JP5739675B2 - Static induction appliance and partial discharge measurement method - Google Patents

Description

  Embodiments described herein relate generally to a static induction appliance and a partial discharge measurement method.

  Static induction machines (hereinafter referred to as equipment) such as transformers and reactors incorporate a high voltage conductor such as a winding, and the high voltage conductor is insulated from the outside by an insulator. When an insulation failure occurs between the high-voltage conductor and the insulator inside the device, a partial discharge may occur at this insulation failure portion. If the internal discharge is left unattended, the defective part of the insulation develops, causing a serious dielectric breakdown and possibly damaging the device.

  As a method for detecting whether or not a partial discharge has occurred at a defective insulation portion of the device, a partial discharge measurement method can be mentioned. This partial discharge measurement method is a method in which a detection impedance is installed at a test terminal of a device, and a current pulse that flows through the detection impedance when a high voltage is applied to a high-voltage conductor inside the device is detected by a measuring instrument. Further, a method is conceivable in which a detection CT is installed on the ground line of the device, and a current pulse flowing in the detection CT when a high voltage is applied to a high-voltage conductor inside the device is detected by a measuring instrument.

  The measuring instrument used for this partial discharge measuring method uses a frequency band of several tens of kHz to several hundreds of kHz. However, in the same frequency band, it detects external noise signals such as current pulses generated when operating power equipment installed in the vicinity, so it is determined whether the measured signal is a partial discharge inside the equipment. There was a problem that was difficult.

  The UHF method has been proposed as a method for solving this problem. The UHF method is a method in which an electromagnetic wave in the UHF band (300 MHz to 3000 MHz) emitted when partial discharge occurs is detected by a UHF sensor.

  Even when this UHF method is used, since the frequency of the UHF band is used for a mobile phone or the like, it overlaps with an external noise signal, and the SN ratio deteriorates. Therefore, in order to determine partial discharge with high sensitivity, it is necessary to insert a UHF sensor in a place where electromagnetic waves are shielded, such as inside the equipment tank. However, the equipment tank is filled with insulating oil, insulating gas, etc., and it is difficult to insert the UHF sensor inside. There is a problem of causing.

JP 2008-64587 A

  An object of an embodiment of the present invention is to provide a stationary induction device and a partial discharge measurement method capable of detecting electromagnetic waves without inserting a sensor inside the stationary induction device.

The static induction device according to the embodiment of the present invention is filled with an insulating material and formed of a metal material that shields electromagnetic waves, and has a tank having an opening, a winding stored in the tank, and transmits electromagnetic waves. An insulating plate formed of an insulating material that closes the opening, a lead portion that is formed of a metal material that covers the insulating plate and shields electromagnetic waves, and a lead portion that is formed by the lead portion and the insulating plate A sensor box that is installed in a space and is formed in a rectangular shape with a metal material that shields electromagnetic waves, has a sensor hole on one surface, and has an opening on a surface facing the one surface on which the sensor hole is provided; And a sensor that is inserted into the sensor box from the sensor hole and outputs a sensor signal based on the received electromagnetic wave.

The figure which shows the structure of the static induction appliance in 1st Embodiment. The figure which shows the structure of the extraction part of the static induction electric machine in 1st Embodiment. The figure which shows the structure at the time of removing the closing lid 61 of the extraction | drawer part of the static induction electric machine in 1st Embodiment. The flowchart which shows the partial discharge measuring method of the static induction appliance in 1st Embodiment. The figure which shows the structure of the extraction part of the static induction electric machine in 2nd Embodiment. The figure which shows the structure of the extraction part of the static induction appliance in 3rd Embodiment. The figure which shows the structure of the sensor of the static induction machine in 3rd Embodiment. The figure which shows the structure of the extraction part of the static induction electric machine in 4th Embodiment. The flowchart which shows the partial discharge measuring method of the static induction appliance in 4th Embodiment.

  A static induction appliance and a partial discharge measuring method according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
The structure of the static induction electric machine of 1st Embodiment is demonstrated using FIG. FIG. 1 shows a configuration of a static induction electric appliance connected with a measuring instrument.

  The stationary induction device 1 includes a tank 2, a winding 3, a lead-out wire 4, a CT 5, a lead-out portion 6, and a conduit tube 7, and a measuring instrument 9 is connected to the lead-out portion 6 via a cable 8. .

