Partial discharge location locating device, partial discharge location locating method, and program

Abstract

To highly precisely locate an occurrence position of a partial discharge at lower costs and within an operationally required range.SOLUTION: A partial discharge position locating device 600 acquires waveform data as a detection result of electromagnetic waves generated when a partial discharge occurs by at least one sensor 190 installed in a gas-insulated switchgear 100. The partial discharge position locating device 600 acquires frequency spectra of the acquired waveform data, and determines whether space existing in an occurrence position CP of a partial discharge is within busbar housing spaces 170a to 170b formed by busbar partial spaces 171a to 174a, and 171b to 174b of at least one unit 110, or within one of branch line housing spaces 180a to 180d of at least one unit 110 on the basis of presence or absence of deviation of distribution of the acquired frequency spectra.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a partial discharge location locating device, a partial discharge location locating method, and a program. [Background technology]

[0002] Patent Documents 1 to 4 disclose techniques for locating the location of partial discharge inside a gas insulated switchgear (GIS). Patent Document 1 describes a method in which sensors for detecting electromagnetic wave signals generated when partial discharge occurs inside the gas-insulated switchgear are installed at multiple positions on the gas-insulated switchgear, and the position where partial discharge occurs is located by comparing the magnitudes of the received electromagnetic wave signals detected by the multiple sensors.

[0003] Patent Document 2 describes a method in which a first sensor and a second sensor that detect the potential difference of a voltage surge due to partial discharge generated inside a gas-insulated switchgear are installed on a flange of a tank of the gas-insulated switchgear, and the position where the partial discharge occurs is located based on the time difference between the signals obtained by the first sensor and the second sensor.

[0004] Patent Document 3 describes a gas-insulated switchgear in which a narrow-diameter section having an inner diameter smaller than the inner diameter of a tank is formed for each of a number of gas compartments separated by insulating spacers. The gas compartment in which the partial discharge has occurred is determined based on whether or not the signal detected by each sensor contains a frequency component equal to or lower than a cutoff frequency determined by the inner diameter of the narrow-diameter section.

[0005] Patent Document 4 describes a method in which sensors for detecting electromagnetic wave signals generated when partial discharge occurs inside a gas-insulated switchgear are installed at multiple positions on the gas-insulated switchgear, and the position with the maximum spectrum intensity is located as the position where partial discharge occurs based on the relationship between the spectrum intensity of the frequency spectrum of the electromagnetic waves detected by the multiple sensors and the installation positions of the multiple sensors. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 1-298907 [Patent Document 2] Japanese Patent Application Publication No. 6-174778 [Patent Document 3] JP 2010-210574 A [Patent Document 4] Japanese Patent Application Publication No. 3-15771 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the signal strength (detection strength) of electromagnetic waves generated by partial discharges received by a sensor decreases exponentially as the propagation distance increases, but the detection strength of a relatively long propagation distance may be higher than that of a relatively short propagation distance due to variations in signal strength, etc. (see, for example, FIG. 3 described later). For this reason, a simple comparison of the detection strength of electromagnetic waves, such as the technology described in Patent Document 1, may result in erroneous determination of the location of partial discharge occurrence. In order to prevent such erroneous determination, it is possible to shorten the distance between the sensors, but this would require a larger number of sensors. Therefore, the device for locating the location of partial discharge occurrence becomes expensive.

[0008] In addition, in the technology described in Patent Document 2, the location of the partial discharge is located based on the time difference between the signals obtained by two sensors. Therefore, in order to locate the location of the partial discharge with high accuracy, for example,-9 It is necessary to have measuring equipment capable of simultaneous measurement of multiple sensors with high accuracy on the order of seconds. Therefore, the equipment for locating the location of partial discharge occurrence is expensive.

[0009] Furthermore, in the technology described in Patent Document 3, the number of sensors required corresponds to the number of gas categories. Therefore, a large number of sensors are required according to the scale of the gas-insulated switchgear. Therefore, the device for locating the partial discharge occurrence position becomes expensive.

[0010] In addition, in the technology described in Patent Document 4, it is necessary to obtain the position with the maximum spectrum intensity from the relationship between the spectrum intensity of the frequency spectrum of the electromagnetic wave and the installation positions of multiple sensors. Therefore, the calculation load for locating the partial discharge occurrence position is large. Therefore, the device for locating the partial discharge occurrence position is expensive.

