JP6153844B2 - Arrestor failure determination system and failure determination program - Google Patents

Description

  The present invention relates to a lightning arrester (including both with and without grounding) used in power distribution equipment, in particular, a lightning arrester (such as a zinc oxide element) having a function of interrupting the current flow inside and a lightning arrester with a gap connected in series ( (Hereinafter referred to as a lightning arrester with a series gap).

The failure mode of a lightning arrester having a series gap includes a case where both the series gap and the lightning arrester fail (both failures), a case where only the series gap fails (gap failure), and a case where only the lightning arrester fails (element) There are three modes of failure.
A failed lightning arrester does not have the performance at the time of introduction, and thus the reliability of the power equipment is lowered. Therefore, in the lightning arrester used for power distribution equipment, establishment of an effective failure determination method is required according to the failure mode.

  As a method for determining a failure of a lightning arrester having a series gap, there are an insulation resistance measurement, a discharge start voltage measurement, a voltage measurement between terminals when an impulse voltage is applied, a leakage current measurement (for example, see Patent Document 1 below), and the like.

JP-A-5-159909

  The failure determination by the insulation resistance measurement and the discharge start voltage measurement can be made based on the decrease in the insulation resistance and the discharge start voltage in the case of both the failures or the gap failure. Therefore, in the case of the element failure, since the insulation resistance and the discharge start voltage are not lowered due to the good insulation performance of the series gap, there is a problem that the failure determination by the insulation resistance measurement and the discharge start voltage measurement cannot be performed.

  Failure determination by measuring voltage between terminals when impulse voltage is applied can be determined even in the case of the element failure, but it is generally difficult to apply to field work because the device is large. There is.

Further, in order to determine the state of the lightning arrester in the lightning arrester disclosed in Patent Document 1, the power arrester is installed between the terminals of the lightning arrester, so that the lightning arrester must be disassembled.
Therefore, even if the result of the determination is a normal product, the lightning arrester cannot be used again, and the lightning arrester is actually replaced. If such a work is carried out on all the lightning arresters, a large amount of cost and labor are required, and the practicality of maintenance / maintenance becomes a problem.

  The present invention has been made in view of the above circumstances, and in a lightning arrester in which a gap is connected in series with a lightning arrester having a continuity interruption function, failure determination such as element failure can be performed without disabling a normal product. The purpose of the present invention is to provide a lightning arrester failure determination system and failure determination program that can be performed accurately.

  The configuration of the lightning arrester failure determination system according to the present invention made to solve the above-mentioned problem is that a direct current voltage higher than the voltage at which the sample lightning arrester connected to both ends of the sample lightning arrester is connected to both ends and starts discharging is obtained. DC voltage generator to be applied, discharge suppression means for reducing the applied voltage of the DC voltage generator in response to the start of discharge of the series gap, and a sample lightning arrester of a specified time sufficient from the start of discharge of the series gap to discharge convergence A current measuring device that detects the discharge current and holds the detection data, and stores the reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired, and the reference data and the detection data Comparison means for comparing the vibration amount from the first wave to the final wave included or from the first wave to the designated wave generated before the final wave; As a result, when there is a difference greater than an allowable value between the amount of vibration indicated by the detection data and the amount of vibration indicated by the reference data, the reference data or the detection data includes a determination unit that determines that the sample arrester is faulty. When the last stagnation period is detected, there is provided a final wave specifying means that recognizes a wave (mountain or valley) that exists immediately before the stagnation period and has the opposite polarity to the first wave as a final wave.

  Another configuration of the lightning arrester failure determination system according to the present invention, which has been made to solve the above problems, is connected to both ends of a sample lightning arrester having a series gap, and the direct current of the sample lightning arrester is higher than the voltage at which discharge starts. A DC voltage generator for applying a voltage, a discharge suppression means for stopping the application of the DC voltage by the DC voltage generator upon receiving a discharge start of the series gap, and from a discharge start of the series gap to a discharge convergence A current measuring device that detects the discharge current of the sample arrester for a specified time and retains the detected data, and stores the reference data of the normal current arrester discharge current detected under the same conditions as when the detection data was acquired. Comparison hand comparing the vibration amount from the first wave to the final wave included in the data and the detection data or from the first wave to the designated wave generated before the final wave And a determination means for determining that the sample arrester is faulty when there is a difference greater than an allowable value between the vibration amount indicated by the detection data and the vibration amount indicated by the reference data as a result of the comparison, When the last dead period of the data or the detection data is detected, a final wave specifying unit is provided which recognizes a wave existing immediately before the dead period as the final wave.

