JP5596525B2 - Solid insulation internal defect detection system - Google Patents

Description

Embodiments of the present invention relate to a solid insulator internal defect detection system that detects defects inside a solid insulator by measuring a partial discharge of the solid insulator while irradiating the defect detection target with radiation.

  In high-voltage devices such as molded transformers, a predetermined voltage is applied to the resin, which is a solid insulator, in order to detect the presence of defects such as peeling at the interface between the conductor and resin and voids inside the resin. The partial discharge is measured. Such partial discharges caused by defects inside the solid insulator may cause a delay of several minutes to several hours until the actual discharge occurs even when a voltage higher than the discharge start voltage is applied. Since no discharge was observed, it was sometimes mistakenly determined that there was no defect.

  In order to solve these problems, proposals have been made to eliminate the time delay phenomenon of discharge by measuring partial discharge while irradiating the solid insulator with X-rays. In order to generate a partial discharge, initial electrons that become seeds of discharge are required inside the void, and usually the gas around the solid insulator is often ionized and supplied by the energy of cosmic rays or ultraviolet rays. However, it is difficult for cosmic rays and ultraviolet rays to reach inside the solid insulator, and the initial electrons are insufficient. When the solid insulator is irradiated with X-rays, it is possible to promote the ionization of the gas inside the void and supply initial electrons, thereby promoting the occurrence of partial discharge.

JP-A-9-105766 JP-A-9-127182 JP 2010-60559 A

  As described above, partial discharge can be promoted by irradiating the defect detection target with radiation such as X-rays. Therefore, it is expected that the partial discharge measurement work or the insulation test work will be completed in a shorter time than conventional. ing. However, in actual work, there are a large number of control elements and detection information such as an X-ray irradiation position, an X-ray dose, a partial discharge detection, and an applied voltage waveform.

  It is too cumbersome and difficult for an operator to appropriately control these many elements while accurately identifying partial discharge and noise and accurately determining the presence or absence of a defect and the position of a defect. Further, since X-rays are irradiated, it is necessary to install a defect detection target in the radiation shielding box. However, since the operator cannot confirm the operation state of the X-ray irradiation apparatus including the defect detection target from the outside, workability is improved. This is a cause of further lowering.

  Therefore, a solid insulator internal defect detection system capable of efficiently and easily performing an operation of detecting defects of the solid insulator while irradiating the defect detection target with radiation is provided.

The solid-insulator internal defect detection system according to the embodiment detects defects inside the solid insulator by measuring a partial discharge of the solid insulator while irradiating the defect detection target with radiation. This solid insulator internal defect detection system includes a radiation irradiation means for irradiating a solid insulator of a defect detection target, a radiation dose control means for controlling a radiation dose irradiated by the radiation irradiation means, and a radiation irradiation means for irradiation. Radiation irradiation position control means for controlling the position of the radiation in the defect detection target, partial discharge detection means for detecting partial discharge generated inside the solid insulator, voltage application means for applying a voltage to the solid insulator, Man-machine interface means. The man-machine interface means has a display means, controls the radiation dose control means, the radiation irradiation position control means, the partial discharge detection means and the voltage application means, as well as the outer shape of the defect detection object, the radiation irradiation position, and the partial discharge detection. The signal waveform and the applied voltage waveform are displayed on the same screen of the display means.

The whole block diagram of the solid insulator internal defect detection system which shows 1st Embodiment The figure which shows an example of the screen display of a display apparatus The figure which shows the relationship between the X-ray dose and the partial discharge start voltage for a solid insulator sample including voids View from the X direction when the defect detection target is irradiated with an X-ray beam FIG. 2 equivalent view showing the second embodiment FIG. 2 equivalent view showing the third embodiment

(First embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is an overall configuration diagram of a solid insulator internal defect detection system showing a combination of a structure for irradiating a defect detection target with radiation and an electrical block configuration. Here, X-rays are used as radiation, and the inside of the X-ray shielding box SB that cannot be seen from the outside is shown transparently.

  The solid-insulator internal defect detection system 1 measures the partial discharge in the resin mold portion of the transformer 2 while irradiating the transformer 2 which is a defect detection target with X-rays, so that the conductor and the resin 2a (solid insulation This is a system for detecting defects such as peeling at the interface with the object and voids inside the resin 2a. This solid insulator internal defect detection system 1 includes a power supply device 3 (voltage application means), a partial discharge detection device 4 (partial discharge detection means), an X-ray irradiation device 5 (radiation irradiation means), and an X-ray dose control device 6 (radiation). (Quantity control means), X-ray module moving device 7 (radiation irradiation position control means), personal computer 8 (man machine interface means), and the like.

