CN104502370B - The non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers - Google Patents

Abstract

The invention discloses the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers, it is according to copper, steel, difference of the aluminium to the attenuation coefficient of X ray, the non-rectangle fuel tank oil immersion Three-Phase Distribution Transformers that disassembles under state are taken pictures using X ray, using black and white densitometer to the radiographic film density measurement taken pictures, by the blackness value input computer of measurement, using industrial radiographic film characteristic curve, through the different x-ray tube voltage copper with storage in a computer, steel, aluminium x-ray attenuation coefficient scanning thickness curve is calculated, compare, the winding coil for determining rectangle fuel tank oil immersion Three-Phase Distribution Transformers is aluminium or copper.

Description

Material identification method for non-disintegrated coils of oil-immersed three-phase distribution transformers with rectangular oil tanks

technical field

The invention relates to a method for identifying the material of a non-disassembled coil of a rectangular oil tank oil-immersed three-phase distribution transformer, which belongs to the technical field of power transmission.

Background technique

In the current market economy, some short-sighted grid distribution network transformer manufacturers use aluminum enameled wire instead of copper enameled wire as the transformer coil winding in order to pursue greater profits, resulting in excessive coil volume and increased coil impedance, which increases the power consumption of the transformer. Increase the cost of power supply and seriously affect the interests of power supply enterprises. Because the transformer coil winding is wrapped with an insulating layer, even if the transformer is disassembled and not damaged, it is still impossible to identify the coil material through electrical tests and visual inspections, unless the coil is damaged and sampled for metal chemical analysis, but this damage test It cannot be carried out one by one, otherwise the cost will be huge, and the transformer will be shut down for maintenance, which will seriously affect the power supply of the power grid and the order of social production and life.

Therefore, a method to identify the coil material of the distribution network transformer without disintegration is the dream method of the power grid enterprise.

The applicant applied to the State Intellectual Property Office on October 25, 2012 for an invention patent titled "Non-destructive identification method for distribution transformer non-disintegrated coil material" and the application number is 201210252278. In this patent, the applicant roughly described the previous However, in the subsequent experiment process, it was found that there are still many details that need to be improved in the above scheme.

Oil-immersed three-phase distribution transformers with rectangular oil tanks are widely used in urban and rural distribution networks. The characteristics of three-phase winding coils are arranged side by side. The transformer is composed of a rectangular oil tank, an EI-shaped iron core or four sets of rectangular amorphous alloy side-by-side iron cores, coil windings, and transformer oil. The appearance of the rectangular transformer is shown in Figure 1. The iron core, coils, and transformer oil are sealed in In the oil tank, the shape and size of the core and coil cannot be seen unless the transformer is disassembled. In order to identify the coil material of the rectangular oil tank oil-immersed three-phase distribution transformer without disintegration and damage, it is necessary to solve the X-ray transillumination method and transillumination process of the transformer oil tank and coil winding.

The technical problem to be solved by the present invention is to provide a method for identifying the winding coil material of a rectangular oil tank oil-immersed three-phase distribution transformer by taking X-ray photographs without dismantling the oil-immersed three-phase distribution transformer. Insufficiency of existing technology.

The technical solution of the present invention is: a method for identifying the non-disintegrated coil material of a rectangular oil tank oil-immersed three-phase distribution transformer, which is aimed at a rectangular oil tank oil-immersed three-phase distribution transformer, and a rectangular oil tank oil-immersed three-phase distribution transformer with three phases juxtaposed. Include the following steps

a. Use the X-ray machine and X-ray film to take pictures of the rectangular oil tank oil-immersed three-phase distribution transformer in the non-disassembled state according to the X-ray machine layout process and the X-ray film layout process. When taking pictures, the ray flaw detector uses different The X-ray tube voltage irradiates the winding area of the oil-immersed three-phase distribution transformer in the rectangular oil tank to obtain a set of photographed industrial ray films. The irradiated area of the winding is a corner of the B-phase winding of the oil-immersed three-phase distribution transformer in the rectangular oil tank;

b. Develop, stop, fix, wash and dry the industrial radiographic film after taking pictures

The image film of the rectangular oil tank oil-immersed three-phase distribution transformer winding coil;

c. According to the blackness measurement method of the rectangular oil tank oil-immersed three-phase distribution transformer non-disintegrated coil X-ray transillumination X-ray film blackness measurement method, the blackness data and position data of the specified measuring points are obtained, and the position data is obtained by using the rectangular oil tank oil-immersed three-phase Distribution transformer non-disintegrated coil material identification Calculation method of X-ray transillumination transillumination thickness; calculate the X-ray transillumination thickness of the measuring point for the rectangular oil tank oil-immersed three-phase distribution transformer coil image blackness, calculate and make the rectangular oil tank oil Immersion three-phase distribution transformer coil image blackness common logarithm - transillumination thickness curve;

d. Compare the X-ray different tube voltage ray attenuation coefficient-transillumination thickness curves of the measured rectangular oil tank oil-immersed three-phase distribution transformer with the X-ray different tube voltage ray attenuation coefficient-transillumination thickness curves of copper and aluminum, Calculate the absolute value of 100 times the average slope of these curves, the measured rectangular oil tank oil-immersed three-phase distribution transformer winding curve value is less than the aluminum curve value is aluminum, the measured rectangular oil tank oil-immersed three-phase distribution transformer winding coil If the curve value is greater than 1.0, it is copper; to identify the material of the winding coil of the measured rectangular oil tank oil-immersed three-phase distribution transformer.

