JP6807259B2 - Insulation oil deterioration diagnosis system and method of transformer - Google Patents

Description

The present invention relates to an insulating oil deterioration diagnosis system and a method for a transformer, which enables deterioration diagnosis of insulating oil in the transformer.

Conventionally, in a transformer, deterioration is confirmed by collecting the insulating oil inside the transformer and performing gas analysis on the insulating oil. However, the collected insulating oil cannot be reused, so it is subject to destructive inspection. Therefore, every time the insulating oil is analyzed, the insulating oil in the transformer decreases, and if the insulating oil decreases from the specified value, it is necessary to add the insulating oil, which increases the maintenance work.

It may also affect the health trend management of insulating oil inside the transformer. In the case of an aged transformer, this point is also an issue in diagnosing the soundness of insulating oil.

As a conventional technique for solving this problem, there is one described in Patent Document 1. Patent Document 1 describes that when an object to be measured is irradiated with ultraviolet light including an absorption wavelength of insulating oil from the outside, fluorescence emitted from the insulating oil is detected, and an electric device is subjected to a non-destructive inspection. It is stated that it is possible to determine oil leakage and corrosion.

Japanese Unexamined Patent Publication No. 2008-116389

However, although the insulating oil can be identified by the technique described in Patent Document 1, there is a problem that the deterioration diagnosis of the insulating oil (the degree of aging deterioration and abnormality of the insulating oil) cannot be determined.

The present invention has been made in view of the above points, and an object of the present invention is to perform non-destructive inspection of the degree of aging deterioration and abnormality of the insulating oil of a transformer with high accuracy without complicating the apparatus. It is to provide an insulating oil deterioration diagnosis system and a method of a transformer which can be performed.

In order to solve the above-mentioned problems, the transformer insulating oil deterioration diagnosis system of the present invention "is a light source that irradiates black light with the insulating oil of the transformer as the object to be measured, and the object to be measured that is irradiated with black light. It is composed of a measuring device including an imager that captures the fluorescence emitted from the measuring device and an analyzer that diagnoses deterioration of the insulating oil using the information from the measuring device. The analyzer is a light source of the measuring device and an image pickup. A drive control unit that controls the operation of the machine, a recording unit that records an image of the object to be measured taken by the imager, an image processing unit that processes the image of the object to be measured recorded by the recording unit, and an image processing unit. The image processing unit includes a display unit that displays the result of the determination in the above, calculates the brightness from the image of the object to be measured, calculates the insulation breakdown voltage of the insulating oil from the brightness, and uses the calculated breakdown voltage. This is a transformer insulating oil deterioration diagnosis system characterized in that the degree of deterioration is calculated from a preset threshold value of the insulation breakdown voltage for the insulating oil and diagnosed.

According to the present invention, it is possible to perform non-destructive inspection on the degree of aging deterioration and abnormality of the insulating oil in the transformer with high accuracy without complicating the apparatus.

The schematic block diagram which shows the insulating oil deterioration diagnosis system of the transformer which concerns on Example 1. FIG. The figure which shows the example which uses the oil-collecting valve 200 provided in advance in the transformer 8 as a light transmission window 9. The figure which shows the example of the flowchart which shows the processing in an image processing unit 5. The figure which shows an example of correspondence table TB1 in the case of the mineral oil prepared in advance by an experiment. The figure which shows the relationship between the dielectric breakdown voltage and the fluorescence intensity in the case of mineral oil. The figure which shows an example of correspondence table TB1 in the case of vegetable oil prepared in advance by an experiment. The figure which shows the relationship between the dielectric breakdown voltage and the fluorescence intensity in the case of vegetable oil. The figure which shows the other embodiment which uses the oil sampling valve 200 provided in advance in the transformer 8 as a light transmission window 9.

Hereinafter, the insulating oil deterioration diagnosis system and method for the transformer according to the present invention will be described based on Examples. However, the present invention is not limited to the following examples, and various improvements and changes by those skilled in the art can be made without changing the gist of the invention. In each embodiment, the same reference numerals are used for the same components.

