Exploration apparatus and method for exploring accident point

Abstract

To facilitate exploration of an accident point in a power distribution line.SOLUTION: An exploration apparatus 1 for exploring an accident point in a high-voltage power distribution line includes: a magnetic field detection unit 12 configured to detect, at an exploration position, a magnetic field generated from a current flowing through the high-voltage power line when a pulse voltage is applied to the high-voltage power line, and to output a magnetic field signal; a control unit 22 configured to output an integrated value obtained by integrating the magnetic field signal over a predetermined time; and a display unit 23 configured to display a level of the integrated value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an exploration device and a fault point exploration method. [Background technology]

[0002] The impact of an electric power outage, or power outage, on daily life is immeasurable. Therefore, even if an accident occurs in part of the power distribution system, causing a power outage, it is necessary to quickly identify the point of the accident, eliminate the cause, and quickly resume the power supply.

[0003] A conventional method for detecting a fault point is to directly contact a CT receiver or probe with an electric wire, measure the pulse current when a voltage is applied, and detect the fault point from the waveform. This method can reliably detect the applied current flowing at the fault point, but it requires climbing up the poles to install the CT receivers on each pole, making it difficult to detect the fault point in a short time.

[0004] Meanwhile, other detection methods have been developed that enable detection of fault points by receiving electromagnetic fields generated by electric currents with a receiver on the ground. For example, this method detects fault points from the magnitude of the time derivative of the magnetic field and the polarity at the time of the rise of the time derivative of the magnetic field (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-204438 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-145117 Summary of the Invention [Problem to be solved by the invention]

[0006] When the above-mentioned method was tested in field demonstration tests, it was found that the magnitude of the magnetic field generated by the applied current was small, especially in resistive ground faults with a ground fault resistance of approximately 10 kΩ or less. The value detected by the magnetic field sensor is the sum of the magnetic field generated by the applied current and the magnetic field generated by the return current. For this reason, when the applied current is small and the return current is large, the polarity of the rising edge may be the same before and after the fault point. Therefore, it may be difficult to locate the fault point on the ground using the polarity of the rising edge waveform.

[0007] The present invention provides an exploration device and a fault point exploration method that enable fault point exploration of a power distribution line to be easily performed. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the exploration device according to the present invention has the following features. An exploration device for exploring fault points in high-voltage power distribution lines, a magnetic field detection unit that detects a magnetic field generated from a current flowing by applying a pulse voltage to the high-voltage electric wire at an inspection position and outputs a magnetic field signal; a calculation unit that outputs an integral value obtained by integrating the magnetic field signal over a predetermined time period; a display unit that displays the level of the integral value, Exploration equipment.

[0009] In order to achieve the above-mentioned object, the fault location detection method according to the present invention has the following features. A fault point exploration method using the exploration device described above, the high-voltage wire has a branch portion, the magnetic field detection unit detects the magnetic field at each inspection position of a plurality of lines extending from the branch section; the calculation unit outputs the integral value at each of the search positions, the display unit displays the level of the integrated value at each of the search positions, The operator determines which of the search positions is in front of the fault point based on the displayed level. Fault point detection method.

[0010] A fault point detection method using the above detection device, the high-voltage wire has a branch portion, the magnetic field detection unit detects the magnetic field at each inspection position of a plurality of lines extending from the branch section; the calculation unit determines which of the search positions is in front of the fault point based on a comparison between the integral value at each of the search positions and a predetermined threshold value; Fault point detection method. [Effects of the Invention]

[0011] According to the present invention, fault point detection of a distribution line can be easily performed.