  Here, the stagnation period refers to a time period in which data having the same polarity as the first wave of the discharge current and exceeding the threshold of the insensitive level continues for a specified time or more, and the threshold of the insensitive level is small. It is a predetermined value as a boundary for distinguishing between a value sufficient to detect and evaluate as effective data for failure determination exceeding the noise level and a value to be treated as invalid data (dead level), and the dead period is It refers to a time period in which data (discharge current) that does not satisfy the threshold continues for a specified time or longer.

  When the voltage at which the series gap starts to discharge is less than a specified value, or as a result of the comparison, the amount of vibration of the first wave included in the detection data, or from the second wave to the final wave, or from the second wave to the previous final wave The vibration amount from the second wave to the final wave or the vibration amount from the second wave to the designated wave generated before the final wave is included in the reference data. It is also possible to employ a configuration including a determination unit that determines that the sample lightning arrester is in failure when there is a difference greater than an allowable value between them.

  The structure of the lightning arrester failure determination program according to the present invention made to solve the above problems is to apply a DC voltage equal to or higher than the voltage at which the sample lightning arrester series gap starts discharging to both ends of the sample lightning arrester having the series gap. In the lightning arrester failure determination performed in this manner, the computer detects the discharge current of the sample lightning arrester for a specified time sufficient from the start of discharge of the series gap to the discharge convergence, and holds the detection data. The reference data of the discharge current of a normal lightning arrester detected under the same conditions as when it was acquired, and the reference data and the detection data included from the first wave to the final wave or from the first wave to the final wave Comparing means for comparing the vibration amount up to the specified wave, and the comparison result, the vibration amount indicated by the detection data and the vibration amount indicated by the reference data are allowed. When there is a difference greater than or equal to the value, there is a determination means for determining that the sample arrester is faulty, and when the applied voltage across the sample arrester is lowered upon receiving the discharge start of the series gap, the reference data or the detection When the last stagnation period of data is detected, it is made to function as a failure determination system for a lightning arrester having a last wave identifying means that exists immediately before the stagnation period and recognizes a wave having the opposite polarity to the first wave as the last wave. Features.

  You may comprise as a failure determination program of a lightning arrester provided with the program which makes the said computer function as the discharge suppression means which receives the discharge start of the said series gap and reduces the voltage applied to the both ends of the said sample lightning arrester.

  Another configuration of the lightning arrester failure determination program according to the present invention made to solve the above-described problem is that a DC voltage equal to or higher than a voltage at which the sample arrester series gap starts discharging at both ends of the sample arrester having the series gap is provided. In the lightning arrester failure determination performed by applying, the computer detects the discharge current of the sample lightning arrester for a specified time sufficient from the start of discharge of the series gap to the discharge convergence, and holds the detection data, and the detection The reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the data was acquired, and from the first wave to the last wave included in the reference data and the detected data, or from the first wave to the last wave Comparing means for comparing the vibration amount up to the designated wave generated, and between the vibration amount indicated by the detection data and the vibration amount indicated by the reference data as a result of the comparison When there is a difference greater than an allowable value, a determination unit that determines that the sample arrester is failed, and the reference voltage is applied when the application of the DC voltage to both ends of the sample arrester is stopped in response to the start of discharge of the series gap. When the last dead period of the data or the detected data is detected, it is made to function as a lightning arrester failure determination system provided with final wave specifying means for recognizing a wave immediately before the dead period as a final wave.

  You may comprise as a failure determination program of a lightning arrester provided with the program which makes the said computer function as the discharge suppression means which stops the application of the said DC voltage to the both ends of the said sample lightning arrester after the discharge start of the said series gap.

In the computer, when the voltage at which the series gap starts to discharge is less than a specified value, or as a result of the comparison, the first wave to the last wave included in the detection data or the first wave to the last wave occurred before the last wave When there is a difference greater than the allowable value between the vibration amount up to the specified wave and the vibration amount from the first wave to the final wave included in the reference data or from the first wave to the specified wave generated before the final wave The lightning arrester failure determination program may include a program that causes the sample arrester to function as determination means for determining failure.
As for the determination based on the vibration amount, the vibration amount of the first wave included in the detection data as a result of the comparison or the vibration amount from the second wave to the final wave or from the second wave to the designated wave generated before the final wave. And the amount of vibration of the first wave included in the reference data or the amount of vibration from the second wave to the final wave or from the second wave to the designated wave generated before the final wave In some cases, it may be configured as a lightning arrester failure determination program including a program that causes the sample lightning arrester to function as determination means for determining failure.

