JP7443181B2 - Withstanding voltage test equipment - Google Patents

Description

Embodiments of the present invention relate to a withstand voltage test device.

Power switchgears are used in power systems for fault current interruption, system switching, equipment maintenance, etc. A power switchgear includes a pair of electrodes, and opens and closes an electric circuit by bringing these electrodes into contact with and away from each other. When a fault current is detected, a cutoff signal is input to the power switchgear, and the power switchgear uses the cutoff signal as a trigger to separate each electrode in order to cut off the current.

Type test items for power switchgears include interruption tests to verify the short-circuit current interrupting ability of the switchgear. In the interruption test, parts between the electrodes and surrounding parts are damaged by arc discharge corresponding to a current of several [A] to several tens [kA] between the electrodes. For this reason, the standard requires that after conducting a current interruption test of 100 [%] or 90 [%] of the specified short circuit breaking current, a withstand voltage test is conducted to demonstrate the soundness of the equipment. .

In the cut-off test, power is generally supplied using a short-circuit generator, which is a power source for the test. However, a short-circuit generator alone does not have enough power capacity to meet the test conditions for switches with high rated voltages. As a test method in this case, there is a test method (composite interruption test method) in which the short-circuit current is supplied from a short-circuit generator, and the transient recovery voltage and recovery voltage after the current interruption are supplied by preparing a separate power supply circuit. The separate power supply circuit that supplies the transient recovery voltage and recovery voltage used in the synthetic cut-off test method generally has a circuit configuration that combines a capacitor, reactor, and resistor, and by adjusting their values, it is possible to create an arbitrary voltage waveform. can be supplied.

On the other hand, according to the standard, the voltage waveform of a withstanding voltage test to verify the soundness of a switchgear after a short-circuit current interruption test is a lightning impulse waveform, a switching impulse waveform, or a transient recovery voltage waveform after short-circuit current interruption. This is the voltage waveform of Lightning impulse waveforms and opening/closing impulse waveforms are generally generated using equipment called impulse generators, but impulse generators are generally not installed in test areas where short-circuit current interruption tests are performed. Therefore, considering the convenience of testing, it is most convenient to use a transient recovery voltage supply circuit of a synthetic short-circuit interruption test circuit. Therefore, after the synthetic short-circuit interruption test, it is common to adjust the parameters of the transient recovery voltage supply circuit and conduct a withstand voltage test. However, when the equipment under test suffers dielectric breakdown, the short-circuit current that flows is on the order of several [kA]. For example, if the insulation of a structure that supports between the electrodes of a switch causes insulation failure, In some cases, the battery was energized and burned out, causing damage.

IEC 62271-101 High-voltage switchgear and Controlgear-Part 101: Synthetic testing IEC 62271-100 High-voltage switchgear and controlgear-Part 100: Alternating-current circuit-breakers

The problem to be solved by the present invention is a withstand voltage test device that can reduce damage to the insulator even if the insulator supporting between the electrodes of the switchgear, which is the device to be tested, has an insulation failure. The goal is to provide the following.

The withstand voltage test device of the embodiment includes a power source, a lightning arrester, a first voltage measuring device, and a second voltage measuring device. The power supply has a first terminal connected to the first terminal of the open-circuit switchgear to be tested, and a second terminal connected to the ground point. A lightning arrester has a first terminal connected to a second terminal of the switchgear, and a second terminal connected to a ground point. The first voltage measuring device has a first terminal connected to a first terminal of the power source and a first terminal of the switching device, and a second terminal connected to a ground point. The second voltage measuring device has a first terminal connected to a second terminal of the switching device and a first terminal of the lightning arrester, and a second terminal connected to a ground point.

FIG. 1 is a block diagram showing an example of the configuration of a withstand voltage test device according to a first embodiment. The figure which shows an example of the structure of a switchgear. A diagram of the inside of an insulator when dielectric breakdown occurs when a switchgear is tested using a conventional withstanding voltage test device. FIG. 2 is a diagram of the inside of an insulator when dielectric breakdown occurs when a switchgear is tested using the withstand voltage test device according to the first embodiment. FIG. 3 is a diagram showing an example of waveforms during a withstand voltage test according to the first embodiment. FIG. 2 is a block diagram showing an example of the configuration of a withstand voltage test device according to a second embodiment. FIG. 7 is a block diagram showing an example of the configuration of a withstand voltage test device according to a third embodiment.