[0012] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a conceptual diagram showing a situation in which a fault point of a high-voltage power line is probed using a probe device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the waveform of a pulse voltage applied to a high-voltage wire by a voltage application device. [Figure 3] FIG. 3 is a conceptual diagram showing the flow of current in a high-voltage power line where a fault has occurred. [Figure 4] FIG. 4 is a block diagram of the exploration device according to the embodiment. [Figure 5] Figure 5 shows graphs of the magnetic field signal obtained by converting the magnetic field detected by the fluxgate sensor into a voltage, where (A) is a graph of the magnetic field signal just before the accident point, and (B) is a graph of the magnetic field signal just after the accident point. [Figure 6] FIG. 6 is a flowchart showing the procedure for fault point detection. [Figure 7] FIG. 7 is an explanatory diagram for explaining specific examples of fault point detection on a high-voltage power line, where (A) shows a first example and (B) shows a second example. [Figure 8] FIG. 8 is a front view of the display. [Figure 9] FIG. 9 is a perspective view showing the appearance of the receiving antenna unit. [Figure 10] FIG. 10 is a flowchart showing the procedure of another form of fault point detection. DETAILED DESCRIPTION OF THE INVENTION

[0014] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0015] When an accident occurs in part of a power distribution system, a power plant or substation temporarily stops supplying power to the power distribution system under the control of the power utility.The accident location is then narrowed down to a general area, and power supply is resumed to normal areas outside of that accident area.The specific point of the accident within the accident area is then identified.Once the specific point of the accident is identified, the cause of the accident is quickly removed and normal power supply is resumed in the accident area as well.

[0016] FIG. 1 is a conceptual diagram illustrating a situation in which a fault point of a high-voltage power line is being probed using an exploration device 1 according to an embodiment of the present invention. Multiple utility poles 101 are installed on the ground, and high-voltage power lines 102 for distribution lines are strung between each of the utility poles 101. The left side of FIG. 1 represents the upstream side, and the right side represents the downstream side. At the fault point of the high-voltage power line 102, the high-voltage power line 102 is broken or otherwise damaged. For example, after a power company narrows down a rough area including the fault point, a worker who will be performing the fault point probe visits the area and probes the fault point. Specifically, the worker uses the exploration device 1 according to the embodiment to detect a magnetic field generated by a current that flows when a pulse voltage is applied to the high-voltage power line 102 by a voltage application device 200 at the probe position, and probes the fault point. The worker attempts to detect the magnetic field while holding the insulated operating rod 30 of the exploration device 1 in an area including positions before and after the fault point.

[0017] The worker detects the magnetic field generated in the high-voltage wire 102 by positioning the receiving antenna unit 10 (see FIG. 4) of the detection device 1 at a position at least distance L1 from the ground wire and at a distance L2 from the high-voltage wire 102, i.e., at the detection position. Distance L1 is, for example, 60 cm, and distance L2 is, for example, 0 to 60 cm. By maintaining such distances L1 and L2 during measurement, it is possible to prevent the magnetic field from the ground wire from being measured and to accurately detect the magnetic field generated in the high-voltage wire 102.

[0018] In the present disclosure, a high-voltage distribution line refers to an electric wire or cable of, for example, 6600 V or more, and the exploration device 1 according to the embodiment is used to explore fault points in such high-voltage wiring.

[0019] 2 is a diagram showing the waveform of a pulse voltage applied to the high-voltage wire 102 by the voltage application device 200. The voltage application device 200 repeatedly applies a predetermined pulse voltage having a predetermined pulse application time to the high-voltage wire 102 for each cycle. The pulse voltage V is, for example, 15 kV, the pulse application time t is, for example, 10 ms (milliseconds), and one cycle is, for example, 4 s (seconds). After the application time t of the pulse voltage (for example, 10 ms) has elapsed, the voltage application device 200 immediately forcibly grounds the high-voltage wire 102, thereby stopping the application of voltage to the high-voltage wire 102.

[0020] 3 is a conceptual diagram showing the flow of current in the high-voltage power line 102 where a fault has occurred at the site shown in FIG. 1. When the voltage application device 200 applies a pulse voltage to the high-voltage power line 102, a charging current i c flows through the high-voltage power line 102 according to the capacitance of the high-voltage power line 102. If an fault point exists in the high-voltage power line 102, the fault current i g branches off and flows toward the fault point, generating a magnetic field around the high-voltage power line 102. The detection device 1 detects and measures the generated magnetic field to detect the fault point.