[0011] The present invention has been made in consideration of the above-mentioned problems, and has an object to make it possible to locate the location of partial discharge occurrence in a gas-insulated switchgear at lower cost and with high accuracy within a range required for operation. [Means for solving the problem]

[0012] The present invention provides a partial discharge location locating device for locating a location of a partial discharge occurring in a gas-insulated switchgear having one or more units formed therein with a busbar partial space for partially accommodating a busbar and a branch line accommodating space for accommodating a branch line branched from the busbar, the gas-insulated switchgear comprising: At least one of the busbar partial space and the branch line accommodating space Installed in Detecting electromagnetic waves generated when the partial discharge occurs. At least one sensor And the electric The present invention is provided with a waveform data acquisition unit that acquires waveform data that is a result of detection of a magnetic wave, and a location unit that locates the occurrence position of the partial discharge based on the waveform data, the location unit including a frequency spectrum acquisition unit that acquires a frequency spectrum of the waveform data, and a distribution bias of the frequency spectrum acquisition unit that acquires a frequency spectrum of the waveform data. If not,The space in which the partial discharge occurs is within a busbar accommodation space formed by the busbar partial spaces of the one or more unitary units. It was determined that , When the distribution of the frequency spectrum is biased, the space in which the partial discharge occurs is Within the branch line accommodating space of any of the one or more units and and a frequency spectrum determining unit for determining

[0013] The partial discharge location locating method of the present invention is a partial discharge location locating method for locating a location of a partial discharge occurring in a gas-insulated switchgear having one or more units formed therein with a busbar partial space in which a busbar is partially accommodated and a branch line accommodating space in which a branch line branched from the busbar is accommodated, At least one of the busbar partial space and the branch line accommodating space Installed in Detecting electromagnetic waves generated when the partial discharge occurs. At least one sensor Using The method includes a waveform data acquisition step of acquiring waveform data that is a detection result of an electromagnetic wave generated when the partial discharge occurs, and a location step of locating the location of the occurrence of the partial discharge based on the waveform data, the location step including a frequency spectrum acquisition step of acquiring a frequency spectrum of the waveform data, and a distribution bias of the frequency spectrum acquisition step of locating the location of the occurrence of the partial discharge based on the waveform data. If not, The space in which the partial discharge occurs is within a busbar accommodation space formed by the busbar partial spaces of the one or more unitary units. It was determined that , When the distribution of the frequency spectrum is biased, the space in which the partial discharge occurs is Within the branch line accommodating space of any of the one or more units and and a frequency spectrum determining step of determining the frequency spectrum of the signal.

[0014] The program of the present invention causes a computer to function as each unit of the partial discharge location device. Effect of the Invention

[0015] According to the present invention, the location of a partial discharge occurring in a gas-insulated switchgear can be located at a lower cost and with a high degree of accuracy within a range required for operation. [Brief description of the drawings]

[0016] [Figure 1A] FIG. 1 is a plan view showing an example of the configuration of a partial discharge position locating system for a gas-insulated switchgear. [Figure 1B] 1B is a cross-sectional view of a unit constituting the gas-insulated switchgear, and shows cross-section II of FIG. 1A. FIG. [Figure 1C] FIG. 1B is a circuit diagram of the gas-insulated switchgear corresponding to FIG. 1A. [Diagram 2] FIG. 13 is a diagram illustrating an example of a sensor arrangement. [Diagram 3] FIG. 11 is a diagram illustrating an example of the relationship between propagation distance and detection intensity. [Figure 4] FIG. 2 is a diagram showing an example of the configuration of a test device for determining a frequency spectrum of waveform data detected by a sensor. [Figure 5A] FIG. 4 is a diagram showing a first example of a frequency spectrum of waveform data corresponding to a simulation signal. [Figure 5B] FIG. 11 is a diagram showing a second example of a frequency spectrum of waveform data corresponding to a simulation signal. [Figure 6] FIG. 2 is a diagram illustrating an example of a functional configuration of a partial discharge position locating device. [Figure 7] 1 is a flowchart illustrating an example of a partial discharge location method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the term "the same objects in terms of length, position, size, spacing, etc." includes not only those that are strictly the same, but also those that are different within the scope of the invention (for example, those that differ within the tolerance range determined at the time of design).