Hereinafter, a withstand voltage test device according to an embodiment will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing an example of the configuration of a withstand voltage test apparatus according to this embodiment. As shown in FIG. 1, the withstand voltage test device 1 includes a power source 2, a switching device 3, a lightning arrester 4, a first voltage measuring device 5, a second voltage measuring device 6, and an arithmetic device 7. Note that the withstand voltage test apparatus 1 also includes a current circuit, but it is omitted in FIG. 1.

Next, the connection relationship of the withstand voltage test device 1 will be explained. The opening/closing device 3 includes a first electrode (electrode 306) and a second electrode (electrode 307) that face each other. The first terminal 31 of the switchgear 3 is connected to the first terminal 21 on the high voltage side of the power supply 2 and the first terminal of the first voltage measuring device 5, and the second terminal 32 is connected to the first terminal 21 on the high voltage side of the power supply 2 and the first terminal of the first voltage measuring device 5. It is connected to the first terminal 41 and the first terminal 61 of the second voltage measuring device 6 . The first terminal 21 on the high voltage side of the power source 2 is connected to the first terminal 31 of the switchgear 3 and the first terminal 51 of the first voltage measuring device 5, and the second terminal 22 is connected to the ground point e. It is connected. The second terminal 52 of the first voltage measuring device 5, the second terminal 62 of the second voltage measuring device 6, and the second terminal 42 of the lightning arrester 4 are connected to the ground point e. The output terminal 53 of the first voltage measuring device 5 is connected to the first terminal 71 of the arithmetic device 7 . The output terminal 63 of the second voltage measuring device 6 is connected to the second terminal 72 of the arithmetic device 7 . The first terminal 31 of the switchgear 3 is connected to the first terminal 41 of the lightning arrester 4 and the first terminal 61 of the second voltage measuring device 6, and the second terminal 32 of the switchgear 3 is connected to the first terminal 41 of the lightning arrester 4 and the first terminal 61 of the second voltage measuring device 6. , may be connected to the first terminal 21 on the high voltage side of the power source 2 and the first terminal of the first voltage measuring device 5.

The power supply 2 is a power supply circuit that supplies a test voltage to the switchgear 3. The switchgear 3 is a test target, for example, a power switchgear. The lightning arrester 4 is a device for suppressing short circuit current when dielectric breakdown occurs. The rated voltage of the lightning arrester 4 is higher than the test voltage.

The first voltage measuring device 5 is a device that measures the voltage between a contact point c between the first terminal 21 of the power supply 2 and the first terminal 31 of the switching device 3, and a ground point e. The second voltage measuring device 6 is a device that measures the voltage between a contact point d between the second terminal 32 of the switching device 3 and the first terminal 41 of the lightning arrester 4, and a ground point e.

The arithmetic device 7 subtracts the voltage waveform measured by the second voltage measuring device 6 from the voltage waveform measured by the first voltage measuring device 5 to calculate the voltage between poles of the switching device 3 .

Note that the arithmetic device 7 may be a hardware functional unit such as an LSI, or may be realized by a software functional unit. The functions of the arithmetic device 7 are realized, for example, by a processor such as a CPU (Central Processing Unit) executing a program (software) stored in a memory. Further, the functions of the arithmetic device 7 may be realized by cooperation of software and hardware.

Next, the test method will be explained. When testing the switchgear 3, a voltage is applied between the electrodes of the switchgear 3 with the switchgear 3 in an open state. If the interelectrode dielectric strength of the switchgear 3 is higher than the test voltage, the test is passed without dielectric breakdown occurring between the electrodes. If the dielectric strength between the electrodes is lower than the test voltage, dielectric breakdown occurs between the electrodes and the electrodes become electrically connected.