[0021] Fig. 4 is a block diagram showing the configuration of the exploration device 1. The exploration device 1 includes a receiving antenna unit 10 and a display 20. The receiving antenna unit 10 is an antenna device that detects a magnetic field generated from a current that flows when a voltage application device 200 applies a pulse voltage to a high-voltage wire 102, and the display 20 is a display device that displays the results of the magnetic field detection by the receiving antenna unit 10. In the example of Fig. 1, the receiving antenna unit 10 and the display 20 are separate entities, but they may also be integrated.

[0022] The receiving antenna unit 10 includes a housing 11 (see FIG. 9 ), as will be described later, and the housing 11 includes at least a magnetic field detection unit 12 that performs the main function of the receiving antenna unit 10. The magnetic field detection unit 12 detects a magnetic field generated from a current that flows when a pulse voltage is applied to a high-voltage wire 102 by a voltage application device 200, at an inspection position where an operator holds the inspection device 1, and outputs a magnetic field signal. The magnetic field detection unit 12 includes a fluxgate sensor 13, an amplifier 14, a filter 15, a control unit 16, and a wireless communication unit 18.

[0023] The fluxgate sensor 13 detects a magnetic field caused by the fault current ig in the high-voltage power line 102 and converts the magnetic field into a voltage signal corresponding to the magnetic field, outputting the converted signal. Instead of the fluxgate sensor 13, a sensor capable of detecting a magnetic field, such as a Hall element, may be used. However, a fluxgate sensor uses a soft magnetic material with high magnetic permeability for the core around which the coil is wound, and can detect magnetic fields ranging from DC components (0 Hz) to several MHz. The pulse voltage shown in FIG. 2 is generally 7.5 kV to 15 kV, so a sensor can be selected taking into account the magnetic field obtained within this voltage range. Note that if a loop antenna were used as the sensor, it would be unable to acquire low-frequency signals. In contrast, in this embodiment, the fluxgate sensor 13 is used as the sensor, enabling acquisition of wide-band signals including low-frequency components, such as those from 0 Hz to 30 Hz.

[0024] The amplifier 14 amplifies the magnetic field signal output by the fluxgate sensor 13. The filter 15 passes a specific frequency band of the magnetic field signal amplified by the amplifier 14, thereby reducing the processing load. The filter 15 includes a high pass filter (HPF) 15a, a low pass filter (LPF) 15b, and a band elimination filter (BEF) 15c. The HPF 15a passes a high frequency band by removing, for example, a band from 0 to 1 Hz. The LPF 15b passes a low frequency band by removing, for example, a band above 720 Hz. The BEF 15c removes a specific frequency band, for example, the commercial frequency band of 50 Hz / 60 Hz in this example. In this case, the filter 15 passes a band from 1 to 720 Hz (excluding the commercial frequency band of 50 Hz / 60 Hz). The filter 15 makes it possible to obtain a signal similar to the current measured by the CT receiver from the high-voltage power line 102.

[0025] The control unit 16 is a computer such as an MCU (Micro Controller Unit) that includes a processor that controls the entire magnetic field detection unit 12, a memory that stores data, and an input / output unit that exchanges data with the inside and outside of the control unit 16. The control unit 16 can control the on / off of the BEF 15c. The wireless communication unit 18 functions as an output unit that outputs the magnetic field signal that has passed through the filter 15 to a display 20, for example, by using short-range wireless communication.

[0026] The display device 20 includes a wireless communication unit 21, a control unit 22, a display unit 23, and an input unit 24. The wireless communication unit 21 functions as a receiving unit that receives a magnetic field signal from the wireless communication unit 18. Instead of the wireless communication unit 18 and the wireless communication unit 21, the receiving antenna unit 10 and the display device 20 may be communicatively connected via wired communication. The control unit 22 is a computer that includes a processor that controls the entire display device 20, a memory that stores data, an input / output unit that exchanges data with the inside and outside of the control unit 22, and the like. In this example, the control unit 22 functions as a calculation unit that outputs an integral value obtained by integrating the magnetic field signal over a predetermined time period.

[0027] The display unit 23 is a display device that displays the level of the integral value output by the control unit 22, and is configured, for example, by a liquid crystal display device. The input unit 24 is, for example, a button or a touch panel that can be operated by an operator, and allows the operator to input operations for the detection device 1.

