JP2013253966A - Charge type electrical circuit accident investigation radar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge type electrical circuit accident investigation radar capable of accurately investigating an accident point by accurately specifying a frequency band of a transmitted electromagnetic wave on the accident point.SOLUTION: An electromagnetic wave generated by ground discharge on an accident point caused by a high voltage pulse from a charge device is detected by a pair of antennas 13a, 13b by using a plurality of resonance frequencies. An FFT analysis device performs fast Fourier transform of detection signals detected by the pair of antennas and detects a resonance frequency of the largest output voltage of the pair of antennas. An arithmetic processing unit defines the resonance frequency of the largest output voltage detected by the FFT analysis device as an accident point resonance frequency, identifies a direction of the accident point on the basis of a time difference between output voltages of the pair of antennas at the accident point resonance frequency and outputs the direction of the accident point identified by the arithmetic processing unit to a display device to display the direction.

Description

  The present invention relates to a power-applying electric circuit accident detection radar that searches a discharge ground fault point by applying a high voltage pulse to a distribution line in a power failure state.

  The power distribution type accident survey radar applies a high voltage pulse from the power distribution device to the power distribution line in the power outage state, and this high voltage pulse detects the electromagnetic waves radiated from the power distribution line with two antennas. This is to explore the ground fault point.

  FIG. 13 is a configuration diagram showing an example of a conventional electric charging type electric circuit accident survey radar. Now, assuming that a ground fault has occurred at the accident point F of the distribution line 11, the distribution line 11 is in a power failure state. When the distribution line 11 is in a power failure state, the inspection and maintenance staff first applies a high voltage pulse periodically from the power distribution device 12 to the power distribution line 11 in a power failure state when searching for the accident point F. The high voltage pulse is grounded at the accident point F, and a current I flows through the distribution line 11. An electromagnetic wave S generated by the current I is radiated from the distribution line 11. The electromagnetic wave S is detected by the two antennas 13a and 13b, and the direction of the accident point F is determined by the time difference between the detection times.

  The two antennas 13 a and 13 b are, for example, loop antennas and are mounted on the automobile 14. As shown in FIG. 13, when the accident point F is in front of the automobile 14 equipped with the two antennas 13a and 13b, the antenna 13a detects the electromagnetic wave S before the antenna 13b. On the other hand, when the accident point F is behind the automobile 14, the antenna 13b detects the electromagnetic wave S before the antenna 13a. Therefore, the direction of the accident point F is determined based on the detection time difference between the electromagnetic waves of the two antennas 13a and 13b.

  Here, there is a power transmission type electric line accident survey radar that removes external noise of the electromagnetic wave S generated by the current I propagating from the accident point F through the distribution line 11 and improves the fault point search accuracy. (For example, refer to Patent Document 1).

Japanese Unexamined Patent Publication No. 63-243771

  However, in the conventional apparatus, the electromagnetic waves of the distribution line 11 due to the high voltage pulse are detected using the antennas 13a and 13b having one resonance point (for example, a fixed frequency of 1.4 MHz). Accident points cannot be detected accurately. This is because the frequency of the electromagnetic wave (transmitted electromagnetic wave) varies depending on the accident situation due to the high-pressure pulse generated at the accident point.

  FIG. 14 is a graph of an example of an electromagnetic wave detection signal in a conventional antenna. FIG. 14 shows a detection signal in a range of 1 to 2 MHz with the resonance point (1.4 MHz fixed frequency) of the antenna as the center. A curve C1 in FIG. 14 represents the sensitivity of the antenna, and the sensitivity is maximum when the resonance frequency is 1.4 MHz. A curve C2 is the magnitude of the electromagnetic field. A curve C3 is an antenna detection signal (output voltage).

  FIG. 14 shows a case where the frequency of the transmitted electromagnetic wave S at the accident point F is 1.8 MHz and there is noise with a frequency of 1.3 MHz or 1.6 MHz. In this case, since the resonance point is an antenna having a frequency of 1.4 MHz, noise having a frequency of 1.3 MHz or 1.6 MHz is detected to be equal to or higher than the intensity of the 1.8 MHz outgoing electromagnetic wave at the accident point F. Therefore, it causes a false detection.

  Thus, although the antenna is resonating at a fixed frequency of 1.4 MHz, the frequency of the transmitted electromagnetic wave changes depending on the accident situation, and therefore the frequency of the transmitted electromagnetic wave at the accident point F is deviated from 1.4 MHz. Since noise electromagnetic waves other than the transmitted electromagnetic waves are also generated in the same band, it is difficult to separate the transmitted electromagnetic waves.

