction of the laser light LB. It is also possible to configure the light receiving unit by a photodiode or the like that can identify the light receiving position on the element by the change in the output current or output voltage.
The light projecting unit E includes an LED or the like instead of the laser oscillator, and can collect light from the LED or the like to improve the directivity. However, it is more preferable to use a laser beam having high straightness and directivity.
Further, in the first aspect of the invention, as long as the detection unit 19 detects the state of the insulating oil 13 in the communication pipe 15, the detection method of the insulating oil (for example, a conventionally known detection method) different from the above embodiment is used. A state may be detected.

DESCRIPTION OF SYMBOLS 10 Oil-filled transformer 11 Tank 12 Transformer part 13 Insulating oil 14 Transformer main body 15 Communication pipe 16 Radiator 18 Inspection apparatus 19 Detection part 20A Incoming side translucent window 20B Outgoing side translucent window 21 Control unit 25 Control part 26 Alarm generating part 27 Transmitter E Emitter R _{1 to} R _n Light Receptor LB _{1 to} LB _n Laser Light

Claims (5)

A transformer main body that contains the insulating oil and the transformer in the tank, and is connected to the transformer main body via a communication pipe, and cools the insulating oil that has flowed in from the transformer main body via the communication pipe. An oil-filled transformer inspection device comprising a radiator,
An inspection apparatus for an oil-filled transformer, wherein the communication pipe is provided with a detection unit that detects a state of insulating oil flowing in the communication pipe. On the tube wall of the communication tube, a light transmissive light transmission window is formed,
A light projecting unit for projecting light from the outside of the communication pipe to the insulating oil in the communication pipe through the light transmission window;
The light that has passed through the insulating oil is received outside the communication pipe through the transparent window, and has a light receiving range that can respond to a change in refractive index accompanying a change in state of the insulating oil, and the light receiving range. The oil-immersed transformer inspection device according to claim 1, further comprising: a light receiving unit configured to be able to identify a light receiving position of the light in the inside. A pair of the translucent windows are provided opposite to each other in a direction crossing the communication pipe,
The light projecting unit projects light into the communication pipe through one translucent window,
The inspection apparatus for an oil-filled transformer according to claim 2, wherein the light receiving unit receives light that has passed through the insulating oil through the other light-transmitting window.   The inspection apparatus for an oil-filled transformer according to claim 3, wherein the other light-transmitting window is formed of a material having a higher refractive index than that of the one light-transmitting window. The translucent window is provided on one side of the pipe wall of the communication pipe;
The light projecting unit projects light into the communication pipe through the translucent window,
The inspection apparatus for an oil-filled transformer according to claim 2, wherein the light receiving unit receives the light reflected by the inner wall portion of the communication pipe facing the light transmitting window through the light transmitting window.

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