[0028] The display 20 may be a display dedicated to the exploration device 1, or may be realized by application software installed in an electronic device such as a general-purpose tablet terminal.

[0029] 5 is a graph of the magnetic field due to the fault current i g in the high-voltage power line 102, detected by the fluxgate sensor 13, and is a graph of the magnetic field signal obtained by converting the magnetic field into a voltage. FIG. 5(A) is a graph of the magnetic field signal just before the fault point, and FIG. 5(B) is a graph of the magnetic field signal just after the fault point (or when there is no fault point). Since this magnetic field signal is weak, it is amplified by the amplifier 14, and unnecessary frequency bands are removed by the filter 15, and then it is sent to the display 20.

[0030] The control unit 22 of the display device 20 outputs an integrated value obtained by integrating the received magnetic field signal over a predetermined time period. The predetermined integration time can be set, for example, between 5 ms and 15 ms, and is 10 ms in this example. The fault current ig flows after the charging current ic flows. Therefore, as shown in Figure 5, the rising period of the magnetic field signal, i.e., the period from when the signal level goes from 0 to when it converges to a constant value, is estimated to be mainly a signal generated by the charging current ic.

[0031] Comparing Figure 5(A) and Figure 5(B), the magnetic field signal in Figure 5(A) before the accident point is larger than the magnetic field signal in Figure 5(B) after the accident point, and in Figure 5(B) the signal level after the rise period has converged to almost 0. Therefore, by comparing the two, it can be determined that the magnetic field signal in Figure 5(A) is the magnetic field signal before the accident point, and the magnetic field signal in Figure 5(B) is the magnetic field signal after the accident point.

[0032] The control unit 22 may also determine whether or not a magnetic field due to the fault current ig exists by integrating the period during which the magnetic field signal reaches a substantially constant value after the rising period has ended. This allows the magnetic field due to the charging current ic to be excluded from the determination. This constant value may be determined appropriately based on actual measurements obtained, for example, through a pre-experiment. The integration period is at most the application time t of the pulse voltage (e.g., 10 ms). This range can be set appropriately depending on the nature of the fault.

[0033] FIG. 6 is a flowchart illustrating the procedure for fault point detection performed by the detection device 1. An operator measures the magnetic field at multiple detection positions to detect the fault point. First, at the first detection position, the receiving antenna unit 10 starts measuring the voltage waveform of the magnetic field signal due to the magnetic field generated from the high-voltage power line 102 (step S1). Upon receiving the magnetic field signal from the receiving antenna unit 10, the control unit 22 calculates an integral value by integrating the magnetic field signal over a predetermined time period and displays it on the level meter (display 20). The operator checks the level meter of the detection device 1 and determines whether the level meter is above a certain level (step S3).

[0034] If the level meter is equal to or greater than a certain value (YES in step S3), the operator determines that the obtained magnetic field signal is a signal before the accident point (step S4). If the level meter is smaller than a certain value (NO in step S3), the operator determines that the obtained magnetic field signal is a signal after the accident point or a signal in a state where there is no accident point (step S5). The value used for determination based on the level meter may be an appropriate value determined based on, for example, an actual measurement value obtained in a previous experiment.

[0035] Furthermore, the worker checks whether or not there is a branch point where the high-voltage power line 102 is connected to the utility pole (step S6). If a branch point exists (YES in step S6), the worker determines whether or not measurements have been completed for all branches (step S7). If measurements have not been completed for all branches (NO in step S7), the process returns to the first step.

[0036] When measurements have been completed for all branches (YES in step S7), or when it is determined in step S6 that there are no branches (NO in step S6), the operator determines whether any of the magnetic field signals measured so far have been determined to be before the accident point (step S8). If there is no determination that any signal is before the accident point (NO in step S8), the operator determines that all measured locations are after the accident point (step S9).

[0037] If there is a determination that the measurement point is before the accident point (YES in step S8), the operator determines that the measurement point of the magnetic field signal that has been determined to be before the accident point is the measurement before the accident point (step S11).