  The power supply device 3 includes a voltage waveform control device 9 that generates a sine wave voltage, an amplifier 10 that amplifies the sine wave voltage, and a transformer 11 that boosts the sine wave voltage and outputs it to the power line 12. The power supply device 3 applies a sinusoidal AC power supply voltage based on a command from the personal computer 8 to the resin mold portion of the transformer 2 installed in the X-ray shielding box SB.

  The partial discharge detection device 4 includes a detection impedance 13 and a partial discharge signal output device 14. The partial discharge detection device 4 detects a partial discharge generated by a defect inside the resin 2 a of the transformer 2 and outputs the partial discharge detection signal to the personal computer 8. To do. The detection impedance 13 is connected between the power supply line 12 and the ground via a coupling capacitor 15 and converts the discharge current into a voltage. The partial discharge signal output device 14 amplifies the converted minute voltage signal and shapes the waveform, and then transmits the partial discharge detection signal to the personal computer 8.

  The X-ray irradiation apparatus 5 includes X-ray modules 16 and 17 having an X-ray tube and a slit. The X-ray module 16 emits an X-ray beam in the −Z direction shown in FIG. 1, and the X-ray module 17 emits an X-ray beam in the + Y direction shown in FIG. The X-ray dose (radiation dose) irradiated by these X-ray modules 16 and 17 is controlled by the X-ray dose control device 6 based on a command from the personal computer 8.

  The X-ray module moving device 7 is disposed on the ceiling surface in the X-ray shielding box SB, and is disposed on the side surface in the X-ray shielding box SB and the moving device 7a that moves the X-ray module 16 on the XY plane. The moving device 7b for moving the X-ray module 17 on the XZ plane and the irradiation position control device 7c for controlling the rotation of motors 19, 20, 22, and 23, which will be described later, based on commands from the personal computer 8. .

  The moving device 7a causes the ball screw mechanism 18 to reciprocate the X-ray module 16 in the X direction and the Y direction according to the rotation amounts of the motors 19 and 20. The moving device 7 b reciprocates the X-ray module 17 in the X direction and the Z direction according to the rotation of the motors 22 and 23 by the ball screw mechanism 21. With this configuration, the X-ray beams emitted from the X-ray modules 16 and 17 can intersect within the resin 2a of the transformer 2.

  The personal computer 8 is installed with a man-machine interface program 24 for operating as man-machine interface means. The man-machine interface program 24 controls the power supply device 3, the partial discharge detection device 4, the X-ray dose control device 6 and the X-ray module moving device 7, as well as the outer shape and X-ray irradiation position of the transformer 2 as a defect detection target. The control information and the detection information including the partial discharge detection signal waveform and the applied voltage waveform are displayed on the screen of the display device 25 (display means).

  FIG. 2 shows an example of a screen displayed on the display device 25 when the personal computer 8 executes the man-machine interface program 24. The outer shape 26 of the transformer 2 which is a defect detection target, the X-ray irradiation position 27 in the transformer 2, the partial discharge detection signal waveform 28 and the applied voltage waveform 29 are displayed on the same screen. An applied voltage 30, an irradiation dose 31, and a measurement period 32 are displayed on the right end of the screen.

  The partial discharge detection signal waveform 28 indicates a signal output from the partial discharge signal output device 14, and one pulse corresponds to one partial discharge. Noise is easily mixed in the partial discharge detection signal, and it is difficult to distinguish between discharge and noise only by observing one pulse. Therefore, in FIG. 2, partial discharge detection signals for six cycles of the applied voltage are measured and displayed. As a result, the operator can determine that partial discharge has occurred when pulses can be observed in a plurality of cycles.

  The display device 25 also functions as touch panel type input means. Based on the man-machine interface program 24, the personal computer 8 displays a button 33 for controlling power application to the defect detection target and stopping (power failure) under the display of the applied voltage 30 on the screen. When the operator touches the display unit of the button 33, input operation information is input to the personal computer 8, and power application and stop to the defect detection target are controlled via the power supply device 3. In addition, a button 34 for controlling the start and stop of X-ray irradiation is displayed below the display of the irradiation dose 31 on the screen. When the operator touches the display section of the button 34, input operation information is input to the personal computer 8, and X-ray irradiation is controlled via the X-ray dose control device 6.

  Further, the personal computer 8 displays buttons 35 to 40 for operating the positions of the X-ray modules 16 and 17 on the upper end portion and the left end portion of the screen based on the man-machine interface program 24. Buttons 35 and 36 are buttons for moving the X-ray modules 16 and 17 in the X direction shown in FIG. 1, buttons 37 and 38 are buttons for moving the X-ray module 16 in the Y direction, and buttons 39 and 40 are buttons for moving the X-ray module 17. A button for moving in the Z direction.