Here, an example of the configuration of the opening/closing device 3 will be explained. FIG. 2 is a diagram showing an example of the configuration of the opening/closing device 3. As shown in FIG. In addition, in FIG. 2, a part of the structure of the opening/closing device 3 is omitted and shown. As shown in FIG. 2, the opening/closing device 3 includes an operating mechanism 301, an exterior tank 302, an insulator 303, a conductor 304, an insulator 305, an electrode 306, an electrode 307, a conductor 308, a bushing 309, and a bushing 310.

The operating mechanism 301 is a solenoid that operates the movement of the electrode 306. The exterior tank 302 is, for example, a cylindrical metal container, and houses a conductor 304, an insulator 305, an electrode 306, an electrode 307, and a conductor 308 inside.

The electrode 306 and the electrode 307 are covered with an insulator 305 (interpolar insulation tube). Electrode 306 is connected to conductor 304. Conductor 304 is connected to a conductor inside bushing 309. Electrode 307 is connected to conductor 308. Conductor 308 is connected to a conductor inside bushing 310. Note that the configuration shown in FIG. 2 is an example, and the configuration is not limited to this.

Next, an example of the results of testing the switchgear 3 using a conventional withstand voltage tester and an example of the results of testing the switchgear 3 using the withstand voltage tester 1 of the present embodiment will be described. FIG. 3 is a diagram of the inside of the insulator 305 when dielectric breakdown occurs when the switchgear 3 is tested using a conventional withstand voltage testing device. As shown in Fig. 3, if dielectric breakdown occurs in the insulator 305 when a withstand voltage test is performed on the switchgear 3 using a conventional withstand voltage test device, there are black burn marks (g101) on the insulator 305. . If dielectric breakdown occurs during a withstand voltage test using a conventional withstand voltage test device, the creeping surface of the insulator 305 will be severely damaged by a short circuit current of several kA as shown in FIG. As a result, as shown in FIG. 3, it was impossible to identify the starting point of dielectric breakdown.

FIG. 4 is a diagram of the inside of the insulator 305 when dielectric breakdown occurs when the switchgear 3 is tested using the withstand voltage testing apparatus 1 according to the present embodiment. As shown in FIG. 4, when dielectric breakdown occurs in the insulator 305 when the dielectric strength test of the switchgear 3 is carried out using the dielectric strength test device 1 of this embodiment, the origin of the dielectric breakdown can be easily identified. It became possible to understand the discharge path in more detail (g111).

The reason why the origin and path of discharge become clear when dielectric breakdown occurs in the insulator 305 as shown in FIG. 4 will be explained. If dielectric breakdown occurs between the electrodes during the withstand voltage test, a voltage approximately equivalent to the test voltage is applied to both ends (de) of the lightning arrester 4 connected to the switchgear 3. Although it depends on the characteristics of the lightning arrester 4 to be connected, when the test voltage is applied, a leakage current of, for example, about 1 [mA] or less flows toward the ground point. When the cause of dielectric breakdown is insufficient dielectric strength of the insulator 305 supporting between the electrodes, the leakage current is passed along the creeping surface of the insulator. As a result, even when dielectric breakdown occurs in the insulator 305 as shown in FIG. 4, the insulator is not severely damaged, and the discharge marks at the time of dielectric breakdown become detailed. Here, the lightning arrester 4 has a non-linear resistance characteristic, and the voltage value when an extremely small current flows is equivalent to the test voltage of the power source 2 based on the characteristic.

In this manner, in this embodiment, it is possible to suppress the short-circuit current to a small current value on the order of leakage current, making it possible to observe discharge marks at the time of dielectric breakdown in detail. As a result, according to the present embodiment, the discharge traces become more detailed, making it possible to identify the starting point of dielectric breakdown.