  An object of the present invention is to provide a power transmission type electric circuit accident survey radar capable of accurately identifying a frequency band of a transmitted electromagnetic wave at an accident point and searching for the accident point with high accuracy.

  According to a first aspect of the present invention, a power distribution type accident survey radar applies a high voltage pulse to a distribution line in a power outage state from a power application device, and generates a pair of electromagnetic waves generated by a ground fault discharge at the accident point due to the high voltage pulse. Electromagnetic wave generated by ground fault discharge at the accident point due to the high voltage pulse in the electric circuit type accident detection radar that detects the direction of the accident point based on the time difference between the output voltages of the pair of antennas. A pair of antennas using a plurality of resonance frequencies, an FFT analysis apparatus for detecting a resonance frequency having a maximum output voltage of the pair of antennas by fast Fourier transforming detection signals of the pair of antennas, and the FFT analysis apparatus Based on the time difference between the output voltages of the pair of antennas at the accident point resonance frequency, the resonance frequency with the highest output voltage detected in step 1 is determined as the accident point resonance frequency. Characterized by comprising a processing unit for determining the direction of the fault point, and a display device for displaying the output direction of the discriminated fault point by the arithmetic processing unit Te.

  According to a second aspect of the invention, the arithmetic processing device is configured to display and output the accident point resonance frequency detected by the FFT analysis device to the display device. It is characterized by.

  According to the first aspect of the present invention, a pair of antennas detects a transmission electromagnetic wave at an accident point using a plurality of resonance frequencies, performs fast Fourier transform on the detection signals of the pair of antennas, and resonates with the highest output voltage of the pair of antennas. Since the frequency is detected as the accident point resonance frequency, the frequency band of the transmitted electromagnetic wave at the accident point can be accurately identified. And since the direction of an accident point is discriminate | determined based on the time difference of the output voltage of a pair of antenna in the accident point resonance frequency of the transmitted electromagnetic wave of the accident point resonance frequency, an accident point can be searched accurately.

  According to the invention of claim 2, since the accident point resonance frequency is displayed and output on the display device, it can be used for estimation of the aspect of the accident.

The block diagram which shows an example of the electric power transmission type electric circuit accident investigation radar which concerns on 1st Embodiment of this invention. Explanatory drawing of the sensitivity of the antenna which enabled the detection of the some zone | band in 1st Embodiment of this invention. The wave form diagram which shows an example of the electromagnetic wave intensity | strength of the frequency band analyzed with the FFT analyzer 18 of 1st Embodiment of this invention. Explanatory drawing of the accident investigation using the electric charging type electric circuit accident investigation radar which concerns on 1st Embodiment of this invention. The wave form diagram which shows an example of the detection signal of the electromagnetic wave in case an accident point exists ahead of an inspection maintenance worker by the accident investigation using the electric charging type electric circuit accident investigation radar which concerns on 1st Embodiment of this invention. The wave form diagram which shows an example of the detection signal of the electromagnetic wave in case an accident point exists in the back of an inspection maintenance worker by the accident investigation using the electric charging type electric circuit accident investigation radar which concerns on 1st Embodiment of this invention. The wave form diagram which shows an example of the environmental noise for every environment investigated in 2nd Embodiment of this invention. The wave form diagram of an example of the electromagnetic wave obtained by the verification experiment according to the aspect of the ground fault accident in 2nd Embodiment of this invention. The wave form diagram of an example of the electromagnetic wave obtained by the verification experiment in case the distance from an accident point is constant and the length of a distribution line is changed in 2nd Embodiment of this invention. The wave form diagram of an example of the electromagnetic wave obtained by the verification experiment when the length of a distribution line is constant in 2nd Embodiment of this invention, and the distance from an accident point is changed. Explanatory drawing of an example of the sensitivity of the antenna which enabled the detection of the some zone | band in 2nd Embodiment of this invention. Explanatory drawing of the other example of the sensitivity of the antenna which enabled the detection of the some zone | band in 2nd Embodiment of this invention. The block diagram which shows an example of the conventional electric charging type electric circuit accident investigation radar. The graph of an example of the detection signal of the electromagnetic wave in the conventional antenna.

  Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing an example of an electric charging type electric circuit accident survey radar according to the first embodiment of the present invention. The charging-type electric circuit accident survey radar includes a pair of antennas 13 a and 13 b and a survey radar main body 15. The pair of antennas 13a and 13b detects an electromagnetic wave (transmitted electromagnetic wave) generated by a ground fault discharge at an accident point due to a high voltage pulse from the power application device using a plurality of resonance frequencies. That is, tuning dials 16a and 16b are provided on the antenna so that electromagnetic waves in a plurality of bands can be detected.

  FIG. 2 is an explanatory diagram of the sensitivity of the antenna that can detect a plurality of bands in the first embodiment of the present invention. Curve C11 is the sensitivity when tuning dials 16a and 16b are 1.0 MHz, curve C12 is the sensitivity when tuning dials 16a and 16b are 1.2 MHz, and curve C13 is tuning dials 16a and 16b is 1.4 MHz. Sensitivity when the tuning dials 16a and 16b are set to 1.6 MHz, the curve C15 is sensitivity when the tuning dials 16a and 16b are set to 1.8 MHz, and the curve C16 indicates that the tuning dials 16a and 16b are 2 Sensitivity at 0 MHz.

  In this way, by providing a plurality of bands with respect to a cross section of one electromagnetic wave intensity, the resonance points are 1.0 MHz, 1.2 MHz, 1.4 MHz, 1.6 MHz, 1. Electromagnetic waves can be captured by six multiple cross sections of 8 MHz and 2.0 MHz. Although the case where electromagnetic waves are captured in six multiple cross sections has been described in FIG. 2, the electromagnetic waves may be captured in six or more or six or fewer multiple cross sections.

  The electromagnetic wave intensity detected by the antennas 13 a and 13 b is input to the input device 17 of the search radar main body 15. The input device 17 samples and captures the electromagnetic wave intensity (output voltage) detected by the antennas 13 a and 13 b at a predetermined period, and outputs the sample to the FFT analysis device 18. The FFT analyzer 18 performs fast Fourier transform on the detection signals of the pair of antennas 13a and 13b, and detects the resonance frequency at which the output voltage of the pair of antennas 13a and 13b is the highest as the accident point resonance frequency.

  FIG. 3 is a waveform diagram showing an example of the electromagnetic wave intensity in the frequency band analyzed by the FFT analyzer 18 according to the first embodiment of the present invention. In FIG. 3, the result of having analyzed the electromagnetic wave shown by the curve C2 of FIG. 14 is shown. In the electromagnetic wave indicated by the curve C2 in FIG. 14, noise having a frequency of 1.3 MHz or 1.6 MHz is included together with a 1.8 MHz outgoing electromagnetic wave at the accident point F. When analyzed by the FFT analyzer 18, the noise is shown in FIG. Thus, the frequency of the accident point F with the strongest electromagnetic wave intensity can be detected as 1.8 MHz.

  The arithmetic processing unit 19 determines the resonance frequency having the highest output voltage detected by the FFT analysis unit 18 as the accident point resonance frequency. And the direction of an accident point is discriminate | determined based on the time difference of the detection time of the output voltage of a pair of antenna 13a, 13b in the accident point resonance frequency. That is, it is determined that there is an accident point on the side of the antenna 13 whose arrival time is early from the acquired electromagnetic wave waveform having the largest output voltage.

  Then, the arithmetic processing device 19 displays and outputs the determined direction of the accident point on the display device 20. Further, the accident point resonance frequency detected by the FFT analyzer 18 is displayed and output on the display device 20 as necessary. This makes it easier for the inspection operator to identify the location of the accident point, and also helps to estimate the aspect of the accident from the accident point resonance frequency, so that the location where the accident has occurred can be quickly identified. it can.

  Here, due to recent technological advancement, the FFT analyzer 18 can acquire a waveform with high accuracy from the [ns] level to the [ps] level. As a result, it becomes possible to determine the direction based on the time difference between the detection times of the output voltages of the pair of antennas 13a and 13b at the [ps] level.

  In the conventional technology, the direction difference is determined with the time difference between the detection times of the output voltages of the pair of antennas 13a and 13b being 10 [ns]. Therefore, the antenna interval is 3 m due to the resolution, and the 3 m antennas 13 a and 13 b are connected. I had to load it in a car. Therefore, although an accident investigation could not be performed in a place where the vehicle cannot enter, by adopting the FFT analyzer 18 having a resolution of [ps] level, the distance between the pair of antennas 13a and 13b can be short and compact. Thereby, it can be set as the electric charging type electric circuit accident investigation radar excellent in the portability compact.