FIG. 1 is a schematic configuration diagram showing an insulating oil deterioration diagnosis system for a transformer according to the first embodiment. The insulating oil deterioration diagnosis system 100 of the transformer of the first embodiment shown in FIG. 1 includes a measuring device 20 and an analyzer 21.

Of these, the measuring device 20 includes a light source 1 that irradiates the object 7 with black light, and an imager 2 that captures the fluorescence emitted from the object 7 irradiated with black light from the light source 1. .. Here, the object to be measured 7 is an insulating oil stored inside the transformer 8, and is a region 10 (irradiation light irradiation region) including a light transmitting window 9 such as glass or acrylic formed on the surface portion of the transformer 8. ) Is irradiated with black light, and the fluorescence emitted from the insulating oil which is the object 7 to be measured is photographed.

FIG. 2 shows an example in which the oil sampling valve 200 provided in advance in the transformer 8 is used as the light transmission window 9. In the case of FIG. 2, one end of the oil sampling valve 200 (left side in the drawing) communicates with the object 7 (that is, insulating oil) inside the transformer 8, and the other end (right side in the drawing) of the oil sampling valve 200 is closed with glass. It is closed by a plate 201. Reference numeral 202 denotes a closing plate and a peephole. The black light from the light source 1 is irradiated to the insulating oil in the oil sampling bulb 200 via the glass closing plate 201, and an image is taken by the imager 2 attached to the glass closing plate 201.

Further, the analyzer 21 includes a drive control unit 3 that controls the operation of the light source 1 and the imager 2 of the measuring device 20, a recording unit 4 that records an image of the object 7 to be measured taken by the imager 2, and a recording unit 4. The image processing unit 5 that calls the image of the object to be measured 7 recorded by the unit 4 and processes the image, and the display unit 6 that displays the result of the determination by the image processing unit 5 are included.

In the insulating oil deterioration diagnosis system 100 of the transformer according to this embodiment, the degree of deterioration is basically calculated in the image processing unit 5 by the correspondence table or calculation formula of the dielectric breakdown voltage and the fluorescence intensity peculiar to the insulating oil. And judge (diagnose).

FIG. 3 is a flowchart showing the processing in the image processing unit 5. In the processing step S1, which is the first processing of the image processing unit 5, the recording unit 4 records the image of the object 7 to be measured taken by the imager 3. The brightness (intensity) of the fluorescence emitted from the insulating oil, which is the object to be measured 7, is obtained by using the image from. The brightness of fluorescence can be obtained, for example, by quantifying the brightness of an image and obtaining the average value of the entire image.

Next, using the obtained brightness (intensity) of fluorescence, one of the treatments of the treatment step S2 and the treatment step S3, or both treatments are performed. In the processing of the processing step S2, the correspondence table TB1 of the insulation breakdown voltage and the fluorescence intensity peculiar to the insulating oil is referred to, and the insulation breakdown voltage at the time of the fluorescence intensity of the measured insulating oil is obtained from the correspondence table peculiar to the oil type. ..

FIG. 4 is an example of the correspondence table TB1 in the case of mineral oil prepared in advance by experiments or the like, and here, the correspondence table TB1 of the insulation breakdown voltage and the fluorescence intensity when the mineral oil is adopted as the oil type of the insulating oil is illustrated. Has been done. The correspondence table is stored in the recording unit 4, for example, for each oil type. In the case of FIG. 4, if the brightness of the mineral oil is 151.3, the breakdown voltage is 13.5 kV, if the brightness of the mineral oil is 153, the breakdown voltage is 19.7 kV, and the brightness of the mineral oil is 152.3. For example, if the insulation breakdown voltage is 29.9 kV and the brightness of the mineral oil is 160.3, the breakdown voltage is 49.3 kV. In addition, FIG. 6 described later exemplifies a correspondence table of dielectric breakdown voltage and fluorescence intensity when vegetable oil is adopted as the oil type of insulating oil. The explanation of the numerical values in FIG. 6 is omitted.