[0018] Fig. 1A is a diagram showing an example of the configuration of a partial discharge position locating system 1 of a gas-insulated switchgear 100. Fig. 1B is a cross-sectional view of a unit 110 constituting the gas-insulated switchgear 100, showing a cross section II of Fig. 1A. Fig. 1C is a circuit diagram of the gas-insulated switchgear 100 corresponding to Fig. 1A. 1A and 1C, the partial discharge location locating system 1 includes one or more sensors 190 installed in the gas-insulated switchgear 100, and a partial discharge location locating device 600. The above-mentioned sensor 190 and the partial discharge location locating device 600 are connected by wire or wirelessly, and are configured so that the detection result by the sensor 190 is input to the partial discharge location locating device 600. Each of these configurations will be described below.

[0019] <Gas-insulated switchgear> 1A and 1C, the gas-insulated switchgear 100 includes one or more unit units 110 (four unit units 110a-110d in this embodiment). The multiple unit units 110a-110d have the same configuration, and FIG. 1B shows a cross-sectional view of one of the multiple unit units 110d as a representative. The multiple unit units 110a-110d are coupled to each other (connected in a row) to form the gas-insulated switchgear 100. The number of unit units 110 included in the gas-insulated switchgear 100 is arbitrary depending on the scale, and may be one or more.

[0020] Each of the unitary units 110a to 110d has a hollow space. The unitary units 110a to 110d are connected to each other, for example, by using a flange joint (not shown) provided in a sealed container portion forming a busbar receiving space described later. When the unitary units 110a to 110d are connected to each other, the hollow spaces of the unitary units 110a to 110d communicate with each other. The hollow spaces of the unitary units 110a to 110d form the hollow space of the gas-insulated switchgear 100. The hollow space of the gas-insulated switchgear 100 is sealed, and an insulating gas such as SF6 gas (sulfur hexafluoride gas) is sealed in the hollow space of the gas-insulated switchgear 100.

[0021] The hollow space of the gas-insulated switchgear 100 accommodates busbars 120a-120b, branch lines 130a-130d, disconnectors 140a-140d, circuit breakers 150a-150d, and cable heads 160a-160d. In FIG. 1A, the busbars 120a, 120b and the branch lines 130a-130d cannot be seen from outside the gas-insulated switchgear 100. However, in order to make the relationship between the figures easier to understand, the busbars 120a, 120b are shown by dashed lines, and the branch lines 130a-130d are shown by dashed lines, and an outline of the state seen through them is shown. As shown in FIG. 1A and FIG. 1C, a double busbar power system is exemplified as the extra-high voltage power system. However, the number of busbars accommodated in the gas-insulated switchgear may be one or more.

[0022] The bus bars 120a-120b function as conductors of the main circuit, and are electric wires that receive all current from the upper power system and distribute it to the branch bars 130a-130d. The branch bars 130a-130d connect the disconnectors 140a-140d, the circuit breakers 150a-150d, and the cable heads 160a-160d in series, and function as conductors for connecting the bus bars 120a-120b and the loads (electrical devices) (not shown) connected to the cable heads 160a-160d (see FIGS. 1B-1C). Note that connecting means electrically connecting. This is the same in other explanations.

[0023] The disconnectors 140a to 140d open and close when no current flows through the circuit. FIG. 1C shows a state in which the disconnectors 140a to 140d are not connected to either the electric wires 131a to 131d connected to the bus bar 120a among the branch lines 130a to 130d or the electric wires 132a to 132d connected to the bus bar 120b among the branch lines 130a to 130d. However, normally, the disconnectors 140a to 140d open and close so as to connect to one of the electric wires 131a to 131d and the electric wires 132a to 132d but not to the other. The disconnectors 140a to 140d are used, for example, to switch the power transmission system (bus bars 120a to 120b) or to reliably disconnect a load (electrical equipment) (not shown) connected to the cable heads 160a to 160d from the main circuit during maintenance and inspection.

[0024] The circuit breakers 150a to 150d have a function of interrupting a load current flowing to a load (electrical device) (not shown) connected to the cable heads 160a to 160d. When a fault current occurs due to a ground fault, a short circuit, or the like, the circuit breakers 150a to 150d automatically open to prevent the fault current from flowing to the load.