  FIG. 4 is an explanatory diagram of an accident survey using the electric charging type electric circuit accident survey radar according to the first embodiment of the present invention. Since the electric charging type electric circuit accident survey radar according to the first embodiment of the present invention is a compact portable type, an inspection maintenance worker can carry out an electric accident investigation by carrying the electric type electric circuit accident detection radar.

  Similarly to FIG. 14, if a ground fault occurs at the accident point F of the distribution line 11, the distribution line 11 is in a power failure state, and the inspection and maintenance staff searches for the accident point F. First, in a state where a high voltage pulse is periodically applied from the power distribution device 12 to the power distribution line 11 in a power outage state, an inspection maintenance worker carries out an accident survey on foot with a power distribution type electric circuit accident survey radar. Since it is not an accident search with the antennas 13a and 13b mounted on a vehicle as in the prior art, an accident investigation can be performed even in a place where the vehicle cannot enter.

  FIG. 5 is a waveform diagram showing an example of a detection signal of the electromagnetic wave S (output voltages of the antennas 13a and 13b) when the ground fault point is in front of the maintenance staff. As shown in FIG. 5, the electromagnetic wave detection signal of the antenna 13a is detected before the electromagnetic wave detection signal of the antenna 13b. Therefore, it is determined that the accident point F is in front of the maintenance personnel.

  FIG. 6 is a waveform diagram showing an example of a detection signal of the electromagnetic wave S (output voltages of the antennas 13a and 13b) when the ground fault point is behind the maintenance staff. As shown in FIG. 6, the electromagnetic wave detection signal of the antenna 13b is detected before the electromagnetic wave detection signal of the antenna 13a. Therefore, it is determined that the accident point F is behind the inspection and maintenance staff.

  Here, the detection signal of the electromagnetic wave of the antenna 13a and the detection signal of the electromagnetic wave of the antenna 13b are signals having the largest output voltage detected by the FFT analyzer 18, and therefore can be accurately detected without being affected by noise. Further, by adopting the FFT analyzer 18 having a resolution of [ps] level, the direction of the accident point can be detected with high accuracy even if the distance between the pair of antennas 13a and 13b is short, and the size can be reduced.

  As described above, in the first embodiment of the present invention, a plurality of bands are provided in one antenna 13a, 13b, and sensitivity adjustment is performed by analyzing the sampling data of the electromagnetic wave emitted from the accident current with the FFT analyzer 18. Increase detection sensitivity. The FFT analyzer 18 is used to examine the frequency distribution. In recent years, some digital oscilloscopes have a built-in FFT function, so the signal processing was previously performed by hardware. The development of performance, digital sampling technology, and the information processing technology of FFT analysis have improved and can be processed by software.

  According to the first embodiment of the present invention, a plurality of bands are provided for one antenna 13a, 13b, and the sampling of the electromagnetic wave emitted from the accident current is analyzed by the FFT analyzer 18 to adjust the sensitivity. Removal is possible. Further, since the tuning dials 16a and 16b are provided so that a plurality of bands are provided in the antennas 13a and 13b, the detection level of the transmitted electromagnetic wave can be improved even in a band other than the 1.4 MHz band. Tuning of a plurality of bands of the antennas 13a and 13b can be performed automatically. Thereby, since the accident point frequency band is specified, the signal level is improved, the distinction from the noise becomes remarkable, and the noise can be removed.

  Next, a second embodiment of the present invention will be described. In the first embodiment, the frequency band of the electromagnetic waves detected by the antennas 13a and 13b is in the range of 1 MHz to 2 MHz. However, in the second embodiment of the present invention, the frequency band of the electromagnetic waves detected by the antennas 13a and 13b is set. The range is 2 MHz to 3 MHz, or 1 MHz to 3 MHz. A duplicate description with the first embodiment is omitted.

  As described above, in the second embodiment of the present invention, the frequency band of the electromagnetic waves detected by the antennas 13a and 13b is added to the range of 2 MHz to 3 MHz or the range of 1 MHz to 2 MHz instead of the range of 1 MHz to 2 MHz. The range is 1 MHz to 3 MHz. That is, a range of 2 MHz to 3 MHz is adopted as a frequency band of electromagnetic waves detected by the antennas 13a and 13b. The reason for paying attention to the range of 2 MHz to 3 MHz is as follows.