  As an example of the final waveform specifying means and the comparison means in case the wave number of the detection data is smaller than the wave number of the reference data, the sample arrester receives the start of discharge of the series gap in the lightning arrester failure determination system. In the case where the voltage applied to both ends of the detection signal is lowered, when the last stagnation period of the detection data is detected, the last wave identification that exists immediately before the stagnation period and recognizes the wave having the opposite polarity to the first wave as the last wave Or when the application of the DC voltage to both ends of the sample arrester is stopped in response to the start of the discharge of the series gap, the last dead period of the detection data is detected immediately before the dead period. A final wave identifying means for recognizing the wave as the final wave, and vibration from the first wave to the designated wave of the reference data and the detection data, with the final wave as the designated wave of the detection data Can be configured to include a comparing means for comparing, also to a computer, it is also possible to configure the failure determination program to function as the final wave identification means and comparison means.

Here, the vibration refers to a continuous wave of the discharge current of the sample arrester, and the first wave refers to the point at which the threshold of the dead level is first exceeded after the DC voltage is applied and the maximum after the threshold is exceeded. The peak or valley generated between the previous zero-cross points refers to the second wave and the subsequent waves, which are adjacent from the end point of the first wave to the end of vibration such as the stagnation period or the dead period. A peak or valley that occurs between zero-cross points.
The amount of vibration refers to the area (absolute value) of the region sandwiched between the time axis and the peak or valley, or the wave height (absolute value), that is, the charge or the peak value.

  According to the lightning arrester failure determination system and program according to the present invention, it is possible to perform non-destructive failure determination of a lightning arrester having a series gap, which is insufficient with the conventional method, and to provide a series gap used in power equipment. The technical improvement and efficiency of the lightning arrester maintenance and maintenance will be achieved.

  In particular, the series gap starts to discharge by taking a method of judging the failure of the arrester by comparing the charge or peak value of the discharge current waveform that shows the damped oscillation aspect of the sample arrester with a series gap when DC voltage is applied. Since a DC voltage generator for applying a DC voltage sufficient for this can be small, a large-scale device is not necessary, and connection to a sample lightning arrester can be performed locally.

  In addition, by obtaining the discharge current of a normal product under the same conditions as reference data in advance and comparing the measured discharge current of the sample lightning arrester with the measured failure detection method, Thus, the lightning arrester leading to the element failure or the like can be detected at an early stage.

  On the other hand, when adopting such a method, it is important to accurately detect the continuation range of the damped vibration waveform and the range of information effective for judgment. If this cannot be accurately grasped, other than the damped vibration waveform is unnecessary. Incorrect judgment ("portion not recognized as a waveform" in FIG. 6) or an abnormal waveform caused by a failure causes a determination error, and the object of the present invention cannot be achieved.

Therefore, in the processing of the comparison unit and the determination unit, the continuation range of the damped vibration waveform and the range of information effective for the determination can be obtained by providing the final wave specifying unit or a program that causes a computer to function as the final wave specifying unit. It can be detected accurately, and stable accuracy can be provided by determining the failure of the lightning arrester.
As a result, the desired quality can be reliably maintained in each lightning arrester in terms of characteristics, so that the reliability of the power equipment can be maintained, and the technology for maintenance / maintenance of the lightning arrester equipped with the series gap used in the power equipment. Improvement and efficiency improvement can be achieved.

  In addition, paying attention to the difference in the shape of the first wave and the second and subsequent waves of the discharge current, if there is a difference greater than the allowable value divided into the amount of vibration of the first wave and the amount of vibration after the second wave, By adopting the determination step (means) for determining that the sample lightning arrester is out of order, it is possible to obtain a more accurate determination result than the conventional method, although it is a relatively simple comparison method.

It is a flowchart explaining an example of a series of failure determination processes in the failure determination system of a lightning arrester according to the present invention. It is a flowchart explaining the form of the 1st determination in the failure determination process of the failure determination method of the lightning arrester by this invention, and the 2nd determination form. It is a flowchart explaining the form of the 3rd determination in the failure determination process of the failure determination method of the lightning arrester by this invention. It is a block diagram which shows an example of the failure determination system of the lightning arrester by this invention. 1 is a block diagram and an equivalent circuit diagram illustrating an example of a lightning arrester failure determination system according to the present invention. It is a timing chart which shows the example of the discharge current waveform explaining the waveform start determination process and the last wave specific process in the failure determination system of the lightning arrester by this invention. It is an example of the timing chart which compares the discharge current waveform of the normal goods and failure goods compared with the failure determination system of the lightning arrester by this invention. It is a table | surface which shows a part of track record of the failure determination system of the lightning arrester by this invention. It is a timing chart explaining the example of the damped vibration characteristic according to the resonance auxiliary | assistance means of the discharge current waveform of the lightning arrester (normal product) in which the failure determination system of the lightning arrester by this invention was used.