In the process of the process step S3, the fluorescence intensity M measured by the following equation (1) is substituted to derive the dielectric breakdown voltage Y at the measured fluorescence intensity of the insulating oil. The coefficients A and B in Eq. (1) are predetermined.
[Number 1]
Dielectric breakdown voltage of insulating oil Y = A × ln (luminance M) −B (1)
The dielectric breakdown voltage Y of the insulating oil of the formula (1) is referred to as a master curve. In this embodiment, in order to create a master curve for the soundness diagnosis of the insulating oil in the transformer, the insulating oil lubricated in the transformer tank is artificially accelerated and deteriorated. The characteristics of the aged insulating oil after artificial acceleration deterioration include the breakdown voltage, total acid value, hue, water content, and fluorescence intensity (fluorescence /) of the insulating oil equivalent to new oil, 30 years after aged, and 50 years after aged. The relationship between incident light) was organized. According to the results of this experiment and measurement, between the characteristics of the dielectric breakdown voltage Y of the insulating oil and the fluorescence intensity M (fluorescence / incident light), the dielectric breakdown voltage of the insulating oil of equation (1) Y = A × ln (brightness). It was found that the correlation equation X) -B was established and a master curve for soundness diagnosis could be created. Incidentally, in the case of mineral oil, the coefficient A was 549.42 and the coefficient B was 2740. Further, in the case of the vegetable oil described later in FIG. 6, the coefficient A was 588.43 and the coefficient B was 2910.5.

By the processing step S2 or the processing step S3 of FIG. 3, the dielectric breakdown voltage of the insulating oil in the oil type could be obtained. On the other hand, the threshold value for the soundness of the deterioration diagnosis of insulating oil is set by the threshold value described in the Institute of Electrical Engineers of Japan, the Petroleum Society, and the Electrical Insulation Oil Maintenance and Management Guideline of the Petroleum Society.

The threshold value of the insulation breakdown voltage of the insulating oil is the insulation breakdown voltage VL1 (kV / 2.5mm) ≥30 when the voltage on the system (for example, the rated voltage of the transformer) is 11 to 77 kV, on the system. When the voltage is 110 to 275 kV, the breakdown voltage is VL2 (kV / 2.5 mm) ≧ 40, and when the voltage on the system is 500 kV, the breakdown voltage is VL3 (kV / 2.5 mm) ≧ 50. ..

FIG. 5 is a diagram showing the relationship between the dielectric breakdown voltage and the fluorescence intensity. In this figure, the dielectric breakdown voltage of the insulating oil and its threshold values VL1, VL2, and VL3 are described in the height direction. Further, in this graph, each point specified by the correspondence table TB1 of FIG. 5 and equation (1) (dielectric breakdown voltage Y of insulating oil) are described. According to this display, the measured value and the threshold value show how close the dielectric breakdown voltage of the insulating oil to be measured at the present time obtained from the correspondence table TB1 or Eq. (1) is to the threshold value of the dielectric breakdown voltage. It is clear from the comparison of.

In the processing step S4 of FIG. 3, for example, the dielectric breakdown voltage of the insulating oil to be measured at the present time obtained from the correspondence table TB1 or the equation (1) is V0, and the threshold value of the dielectric breakdown voltage of the insulating oil is VL2. When ΔV = VL2-V0 is determined as an index indicating the degree of proximity, and by monitoring how much the value of ΔV measured at the beginning of transformer installation changes thereafter, the aged deterioration of the insulating oil And monitor the degree of abnormality.

As described above, in the transformer insulating oil deterioration diagnosis system according to the present embodiment, there is a correlation between the breakdown voltage and the fluorescence intensity, and the threshold value (ΔV) for determining the deterioration diagnosis of the transformer insulating oil has a correlation. As the threshold value), it is preferable to calculate the threshold value by calculating from the breakdown voltage value and the fluorescence intensity value using a correspondence table or a calculation formula.