[0038] The flowchart in Figure 6 shows the procedure for fault point detection when an operator determines whether the measurement location is before or after the fault point by referring to the level meter, but when the control unit 22 of the detection device 1 makes the determination, the procedure is as shown in Figure 10. In the following explanation, explanations of the same procedures as those in the flowchart in Figure 6 will be omitted.

[0039] When the receiving antenna unit 10 starts receiving the magnetic field signal, the control unit 22 calculates an integral value by integrating the magnetic field signal over a predetermined time period, and determines whether the integral value is equal to or greater than a predetermined threshold value (step S3).

[0040] If the integral value is equal to or greater than the predetermined threshold value (YES in step S3), the control unit 22 determines that the obtained magnetic field signal is a signal obtained before the accident point (step S4), and the display unit 23 displays the fact that the measurement was performed before the accident point and the measurement number (step S4A). This display may indicate, for example, that the level of the integral value is one of 1 to 8 (see FIG. 8). The measurement number indicates the number of the measurement in the series of measurements, and is displayed as a number or the like. The predetermined threshold value may be determined appropriately based on actual measurement values ​​obtained, for example, from experiments performed in advance.

[0041] If the integral value is smaller than the predetermined threshold value (NO in step S3), the control unit 22 determines that the obtained magnetic field signal is a signal after the accident point or a signal in a state where there is no accident point (step S5), and the display unit 23 displays that the measurement is after the accident point (step S5A). This display indicates, for example, that the level of the integral value is 0 (see FIG. 8).

[0042] The worker checks whether the high-voltage power line 102 is connected to the utility pole and whether there is a branch point (step S6). If there is a branch (YES in step S6), the worker determines whether measurements have been completed for all branches (step S7). If measurements have not been completed for all branches (NO in step S7), the process returns to step S1 and continues.

[0043] When measurements have been completed for all branches (YES in step S7), or when it is determined in step S6 that there are no branches (NO in step S6), the control unit 22 determines whether any of the magnetic field signals measured so far have been determined to be before the accident point (step S8). If there is no determination before the accident point (NO in step S8), it determines that all measured locations are after the accident point (step S9). If there is a determination before the accident point (YES in step S8), it determines that the measurement number of the magnetic field signal determined to be before the accident point is a measurement before the accident point (step S11).

[0044] According to the exploration device 1 of this embodiment, the magnetic field detection unit 12 detects the magnetic field generated from the current flowing when a pulse voltage is applied to the high-voltage power line and outputs a magnetic field signal, the control unit 22 outputs an integral value obtained by integrating the magnetic field signal over a predetermined time, and the display unit 23 displays the level of the integral value.

[0045] As a result, current flows from the applied voltage point where a pulse voltage is applied in the high-voltage distribution line wire 102 toward the fault point, and therefore, if the level of the integral value obtained by integrating the value detected by the magnetic field detection unit 12 is high, it means that the position is just before the fault point (between the applied voltage point and the fault point). With the above configuration, the level of the integral value is displayed on the display unit 23, so that an operator conducting fault point detection can easily determine whether the detection position is just before the fault point. Therefore, fault point detection of a distribution line electric wire can be easily performed.

[0046] The magnetic field detection unit 12 can include a fluxgate sensor 13 that detects a magnetic field at an inspection position, converts the magnetic field into a voltage corresponding to the magnetic field, and outputs a magnetic field signal, an HPF 15a and an LPF 15b that pass a specific frequency band of the magnetic field signal, and a wireless communication unit 18 that outputs the magnetic field signal that has passed through the HPF 15a and the LPF 15b to the control unit 22. As a result, the magnetic field signal from which unnecessary frequency bands have been removed is output to the control unit 22, thereby reducing the processing load on the control unit 22.

[0047] 7A and 7B are explanatory diagrams illustrating specific examples of fault point detection on a high-voltage power line 102, with (A) showing a first example and (B) showing a second example. In the example of Fig. 7A, an operator proceeds with the detection of the fault point in the order of detection range A, detection range B, detection range C, and detection range D, each of which includes at least one detection position. Detection range A includes detection position A-1 and detection position A-2, and also includes a charging point between detection position A-1 and detection position A-2 where the voltage charging device 200 applies a pulse voltage to the high-voltage power line 102.