DESCRIPTION OF EMBODIMENTS Embodiments of a lightning arrester failure determination system and failure determination program according to the present invention will be described below with reference to the drawings.
FIG. 4 is a schematic diagram illustrating an example of a lightning arrester having a series gap, and a configuration diagram of a failure determination system.
The sample lightning arrester 1 is a lightning arrester in which a lightning arrester 2 and a series gap 3 are connected in series.

The present invention makes it possible to determine the failure of a lightning arrester including the element failure by utilizing the time-discharge current characteristic unique to the lightning arrester.
Specifically, the time-discharge current characteristic unique to the lightning arrester is a transient phenomenon of a discharge current accompanying an instantaneous voltage when a voltage that discharges the series gap 3 is applied, and is a direct current whose application time is limited. This includes transient phenomena when a pulse voltage is applied, or when a so-called DC voltage is applied that continues to be applied after application.

<Principle>
In general, such a lightning arrester includes inherent resistance R, inductance L, or capacitance C components. When a DC voltage (including a pulsed one) is applied, it is considered that resonance of frequency f ₁ (see the following formula 1) based on the inductance L and capacitance C occurs, and the discharge current characteristic unique to the above-mentioned lightning arrester. In the method of comparing the sample lightning arrester 1 with a normal lightning arrester, it is considered that this resonance contributes to accurate failure determination by providing a damping vibration characteristic such as an inherent amplitude and period advantageous for failure determination. Has reached.

  Among various lightning arresters supplied today, there are lightning arresters having inherent inductances L and capacitances C that can provide inherent amplitude and damped vibration characteristics sufficient for failure determination, but some of them have inherent inductances L and capacitances C. There are not a few small lightning arresters, and since resonance is suppressed, inherent amplitude and damped vibration characteristics advantageous for failure determination cannot be obtained, and accurate failure determination may not be possible.

  In this way, with respect to the sample arrester 1 having a small intrinsic inductance L and capacitance C, by connecting an inductor in series as the resonance auxiliary means 4 to one terminal of the sample arrester 1, the sample arrester 1 and the resonance auxiliary means 4 are connected. And a DC voltage generator 5 is connected to both ends of the series circuit (see FIG. 5).

Next, a series circuit in which the sample arrester 1 or the resonance auxiliary means 4 as described above is inserted in series through the application step of applying a DC voltage equal to or higher than the voltage at which the series gap 3 starts discharging in the DC voltage generator 5. By applying a DC voltage to the resonance of the frequency f ₁ due to the inherent inductance L and capacitance C of the sample arrester 1, or the inductance Lo of the resonance auxiliary means 4 and the inherent inductance L of the sample arrester 1 and The resonance of the frequency f ₂ (refer to the following formula 2) that is advantageous for the failure determination combined with the capacitance C is induced.

On the other hand, when the lightning arrester fails, the value of the resistance R or capacitance C of the internal lightning arrester 2 changes, and the amplitude, frequency, or vibration period of the discharge current changes (see Equations 1 and 2 above).
Failure detection is possible by detecting and evaluating such an event.

<Lightning arrester failure judgment method>
A failure arrester failure determination method based on the above theory includes a discharge step in which a DC voltage higher than a voltage at which the series gap 3 of the sample arrester 1 starts discharging is applied to both ends of the sample arrester 1; In response to the start of discharge, the applied voltage of the DC voltage generator 5 is reduced below the voltage at which the series gap 3 stops discharging, or the discharge suppression step in which the application of the DC voltage is stopped, and the discharge of the series gap 3 A measurement step for detecting the discharge current of the sample lightning arrester 1 for a specified time from the start to the discharge convergence and holding the detection data, and a discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired Specified from the first wave to the last wave included in the reference data and the detection data, or from the first wave to the last wave The comparison step of comparing the vibration amount up to and the result of the comparison, if the difference between the vibration amount indicated by the detection data and the vibration amount indicated by the reference data is more than an allowable value, the sample arrester 1 is broken. It passes through the determination step which determines.
Then, in the comparison step, a final wave specifying step for recognizing a wave satisfying the prescribed requirement as the final wave is performed.

<Lightning arrester failure judgment system>
The lightning arrester failure determination system used for carrying out the lightning arrester failure determination method includes a DC voltage generator 5, a discharge suppression means, a current measuring device 6, a comparison means, and a determination means.
The DC voltage generator 5 is connected to both ends of the sample lightning arrester 1 having the series gap 3, and has the ability to apply a DC voltage equal to or higher than the voltage at which the series gap 3 of the sample lightning arrester 1 starts discharging. It has a built-in suppression means.