  When the operator touches the display part of the buttons 35 to 40, input operation information is input to the personal computer 8. The personal computer 8 outputs a movement command signal corresponding to the input operation information to the irradiation position control device 7c. As a result, the corresponding motors 19, 20, 22, and 23 rotate forward and backward, and the X-ray modules 16 and 17 move in the XY direction and the XZ direction, respectively. At the same time, the personal computer 8 moves the X-ray irradiation position 27 drawn on the outer shape 26 of the transformer 2 on the screen of the display device 25 to the corresponding position based on the movement command signal. If it does in this way, the operator can irradiate X-rays to the arbitrary positions of the transformer 2 in the X-ray shielding box SB.

  Next, the operation when a plurality of X-ray beams are crossed will be described. FIG. 3 shows the result of actual measurement of the partial discharge start voltage during X-ray irradiation by changing the X-ray dose applied to the solid insulator sample including voids. The vertical axis indicating the partial discharge start voltage is normalized by setting the partial discharge start voltage when the X-ray is not irradiated to 1. The horizontal axis represents the X-ray dose (radiation dose). A two-dot chain line connecting the measured points is an auxiliary line for complementing the measured points. The X-ray dose and the partial discharge start voltage are inversely proportional, and the partial discharge start voltage tends to increase as the X-ray dose decreases.

  FIG. 4 is a diagram observed from the X direction when the X-ray modules 16 and 17 irradiate the transformer 2 which is a defect detection target. If the X-ray beam 41 emitted from the X-ray module 16 has a dose sufficient to generate a partial discharge, the partial discharge is generated in any of the Z-direction line regions irradiated with the X-ray beam 41. Since it occurs, the position of the defect is indefinite in the Z direction. Similarly, for the X-ray beam 42 emitted from the X-ray module 17, the position of the defect is indefinite in the Y direction.

  Therefore, the personal computer 8 uses the X-ray dose control device 6 to set the dose of the single X-ray beams 41 and 42 to a dose lower than the dose at which the partial discharge occurs, and applies the X-ray beam 41 emitted from the X-ray module 16 to the X-ray beam 41. When the X-ray beam 42 radiated from the line module 17 is added, the X-ray dose is controlled so as to reach a dose at which partial discharge occurs. Therefore, the irradiation position control device 7c controls the position so that the X coordinate of the X-ray module 16 and the X coordinate of the X-ray module 17 coincide, and the X-ray beam 41 and the X-ray emitted from the X-ray module 16 are controlled. The X-ray beam 42 emitted from the module 17 is crossed at a desired region 43.

  Referring to FIG. 3, for example, when a voltage of 0.5 (normalized value) is applied to the resin 2a of the transformer 2, a partial discharge is generated in a line region through which a single radiation beam having a dose R1 passes. Although the dose is insufficient to be generated, the dose is R2 (= 2 × R1) in the region 43 where the two X-ray beams having the dose R1 intersect, so that the dose is sufficient to generate the partial discharge. Become.

  From another viewpoint, partial discharge does not occur in a line region through which a single X-ray beam having a dose R1 passes, and partial discharge occurs in a region 43 where two X-ray beams having a dose R1 intersect. For example, a voltage of 0.5 (standardized value) may be applied. As a result, in the region 43 where the X-ray beams 41 and 42 intersect, a dose sufficient to generate a partial discharge is reached and initial electrons are supplied, and a partial discharge can be generated only in the region 43. The defect position inside 2a can be detected with high accuracy.

As described above, the solid insulator internal defect detection system 1 of the present embodiment is a portion of the resin 2a in which a winding or the like is molded while irradiating the transformer 2 as a defect detection target with X-rays. Measure the discharge. As a result, ionization of the gas inside the defect such as a void can be promoted to supply initial electrons, a partial discharge can be generated in a shorter time, and the defect inside the solid insulator can be detected efficiently.

  The solid-insulator internal defect detection system 1 includes a personal computer 8 that functions as a man-machine interface means. 28 and the applied voltage waveform 29 are displayed on the same screen of the display device 25. Conventionally, the partial discharge detection signal waveform and the applied voltage waveform have been prepared and displayed by a device such as an oscilloscope.