  As described above, in the conventional charging-type electric circuit accident survey radar, the antennas 13a and 13b having one resonance point (for example, a fixed frequency of 1.4 MHz) are used to generate electromagnetic waves of the distribution line 11 due to high voltage pulses. Since the detection is performed, there is a possibility that the accident point is erroneously determined due to the influence of noise. Therefore, in the second embodiment, noise is studied in order to grasp the influence of noise.

  First, the influence of noise caused by the power-applying device itself was examined. Although the charging noise appears in a high frequency band of 30 MHz to 100 MHz, it was confirmed that it attenuated as the distance from the charging device increased and was hardly detected at a point of 40 m. Next, environmental noise was investigated for each environment to determine whether the noise varies depending on the environment.

  FIG. 7 is a waveform diagram showing an example of environmental noise for each environment, FIG. 7A is a waveform diagram showing an example of noise in a downtown area, and FIG. 7B is a diagram of noise along a train line. FIG. 7C is a waveform diagram illustrating an example of noise in an industrial park, and FIG. 7D is a waveform diagram illustrating an example of noise in a residential area. As can be seen from FIGS. 7A to 7D, the range of 1.5 MHz or less is the frequency band of AM radio broadcasting, and the band in the vicinity of 4 MHz is the frequency band of shortwave broadcasting. Detected as noise. And in any environment, it turns out that there is little noise in the range of 2 MHz-3 MHz.

  Next, the range of 0 MHz to 5 MHz was investigated for electromagnetic waves generated by ground fault discharge. FIG. 8 is a waveform diagram of an example of an electromagnetic wave obtained by a verification experiment for each aspect of the ground fault (accident point member). In FIG. 8, the measurement point of the electromagnetic wave is 0.14 km from the accident point, and the length is The case of a 0.15 km distribution line is shown. Fig. 8 (a) is a waveform diagram showing an example of an electromagnetic wave simulating the appearance of a ground fault with a ball gap (discharge voltage 3.8kv), and Fig. 8 (b) is a diagram showing the appearance of a ground fault caused by insulation deterioration of the mold bus. Waveform diagram showing an example of simulated electromagnetic waves, FIG. 8C is a waveform diagram showing an example of electromagnetic waves simulating a ground fault accident with a ball gap (discharge voltage 5.0 kv), and FIG. 8D is a ground fault. It is a wave form diagram which shows an example of the electromagnetic wave which simulated the aspect of the accident with the insulation deterioration of the CVT cable. As can be seen from FIGS. 8A to 8D, even if the aspect of the ground fault (accident point member) changes, the electromagnetic wave generated by the ground fault discharge is high in the range of 2 MHz to 3 MHz with less noise. It can be seen that it has a signal level.

  FIG. 8 shows the case where the distance from the accident point and the length of the distribution line are constant (distance from the accident point: 0.14 km, the length: 0.15 km). The electromagnetic wave generated by the ground fault discharge when the distance and the length of the distribution line were changed was investigated. FIG. 9 is a waveform diagram of an example of an electromagnetic wave obtained by a verification experiment when the distance from the accident point is constant and the length of the distribution line is changed. In FIG. 9, the state of the ground fault accident (accident point member). Indicates a ball gap (discharge voltage 3.8 kv). 9A is a waveform diagram showing an example of an electromagnetic wave obtained by a verification experiment when the distance from the accident point is 0.2 km and the length of the distribution line is 0.7 km, and FIG. 9B is the accident point. A waveform diagram showing an example of an electromagnetic wave obtained by a verification experiment when the distance from the center is 0.2 km and the length of the distribution line is 1.2 km, FIG. 9C is a distance from the accident point is 0.2 km It is a wave form diagram which shows an example of the electromagnetic waves obtained by the verification experiment in case the length of a distribution line is 1.9 km. As can be seen from FIGS. 9A to 9C, even when the length of the distribution line changes, the electromagnetic wave generated by the ground fault discharge has a high signal level in the range of 2 MHz to 3 MHz with less noise. I understand.