Next, examples of waveforms measured by the first voltage measuring device 5 and the second voltage measuring device 6 during the withstand voltage test will be described. FIG. 5 is a diagram showing an example of waveforms during a withstand voltage test according to the present embodiment. In FIG. 5, the horizontal axis is time [ms], and the vertical axis is voltage [kV]. Note that the example in FIG. 5 is a waveform when dielectric breakdown occurs between the poles of the switchgear 3 due to a withstand voltage test. The waveform g101 is the voltage waveform measured by the first voltage measuring device 5, and is also the waveform of the test voltage. The waveform g102 is the voltage waveform measured by the second voltage measuring device 6, and is also the voltage waveform between the terminals of the lightning arrester 4. The waveform g103 is a voltage waveform between electrodes of the switching device 3 obtained by subtracting the waveform g102 from the waveform g101. Note that the waveform shown in FIG. 5 is an example, and the waveform varies depending on conditions such as the switching device 3 and the applied voltage.

In this embodiment, even when the test object undergoes dielectric breakdown, no significant change is observed in the waveform g101 measured by the first voltage measuring device 5. Since it is not possible to determine whether the test was completed normally or whether dielectric breakdown occurred, in this embodiment, the waveform g102 is measured by the second voltage measuring device 6.

When the test object has dielectric breakdown, the first voltage measuring device 5 and the second voltage measuring device 6 are temporarily in a conductive state, so it is thought that similar voltages will be measured. Therefore, the voltage waveform of the second voltage measuring device 6 is monitored, and if a voltage corresponding to the test voltage is measured, it is determined that insulation breakdown has occurred, and the voltage corresponding to the test voltage is measured. If not, it can be determined that the test has been successfully completed.

Furthermore, the calculation device 7 can measure the voltage waveform between the poles of the switching device 3 by subtracting the waveform g102 from the waveform g101. Therefore, according to this embodiment, even when dielectric breakdown occurs, it is possible to know at what voltage value the dielectric breakdown occurred. Note that the arithmetic device 7 may detect the maximum value or local maximum value of the voltage value by a technique such as peak detection.

(Second embodiment)
In the first embodiment, an example was explained in which a voltage is applied between the electrodes of the switchgear 3 when the switchgear 3 is in an open state, but in this embodiment, a voltage is applied between the electrodes of the switchgear 3 when the switchgear 3 is in a closed state. An example of a test device that applies a voltage to

FIG. 6 is a block diagram showing an example of the configuration of the withstand voltage testing apparatus according to the present embodiment. As shown in FIG. 6, the withstand voltage test device 1A includes a power source 2, a switchgear 3, a lightning arrester 4, a first voltage measuring device 5, a second voltage measuring device 6, and an arithmetic device 7. Note that the same reference numerals are used for devices having the same functions as the withstand voltage test device 1, and the description thereof will be omitted. Note that the withstand voltage test apparatus 1A also includes a current circuit, but this is omitted in FIG.

Next, the connection relationship of the withstand voltage test apparatus 1A will be explained. The first terminal of the switching device 3 is connected to the first terminal 21 on the high voltage side of the power source 2 and the first terminal 51 of the first voltage measuring device 5, and the exterior tank 302 is connected to the first terminal 21 on the high voltage side of the power source 2 and the first terminal 51 of the first voltage measuring device 5. 6 and the first terminal 41 of the lightning arrester 4, and the second terminal 32 is not connected to any other device and is in an open state. The first terminal 21 on the high voltage side of the power source 2 is connected to the first terminal 31 of the switchgear 3 and the first terminal 51 of the first voltage measuring device 5, and the second terminal 22 is connected to the ground point e. It is connected to the. The second terminal 52 of the first voltage measuring device 5, the second terminal 62 of the second voltage measuring device 6, and the second terminal 42 of the lightning arrester 4 are connected to the ground point e. The output terminal 53 of the first voltage measuring device 5 is connected to the first terminal 71 of the arithmetic device 7 . The output terminal 63 of the second voltage measuring device 6 is connected to the second terminal 72 of the arithmetic device 7 . Note that the first terminal 31 of the switching device 3 is not connected to any other device and is in an open state, and the second terminal 32 of the switching device 3 is connected to the first terminal 21 on the high voltage side of the power source 2. It may be connected to the first terminal 51 of the first voltage measuring device 5 .