  With this unified management, the operator can move the X-ray irradiation position to a desired position by operating the personal computer 8 while looking at the display device 25 for the transformer 2 in the X-ray shielding box SB that cannot be seen from the outside. The X-ray irradiation position, the partial discharge detection signal waveform, and the applied voltage waveform in the transformer 2 can be confirmed at the same time. Thereby, it becomes easy to distinguish the pulse signal due to the occurrence of the partial discharge from noise, and the defect can be detected efficiently and easily without erroneous determination. For example, when it is difficult to determine the occurrence of partial discharge, the operator shifts while checking the X-ray irradiation position displayed on the same screen while paying attention to the partial discharge detection signal waveform and the applied voltage waveform on the screen. This makes it possible to more accurately determine whether the pulse is due to partial discharge or noise.

  The personal computer 8 displays the applied voltage 30, the irradiation dose 31, and the measurement cycle 32 on the screen, and the operator can operate the personal computer 8 to change the applied voltage, the irradiation dose, and the measurement cycle. Thereby, the operator can simultaneously set and check the applied voltage and the irradiation dose, which are partial discharge occurrence conditions, and can more reliably identify the partial discharge signal and noise. Further, since the personal computer 8 displays the partial discharge detection signal waveform 28 and the applied voltage waveform 29 on the screen for the set period, it is assumed that the operator has generated a partial discharge when a pulse can be observed in a plurality of periods. Can be determined.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. The overall configuration of this embodiment is the same as that of the first embodiment. In FIG. 5 showing the screen display, the same parts as those in FIG. The personal computer 8 displays a button 34 for controlling the start and stop of the X-ray irradiation on the screen, and performs X-ray irradiation and stop on the defect detection target object by a touch operation of the operator's button 34 or based on its own control. Control.

  Sudden noise is likely to be mixed into the signal output from the partial discharge signal output device 14, and it is difficult to distinguish between discharge and noise only by observing one pulse. Therefore, when a pulse is observed in the signal output from the partial discharge signal output device 14 in the transformer 2 irradiated with X-rays, the X-ray irradiation is temporarily stopped while the X-ray irradiation position remains unchanged, and the disappearance of the pulse is confirmed. Then, X-rays are irradiated again to confirm that a pulse appears. As described above, since the partial discharge is excited by X-ray irradiation, the partial discharge does not occur when the X-ray irradiation is stopped. If a pulse appears, disappears, or appears in the output signal of the partial discharge signal output device 14 in response to X-ray irradiation, stop, or irradiation, it can be determined that a partial discharge has occurred.

  The personal computer 8 sequentially repeats X-ray irradiation and stop according to the operator's touch operation on the button 33, or can automatically perform the operation itself based on the irradiation mode program. At that time, the partial discharge detection signal waveform 28 and the applied voltage waveform 29 at the time of X-ray irradiation, stop, and re-irradiation are displayed side by side on the same screen of the display device 25. The operator can easily confirm the relationship between the presence / absence of X-ray irradiation and the presence / absence of a pulse waveform by comparing these waveforms. Since the pulse due to the partial discharge is linked with the X-ray irradiation and the appearance of the pulse, the partial discharge and the noise can be accurately distinguished according to the present embodiment.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The overall configuration of this embodiment is the same as that of the first embodiment. In FIG. 6 showing the screen display, the same parts as those in FIG. The personal computer 8 displays on the screen a button 33 for controlling the charging and stopping of the defect detection target object, and applying the power to the defect detection target object by touching the operator with the button 33 or based on its own control. Control the stop.

  When a pulse is observed in the signal output from the partial discharge signal output device 14 in the transformer 2 irradiated with X-rays, the application of power is stopped once, the disappearance of the pulse is confirmed, and the pulse is applied again to generate a pulse. Check that. Since the partial discharge is generated by irradiating the defect detection target with X-rays and applying power, the partial discharge does not occur when the application of power is stopped. If a pulse appears, disappears, or appears in the output signal of the partial discharge signal output device 14 in response to power application, stop, and power application, it can be determined that partial discharge has occurred.

  The personal computer 8 can repeat the power application and the stop in order according to the touch operation on the button 33 by the operator, or can automatically perform the operation based on the power supply mode program. At that time, the partial discharge detection signal waveform 28 and the applied voltage waveform 29 at the time of applying power, at the time of stopping, and at the time of applying power again are displayed side by side on the same screen of the display device 25. The operator can easily confirm the relationship between the presence / absence of power application and the presence / absence of generation of a pulse waveform by comparing these waveforms with each other. In the case of a pulse due to partial discharge, voltage application and the appearance of the pulse are linked, and according to this embodiment, partial discharge and noise can be accurately identified.

(Other embodiments)
In addition to the plurality of embodiments described above, the following configuration may be adopted.
The radiation is not limited to X-rays, and may be γ-rays, for example. In addition, the defect detection target is not limited to a transformer, and may be another electrical device.
In the power supply device 3, if the amplifier 10 can amplify to a desired voltage, the transformer 11 may not be provided.
The partial discharge detection device 4 may use CT instead of the detection impedance 13.