  The tank 2 is made of a metal material that shields electromagnetic waves, and stores the winding 3. Further, a bushing 21 is formed in the tank 2, and a connection line for connecting to another power device is provided at an end of the bushing 21. Further, the tank 2 is filled with an insulating material such as insulating oil or insulating gas.

  The winding 3 is formed of a copper wire and an insulating material, and a lead wire 4 is taken out from the copper wire.

  The lead-out wire 4 is made of the same material as the copper wire forming the winding 3 and is connected to the end of the bushing 21.

  CT5 is a current transformer and detects the current flowing through the lead-out line 4 with a predetermined CT ratio.

  The lead part 6 is formed of a metal material that shields electromagnetic waves, and takes out the electric wire connected to the CT 5 to the outside of the tank 2. Hereinafter, the space in the mouth portion 6 is referred to as a mouth portion space.

  The electric conduit 7 is formed of a metal material that shields electromagnetic waves, and is a metal tube that protects the electric wire connected to the CT 5 taken out by the lead-out portion 6. Therefore, the electric wire connected with CT5 is stored in this conduit 7 inside. The current value detected by this CT5 is used for monitoring and control.

  The cable 8 is connected to a sensor (not shown) stored in the outlet portion 6. The opposite end of the cable 8 to the sensor is connected to the measuring instrument 9.

  The measuring instrument 9 receives a sensor signal from the sensor via the cable 8.

  Next, the structure of the extraction part 6 of this embodiment is demonstrated using FIG. 2 thru | or FIG. FIG. 2 shows a cross-sectional view of the lead portion 6.

  The lead portion 6 is installed outside the tank 2 filled with the insulating material 11 and includes a closing lid 61, a bake plate 62, and a terminal 63.

  The closing lid 61 is made of a metal material that shields electromagnetic waves, and prevents the electromagnetic waves from entering the inside of the outlet portion 6 from the outside of the tank 2. The closing lid 61 is provided with a sensor hole 611, and the sensor 10 can be inserted through the sensor hole 611. The sensor 10 inserted from the sensor hole 611 is installed in the extraction portion space inside the extraction portion 6.

  The bake plate 62 is formed of an insulating material through which electromagnetic waves are transmitted. By blocking an opening provided in the tank 2, the insulating material 11 filled in the tank 2 is prevented from flowing into the outlet portion 6. ing. Moreover, the terminal 63 is installed in the bake board 62, and the tank 2 side of the terminal 63 is connected with CT5 via the electric wire.

  FIG. 3 shows a structure when the closing lid 61 of the outlet portion 6 is removed.

  The closing lid 61 is detachable from the opening portion 6, and the sensor 10 is inserted from a sensor hole 611 provided in the closing lid 61. When the closing plate 61 is attached to the opening portion 6, the opening portion 6. Stored internally.

Next, the partial discharge measuring method of the static induction appliance of this embodiment is demonstrated using FIG. FIG. 4 is a flowchart showing a partial discharge measuring method. The method for measuring partial discharge of a static induction electric machine according to this embodiment includes the following steps.

  The process of inserting the sensor 10 from the sensor hole 611 of the closing lid 61 (S1).

  A process of applying a high voltage to the winding 3 (S2).

  A step of determining whether or not partial discharge is generated in the winding 3 by the measuring instrument 9 (S3).

  Here, when a partial discharge is generated in the winding 3, an electromagnetic wave is generated from the partial discharge portion. The electromagnetic wave reflects inside the tank 2, passes through the baking plate 62, and comes into contact with the sensor 10. The sensor 10 outputs a sensor signal generated by the contacted electromagnetic wave to the measuring device 9 via the cable 8. The measuring instrument 9 that has received the sensor signal determines whether or not the intensity of the electromagnetic wave in the UHF band is greater than a preset threshold value. .

  When the partial discharge is not generated in the winding 3, the measuring instrument 9 determines whether or not the intensity of the electromagnetic wave is larger than a preset threshold value. It is determined that partial discharge has not occurred.

According to the static induction appliance of the present embodiment described above, since the sensor 10 is not installed in the tank 2 but in the outlet portion 6, moisture and foreign matter are mixed in the insulating material filled in the tank 2. There is nothing to do.