The first voltage measuring device 5 is a device that measures the voltage between a contact point f between the first terminal 21 of the power supply 2 and the first terminal 31 of the switching device 3, and a ground point e. The second voltage measurement device 6 is a device that measures the voltage between a contact point k between the insulator 305 of the switchgear 3 and the first terminal 41 of the lightning arrester 4, and a ground point e.

The calculation device 7 subtracts the voltage waveform measured by the second voltage measurement device 6 from the voltage waveform measured by the first voltage measurement device 5 to calculate the ground voltage of the switchgear 3 .

Next, the test method will be explained. When testing the switchgear 3, a voltage is applied between the electrodes of the switchgear 3 with the switchgear 3 in a closed circuit state. If the dielectric strength to the ground of the switchgear 3 is higher than the test voltage, the test is passed without dielectric breakdown occurring between the switchgear 3 and the ground. If the dielectric strength between the ground and the ground is lower than the test voltage, dielectric breakdown occurs between the ground and the ground, and the ground is electrically connected. Here, the lightning arrester 4 has a non-linear resistance characteristic, and the voltage value when an extremely small current flows is equivalent to the test voltage of the power source 2 based on the characteristic.

Next, an example of the results of testing the switchgear 3 using a conventional withstand voltage tester and an example of the results of testing the switchgear 3 using the withstand voltage tester 1A of the present embodiment will be described. Also in the second embodiment, when the cause of dielectric breakdown is insufficient dielectric strength of the insulator 303 or the insulating spacer 311 supporting the ground, the leakage current is passed along the creeping surface of the insulator. As a result, even when dielectric breakdown occurs in the insulator 303 as shown in FIG. 4, the insulator is not severely damaged, and the discharge marks at the time of dielectric breakdown become detailed.

In this manner, in this embodiment, it is possible to suppress the short-circuit current to a small current value on the order of leakage current, making it possible to observe discharge marks at the time of dielectric breakdown in detail. As a result, according to this embodiment, the starting point of dielectric breakdown can be identified by observing the discharge trace in detail.

Next, examples of waveforms measured by the first voltage measuring device 5 and the second voltage measuring device 6 during the withstand voltage test will be described. Each measured voltage waveform is similar to that shown in FIG. In addition, in this embodiment, the waveform g103 is the switchgear 3 ground voltage waveform.

In this embodiment as well, if the test object has dielectric breakdown, the voltage waveform of the second voltage measuring device 6 is monitored, and if a voltage corresponding to the test voltage is measured, it is determined that dielectric breakdown has occurred. If a voltage corresponding to the test voltage is not measured, it can be determined that the test has been successfully completed.

Furthermore, the arithmetic unit 7 can measure the voltage waveform of the voltage to the ground of the switchgear 3 by subtracting the waveform g102 from the waveform g101. Therefore, according to this embodiment, even when dielectric breakdown occurs, it is possible to know at what voltage value the dielectric breakdown occurred.

According to at least one embodiment described above, by having the lightning arrester 4 connected to the switchgear 3, damage to the insulator 305 or 303 and the insulating spacer 311 included in the switchgear 3 can be reduced. Furthermore, according to at least one embodiment described above, damage to the insulator 305 or 303 and the insulating spacer 311 of the switchgear 3 can be reduced, so that the discharge marks become more detailed, thereby preventing dielectric breakdown. The starting point can be specified. Furthermore, according to at least one embodiment described above, by having the first voltage measuring device 5 that measures the test voltage and the second voltage measuring device 6 that measures the voltage of the lightning arrester 4, switching The voltage waveform between the poles of the device 3 or the voltage waveform of the voltage to the ground of the switchgear 3 can be measured. Thus, according to at least one embodiment described above, even when dielectric breakdown occurs, it is possible to know at what voltage value the dielectric breakdown occurred.

(Third embodiment)
Next, a third embodiment will be described. The third embodiment is a modification of the second embodiment.