In the first embodiment, six periods are set as the period for measuring the partial discharge detection signal. However, the period is not necessarily limited to six periods of the AC power supply voltage, and is preferably at least two periods.
In the second embodiment, the partial discharge detection signal waveform 28 and the applied voltage waveform 29 for a plurality of periods may be displayed during X-ray irradiation, stoppage, and re-irradiation, respectively. Moreover, you may perform X-ray irradiation and a stop over 3 times or more sequentially.

In the third embodiment, the partial discharge detection signal waveform 28 and the applied voltage waveform 29 for a plurality of periods may be displayed during power application, when stopped, and when power is applied again. Moreover, you may perform a power application and a stop over multiple times 3 times or more.
The second embodiment and the third embodiment may be combined. In addition, the combination of X-ray irradiation and power application may be variously changed to display the partial discharge detection signal waveform 28 and the applied voltage waveform 29 for each.

In each embodiment, two X-ray modules 16 and 17 and moving devices 7a and 7b are provided to irradiate two X-ray beams in different directions, but three or more X-ray beams are provided in different directions. Three or more X-ray modules and a moving device may be provided to irradiate the light. In this case as well, the radiation dose is adjusted so that the region where the plurality of radiation beams intersect has a radiation dose sufficient to generate a partial discharge, and the region through which a single radiation beam passes has a radiation dose insufficient to generate a partial discharge. Control.
If it is sufficient to detect that a partial discharge has occurred in any of the line areas of the defect detection target, it is possible to provide a single X-ray beam with one X-ray module and moving device.

According to the embodiment described above, since the measured partial discharge of the solid insulator while irradiating X-ray to the defect detection object, can be generated in a shorter time to partial discharge, solid insulator internal Defects can be detected efficiently. In addition, the solid insulator internal defect detection system includes man-machine interface means, and displays the external shape of the defect detection object, the X-ray irradiation position, the partial discharge detection signal waveform and the applied voltage waveform on the same screen. The generated pulse signal can be easily distinguished from noise, and defects can be detected efficiently and easily without erroneous determination.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  In the drawings, 1 is a solid insulator internal defect detection system, 2 is a transformer (defect detection object), 2a is a resin (solid insulator), 3 is a power supply device (voltage applying means), and 4 is a partial discharge detection device ( (Partial discharge detection means), 5 is an X-ray irradiation apparatus (radiation irradiation means), 6 is an X-ray dose control apparatus (radiation dose control means), 7 is an X-ray module moving apparatus (radiation irradiation position control means), and 8 is a personal computer. (Man-machine interface means) 25 is a display device (display means).

Claims (4)

A solid insulator internal defect detection system for detecting defects inside the solid insulator by measuring a partial discharge of the solid insulator while irradiating the defect detection target with radiation,
Radiation irradiating means for irradiating the solid insulator of the defect detection object with radiation;
A radiation dose control means for controlling the radiation dose emitted by the radiation irradiating means;
Radiation irradiation position control means for controlling the position of the radiation irradiated by the radiation irradiation means in the defect detection object;
Partial discharge detecting means for detecting partial discharge generated inside the solid insulator;
Voltage applying means for applying a voltage to the solid insulator;
A display means for controlling the radiation dose control means, the radiation irradiation position control means, the partial discharge detection means and the voltage application means, and the outer shape of the defect detection object, the radiation irradiation position, the partial discharge detection signal waveform and the application; A solid-insulator internal defect detection system comprising: a man-machine interface means for displaying a voltage waveform on the same screen of the display means. The radiation irradiating means is configured to be capable of irradiating the solid insulator with a plurality of radiation beams,
The radiation irradiation position control means is configured to be able to control an irradiation position in the defect detection object for each of the plurality of radiation beams,
In the man-machine interface means, the radiation dose control means allows a region where the plurality of radiation beams intersect to have a radiation dose sufficient for generation of partial discharge, and a region through which a single radiation beam passes generates partial discharge. 2. The solid insulator internal defect detection system according to claim 1, wherein the radiation dose is controlled so that the radiation dose is insufficient.   3. The solid insulator internal defect according to claim 1, wherein the man-machine interface unit controls the radiation irradiating unit to sequentially irradiate and stop the defect detection target object a plurality of times. Detection system.   4. The solid insulation according to claim 1, wherein the man-machine interface unit controls the voltage application unit to sequentially apply power to and stop the defect detection object a plurality of times. 5. Internal defect detection system.

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