  Further, since the terminal 63 is connected to the CT 5 via a connection line, a voltage is applied. Therefore, the terminal 63 and the tank 2, and the terminal 63 and the lead-out portion 6 are isolated by a bake plate 62 formed of an insulating material. Therefore, since the bake plate 62 is not formed of a metal material that shields electromagnetic waves, the partial discharge measurement method of the present embodiment can be applied to any static induction appliance including the lead-out portion 6.

In this embodiment, the measuring device 9 determines that a partial discharge has occurred when the intensity of the electromagnetic wave having a frequency in an arbitrary UHF band is greater than a preset threshold value. The user may determine whether or not a partial discharge has occurred by displaying the waveform or frequency and intensity of the electromagnetic wave based on the received sensor signal with a display means such as an oscilloscope.

(Second Embodiment)
Next, the structure of the static induction electric machine of 2nd Embodiment is demonstrated using FIG. FIG. 5 is a diagram showing the configuration of the lead portion 6 and the conduit 7 from which the closing lid 61 of the present embodiment is removed. This embodiment is different from the first embodiment in that the sensor hole 611 is provided in the conduit 7 instead of the closing lid 61 and the sensor 10 is inserted from the sensor hole 611 to the vicinity of the bake plate 62. .

  The sensor hole 611 is provided for improving workability during installation or operation of the conduit 71, and is closed by a conduit closure lid (not shown) except during operation.

  According to the present embodiment, in addition to the effects of the first embodiment, since it is not necessary to provide a sensor hole in the lead-out portion 6, man-hour reduction in the partial discharge detection method can be realized.

(Third embodiment)
Next, the structure of the static induction electric machine of 3rd Embodiment is demonstrated using FIG. 6 and FIG. FIG. 6 is a cross-sectional view showing a configuration of the lead portion 6 of the present embodiment. This embodiment is different from the first embodiment in that the sensor 10 is stored in the sensor box 12.

  The sensor box 12 is formed in a rectangular shape with a metal material that shields electromagnetic waves.

  Next, an enlarged view of the sensor box 12 in which the sensor 10 is inserted is shown in FIG.

  The sensor box 12 includes a sensor hole 121 and a sensor box opening 122.

  The sensor hole 121 is provided on one surface of the sensor box 12 and has a size that allows the sensor 10 to be inserted.

  The sensor box opening 122 is an opening formed by removing a surface of the sensor box 12 formed in a rectangular shape and facing one surface provided with the sensor hole 121.

With the above-described configuration, when an electromagnetic wave is generated when a partial discharge is generated in the winding 3, the electromagnetic wave causes electromagnetic field resonance in the sensor box 12. Therefore, the electromagnetic wave detected by the sensor 10 has a resonance frequency fr represented by the equation (1).

Here, c0 is the speed of light, εr is the relative permittivity of the medium in the sensor box 12, m, n, and p are the TE and TM wave mode orders, W, H, and D are the width and height of the sensor box 12, respectively. Indicates depth.

However, since the sensor box 12 in the present embodiment includes the sensor box opening 122, the width W of the sensor box 12 can be approximated to infinity, and therefore, the resonance frequency of the electromagnetic wave detected by the sensor 10 of the present embodiment. fr1 is calculated by equation (2). This resonance frequency fr1 is included in the UHF band.

Therefore, according to this embodiment, in addition to the effects of the first embodiment, the resonance frequency fr1 can be measured by the sensor 12, and the measuring instrument 9 and the sensor 12 that can measure the resonance frequency fr1 can be selected.

  The resonance frequency fr1 is determined by the dimensions of the sensor box 12 and does not contribute to the shapes of the static induction electric appliance 1, the tank 2, and the lead-out portion 6, and therefore the same when performing partial discharge measurement of other static induction electric appliances. An electromagnetic wave having a resonance frequency fr1 is generated. For this reason, it is possible to determine the presence or absence of partial discharge with the same measuring device 9 and sensor 12 for partial discharge measurement of other static induction devices.

(Fourth embodiment)
Next, the structure of the static induction electric machine of 4th Embodiment is demonstrated using FIG. FIG. 8 is a cross-sectional view showing a configuration of the lead portion 6 of the present embodiment. The present embodiment is different from the first embodiment in that an empty terminal 64 is connected to the cable 8 instead of the sensor 10.