FIG. 7 is a block diagram showing an example of the configuration of the withstand voltage test apparatus 1B according to the present embodiment. As shown in FIG. 7, the withstand voltage test device 1B includes a power supply 2, a switchgear 3, a first lightning arrester 4, a first voltage measurement device 5, a second voltage measurement device 6, an arithmetic device 7, and a second lightning protection device 4. A lightning arrester 8 and a third voltage measuring device 9 are provided. Note that the same reference numerals are used for devices having the same functions as the withstand voltage test device 1A, and the description thereof will be omitted. Note that the withstand voltage test apparatus 1B also includes a current circuit, but it is omitted in FIG. 7.

The differences between the withstand voltage test device 1B and the withstand voltage test device 1A are as follows. The second terminal 32 of the switching device 3 is connected to the first terminal 81 of the second lightning arrester 8 and the first terminal 91 of the third voltage measuring device 9. The second terminal 82 of the second lightning arrester 8 and the second terminal 92 of the third voltage measuring device 9 are connected to the ground point e. The output terminal 93 of the third voltage measuring device 9 is connected to the third terminal 73 of the arithmetic device 7B. Note that the first terminal 31 of the switchgear 3 is connected to the first terminal 81 of the second lightning arrester 8 and the first terminal 91 of the third voltage measuring device 9, and The terminal 32 may be connected to the first terminal 21 on the high voltage side of the power source 2 and the first terminal 51 of the first voltage measuring device 5 .

The third voltage measuring device 9 is a device that measures the voltage between the contact point m between the second terminal 32 of the switchgear 3 and the first terminal 81 of the second lightning arrester 8, and the ground point e. be.

The calculation device 7B subtracts the voltage waveform measured by the second voltage measurement device 6 from the voltage waveform measured by the first voltage measurement device 5 to calculate the ground voltage of the switchgear 3. Further, the voltage waveform measured by the third voltage measuring device 9 is subtracted from the voltage waveform measured by the first voltage measuring device 5 to calculate the voltage between the electrodes of the switching device 3.

Here, the first lightning arrester 4 and the second lightning arrester 8 have non-linear resistance characteristics, and from the characteristics, the voltage value when an extremely small current flows is equivalent to the test voltage of the power source 2.

In the third embodiment, during a withstand voltage test, a voltage is applied to the switchgear 3 with the switchgear 3 in an open state. By connecting the second lightning arrester 8 and the third voltage measuring device 9, it is possible to simultaneously verify between the electrodes of the switchgear 3 and between the first terminal 31 of the switchgear 3 and the ground.

Note that in each of the embodiments described above, by adjusting the impedance of the second voltage measuring device 6, it can also serve as a lightning arrester. Therefore, in each of the embodiments described above, by adjusting the impedance of the second voltage measurement device 6, even if the lightning arrester 4 is removed from the configurations of FIGS. 1, 6, and 7, each of the embodiments described above An equivalent test can be performed.

According to at least one embodiment described above, the first terminal (21) is connected to the first terminal (31 or 32) of the open-circuit switchgear (3) to be tested, and the second terminal ( 22) is connected to the ground point (e), a first terminal (41) is connected to the second terminal (32 or 31) of the switchgear, and the second terminal (42) is connected to the second terminal (32 or 31) of the switchgear; a lightning arrester (4) connected to a ground point, a first terminal (51) connected to a first terminal of the power source and a first terminal of the switchgear, and a second terminal (52) connected to a first terminal of the power source and a first terminal of the switchgear; a first voltage measuring device (5) connected to a ground point; a first terminal (61) connected to a second terminal of the switchgear and a first terminal of the lightning arrester; (62) is connected to a ground point, and a second voltage measuring device (6). This makes it possible to reduce damage to the insulator even if the insulator that supports between the electrodes of the switchgear, which is the device to be tested, suffers from poor insulation.

Although the mode for implementing the present invention has been described above using embodiments, the present invention is not limited to these embodiments in any way, and various modifications and substitutions can be made without departing from the gist of the present invention. can be added.