The method for identifying the material of the non-disassembled coil of the oil-immersed three-phase distribution transformer in the rectangular oil tank mentioned above is that in step a, the X-ray machine is placed as follows: the window of the X-ray machine is vertically downward, and the X-ray film is placed in the oil-immersed three-phase distribution transformer Below the B-phase winding coil of the electric transformer, the long axis of the X-ray film is parallel to the window of the X-ray machine; the focal length F from the center line of the X-ray machine to the X-ray film is greater than 700mm; The distance of the outer wall of the winding at the transillumination part of the transformer is calculated by the formula of eccentricity, the focal length F is the distance from the center line of the X-ray machine to the X-ray film, the unit is mm; the voltage of the transillumination tube of the X-ray machine is 320kV, and the exposure is calculated by the formula of exposure: The X-ray machine exposure is the X-ray machine tube current multiplied by time, the unit is mA min (milliampere min), the focal length F is the distance from the X-ray machine center line to the X-ray film; the X-ray film is Agfa D4 , The intensifying screen is a lead foil intensifying screen with 0.15mm front and rear screens.

The method for identifying the material of the non-disassembled coil of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is to affix the detection number mark and lead type code on the X-ray film dark bag, and clamp the X-ray film dark bag with the X-ray film holder, and then place the X-ray film The X-ray film support is attached to the outer wall of the bottom plate of the oil tank under the B-phase coil of the oil-immersed three-phase distribution transformer of the rectangular oil tank, and the X-ray film support and the center line of the film, the center line of the X-ray machine window, and the center line of the X-ray machine are in the same plane. The X-ray film bracket and the film expose the edge of the bottom plate of the fuel tank by 10-20mm, and the inclined K value measuring device is vertically pasted on the outer wall of the B-phase coil oil tank panel of the oil-immersed three-phase distribution transformer of the rectangular fuel tank, and the lead rod of the inclined K value measuring device is perpendicular to X The radiographic film support is also positioned at the X-ray film support and the film midline, and the lower end of the lead rod of the inclined K value measuring device is against the film dark bag.

The method for identifying the non-disintegrated coil material of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that the X-ray film dark bag is 125mm long and 85mm wide, and the front and rear sense screens in the dark bag are 0.15mm lead Foil intensifying screen. The X-ray film between the two intensifying screens is 80×120mm Agfa D4 film. After the X-ray film is installed in the darkroom, it is covered with a dark bag.

The method for identifying the non-disintegrated coil material of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that in step c, the X-ray transillumination thickness calculation method is to use the rectangular oil tank oil-immersed three-phase distribution transformer coil cylinder end angle close to a right angle To calculate the X-ray transillumination thickness of the oil-immersed three-phase distribution transformer winding coil of a rectangular oil tank, when performing transillumination, a tilt K value measurement that is convenient for calculating the tilt K value should be placed under the center of the X-ray window on the outer wall of the oil tank or the outer wall of the winding insulation A 6mm×6mm×50mm lead rod is installed on the inclined K value measuring device, and the lower end of the inclined K value measuring device is against the X-ray film;

OM is the distance from the focal center of the X-ray machine to the X-ray film setting plane (focal length F), in mm;

CP is the distance from the end of the lead rod image of the tilted K value measuring device displayed on the X-ray film to the first measuring point specified for the blackness of the transformer winding image, in mm;

AB is the length of the lead rod of the K value measuring device, in mm;

T is the thickness of the lead rod of the K value measuring device, in mm;

GH-T is the distance from the projection point of the X-ray machine window center on the X-ray film setting plane to the end face of the lead rod of the K value measuring device, or the eccentricity L minus the distance from the outer end face of the lead rod of the K value measuring device to the outer wall of the transformer oil tank distance, in mm;

After calculating the tilt K value, calculate the X-ray transillumination thickness difference corresponding to the distance between any two points on the coil image on the X-ray film, (unit: mm)

△T is the thickness difference of X-ray transillumination; △X is the distance between any two points on the coil image on the X-ray film.

The method for identifying the material of the non-disintegrated coil of the rectangular oil-immersed three-phase distribution transformer mentioned above is that the method of measuring the blackness of the non-disassembled coil of the rectangular oil-immersed three-phase distribution transformer by X-ray transillumination X-ray film is as follows: three-phase oil-immersed rectangular oil tank Matching power transformer non-disintegrated coil material identification X-ray transillumination X-ray film is placed on the film viewing lamp, and the image of the tilt K value measuring device is found, and the X-ray film is loaded into the film positioning ruler, and the length direction of the film positioning ruler is along the coil image Vertical direction, and near the blackness measurement area of the X-ray film, fix the film positioning ruler and the film together, use the film positioning ruler to measure the image end position data of the tilt K value measuring device along the vertical direction of the coil image; use the black and white density meter along the Touch the edge of the film positioning ruler to measure the blackness of the film, find the blackness measuring point A with a blackness of 2.10-2.00, record the blackness value of the blackness measuring point A and the position data of the film positioning ruler; find the blackness measuring point A with a blackness of 1.85-1.75 Blackness measurement point B, record the blackness value of blackness measurement point B and the position data of the film positioning ruler; find the blackness measurement point C with a blackness of 1.65 to 1.55, record the blackness value of blackness measurement point C and the film positioning ruler location data.

The method for identifying the material of the non-disassembled coil of the rectangular oil-immersed three-phase distribution transformer mentioned above is that the blackness measurement area of the X-ray film must be selected in the coil image area of the rectangular oil-immersed three-phase distribution transformer with a blackness of 1.5 to 2.1. The three points of blackness measurement must lie on a straight line perpendicular to the tangent of the coil shape.

The method for identifying the non-disassembled coil material of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that in order to facilitate the recording of the blackness measurement position of the X-ray film, a vertical thin line must be marked in the center of the optical measuring head of the black and white density meter.