  In this example, the DC voltage generator 5 is connected via an inductance (resonance assisting means 4) connected in series to the sample arrester 1 having the series gap 3. When the series gap 3 starts discharging, A large current flows in a circuit including the lightning arrester 2 having a function of interrupting a continuous current connected in series with the series gap 3 in the sample lightning arrester 1. Therefore, in order to protect the circuit from a large current, the discharge suppression means reduces the applied voltage of the DC voltage generator 5 to a voltage at which the series gap 3 stops discharging after receiving the discharge start of the series gap 3. The application of the DC voltage by the pulling down or the DC voltage generator 5 is stopped.

  The current measuring device 6, the comparing means, and the determining means can function by installing a lightning arrester failure determination program (hereinafter referred to as a failure determination program) in a computer. A measurement module, a comparison module, and a determination module are provided.

<Current measuring instrument>
The current measuring device 6 detects the discharge current of the sample lightning arrester 1 for a specified time sufficient from the start of discharge of the series gap 3 to the discharge convergence, and holds the detected data in the recording means. Here, a current sensor (for example, output: 0.1 V / A, maximum current) that detects a current flowing in the output circuit of the DC voltage generator (for example, output power: 30 W, maximum voltage: 30 kV, maximum current: 1 mA) 5 : 400 A), an oscilloscope (for example, frequency band: 200 MHz, maximum sample rate: 2 GS / s) displaying the discharge current detected by the current sensor as the vertical axis and time as the horizontal axis, and the waveform displayed on the oscilloscope It is comprised with the personal computer (computer 7) which installed the said current measurement module which takes in the image | video data.

As shown in FIG. 1, the current measuring device 6 functioning by the current measuring module starts the discharge step, performs the discharge suppression step, and then collects the detection data and detects the detection over a specified time. The measurement step (data sampling process) for holding data is performed.
The specified time for performing the data sampling process is sufficient to detect the oscillation end period once after the oscillation of the DC discharge current is attenuated after the DC discharge current starts flowing in the DC gap 3. Set the time.
The sample rate used in the data sampling process knows the duration, vibration amount, and polarity of each wave at the estimated time that each wave will be obtained by the damped vibration characteristics of the sample arrester 1 that performs failure determination. It must be sufficient.
In principle, the same condition is adopted for the prescribed time and sample rate of the reference data (the sample rate may be higher in accuracy than the same condition).

<Comparison means>
The comparison means in the example is configured by a computer in which the comparison module is installed, holds the reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired, and the reference data The amount of vibration from the first wave to the final wave included in the reference data and the detection data, or from the first wave to the specified wave generated before the final wave, depending on the wave number until the vibration end period appearing in Compare
At that time, the comparison means performs a zero correction process for the held detection data and a detection data evaluation process for evaluating the detection data after the zero correction process (comparison step).
The detection data evaluation process is performed after evaluating the instantaneous value and polarity of the DC discharge current held as the detection data.
In the detection data evaluation process in this example, a waveform start determination process, the final wave identification process, and a waveform comparison process are performed.

  In the zero correction process, a level (a level regarded as 0 A) used as a reference of the process performed by the comparison unit is a level of data detected before the DC voltage generator 5 is connected and a discharge step is started. It is a process to set.

  The waveform start determination process is a process of detecting the starting point of the detection data evaluation process from the data obtained by the data sampling process. After the discharge step starts, for example, the detection data obtained in the measurement step is specified. The number (the number sufficient to confirm the presence of individual waves and the change in polarity according to the sample rate) When the discharge current exceeding the threshold of the dead level is detected for the first time only when the polarity is continuous Is determined to be when the first wave occurs.

The final wave specifying process is performed by the final wave specifying means, and a wave that satisfies a prescribed requirement is recognized as a final wave.
The specified requirement in the final wave specifying process is based on the premise that it exists immediately before the end of the vibration as viewed from the end of the reference data or the detection data, and specifically, the discharge of the series gap 3 When the voltage applied to both ends of the sample lightning arrester 1 is lowered after the start, the evaluation starts from the end of the reference data or detection data and immediately before the stagnation period (see FIG. 6) detected first. When the application of the DC voltage to both ends of the sample lightning arrester 1 is stopped in response to the start of the discharge of the series gap 3, It is necessary to start the evaluation from the tail of the reference data or the detection data and to be a wave that exists immediately before the dead period detected first.
For example, the tenth wave is the final wave in FIG. 6A, and the sixth wave is the final wave in FIG. 6B.

  In this way, by recognizing the wave guided by the final wave specifying means as the final wave, the damped oscillation waveform in the reference data and the detection data obtained by one discharge step and the discharge suppression step is configured. The number of waves (hereinafter referred to as the target wave) (hereinafter referred to as the target wave number) can be known before the waveform comparison process.