DESCRIPTION OF SYMBOLS 1, 1A... withstanding voltage test device, 2... power supply, 3... switchgear, 4... lightning arrester (first lightning arrester), 5... first voltage measuring device, 6... second voltage measuring device, 7... Arithmetic device, 8... Second lightning arrester, 9... Third voltage measuring device, 305... Insulator, 21... First terminal of power source, 22... Second terminal of power source, 31... First terminal of switchgear Terminal 32... Second terminal of the switchgear, 41... First terminal of the lightning arrester (first lightning arrester), 42... Second terminal of the lightning arrester (first lightning arrester), 51... Second terminal of the lightning arrester (first lightning arrester) 1 first terminal of the first voltage measuring device, 52... second terminal of the first voltage measuring device, 53... output terminal of the first voltage measuring device, 61... first terminal of the second voltage measuring device , 62... Second terminal of the second voltage measuring device, 63... Output terminal of the second voltage measuring device, 71... First terminal of the arithmetic device, 72... Second terminal of the arithmetic device, 81... 2. The first terminal of the second lightning arrester, 82... The second terminal of the second lightning arrester, 91... The first terminal of the third voltage measuring device, 92... The second terminal of the third voltage measuring device. , 93...Output terminal of the third voltage measuring device

Claims (7)

a power supply having a first terminal connected to a first terminal of an open circuit switchgear to be tested and a second terminal connected to a ground point;
a lightning arrester whose first terminal is connected to a second terminal of the switchgear, and whose second terminal is connected to a ground point;
a first voltage measuring device having a first terminal connected to a first terminal of the power source and a first terminal of the switchgear, and a second terminal connected to a ground point;
a second voltage measuring device whose first terminal is connected to a second terminal of the switchgear and the first terminal of the lightning arrester, and whose second terminal is connected to a ground point;
Withstanding voltage test equipment. Further equipped with a computing device,
The arithmetic device calculates the voltage waveform at both ends of the switching device by subtracting the voltage waveform measured by the second voltage measuring device from the voltage waveform measured by the first voltage measuring device. 1. The withstand voltage test device according to 1. The lightning arrester has a non-linear resistance characteristic, and the voltage value at both ends of the lightning arrester when an extremely small current is passed is the same as the test voltage of the power source.
The withstand voltage test device according to claim 1 or 2. a power supply having a first terminal connected to a first terminal of a closed circuit switchgear to be tested and a second terminal connected to a ground point;
A lightning arrester in which a first terminal is connected to an insulating part of the switchgear and a second terminal is connected to a grounding point;
a first voltage measuring device having a first terminal connected to a first terminal of the power source and a first terminal of the switchgear, and a second terminal connected to a ground point;
a second voltage measuring device, a first terminal of which is connected to the insulating part of the switchgear and a first terminal of the lightning arrester, and a second terminal of which is connected to a ground point;
Withstanding voltage test equipment. Further equipped with a computing device,
The arithmetic device calculates a grounding voltage waveform for the switchgear by subtracting the voltage waveform measured by the second voltage measuring device from the voltage waveform measured by the first voltage measuring device. 4. The withstand voltage test device according to 4. The lightning arrester has a non-linear resistance characteristic, and the voltage value at both ends of the lightning arrester when an extremely small current is passed is the same as the test voltage of the power source.
The withstand voltage test device according to claim 4 or 5. a power supply having a first terminal connected to a first terminal of an open circuit switchgear to be tested and a second terminal connected to a ground point;
a first lightning arrester device having a first terminal connected to an exterior tank of the switchgear and a second terminal connected to a grounding point;
a first voltage measuring device having a first terminal connected to a first terminal of the power source and a first terminal of the switchgear, and a second terminal connected to a ground point;
a second voltage measuring device whose first terminal is connected to the exterior tank of the switchgear and the first terminal of the first lightning arrester, and whose second terminal is connected to a ground point;
a second lightning arrester whose first terminal is connected to a second terminal of the switchgear and whose second terminal is connected to a ground point;
a third voltage measuring device whose first terminal is connected to the second terminal of the switchgear and the first terminal of the second lightning arrester, and whose second terminal is connected to a ground point;
Withstanding voltage test equipment.

Images