The method for identifying the non-disintegrated coil material of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that the different X-ray tube voltage ray attenuation coefficient-transillumination thickness curves of copper and aluminum are generated by using an X-ray machine with a focal length of F=700mm The tube voltage is 270kV and 320KV respectively, the exposure is 20mA min, the X-ray film is Agfa D4 type, the front and rear screens of the intensifying screen are 0.15mmPb, and the thickness of the equal-thickness steel plate placed on the X-ray film is 10mm and 20mm respectively. ; Transilluminate the 10-50mm copper ladder test block, 10-50mm aluminum ladder test block, and 60-100mm aluminum ladder test block respectively, and get 12 films with numbers. Each step of the 8 Al ladder test blocks in the 12 negative films is measured for blackness, and filled in the aluminum transillumination thickness blackness table; each step of the 4 Cu step test blocks in the 12 negative films is measured. Blackness measurement, and fill in the copper transillumination thickness blackness table; remove the value of the blackness lower than 0.3 in the aluminum transillumination thickness blackness table and take the common logarithm to generate the aluminum transillumination thickness blackness common logarithm table; Remove the value of the blackness lower than 0.3 in the copper transillumination thickness blackness table and take the common logarithm to generate the copper transillumination thickness blackness common logarithm table; the aluminum transillumination thickness blackness common logarithm table and the copper transillumination The data of the common logarithm table of the thickness blackness is plotted in a common logarithm-transillumination thickness curve of the X-ray film blackness of the copper-aluminum stepped test block, and four aluminum X-ray attenuation curves are obtained, and four copper X-ray attenuation curves are obtained; The common logarithm-transillumination thickness curves of the four aluminum blackness are close to a straight line, and 100 times the slope is about -1.0; the common logarithm-transillumination thickness curves of the four copper blackness are close to a straight line, and the slope is about -1.0. 3.7.

The method for identifying the non-disintegrated coil material of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that the X-ray film support includes a support plate, and two ends of the support plate are respectively connected with two coils that can be absorbed in the rectangular oil tank oil-immersed three-phase coil. The magnet sucker on the outer wall of the bottom plate of the oil tank under the coil of the distribution transformer is connected to a lead support plate on the support plate, and a corrosion reduction plate is connected to the lead support plate through a rope. After the X-ray film dark bag is placed on the lead support plate, The etching plate presses the right side of the X-ray film dark bag; the composition of the lead pallet includes a lead plate, the support plate is connected to the lead plate, and the connection between the lead plate, the lead plate and the support plate is covered with carbon fiber cloth, and the carbon fiber cloth passes through the resin. Cured in its covered area; the composition of the corrosion reducing plate includes a lead plate covered with carbon fiber cloth, and the carbon fiber cloth is cured in its covered area by resin.

The method for identifying the material of the non-disintegrated coil of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that the K value measuring device includes a carbon fiber plate, and two ends of the carbon fiber plate are connected with magnet suckers, and the carbon fiber plate between the two magnet suckers A lead rod is connected to the center line of the X-ray film, and the carbon fiber plate is vertically pasted on the outer wall of the oil-immersed three-phase distribution transformer coil oil tank panel of the rectangular oil tank. The lead rod is perpendicular to the X-ray film and is located on the center line of the X-ray film. The bottom plate of the three-phase distribution transformer oil tank is flush; the cross section of the lead rod is square, the side length is 6mm, and the length is 50mm. The lead rod and the carbon fiber plate are wrapped with fiber cloth. The resin is cured between the boards.

The method for identifying the non-disintegrated coil material of the aforementioned rectangular oil tank oil-immersed three-phase distribution transformer is that it includes a transparent scale, and a back sheet is provided below the transparent scale, and the area before the scale 0 of the transparent scale is connected to the end of the back sheet interconnected; the back sheet is a transparent scale, and the transparent scale and the scale 0 line of the back sheet coincide with each other; the transparent scale and the back sheet are rulers made of film material.

Compared with the prior art, the present invention uses X-rays to take pictures of the rectangular oil tank oil-immersed three-phase distribution transformer in a non-disassembled state according to the difference in the attenuation coefficients of copper and aluminum to X-rays, and uses a black-and-white density meter to take pictures of the three-phase distribution transformers in the non-disassembled state. X-ray negative film blackness measurement, input the measured blackness value into the computer to obtain the X-ray attenuation coefficient-transillumination thickness curve, by comparing the curve with the X-ray attenuation coefficient of copper, steel and aluminum with different X-ray tube voltages stored in the computer —Comparing the transilluminated thickness curves, it can be judged that the winding coils of the oil-immersed three-phase distribution transformer of the rectangular oil tank are made of aluminum and copper, which has the advantages of saving time, labor and no damage to the equipment. At the same time, due to the ability to quickly inspect the material of the transformer winding coil, the transformer that violates the contract and design and substitutes aluminum for copper can be claimed and replaced in time, reducing the loss of the distribution network transformer.

Description of drawings

Fig. 1 is a transillumination schematic diagram of the present invention;

Fig. 2 is the structural schematic diagram of X-ray film support;

Fig. 3 is the top view of Fig. 2;

Fig. 4 is the structural representation of inclined K value measurer;

Fig. 5 is the top view of inclined K value measurer;

Fig. 6 is the schematic diagram of calculating tilt K value;

Fig. 7 is the commonly used logarithm-transillumination thickness curve of copper-aluminum step test block X-ray film blackness;

Fig. 8 is a structural schematic diagram of the film positioning ruler.

detailed description

Embodiment, as shown in Figure 1, due to the core and coil structure of the oil-immersed three-phase distribution transformer in the rectangular oil tank, the X-rays of the portable X-ray flaw detector below 350kV cannot penetrate the windings of the oil-immersed three-phase distribution transformer in the rectangular oil tank from top to bottom For the coil, even if the X-ray passes through the tangential direction of the winding coil circle, the X-ray penetration thickness of the winding coil cannot be calculated due to the determination of the coil shape and size of the penetration part, and the coil material identification cannot be carried out. Therefore, X-rays are used to penetrate the lower end angle of the coil cylinder at a certain small angle, and the X-ray transillumination thickness difference of the winding coil can be calculated by using the end angle of the coil cylinder close to a right angle, and then according to the rectangular oil tank oil-immersed three-phase distribution transformer The non-destructive identification method of the disassembled coil material and the identification method of the X-ray attenuation law of copper and aluminum in the airtight container can be used to identify the coil material. The following is the specific identification method. The method includes the following steps:

a. Use an X-ray machine and X-ray film to take pictures of the oil-immersed three-phase distribution transformer of the measured rectangular oil tank in the non-disassembled state. When taking pictures, the ray flaw detector uses different X-ray tube voltages to irradiate the oil-immersed rectangular oil tank under test. The three-phase distribution transformer has a winding area, and a set of photographed industrial radiographic films is obtained. The winding area is a corner of the B-phase winding of the transformer;