[0048] If, as a result of the inspection by the inspection device 1, the display unit 23 displays a higher integral value level for the inspection position A-2 than for the inspection position A-1, it can be determined that the inspection position A-2 is closer to the accident point than the inspection position A-1 (the inspection position A-2 is closer to the accident point than the inspection position A-1). The inspection range B includes the inspection position B-1. If, as a result of the inspection by the inspection device 1, the display unit 23 displays a higher integral value level for the inspection position B-1 than for the inspection position A-2, it can be determined that the inspection position B-1 is closer to the accident point than the inspection position A-2.

[0049] The inspection range C has a branching section where multiple tracks extend, and includes inspection positions C-1, C-2, and C-3. Inspection positions C-1, C-2, and C-3 are located on each of the branching tracks. If, as a result of inspection by the inspection device 1, the display unit 23 displays a higher integrated value level for inspection position C-3 than for inspection positions C-1 and C-2, it can be determined that inspection position C-3 is closer to the fault point than inspection positions C-1 and C-2.

[0050] The search range D includes the search position D-1. If, as a result of the search by the search device 1, the display unit 23 displays a lower integrated value level for the search position D-1 than for the search position C-3, it can be determined that the search position D-1 is behind the accident point and that the accident point is located between the search position C-3 and the search position D-1.

[0051] In the example of Figure 7(B), the worker proceeds with the search for the accident point in the order of search area A, search area B, and search area C, each of which contains at least one search position. The search in search area A and search area B is the same as in the example of Figure 7(A). Search area C, like the example of Figure 7(A), has a branching section where multiple tracks extend, and search positions C-1, C-2, and C-3 are located on each of the branching tracks.

[0052] As a result of the inspection by the inspection device 1, the display unit 23 displays lower integral value levels for inspection positions C-1, C-2, and C-3 than for inspection position B-1. Looking at this display, an operator can determine that inspection positions C-1, C-2, and C-3 are behind the accident point, and that the accident point is located between inspection position B-1 and inspection position C-1, C-2, and C-3 (at the branch point in the figure).

[0053] As described above, an operator can use the inspection device 1 according to the embodiment to perform fault point inspection. In particular, when the high-voltage power line 102 has a branch, the magnetic field detection unit 12 of the inspection device 1 detects a magnetic field at each inspection position of multiple lines extending from the branch, and the control unit 22 outputs an integral value at each inspection position. The display unit 23 displays the level of the integral value at each inspection position, and the operator can determine which inspection position is closer to the fault point based on the displayed level.

[0054] 8 is a front view of the display 20 according to the embodiment. As described above, in this embodiment, the display 20 is separate from the receiving antenna unit 10, and the display unit 23 is provided in a device (display 20) outside the housing 11 of the receiving antenna unit 10. Because the display unit 23 is provided in a device outside the housing 11 of the receiving antenna unit 10, the level of the integrated value can be confirmed in a location away from the receiving antenna unit 10, such as at the operator's hand.

[0055] As shown in the example of Fig. 8, the display unit 23 displays the integral value in levels ranging from 0 to 8. For example, level 0 indicates that there is no accident point (not near the accident point), and levels 1 to 8 indicate that there is an accident point. The operator can estimate the type of accident (discharge, short circuit, etc.) based on the level.

[0056] FIG. 9 is an external perspective view of the receiving antenna unit 10. As described above, the receiving antenna unit 10 has a housing 11 that houses the magnetic field detection unit 12. The housing 11 is made of, for example, resin, and is equipped with a waterproof shield and holds the electronic circuitry that constitutes the magnetic field detection unit 12 inside. The detection device 1 also has an insulated operating rod 30 attached to the housing 11 of the receiving antenna unit 10. As shown in FIG. 1, an operator can bring the receiving antenna unit 10 close to the high-voltage power line 102 via the insulated operating rod 30, making it possible to detect the fault point without climbing a pole.