The waveform comparison process includes a setting step for determining a failure determination criterion for each model of the sample arrester 1 and a difference between the vibration amount indicated by the detection data and the reference data determined by the set failure determination criterion (hereinafter referred to as a determination value) And a calculation step for deriving).
The failure determination criteria include failure determination requirements for each type of lightning arrester, the reference data as a comparison reference, the allowable value, the number of waves (effective waves) to be compared at the time of failure determination, and the like.

  The setting step includes comparing the reference data and the detection when comparing all the target waves included in the reference data and the detection data according to the damping vibration characteristic and failure mode specific to each model (manufacturer and model). The target wave number is used as a guide when selectively comparing the vibration amount from the first wave of the target wave included in the data to the specified wave generated before the final wave. It is determined whether to compare up to the next wave as the effective wave.

  For example, in the final wave specifying process, when the final wave of the reference data and the detection data is detected and all the target waves included in the reference data are used as a comparison reference, the waveform comparison process A wave corresponding to the target wave number from the first wave of the reference data is compared with a wave corresponding to the target wave number from the first wave of the detection data.

If the target wave number of the detection data is greater than the target wave number of the reference data, the wave exceeding the target wave number of the reference data in the detection data is not subject to comparison, and conversely When the target wave number of the detection data is smaller than the target wave number of the reference data, the amount of vibration after the final wave of the detection data guided by the final wave specifying means included in the detection data It is assumed that the waveform comparison processing up to the final wave of the reference data is performed by regarding the wave as “0”.
In this example, the target wave number of the reference data is an effective wave number used for failure determination among the waves included in the detection data, but the target wave number depends on the damping vibration characteristic and failure mode specific to each model. Needless to say, the effective wave number may be the wave number from the first wave to the designated wave generated before the final wave.

  The determination means includes a computer in which the determination module is installed, and performs a lightning arrester failure determination based on the allowable value set in the waveform comparison process and the determination value derived in the calculation step. That is, as a result of the comparison by the comparison means, if there is a difference greater than an allowable value between the vibration amount indicated by the detection data and the vibration amount indicated by the reference data, the sample lightning arrester 1 is determined to be faulty, and the detection When the difference between the vibration amount indicated by the data and the vibration amount indicated by the reference data is less than the allowable value, a failure determination process is performed to determine that the sample arrester 1 is normal (determination step).

Hereinafter, examples of the determination process will be described.
In the following embodiment, an average value of normal products of the same product is adopted as the reference data, and the vibration amount indicated by the detection data and the vibration amount indicated by the reference data with respect to the vibration amount indicated by the reference data Is defined as the allowable value.

<Judgment by single step>
The first determination mode of the lightning arrester failure determination method according to the present invention is the first wave and thereafter in the sample lightning arrester 1 (in the case of FIG. 6 (A), from the first wave to the tenth wave, in the case of FIG. 6 (B)). Is determined as a failure when the sum or peak value of the integral values (absolute values) of the amplitudes of the individual waves from the first wave to the sixth wave exceeds the allowable value, but not as a failure The product is determined to be a normal product (see FIG. 2A).

<Determination by two steps>
The second determination form of the lightning arrester failure determination method according to the present invention is that the integrated value or peak value of the amplitude of the first wave in the sample lightning arrester 1 is an allowable value (ratio) relative to the average value of normal products of the same product. Etc .: For example, a first step for determining a failure when a deviation exceeding ± 20% occurs, and a second wave or later when it is not determined that there is a failure (FIG. 6A). In the case of the second wave to the tenth wave, in the case of FIG. 6B, the second wave to the sixth wave) the sum of the integrated values or peak values of the amplitudes of the individual waves, the average of normal products of the same product A second step for determining a failure when there is a deviation exceeding an allowable value (for example, a range of ± 20%) with respect to the value, and a product that has not been determined to be a failure through these two steps is a normal product On the other hand, a product that is not determined to be a failure is determined to be a normal product (FIG. 2 (B )reference).

  FIG. 7B is an example that can be determined in the first step, FIG. 7C is an example of the discharge current that can be determined in the second step, and FIG. It is an example of the discharge current which can be determined in any step of the first step and the second step.

<Addition of serial gap fault judgment function>
In the third determination mode of the lightning arrester failure determination method according to the present invention, the DC discharge start voltage is evaluated before the second determination mode in order to provide a function for determining the series gap 3 failure. Is what you do. In other words, when the voltage at which the series gap 3 of the sample lightning arrester 1 starts to discharge is less than a specified value (for example, 20 kV), the step of determining that the sample lightning arrester 1 is faulty is placed. That is, only the sample lightning arrester 1 determined to be a normal product in this step is subjected to the second determination mode (see FIG. 3).

By adopting the above method, a function of finding a failure of the series gap 3 is added, and the failure of the sample lightning arrester 1 can be determined with higher accuracy.
Instead of the second determination mode, the DC discharge start voltage may be evaluated before the first determination mode.