In step a, the placement requirements of the X-ray machine are as follows: the window of the X-ray machine is vertically downward, and the X-ray film is placed under the B-phase winding coil of the oil-immersed three-phase distribution transformer in the rectangular oil tank. Parallel; the distance from the center line of the X-ray machine to the X-ray film is greater than 700mm and less than 900mm; the distance from the center of the X-ray machine window to the outer wall of the transilluminated part of the rectangular oil tank oil-immersed three-phase distribution transformer winding is calculated by the eccentricity formula, and the focal length is F It is the distance from the center line of the X-ray machine to the X-ray film, in mm; the voltage of the transillumination tube of the X-ray machine is 320kV, and the exposure is calculated by the formula of exposure, and the exposure of the X-ray machine is the current of the X-ray machine multiplied by the time, and the unit is It is mA·min (milliamp·min), the focal length F is the distance from the X-ray machine center line to the X-ray film; the X-ray film is Agfa D4, and the intensifying screen is lead foil intensifying with 0.15mm front and rear screens. Screen.

The X-ray film placement requirements are as follows: the inspection number mark and lead code are pasted on the X-ray film dark bag, the X-ray film dark bag is clamped with the X-ray film holder, and then the X-ray film holder is pasted under the B-phase coil of the distribution transformer The outer wall of the fuel tank bottom plate, and ensure that the X-ray film bracket and the center line of the film, the center line of the X-ray machine window, and the center line of the X-ray machine are in the same plane, and the X-ray film bracket and the film are exposed to the edge of the fuel tank bottom plate (or edge) by 10-20mm. Stick the inclined K value measuring device vertically on the outer wall of the B-phase coil oil tank panel of the rectangular oil tank oil-immersed three-phase distribution transformer. The lead rod of the inclined K value measuring device is perpendicular to the X-ray film support and is located on the X-ray film support and the center line of the film. The lower end of the lead rod of the inclined K value measuring device is against the film dark bag. The length of the X-ray film dark bag is 125mm, and the width is 85mm. The front intensifying screen and the rear intensifying screen in the dark bag are both 0.15mm lead foil intensifying screens of 80×120mm, and the X-ray film between the two intensifying screens is 80×120mm Agfa D4 film and X-ray film are covered with a dark bag after they are installed in the darkroom.

The X-ray film bracket is used to fix the X-ray film on the outer wall of the bottom plate of the oil tank under the B-phase coil of the oil-immersed three-phase distribution transformer in the rectangular oil tank. Its specific structure is shown in 2 and 3. The support plate 1 is installed on the two On the first magnetic sucker 2, the specification of the support plate is 20×1.5×150mm carbon fiber slats. The diameter of the magnet sucker 2 is 30mm, the thickness is 11mm, and there is an M3 screw hole in the center of the back; the lead support plate 3 is installed on the support plate 1, and the lead support plate 3 is made of a 90×2×120mm lead plate and carbon fiber cloth. The lead plate is wrapped, and then the carbon fiber cloth wrapping the lead plate is cured with resin to form a lead pallet, the support plate 1 and the lead pallet 3 are wrapped together with carbon fiber cloth, and then the resin carbon fiber cloth is cured. Corrosion reduction plate 4 is connected to the lead supporting plate by two 25mm wide and 2mm thick polypropylene ribbons. The corrosion reduction plate 4 is made of 20×1×120mm lead plate and carbon fiber cloth. The carbon fiber cloth wraps the lead plate and then wraps it with resin. The carbon fiber cloth wrapping the lead plate is solidified to form the corrosion-reducing plate 4, and then two 25mm wide and 2mm thick polypropylene webbings are connected to the lead supporting plate with resin. When patching, the X-ray film dark bag is placed in the X-ray film holder, the X-ray film dark bag is aligned with the back plate of the X-ray film holder, and the X-ray film dark bag is pasted with the typeface facing up (towards the direction of the X-ray machine), The erosion plate presses the right side of the X-ray film pocket.

The structure of the inclined K value measuring device is shown in Figures 4, 5 and 6. The rectangular oil tank oil-immersed three-phase distribution transformer coil material is identified. The X-ray transillumination inclined K value measuring device includes a carbon fiber plate 5, and the carbon fiber plate 5 Both ends are connected with magnet suckers 6, and lead rods 7 are connected at the center line of the carbon fiber board 5 between the measuring magnet suckers 6, and the carbon fiber board 5 is vertically pasted on the outer wall of the oil-immersed three-phase distribution transformer coil oil tank panel of the rectangular oil tank, The lead rod 7 is perpendicular to the X-ray film and is located at the center line of the X-ray film, and the lower end of the lead rod 7 is flush with the oil tank bottom plate of the rectangular oil tank oil-immersed three-phase distribution transformer. The width of the carbon fiber plate 5 is 20 mm, the thickness is 1.5 mm, and the length is 150 mm. Lead rod 7 section is square, and length is 6mm, length 50mm, is wrapped with fiber cloth outside lead rod 7 and carbon fiber plate 5, and fiber cloth and lead rod 7 are solidified with resin, between fiber cloth and carbon fiber plate 5, are cured with resin.