[0057] The housing 11 also has a recess 11a that corresponds to the outer shape of the high-voltage wire 102. By arranging the high-voltage wire 102 in the recess 11a, it is possible to reduce changes in the relative position between the high-voltage wire 102 and the magnetic field detection unit 12, thereby enabling stable magnetic field measurement. If the electric wire to be inspected is a high-voltage wire such as the high-voltage wire 102, the magnetic field can be detected by placing the receiving antenna unit 10 at a position away from the electric wire. If the electric wire to be inspected is a cable in which the high-voltage wire is covered with copper foil, and the copper foil serves as a ground wire, the magnetic field can be detected by placing the receiving antenna unit 10 directly against the cable.

[0058] Here, the features of the exploration device and the fault point exploration method according to the above-described embodiment of the present invention will be briefly summarized and listed below in [1] to [8].

[0059] [1] An inspection device (1) for detecting fault points in high-voltage power distribution lines, a magnetic field detection unit (12) that detects a magnetic field generated from a current flowing by applying a pulse voltage to the high-voltage electric wire at an inspection position and outputs a magnetic field signal; a calculation unit (control unit 22) that outputs an integral value obtained by integrating the magnetic field signal over a predetermined time period; and a display unit (23) that displays the level of the integral value. Exploration equipment.

[0060] According to the exploration device having the configuration [1] above, current flows from the applied voltage point where a pulse voltage is applied in a high-voltage distribution line toward the fault point. Therefore, if the level of the integrated value obtained by integrating the value detected by the magnetic field detection unit is high, it means that the location is just before the fault point (between the applied voltage point and the fault point). According to the configuration above, the level of the integrated value is displayed on the display unit, so that the operator conducting the fault point exploration can easily determine whether the exploration position is just before the fault point. Therefore, fault point exploration of a distribution line can be easily performed.

[0061] [2] The predetermined time is the time during which a fault current flows when the pulse voltage is applied in the case where a fault point exists in the high-voltage power line. The exploration device according to [1] above.

[0062] According to the detection device having the configuration of [2] above, the fault current is integrated, so it is possible to determine whether the detection position is before or after the fault point depending on the magnitude of the integral value.

[0063] [3] The magnetic field detection unit a sensor (fluxgate sensor 13) that detects the magnetic field at the detection position, converts the magnetic field into a voltage corresponding to the magnetic field, and outputs the magnetic field signal; filters (HPF 15a, LPF 15b, BEF 15c) that pass specific frequency bands of the magnetic field signal; an output unit (wireless communication unit 18) that outputs the magnetic field signal that has passed through the filter to the calculation unit, The exploration device according to [1] or [2] above.

[0064] According to the probe device having the configuration [3] above, the magnetic field signal from which unnecessary frequency bands have been removed is output to the calculation unit, thereby reducing the processing load on the calculation unit.

[0065] [4] A receiving antenna unit (10) having a housing (11) that houses the magnetic field detection unit; and an insulating operating rod (30) attached to the receiving antenna section. An exploration device according to any one of [1] to [3] above.

[0066] According to the detection device having the configuration [4] above, the operator can move the receiving antenna unit close to the high-voltage power line via the insulated control rod, making it possible to detect the fault point without climbing the pole.

[0067] [5] The housing has a recess (11a) corresponding to the outer shape of the high-voltage wire. The exploration device according to [4] above.

[0068] According to the probe device having the configuration [5] above, by arranging the high-voltage electric wire in the recess, it is possible to reduce the change in the relative position between the high-voltage electric wire and the magnetic field detector, thereby enabling stable magnetic field measurement.

[0069] [6] The display unit is provided on a device outside the housing. The exploration device according to [4] or [5] above.

[0070] According to the detection device having the configuration [6] above, the display unit is provided on the device outside the housing of the receiving antenna unit, so that the level of the integrated value can be checked at a location away from the receiving antenna unit, such as at the operator's hand.

[0071] [7] A fault point exploration method using the exploration device according to any one of [2] to [6] above, the high-voltage wire has a branch portion, the magnetic field detection unit detects the magnetic field at each inspection position of a plurality of lines extending from the branch section; the calculation unit outputs the integral value at each of the search positions, the display unit displays the level of the integrated value at each of the search positions, The operator determines which of the search positions is in front of the fault point based on the displayed level. Fault point detection method.