  The empty terminal 8 is formed of a metal material and is installed on the bake plate 62 like the terminal 63. The closed lid 61 side of the empty terminal 8 is connected to the measuring instrument 9 via the cable 8 and is not connected to the insulating material 11 side.

  Next, the partial discharge measuring method of the static induction appliance of this embodiment is demonstrated using FIG. FIG. 9 is a flowchart showing a partial discharge measuring method. The partial discharge measuring method of this embodiment includes the following steps.

  The process of inserting the cable 8 from the sensor hole 611 and connecting it to the terminal 64 (S1).

  A process of applying a high voltage to the winding 3 (S2).

  A step of determining whether or not partial discharge is generated in the winding 3 by the measuring instrument 9 (S3).

  Here, when a partial discharge is generated in the winding 3, an electromagnetic wave is generated from the partial discharge portion. The electromagnetic wave reflects inside the tank 2, passes through the bake plate 62, and comes into contact with the sensor 10. The sensor 10 outputs a sensor signal generated by the contacted electromagnetic wave to the measuring device 9 via the cable 8. The measuring device 9 that has received the sensor signal determines whether or not the intensity of the electromagnetic wave having an arbitrary frequency is greater than a preset threshold value. to decide.

  When the partial discharge is not generated in the winding 3, the measuring instrument 9 determines whether or not the intensity of the electromagnetic wave having an arbitrary frequency is larger than a preset threshold value, and is not large (that is, small). If it is determined, partial discharge is determined not to have occurred.

  According to the present embodiment, in addition to the effects of the first embodiment, when the stationary induction device 1 includes the empty terminal 64 in the lead-out portion 6, partial discharge measurement can be performed without using the sensor 10. .

According to the embodiment of the present invention, it is possible to provide a stationary induction device and a partial discharge measurement method that can detect electromagnetic waves without inserting a sensor inside the stationary induction device.

As mentioned above, although some embodiment of this invention was described, these embodiment was shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Static induction machine 2 ... Tank 3 ... Winding 4 ... Lead-out line 5 ... CT
6 ... Leading part 7 ... Conduit 8 ... Cable 9 ... Measuring instrument 10 ... Sensor 11 ... Insulating material 12 ... Sensor box 21 ... Bushing 61 ... Closing lid 62 ... Bake plate 63 ... Terminal 64 ... Empty terminal 121 ... Sensor hole 122 ... Sensor box opening 611 ... sensor hole

Claims (4)

A tank filled with an insulating material, formed of a metal material that shields electromagnetic waves, and having an opening;
Windings stored in the tank;
An insulating plate that is formed of an insulating material that transmits electromagnetic waves and closes the opening;
An opening formed of a metal material that covers the insulating plate and shields electromagnetic waves;
Installed in the lead part space formed by the lead part and the insulating plate, formed in a rectangular shape with a metal material that shields electromagnetic waves, provided with a sensor hole on one side, and provided with the sensor hole A sensor box having an opening on a surface facing one surface;
A sensor that is inserted into the sensor box from the sensor hole and outputs a sensor signal based on the received electromagnetic wave,
A static induction machine. Measuring means for determining the presence or absence of partial discharge of the winding based on a sensor signal output from the sensor;
The static induction machine of Claim 1 provided with. Display means for displaying a sensor signal output from the sensor;
The static induction machine of Claim 1 provided with. A tank filled with an insulating material, formed of a metal material that shields electromagnetic waves, and having an opening;
Windings stored in the tank;
An insulating plate that is formed of an insulating material that transmits electromagnetic waves and closes the opening;
An opening formed of a metal material that covers the insulating plate and shields electromagnetic waves;
In a partial discharge measuring method of a static induction machine comprising:
A sensor box that is formed in a rectangular shape with a metal material that shields electromagnetic waves, has a sensor hole on one surface, and has an opening on a surface facing the one surface on which the sensor hole is provided, A step of installing in the lead portion space formed by the insulating plate;
A step of inserting a sensor that outputs a sensor signal based on the received electromagnetic wave into the sensor box from the sensor hole;
Applying a voltage to the winding;
A process of determining the presence or absence of partial discharge based on the sensor signal output from the sensor;
A partial discharge measuring method comprising:

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