Described film positioning ruler, it comprises transparent scale 8, is provided with back sheet 9 below transparent scale 8, and the end portion of back sheet 9 is interconnected with the area before the scale 0 of transparent scale 8; Described back Sheet 9 is a transparent scale, and the scale 0 line of transparent scale 8 and back sheet 9 coincides with each other; transparent scale 8 and back sheet 9 are rulers made of film material.

b. Develop, stop, fix, wash, and dry the industrial radiographic film after taking the photo, and turn it into a rectangular oil tank oil-immersed three-phase distribution transformer winding coil image film.

c. According to the X-ray transillumination X-ray film blackness measurement method of the non-disintegrated coil of the oil-immersed three-phase distribution transformer in the rectangular oil tank, the measured results are obtained, and the results are identified by the material of the non-disintegrated coil of the oil-immersed three-phase distribution transformer in the rectangular oil tank. The calculation method of ray transillumination transillumination thickness calculates the image blackness and X-ray transillumination transillumination thickness of rectangular oil tank oil-immersed three-phase distribution transformer coils, calculates and makes rectangular oil tank oil-immersed three-phase distribution transformer coil image blackness commonly used Number-transillumination thickness curve, find 100 times the average slope of the curve.

In step c, the X-ray transillumination thickness calculation method is to calculate the X-ray transillumination thickness of the rectangular oil tank oil-immersed three-phase distribution transformer winding coil by using the end angle of the rectangular oil tank oil-immersed three-phase distribution transformer coil cylinder close to a right angle , when performing transillumination, an inclined K value measuring device for easy calculation of the inclined K value should be placed under the center of the X-ray window on the outer wall of the fuel tank or the insulating outer wall of the winding, and a lead rod of 6mm×6mm×50mm should be set on the inclined K value measuring device , tilt the lower end of the K value measuring device against the X-ray film;

OM is the distance from the focal center of the X-ray machine to the X-ray film setting plane (focal length F), in mm;

CP is the distance from the end of the lead rod image of the tilted K value measuring device displayed on the X-ray film to the first measuring point specified for the blackness of the transformer winding image, in mm;

AB is the length of the lead rod of the K value measuring device, in mm;

T is the thickness of the lead rod of the K value measuring device, in mm;

GH-T is the distance from the projection point of the X-ray machine window center on the X-ray film setting plane to the end face of the lead rod of the K value measuring device, or the eccentricity L minus the distance from the outer end face of the lead rod of the K value measuring device to the outer wall of the transformer oil tank Distance, in mm.

The calculation formula of the slope K value is calculated as follows:

On the X-ray film, C' is the projection of point A of the tilt K value measuring device, point P is the first measurement point of blackness, point N is the second or third measurement point of blackness, and T is the tilt K value The thickness (side length) of the measuring device, then the slope K value of point P is:

In the right triangle OMP

And because in ΔOMC is similar to ΔABC’

In order to eliminate the influence of the thickness of the inclined K value measuring device on the actual influence error,

After calculating the tilt K value, calculate the X-ray transillumination thickness difference corresponding to the distance between any two points on the coil image on the X-ray film.

△T is the thickness difference of X-ray transillumination; △X is the distance between any two points on the coil image on the X-ray film.

The blackness measurement method of X-ray transillumination X-ray film blackness of non-disintegrated coil of oil-immersed three-phase distribution transformer in rectangular oil tank is as follows: put the X-ray film of non-disintegrated coil material identification of oil-immersed three-phase distribution transformer in rectangular oil tank into the observation On the film lamp, find the image of the tilted K value measuring device, put the X-ray film into the film positioning ruler, the length direction of the film positioning ruler is along the vertical direction of the coil image, and is located near the blackness measurement area of the X-ray film, place the film positioning ruler and Fix the film together, use the film positioning ruler to measure the position data of the image end of the tilt K value measuring device along the vertical direction of the coil image; use a black and white densitometer to measure the blackness of the film along the edge of the film positioning ruler, and find the blackness with a blackness of 2.10 to 2.00. Blackness measurement point A, record the blackness value of blackness measurement point A and the position data of the film positioning ruler; find the blackness measurement point B with a blackness of 1.85 to 1.75, record the blackness value of blackness measurement point B and the film positioning ruler Position data; find the blackness measurement point C with a blackness of 1.65 to 1.55, and record the blackness value of the blackness measurement point C and the position data of the film positioning ruler.

The X-ray negative film blackness measurement area must be selected in the image area of the rectangular oil tank oil-immersed three-phase distribution transformer coil with a blackness of 1.5 to 4.5. The three points of the blackness measurement are located on a straight line perpendicular to the tangent of the coil shape.

d. Compare the different X-ray tube voltage ray attenuation coefficient-transillumination thickness curves of the measured rectangular oil tank oil-immersed three-phase distribution transformer with the different X-ray tube voltage ray attenuation coefficient-transillumination thickness curves of copper and aluminum, If the value is close to -1.0, the coil is aluminum, and if the value is close to -3.7, the coil is copper; to identify the material of the winding coil of the measured rectangular oil tank oil-immersed three-phase distribution transformer.

The generation method of different X-ray tube voltage ray attenuation coefficient-transillumination thickness curves of copper and aluminum is that the focal length is F=700mm, the X-ray machine tube voltage is 270kV and 320KV respectively, the exposure is 20mA min, and the X-ray film loves Kefa D4 type, the front and rear screens of the intensifying screen are both 0.15mmPb, and the thickness of the equal-thickness steel plate placed on the X-ray film is 10mm and 20mm respectively; the copper ladder test block of 10-50mm and the aluminum ladder test block of 10-50mm are transilluminated respectively , 60 ~ 100mm aluminum ladder test block, get 12 films marked with numbers, 12 negatives obtained after the film was developed in the dark room for 5 minutes, and fixed in the dark room for 15 minutes, and each step of the 8 Al ladder test blocks in the 12 negatives was tested. Blackness measurement, and fill in the aluminum transillumination thickness blackness table; measure the blackness of each step of the 4 Cu ladder test blocks in the 12 negatives, and fill in the copper transillumination thickness blackness table; aluminum transillumination Remove the value of blackness lower than 0.3 in the thickness blackness table and take the common logarithm to generate the common logarithm table of aluminum transillumination thickness blackness; remove the value of blackness lower than 0.3 in the copper transillumination thickness blackness table and take Commonly used logarithm, generate the common logarithm table of copper transillumination thickness blackness; draw the data of the common logarithm table of aluminum transillumination thickness blackness and the common logarithm table of copper transillumination thickness blackness on a copper-aluminum ladder test block X In the commonly used logarithm-transillumination thickness curve diagram of the blackness of radiographs, four aluminum X-ray attenuation curves are obtained, and four copper X-ray attenuation curves are obtained; the common logarithm-transillumination thickness curves of the four aluminum blackness are close to a straight line. The absolute value of 100 times the average slope of these curves, the measured rectangular oil tank oil-immersed three-phase distribution transformer winding coil curve value is less than the aluminum curve value is aluminum, the measured rectangular oil tank oil-immersed three-phase distribution transformer winding coil curve value If it is greater than 1.0, it is copper; to identify the material of the winding coil of the oil-immersed three-phase distribution transformer of the measured rectangular oil tank.