<Selection of resonance auxiliary means>
In order to obtain a series discharge current waveform suitable for determining a failure of a lightning arrester having the series gap 3, it is desirable to appropriately select the resonance assisting means 4.
An example of the selection process is shown below.
Here, as a candidate of resonance auxiliary means to be selected,
Sample 1: Inductance = 5μH
Sample 2: Inductance = 15μH
Sample 3: Inductance = 25μH
Were inserted into the series circuit individually as resonance auxiliary means 4, and a DC discharge current was measured when a DC voltage of 20 kV or more was applied (see FIG. 9).
As a result, the sample 1 has a short resonance time, and the sample 3 has a small amplitude, so it is difficult to determine a failure. Therefore, among these, it can be said that the sample 2 is desirable as the resonance assisting means 4.

  Even when the sample arrester 1 is a lightning arrester including the lightning arrester element 2 having a small specific inductance or capacitance (a lightning arrester having a series gap), the resonance auxiliary means 4 is inserted in series with respect to the lightning arrester. By doing so, it can be said that a discharge current (waveform) that enables failure determination can be detected.

<Failure judgment>
The sample 2 was adopted as the resonance auxiliary means 4, and failure determination was performed on 38 of the sample lightning arresters 1 used in the power distribution equipment in which the commercial lightning current element 2 was broken by injecting a large commercial frequency current in advance.
For example, in FIG. 7A, the resistance R and the capacitance C of the lightning arrester 2 are reduced, so that the amplitude is decreased, the frequency is decreased, and the vibration period is decreased.

  Comparing the measured discharge current waveforms of the normal product and the faulty product, in general, the normal product shows a remarkable vibration of about 5 times, but in the faulty product all the amplitudes are reduced and the frequency is 3 times. There is a tendency to decrease to a certain extent. If the first wave and the second and subsequent waves are separately observed, at least the discharge scale in the transient phenomenon can be evaluated with the first wave, and the damped oscillation characteristics can be simply evaluated with the second and subsequent waves.

<Judgment accuracy>
For the 38 pieces of the sample lightning arrester 1, a failure determination method by charge comparison and peak value comparison (with resonance auxiliary means), and the first method: DC discharge start voltage measurement and second method that have been conventionally employed: The determination accuracy was compared by two methods consisting of insulation resistance measurement (see FIG. 8). As a result, in the failure method according to the present invention, the detection rate of the failed sample arrester 1 was 89.5% in charge comparison and 63.2% in wave height comparison. On the other hand, it was 39.5% in the first method and 5.3% in the second method.

  As described above, the failure determination of the lightning arrester having the series gap 3 which is insufficient with the first method or the second method can be performed without disassembling the lightning arrester, and the inductance L and the capacitance C are small. Even for lightning arresters, it was possible to accurately determine the failure, and by discovering a malfunctioning lightning arrester with high accuracy, we were able to verify the practical effect of preventing power outages caused by the failure lightning arrester.

  Moreover, even if it exists in an apparatus, since it is a simple apparatus as described in FIG. 4, it will not become large-sized so that it is inconvenient to carry, and it can determine a failure without removing a lightning arrester in the field. Note that the comparison may be made by any of the timing chart patterns and the like in addition to the above-described numerical comparison method.

1 sample arrester, 2 lightning arrester, 3 series gap,
4 Auxiliary resonance means, 5 DC voltage generator, 6 Current measuring device, 7 Computer,

Claims (8)