[0072] According to the fault point detection method configured as described above in [7], current flows from the applied voltage point where a pulse voltage is applied in a high-voltage distribution line toward the fault point. Therefore, if the level of the integrated value obtained by integrating the value detected by the magnetic field detection unit is high, it means that the fault point is just before the fault point (between the applied voltage point and the fault point). According to the above configuration, the level of the integrated value is displayed on the display unit, so that the worker performing the fault point detection can easily determine whether the detection point on the electric line is just before the fault point. Therefore, fault point detection can be easily performed on electric distribution lines.

[0073] [8] A fault point exploration method using the exploration device according to any one of [2] to [6] above, the high-voltage wire has a branch portion, the magnetic field detection unit detects the magnetic field at each inspection position of a plurality of lines extending from the branch section; the calculation unit determines which of the search positions is in front of the fault point based on a comparison between the integral value at each of the search positions and a predetermined threshold value; Fault point detection method.

[0074] According to the fault point detection method configured as described above in [8], since current flows from the applied voltage point where a pulse voltage is applied in a high-voltage distribution line toward the fault point, if the level of the integrated value obtained by integrating the value detected by the magnetic field detection unit is high, it means that the line is just before the fault point (between the applied voltage point and the fault point). According to the above configuration, the calculation unit can determine whether the detection point of the line is just before the fault point based on the integrated value. Therefore, fault point detection of a distribution line can be easily performed. [Explanation of symbols]

[0075] 1. Exploration equipment 10 Receiving antenna section 11. Housing 11a Recess 12 Magnetic field detection unit 13 Fluxgate sensor (sensor) 14 Amplifier 15 filters 15a HPF (filter) 15b LPF (filter) 15c BEF (filter) 16 Control Unit 18 Wireless communication unit (output unit) 20 Display 21 Wireless communication unit (receiving unit) 22 Control unit (calculation unit) 23 Display section 24 Input section 30 Insulated operating rod 102 High-voltage power lines 200 Power charging device

Claims

1. An exploration device for exploring fault points in high-voltage power distribution lines, a magnetic field detection unit that detects a magnetic field generated from a current flowing by applying a pulse voltage to the high-voltage electric wire at an inspection position and outputs a magnetic field signal; a calculation unit that outputs an integral value obtained by integrating the magnetic field signal over a predetermined time period; a display unit that displays the level of the integral value, Exploration equipment.

2. The predetermined time is a time during which a fault current flows when the pulse voltage is applied in the case where a fault point exists in the high-voltage power line. The exploration device according to claim 1 .

3. The magnetic field detection unit a sensor that detects the magnetic field at the detection position, converts the magnetic field into a voltage corresponding to the magnetic field, and outputs the magnetic field signal; a filter that passes a specific frequency band of the magnetic field signal; an output unit that outputs the magnetic field signal that has passed through the filter to the calculation unit, The exploration device according to claim 2 .

4. a receiving antenna unit having a housing that houses the magnetic field detection unit; an insulating operating rod attached to the receiving antenna unit, The exploration device according to claim 2 .

5. The housing has a recess corresponding to the outer shape of the high-voltage wire. The exploration device according to claim 4.

6. The display unit is provided on a device outside the housing. The exploration device according to claim 4.

7. A fault point exploration method using the exploration device according to any one of claims 2 to 6, the high-voltage wire has a branch portion, the magnetic field detection unit detects the magnetic field at each inspection position of a plurality of lines extending from the branch section; the calculation unit outputs the integral value at each of the search positions, the display unit displays the level of the integrated value at each of the search positions, The operator determines which of the search positions is in front of the fault point based on the displayed level. Fault point detection method.

8. A fault point exploration method using the exploration device according to any one of claims 2 to 6, the high-voltage wire has a branch portion, the magnetic field detection unit detects the magnetic field at each inspection position of a plurality of lines extending from the branch section; the calculation unit determines which of the search positions is in front of the fault point based on a comparison between the integral value at each of the search positions and a predetermined threshold value; Fault point detection method.

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