The specific process is

1. Laboratory copper and aluminum X-ray attenuation coefficient transillumination process I: X-ray transillumination is shown in Figure 7, focal length F=700mm, X-ray machine tube voltage is 270kV, exposure is 20mA min, X-ray film Agfa D4 type, the front and rear screens of the intensifying screen are 0.15mmPb, and the thickness of the equal-thickness steel plate is 10mm.

2. Laboratory copper and aluminum X-ray attenuation coefficient transillumination process II: X-ray transillumination is shown in Figure 7, focal length F=700mm, X-ray machine tube voltage is 270kV, exposure is 20mA min, X-ray film Agfa D4 type, the front and rear screens of the intensifying screen are 0.15mmPb, and the thickness of the equal-thickness steel plate is 20mm.

3. Laboratory copper and aluminum X-ray attenuation coefficient transillumination process III: X-ray transillumination is shown in Figure 7, focal length F=700mm, X-ray machine tube voltage is 320kV, exposure is 20mA min, X-ray film Agfa D4 type, the front and rear screens of the intensifying screen are 0.15mmPb, and the thickness of the equal-thickness steel plate is 10mm.

4. Laboratory copper and aluminum X-ray attenuation coefficient transillumination process IV: X-ray transillumination is shown in Figure 7, focal length F=700mm, X-ray machine tube voltage is 320kV, exposure is 20mA min, X-ray film Agfa D4 type, the front and rear screens of the intensifying screen are 0.15mmPb, and the thickness of the equal-thickness steel plate is 20mm.

5. Use the transillumination process I to transilluminate a group of 10-50mm copper ladder test blocks in the laboratory. The X-ray film number is 270kVFe10Cu10-50, and the number of the negative film obtained after darkroom development for 5 minutes and darkroom fixation for 15 minutes is 270kVFe10Cu10-50.

6. Use Transillumination Industry III to transilluminate a group of 10-50mm copper ladder test blocks in the laboratory. The X-ray film number is 320kVFe10Cu10-50. After 5 minutes of darkroom development and darkroom fixation for 15 minutes, the negative film number is 320kVFe10Cu10-50.

7. Use the transillumination process II to transilluminate a group of 10-50mm copper ladder test blocks in the laboratory. The X-ray film number is 270kVFe20Cu10-50. After 5 minutes of darkroom development and darkroom fixation for 15 minutes, the negative film number is 270kVFe20Cu10-50.

8. Use the transillumination process IV to transilluminate a group of 10-50mm copper ladder test blocks in the laboratory. The X-ray film number is 320kVFe20Cu10-50, and the number of the negative film obtained after darkroom development for 5min and darkroom fixation for 15min is 320kVFe20Cu10-50.

9. Use the transillumination process I to transilluminate a group of 10-50mm aluminum ladder test blocks in the laboratory. The X-ray film number is 270kVFe10Al10-50, and the number of the negative film obtained after darkroom development for 5 minutes and darkroom fixation for 15 minutes is 270kVFe10Al10-50.

10. Use the transillumination process I to transilluminate a group of 60-100mm aluminum ladder test blocks in the laboratory. The X-ray film number is 270kVFe10Al60-100, and the number of the negative film obtained after darkroom development for 5min and darkroom fixation for 15min is 270kVFe10Al60-100.

11. Transilluminate a group of 10-50mm aluminum ladder test blocks in the laboratory using Transillumination Industry III. The X-ray film number is 320kVFe10Al10-50. The number of the negative film obtained after darkroom development for 5 minutes and darkroom fixation for 15 minutes is 320kVFe10Al10-50.

12. Transilluminate a group of 60-100mm aluminum ladder test blocks in the laboratory using Transillumination Industry III. The X-ray film number is 320kVFe10Al60-100. After 5 minutes of darkroom development and darkroom fixation for 15 minutes, the negative film number is 320kVFe10Al60-100.

13. Use the transillumination process II to transilluminate a group of 10-50mm aluminum ladder test blocks in the laboratory. The X-ray film number is 270kVFe20Al10-50. The number of the negative film obtained after darkroom development for 5min and darkroom fixation for 15min is .

14. Use the transillumination process II to transilluminate a group of 60-100mm aluminum ladder test blocks in the laboratory. The X-ray film number is 270kVFe20Al60-100, and the number of the negative film obtained after darkroom development for 5min and darkroom fixation for 15min is 270kVFe20Al60-100.

15. Use the transillumination process IV to transilluminate a group of 10-50mm aluminum ladder test blocks in the laboratory. The X-ray film number is 320kVFe20Al10-50, and the number of the negative film obtained after darkroom development for 5min and darkroom fixation for 15min is 320kVFe20Al10-50.

16. Use the transillumination process IV to transilluminate a group of 60-100mm aluminum ladder test blocks in the laboratory. The X-ray film number is 320kVFe20Al60-100, and the number of the negative film obtained after darkroom development for 5min and darkroom fixation for 15min is 320kVFe20Al60-100.

17. Using a black-and-white densitometer, the steps of V, Fe20Al10-50, 270kVFe20Al60-100, 320kVFe20Al10Al10-50, Measure the blackness and fill in the aluminum transillumination thickness blackness table (Table 1).