  Although FIG. 9 shows the case where the distance from the accident point is constant and the length of the distribution line is changed, the ground fault when the length of the distribution line is constant and the distance from the accident point is changed is shown. The electromagnetic waves generated by the discharge were investigated. FIG. 10 is a waveform diagram of an example of an electromagnetic wave obtained by a verification experiment in the case where the length of the distribution line is constant and the distance from the accident point is changed. In FIG. Indicates a ball gap (discharge voltage 3.8 kv). FIG. 10A is a waveform diagram showing an example of an electromagnetic wave obtained by a verification experiment when the distance from the accident point is 0.6 km and the length of the distribution line is 1.9 km, and FIG. 10B is the accident point. It is a wave form diagram which shows an example of the electromagnetic waves obtained by the verification experiment in case the distance from is 1.2 km and the length of the distribution line is 1.9 km. As can be seen from FIGS. 10 (a) and 10 (b), even if the distance from the accident point changes, the electromagnetic wave generated by the ground fault discharge has a high signal level in the range of 2 MHz to 3 MHz with less noise. I understand.

  Thus, even if the aspect of the ground fault (accident point member), the length of the distribution line, and the distance from the accident point change, the electromagnetic wave generated by the ground fault discharge is in the range of 2 MHz to 3 MHz with less noise. Has a high signal level. Therefore, in the second embodiment of the present invention, the frequency band of 2 MHz to 3 MHz, which is a frequency band with less noise, is adopted as the frequency band of the electromagnetic waves detected by the antennas 13a and 13b.

  FIG. 11 is an explanatory diagram of an example of the sensitivity of an antenna that can detect a plurality of bands in the second embodiment of the present invention. Curves C16, C17, C18, C19, C20, and C21 are the sensitivity when the tuning dials 16a and 16b are set to 2.0 MHz, 2.2 MHz, 2.4 MHz, 2.6 MHz, 2.8 MHz, and 3.0 MHz. . In this way, by providing a plurality of bands for a cross section of one electromagnetic wave intensity, the resonance points are 2.0 MHz, 2.2 MHz, 2.4 MHz, 2.6 MHz, 2. Electromagnetic waves can be captured with six cross sections of 8 MHz and 3.0 MHz. Although the case where electromagnetic waves are captured in six multiple cross sections has been described with reference to FIG. 11, the electromagnetic waves may be captured in multiple cross sections of six or more or less than six.

  FIG. 12 is an explanatory diagram of another example of the sensitivity of the antenna that can detect a plurality of bands in the second embodiment of the present invention. In another example, the frequency band of the electromagnetic waves detected by the antennas 13a and 13b is set in the range of 1 MHz to 3 MHz, compared to the example shown in FIG. That is, in the example shown in FIG. 11, the frequency band of the electromagnetic waves detected by the antennas 13a and 13b is in the range of 2 MHz to 3 MHz. In another example, the range of 1 MHz to 2 MHz is also included in the range of 2 MHz to 3 MHz. Including the range of 1 MHz to 3 MHz. As a result, the electromagnetic wave is captured by 11 multiple cross sections in the range of 1 MHz to 3 MHz. In this case, the electromagnetic waves may be captured by a plurality of cross sections of 11 or more or less than 11.

  According to the second embodiment of the present invention, in addition to the effects of the first embodiment, an electromagnetic wave generated by a ground fault discharge can be captured in the range of 2 MHz to 3 MHz, which is a frequency band with less noise, and thus erroneous detection is performed. The accident point can be searched more accurately.

  The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications 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 11 ... Distribution line, 12 ... Electric power distribution apparatus, 13 ... Antenna, 14 ... Automobile, 15 ... Exploration radar main body, 16 ... Tuning dial, 17 ... Input device, 18 ... FFT analysis device, 19 ... Arithmetic processing device, 20 ... Display apparatus

Claims (2)

Apply a high-voltage pulse from the power applicator to the power distribution line
A pair of antennas detect electromagnetic waves generated by ground fault discharge at the accident point due to high voltage pulses,
In the electric circuit accident survey radar that determines the direction of the accident point based on the time difference between the output voltages of the pair of antennas,
A pair of antennas for detecting electromagnetic waves generated by a ground fault discharge at an accident point due to the high voltage pulse using a plurality of resonance frequencies;
An FFT analyzer for detecting a resonance frequency at which the output voltage of the pair of antennas is the highest by performing a fast Fourier transform on the detection signals of the pair of antennas;
Arithmetic processing that determines the resonance frequency with the highest output voltage detected by the FFT analyzer as the accident point resonance frequency and determines the direction of the accident point based on the time difference between the output voltages of the pair of antennas at the accident point resonance frequency Equipment,
And a display device for displaying and outputting the direction of the accident point determined by the arithmetic processing unit.   The power processing type electric circuit accident investigation radar according to claim 1, wherein the arithmetic processing unit displays and outputs the accident point resonance frequency detected by the FFT analysis device on the display device.

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