A DC voltage generator for applying a DC voltage equal to or higher than a voltage at which the series gap of the sample arrester starts discharging, connected to both ends of the sample arrester having a series gap;
A discharge suppression means for reducing the applied voltage of the DC voltage generator upon receiving the discharge of the series gap;
A current measuring device that detects the discharge current of the sample lightning arrester for a specified time from the start of discharge of the series gap to the discharge convergence, and holds the detection data;
The reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired, and from the first wave to the final wave or from the first wave to the final wave included in the reference data and the detection data Comparison means for comparing the amount of vibration up to the specified wave that occurred before,
As a result of the comparison, when there is a difference greater than an allowable value between the amount of vibration indicated by the detection data and the amount of vibration indicated by the reference data, a determination unit that determines that the sample arrester is a failure,
When the last stagnation period of the reference data or the detection data is detected, it is provided with a final wave specifying means that recognizes a wave having a polarity opposite to that of the first wave as a final wave immediately before the time period. A fault determination system for lightning arresters. A DC voltage generator for applying a DC voltage equal to or higher than a voltage at which the series gap of the sample arrester starts discharging, connected to both ends of the sample arrester having a series gap;
A discharge suppression means for stopping the application of the DC voltage by the DC voltage generator upon receiving the discharge start of the series gap;
A current measuring device that detects the discharge current of the sample lightning arrester for a specified time from the start of discharge of the series gap to the discharge convergence, and holds the detection data;
The reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired, and from the first wave to the final wave or from the first wave to the final wave included in the reference data and the detection data Comparison means for comparing the amount of vibration up to the specified wave that occurred before,
As a result of the comparison, when there is a difference greater than an allowable value between the amount of vibration indicated by the detection data and the amount of vibration indicated by the reference data, a determination unit that determines that the sample arrester is a failure,
A lightning arrester failure determination system comprising: a final wave specifying unit that recognizes a wave existing immediately before the dead period when the last dead period of the reference data or the detection data is detected. When the voltage at which the series gap starts discharging is below a specified value,
As a result of the comparison, when there is a difference greater than an allowable value between the vibration amount of the first wave included in the detection data and the vibration amount of the first wave included in the reference data,
Or, as a result of the comparison, from the second wave to the final wave included in the detection data, or from the second wave to the final wave included in the reference data and the vibration amount from the second wave to the designated wave generated before the final wave. Alternatively, when there is a difference greater than an allowable value between the amount of vibration from the second wave to the specified wave generated before the final wave, the determination unit includes a determination unit that determines that the sample arrester is a failure. The lightning arrester failure determination system according to claim 1 or 2. In the lightning arrester failure determination performed by applying a DC voltage higher than the voltage at which the series gap of the sample lightning arrester starts discharging to both ends of the sample lightning arrester having a series gap,
On the computer,
A current measuring device that detects the discharge current of the sample lightning arrester for a specified time from the start of discharge of the series gap to the discharge convergence, and holds the detection data;
The reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired, and from the first wave to the final wave or from the first wave to the final wave included in the reference data and the detection data Comparison means for comparing the amount of vibration up to the specified wave that occurred before,
As a result of the comparison, when there is a difference greater than an allowable value between the amount of vibration indicated by the detection data and the amount of vibration indicated by the reference data, a determination unit that determines that the sample arrester is a failure,
When the voltage applied to both ends of the sample lightning arrester is lowered in response to the start of discharge of the series gap, when the last stagnation period of the reference data or the detection data is detected, it exists immediately before the time zone and the A lightning arrester failure determination program that functions as a lightning arrester failure determination system including a final wave identification unit that recognizes a wave having a polarity opposite to the first wave as a final wave. In the computer,
5. The lightning arrester failure determination program according to claim 4, further comprising a program that functions as a discharge suppression unit that reduces the voltage applied to both ends of the sample lightning arrester in response to the start of discharge of the series gap. In the lightning arrester failure determination performed by applying a DC voltage higher than the voltage at which the series gap of the sample lightning arrester starts discharging to both ends of the sample lightning arrester having a series gap,
On the computer,
A current measuring device that detects the discharge current of the sample lightning arrester for a specified time from the start of discharge of the series gap to the discharge convergence, and holds the detection data;
The reference data of the discharge current of a normal lightning arrester detected under the same conditions as when the detection data was acquired, and from the first wave to the final wave or from the first wave to the final wave included in the reference data and the detection data Comparison means for comparing the amount of vibration up to the specified wave that occurred before,
As a result of the comparison, when there is a difference greater than an allowable value between the amount of vibration indicated by the detection data and the amount of vibration indicated by the reference data, a determination unit that determines that the sample arrester is a failure,
When the application of the DC voltage to both ends of the sample arrester is stopped in response to the start of discharge of the series gap, it exists immediately before the dead period when the last dead period of the reference data or the detection data is detected. A lightning arrester failure determination program that functions as a lightning arrester failure determination system including a final wave identification unit that recognizes a wave to be transmitted as a final wave. In the computer,
The lightning arrester failure determination program according to claim 6, further comprising a program that functions as a discharge suppression unit that stops the application of the DC voltage to both ends of the sample lightning arrester upon receiving the start of discharge of the series gap. In the computer,
When the voltage at which the series gap starts discharging is below a specified value,
As a result of the comparison, when there is a difference greater than an allowable value between the vibration amount of the first wave included in the detection data and the vibration amount of the first wave included in the reference data,
Or, as a result of the comparison, from the second wave to the final wave included in the detection data, or from the second wave to the final wave included in the reference data and the vibration amount from the second wave to the designated wave generated before the final wave. Or, when there is a difference greater than an allowable value between the amount of vibration from the second wave to the designated wave generated before the final wave, a program for causing the sample lightning arrester to function as a determination means for determining a failure is provided. The lightning arrester failure determination program according to any one of claims 4 to 7, characterized in that the lightning arrester is faulty.

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