18. Using a black and white densitometer, measure the blackness of each step of the ladder test block image negative film 270kVFe10Cu10-50, 320kVFe10Cu10-50, 270kVFe20Cu10-50, 320kVFe20Cu10-50, and fill in the copper transillumination thickness blackness table (Table 2).

19. Remove the value of the blackness lower than 0.3 in the aluminum transillumination thickness blackness table (Table 1) and take the common logarithm to generate the aluminum transillumination thickness blackness common logarithm table (Table 3).

20. Remove the value of the blackness lower than 0.3 in the copper transillumination thickness blackness table (Table 2) and take the common logarithm to generate the copper transillumination thickness blackness common logarithm table (Table 4).

21. Draw the data of the common logarithm table (Table 3) and the common logarithm table (Table 4) of the thickness blackness of aluminum transillumination on a common pair of blackness of X-ray film blackness of copper-aluminum ladder test block In the number-transillumination thickness curve (Figure 8), four aluminum X-ray attenuation curves of 270kVFe10Al, 270kVFe20Al, 320kVFe10Al, and 320kVFe20Al are obtained, and four copper X-ray attenuation curves of 270kVFe10Cu, 270kVFe20Cu, 320kVFe10Cu, and 320kVFe20Cu are obtained. The four common logarithm-transillumination thickness curves of aluminum blackness in the figure are close to a straight line, and the slope of 100 times is about -1.0; The times are about -3.7.

22. In the actual non-destructive testing of the coil material identification of rectangular oil-immersed three-phase distribution transformers, first use the X-ray transillumination method to identify the non-disintegrated coil materials of rectangular oil-immersed three-phase distribution transformers. Three-phase distribution transformer coil image film, and then according to the rectangular oil tank oil-immersed three-phase distribution transformer non-disintegrated coil material identification X-ray transillumination transillumination thickness calculation method, rectangular oil tank oil-immersed three-phase distribution transformer non-disintegrated coil X-ray transmission Measure and calculate the image blackness and X-ray transillumination thickness of the oil-immersed three-phase distribution transformer coil of the rectangular oil tank according to the X-ray film blackness measurement method, and calculate and make the image blackness of the oil-immersed three-phase distribution transformer coil of the rectangular oil tank The logarithm-transillumination thickness curve is commonly used to obtain 100 times the average slope of the curve. If the value is close to -1.0, the coil is aluminum, and if the value is close to -3.7, the coil is copper.

Table 1. Aluminum transillumination thickness blackness table

Table 2. Blackness table of copper transillumination thickness

Table 3. Commonly used logarithmic table of aluminum transillumination thickness blackness

Table 4. Copper transillumination thickness blackness common logarithm table

Claims (8)

1. the non-disintegration texture of coil discrimination method of a kind of rectangle fuel tank oil immersion Three-Phase Distribution Transformers, which is directed to rectangle fuel tank oil immersion Three-Phase Distribution Transformers, have fin outside fuel tank, it is characterised in that：The method is comprised the following steps

A, using X-ray production apparatus and X-ray film, shape is disassembled to non-according to X-ray production apparatus arrangement technology, X-ray film arrangement technology Rectangle fuel tank oil immersion Three-Phase Distribution Transformers under state are taken pictures, and when taking pictures, ray inspection machine is using different x-ray pipe electricity Pressure irradiation rectangle fuel tank oil immersion Three-Phase Distribution Transformers have winding area, obtain one group of postindustrial radiographic film of taking pictures, and the winding shines It is one jiao of rectangle fuel tank oil immersion Three-Phase Distribution Transformers B phase windings to penetrate region；

B, postindustrial radiographic film of taking pictures carry out developing, stop shadow, fixing, washing, drying and processing are changed into rectangle fuel tank oil immersion three Phase distribution transformer winding coil image egative film；

C, according to rectangle fuel tank oil immersion Three-Phase Distribution Transformers non-solution body coil X ray transillumination x-ray film density measurement method Blackness regulation measuring point blackness data and position data is drawn, its position data is non-using rectangle fuel tank oil immersion Three-Phase Distribution Transformers Disintegration texture of coil differentiates that X ray transillumination scanning thickness computational methods are calculated；Calculate rectangle fuel tank oil immersion three-phase distribution transformation Device coil image blackness specifies the X ray scanning thickness of measuring point, calculates and make rectangle fuel tank oil immersion Three-Phase Distribution Transformers line Circle image blackness common logarithm-scanning thickness curve；

D, will be bent for tested rectangle fuel tank oil immersion Three-Phase Distribution Transformers X ray difference tube voltage attenuation coefficient scanning thickness Compare respectively by tube voltage attenuation coefficient scanning thickness curves different from the X ray of copper and aluminium for line, obtains this respectively The absolute value of 100 times of a little curve G-bars, tested rectangle fuel tank oil immersion Three-Phase Distribution Transformers winding coil curve values are little It is then aluminium in aluminium curve values, tested rectangle fuel tank oil immersion Three-Phase Distribution Transformers winding coil curve values are copper more than 1.0；With Differentiate the material of tested rectangle fuel tank oil immersion Three-Phase Distribution Transformers winding coil；

Detection numbering mark lead word number is posted on radiographic film camera bag, and X-ray film camera bag X-ray film support is clipped, Then X-ray film support is affixed on rectangle fuel tank oil immersion Three-Phase Distribution Transformers B phase coil lower fuel tank base plate outer walls, and is guaranteed X-ray film support and film center line, X-ray production apparatus window center line, X-ray production apparatus center line in the same plane, X ray glue Plate rack and film expose oil tank bottom plate edge 10-20mm, will incline K values measuring appliance and are vertically attached to three matching of rectangle fuel tank oil immersion Piezoelectric transformer B phase coil fuel tank panel outer walls, incline the lead rod of K value measuring appliances perpendicular to X-ray film support and are located at X ray Film rack and film center line, the lead rod lower end for inclining K value measuring appliances prop up film camera bag；

Described K value measuring appliances include carbon fiber board (5), are connected with magnet sucking disc (6) at the two ends of carbon fiber board (5), two The position of center line of the carbon fiber board (5) between magnet sucking disc (6) is connected with lead rod (7), and carbon fiber board (5) is vertically attached to rectangle Fuel tank oil immersion Three-Phase Distribution Transformers coil fuel tank panel plate outer wall, lead rod (7) perpendicular to X-ray film and are located at X ray glue Piece center line, lead rod (7) lower end are flushed with rectangle fuel tank oil immersion Three-Phase Distribution Transformers oil tank bottom plate；Lead rod (7) section is pros Shape, the length of side are 6mm, length 50mm, are wrapped with fiber cloth in lead rod (7) and carbon fiber board (5), and fiber cloth is used with lead rod (7) Resin solidification, fiber cloth and carbon fiber board use resin solidification between (5).

2. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 1, its It is characterised by：The long 125mm of X-ray film camera bag, wide 85mm, in camera bag, front intensifying screen and rear sense screen are 80 × 120mm's 0.15mm lead foil screens, the X-ray film between two intensifying screens are that 80 × 120mm love gram sends out D4 films, and X-ray film is dark Room is covered with camera bag lid after installing.

3. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 1, its It is characterised by：The non-solution body coil X ray transillumination x-ray film density measurement method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers For non-for rectangle fuel tank oil immersion Three-Phase Distribution Transformers disintegration texture of coil discriminating X ray transillumination x-ray film is put into sight piece On lamp, inclination K value measuring appliance images are found, x-ray film loads in egative film positioning rule, and egative film positioning rule length direction is along line Circle image vertical direction, and x-ray film density measurement areas adjacent is located at, egative film positioning rule and egative film are fixed together, K value measuring appliance image terminal position data are inclined with egative film positioning rule along the measurement of coil image vertical direction；Close using black and white Degree meter finds the density measurement point A that blackness is 2.10～2.00 along egative film positioning rule edge metering photographic density, records blackness The blackness value of measurement point A and egative film positioning rule position data；The density measurement point B that blackness is 1.85～1.75 is found, is recorded black The blackness value of degree measurement point B and egative film positioning rule position data；The density measurement point C that blackness is 1.65～1.55 is found, is recorded The blackness value of density measurement point C and egative film positioning rule position data.

4. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 1, its It is characterised by：X-ray film density measurement region must be chosen to be at the rectangle fuel tank oil immersion three-phase distribution that blackness is 1.5～2.1 In transformer coil imagery zone, 3 points of density measurement are necessarily located normal on the straight line of coil shape tangent line.

5. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 1, its It is characterised by：For the ease of the record of x-ray film density measurement position, the densitometric optical measuring head center of black and white must be made One Thin vertical lines mark.

6. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 1, its It is characterised by：The generation method of the different x-ray tube voltage attenuation coefficient scanning thickness curve of copper and aluminium is, focal length F =700mm, is respectively 270kV and 320KV using X-ray production apparatus tube voltage, and light exposure is 20mA min, X-ray film Ai Kefa D4 types, before and after intensifying screen screen be 0.15mmPb, the uniform thickness steel plate thickness being placed on X-ray film be respectively adopted 10mm and 20mm；Transillumination 10～50mm copper step bars, 10～50mm aluminum step wedge or ladder test blocks, 60～100mm aluminum step wedge or ladder test blocks, obtain 12 respectively The film for bearing serial numbers, 12 egative films that film is obtained after scotography 5min, the fixing 15min in darkroom, by 12 egative films In each ladders of 8 Al step bars carry out density measurement, and insert aluminium scanning thickness blackness table；By in 12 egative films Each ladder of 4 Cu step bars carries out density measurement, and inserts copper scanning thickness blackness table；By aluminium scanning thickness blackness table Value of the middle blackness less than 0.3 takes common logarithm after removing, and generates aluminium scanning thickness blackness common logarithm table；Will be black for copper scanning thickness In degree table, value of the blackness less than 0.3 takes common logarithm after removing, and generates copper scanning thickness blackness common logarithm table；Aluminium transillumination is thick The data of degree blackness common logarithm table and copper scanning thickness blackness common logarithm table are plotted in a copper aluminum step wedge or ladder test block X ray bottom In piece blackness common logarithm-scanning thickness curve map, four aluminium X-ray attenuation curves are obtained, obtain four copper X-ray attenuations bent Line；Blackness common logarithm-scanning thickness the curve of four aluminium is close to straight line, and 100 times of slope are about -1.0；Four copper black Degree common logarithm-scanning thickness curve is close to straight line, and 100 times of slope are about -3.7.

7. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 3, its It is characterised by：Described X-ray film support includes gripper shoe (1), and being connected to two at the two ends of gripper shoe (1) can inhale The magnet sucking disc (2) of rectangle fuel tank oil immersion Three-Phase Distribution Transformers coil lower fuel tank base plate outer wall is attached to, is connected in gripper shoe (1) Lead supporting plate (3) is connected to, corrosion inhibitor plate (4) is connected with by rope band on lead supporting plate (3), X-ray film camera bag is placed on lead supporting plate (3), after upper, corrosion inhibitor plate (4) is pushed down on the right of X-ray film camera bag；The composition of lead supporting plate (3) includes that stereotype, gripper shoe (1) connect On stereotype, carbon cloth is coated with the junction of stereotype, stereotype and gripper shoe (1), carbon cloth is existed by resin solidification Its overlay area；The composition of corrosion inhibitor plate (4) includes stereotype, is covered with carbon cloth on stereotype, and carbon cloth passes through resin solidification In its overlay area.

8. the non-disintegration texture of coil discrimination method of rectangle fuel tank oil immersion Three-Phase Distribution Transformers according to claim 3, its It is characterised by：Including transparent scale chi (8), tergite (9), the quarter of transparent scale chi (8) is provided with below transparent scale chi (8) The forefoot area of degree 0 is connected with each other with the end of tergite (9)；Described tergite (9) is transparent rule, transparent scale chi (8) Overlap with 0 line of scale of tergite (9)；Transparent scale chi (8) and tergite (9) are ruler obtained in film material.