The mineral oil most used in oil-immersed transformers is derived from the correlation equation obtained from the above experiment, and as shown in FIG. 5, the breakdown voltage of the mineral oil Y = 549.42 × ln (luminance M)- It becomes an approximate expression of 2740.

In the above correlation formula, the disturbance factors in the field are taken into consideration when the transformer is delivered, and the initial brightness is measured with the insulating oil used for the transformer, and the correction items A and B are finely adjusted as appropriate. It is expected that the accuracy of soundness diagnosis will be improved by using it.

From these facts, the soundness diagnosis of the insulating oil of the aged transformer can be carried out by the non-destructive (non-contact) method.

In the first embodiment, the case where the insulating oil used in the transformer is mineral oil has been described, but in the second embodiment, the vegetable oil most used in the vegetable oil-filled transformer, which has become widespread in response to the environment in recent years, will be described.

FIG. 6 is a diagram showing an example of the correspondence table TB2 in the case of vegetable oil prepared in advance by an experiment or the like, and FIG. 7 is a diagram showing the dielectric breakdown voltage Y = 588.43 × ln (luminance M) −2910 in the case of vegetable oil. The approximate expression of 5 is shown. Although the explanation with specific numerical values is omitted here, the same tendency as in Example 1 is shown in the case of vegetable oil, and the processing of FIG. 3 can be performed by preparing the relevant numerical relations and formulas in advance. In the same way, monitor the degree of deterioration and abnormality of the insulating oil over time.

In the above correlation formula, the disturbance factors in the field are taken into consideration when the transformer is delivered, and the initial brightness is measured with the insulating oil used for the transformer, and the correction items A and B are finely adjusted as appropriate. It is expected that the accuracy of soundness diagnosis will be improved by using it.

From these facts, the soundness diagnosis of the insulating oil of the aged transformer can be carried out by the non-destructive (non-contact) method.

In the third embodiment, it is a diagram showing an example in which the oil sampling valve 200 provided in advance in the oil filling device 8 is used as the light transmission window 9, which is different from the method of FIG. It differs from FIG. 2 in that the imager 2 is provided at a position where it is immersed in the insulating oil 7 of the oil sampling valve 200.

In the case of the first embodiment, it is necessary to re-install the measuring device 20 (light source 1 and the imager 2) each time the measurement is performed, but in the case of the third embodiment, only the wiring to the imager 2 needs to be performed. Since the position of the imager 2 is fixed, there is an effect that the same conditions can be easily maintained even in the measurement after the lapse of time.

As described above, according to the configuration of the third embodiment, it is possible to provide the insulating oil deterioration diagnosis system of the transformer with high accuracy without complicating the apparatus.

The present invention is not limited to the above-mentioned examples, and includes various modifications. The above-described embodiment describes the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the configurations described. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 ... light source, 2 ... imager, 3 ... drive control unit, 4 ... recording unit, 5 ... image processing unit, 6 ... display unit, 7 ... object to be measured, 8 ... transformer, 9 ... light transmission window, 20 ... Measuring device, 21 ... Analytical device, 100 ... Transformer insulating oil deterioration diagnosis system, 200 ... Oil sampling valve, 201 ... Glass closing plate, 202 ... Closing plate and peephole

Claims (11)

A measuring device including a light source that irradiates a black light using the insulating oil of a transformer as an object to be measured, and an imager that captures fluorescence emitted from the object to be measured that is irradiated with the black light, and a measuring device from the measuring device. It is composed of an analyzer that diagnoses the deterioration of the insulating oil using information.
The analyzer includes a drive control unit that controls the operation of the light source of the measuring device and the imager, a recording unit that records an image of the object to be measured taken by the imager, and an object to be measured recorded by the recording unit. It includes an image processing unit that processes an image and a display unit that displays the result of determination by the image processing unit.
The image processing unit calculates the brightness from the image of the object to be measured, calculates the insulation breakdown voltage of the insulating oil from the brightness, and calculates the insulation breakdown voltage and the insulation breakdown voltage preset for the insulating oil. An insulating oil deterioration diagnosis system for transformers, which is characterized by calculating the degree of deterioration from a threshold value and diagnosing it. The transformer insulating oil deterioration diagnosis system according to claim 1.
An insulating oil deterioration diagnosis system for a transformer, wherein the threshold value of the insulating breakdown voltage set in advance for the insulating oil is determined according to the oil type of the insulating oil. The transformer insulating oil deterioration diagnosis system according to claim 1 or 2.
Insulation of a transformer, characterized in that the difference between the calculated dielectric breakdown voltage and the threshold value of the dielectric breakdown voltage set in advance for the insulating oil is obtained, and the degree of deterioration is calculated from the magnitude of the obtained difference. Oil deterioration diagnosis system. The transformer insulating oil deterioration diagnosis system according to any one of claims 1 to 3.
In order to calculate the dielectric breakdown voltage of the insulating oil from the brightness, a correspondence table showing the relationship between the brightness and the dielectric breakdown voltage of the insulating oil is prepared and recorded in the recording unit. Transformer oil breakdown diagnostic system. The transformer insulating oil deterioration diagnosis system according to any one of claims 1 to 3.
In order to calculate the insulation breakdown voltage of the insulating oil from the brightness, the relationship between the brightness and the insulation breakdown voltage of the insulating oil is formulated, and the calculated brightness is substituted into the formula to calculate the insulation breakdown voltage of the insulating oil. A transformer insulating oil deterioration diagnosis system characterized by finding. The transformer insulating oil deterioration diagnosis system according to any one of claims 1 to 5.
An insulating oil deterioration diagnosis system for a transformer, wherein the imager is provided with a light receiving portion for light emission of the insulating oil inside the transformer. Black light is irradiated using the insulating oil of the transformer as the object to be measured, the brightness of the fluorescence emitted from the object to be measured irradiated with the black light is obtained, and the insulation breakdown voltage of the insulating oil is calculated from the brightness. A method for diagnosing deterioration of insulating oil of a transformer, which comprises calculating the degree of deterioration from the calculated insulation breakdown voltage and a preset threshold value of the insulation breakdown voltage and determining (diagnosing) the degree of deterioration. The method for diagnosing deterioration of insulating oil of a transformer according to claim 7.
A method for diagnosing deterioration of insulating oil in a transformer, wherein the threshold value of the insulating breakdown voltage set in advance for the insulating oil is determined according to the oil type of the insulating oil. The method for diagnosing deterioration of insulating oil of a transformer according to claim 7 or 8.
Insulation of a transformer, characterized in that the difference between the calculated dielectric breakdown voltage and the threshold value of the dielectric breakdown voltage set in advance for the insulating oil is obtained, and the degree of deterioration is calculated from the magnitude of the obtained difference. Oil deterioration diagnosis method. The method for diagnosing deterioration of insulating oil of a transformer according to any one of claims 7 to 9.
A method for diagnosing deterioration of insulating oil of a transformer, which comprises preparing a correspondence table showing the relationship between the brightness and the insulating breakdown voltage of the insulating oil in order to calculate the insulation breakdown voltage of the insulating oil from the luminance. The method for diagnosing deterioration of insulating oil of a transformer according to any one of claims 7 to 9.
In order to calculate the insulation breakdown voltage of the insulating oil from the brightness, the relationship between the brightness and the insulation breakdown voltage of the insulating oil is formulated, and the calculated brightness is substituted into the formula to calculate the insulation breakdown voltage of the insulating oil. A method for diagnosing deterioration of insulating oil of a transformer, which is characterized by obtaining.

Images