[0025] The cable heads 160a to 160d are connected to a load (electrical equipment) (not shown). A current flowing from the bus bars 120a to 120b via the disconnectors 140a to 140d and the circuit breakers 150a to 150d is supplied as a load current from the cable heads 160a to 160d to the load (electrical equipment) (not shown).

[0026] As shown in Fig. 1A and Fig. 1B, the hollow space of the gas-insulated switchgear 100 has busbar accommodating spaces 170a-170b corresponding to the spaces in which the busbars 120a-120b are accommodated, and branch line accommodating spaces 180a-180d corresponding to the spaces in which the branch lines 130a-130d are accommodated. The busbar accommodating spaces are spaces formed inside the gas-insulated switchgear 100 by connecting one or more unit units 110 (110a-110d) in a row, and by connecting busbar partial spaces 171a-174a, 171b-174b formed in each unit unit 110a-110d in one direction (the extension direction of the busbars 120a-120b). In the example shown in Fig. 1A, two busbar partial accommodating spaces 170a-170b and one branch line accommodating space 180a-180d are formed inside each unit unit 110. Therefore, the gas-insulated switchgear 100 has two busbar accommodating spaces 170a-170b extending in the longitudinal direction of the busbars 120a-120b, and the same number (four) of branch line accommodating spaces 180a-180d as the number of units 110, extending in a direction perpendicular to the busbars 120a-120b. In Fig. 1A and Fig. 1B, the busbar accommodating spaces 170a-170b are shown in a relatively dark gray, and the branch line accommodating spaces 180a-180d are shown in a relatively light gray. The number of busbar accommodating spaces provided in the gas-insulated switchgear 100 may be one or more.

[0027] Incidentally, since the gas insulated switchgear 100 itself can be realized by known technology, only an outline of the gas insulated switchgear 100 has been described here. In addition, the gas insulated switchgear is not limited to the gas insulated switchgear 100 shown in Figs. 1A to 1C, and may be any of various known duct-type gas insulated switchgears.

[0028] <Sensor> In the gas-insulated switchgear 100, one or more sensors are installed depending on the scale of the device, such as the number of individual units. Normally, the gas-insulated switchgear 100 is installed with a plurality of sensors since it has a plurality of individual units. In this embodiment, one sensor 190a-190f is installed in each of the two busbar accommodating spaces 170a-170b and the four branch line accommodating spaces 180a-180d. In FIG. 1A, the sensors 190a-190f cannot actually be seen from outside the gas-insulated switchgear 100, but in order to make the relationship between the figures easier to understand, the sensors 190a-190f are shown by dotted lines, and an outline of the sensors as seen through them is shown.

[0029] When a partial discharge occurs in the bus bars 120a-120b or the branch lines 130a-130d as a precursor to an internal accident (such as a short circuit accident or a ground fault accident) in the gas insulated switchgear 100, an electromagnetic wave is generated starting from the position where the partial discharge occurs. The sensors 190a-190f detect the electromagnetic waves (hereinafter simply referred to as electromagnetic waves as appropriate) generated by the partial discharge and output a detection value corresponding to the intensity of the detected electromagnetic waves. In this embodiment, the sensors 190a-190f are exemplified as sensors equipped with UHF (Ultra High Frequency) antennas and outputting a voltage value corresponding to the intensity of the electromagnetic waves.

[0030] Fig. 2 is a diagram showing an example of the arrangement of the sensor 190a. In Fig. 2, the electromagnetic wave propagating from the occurrence position CP of the partial discharge generated inside the gas insulated switchgear 100 (bus bar 120a) is shown by a broken line. In Fig. 2, an insulating spacer 210 is a member for supporting the bus bar 120a. Such insulating spacers are also installed for the bus bar 120b and the branch lines 130a to 130d.

[0031] 2, the sensor 190a is disposed in a recess in the inner wall surface of the gas insulated switchgear 100 such that the detection surface of the sensor 190a is exposed to the hollow space (busbar accommodating space 170a) of the gas insulated switchgear 100. The other sensors 190b to 190f are also disposed such that the detection surfaces of the sensors 190b to 190f are exposed to the hollow spaces (busbar accommodating space 170b, branch line accommodating spaces 180a to 180d) of the gas insulated switchgear 100, similar to the sensor 190a.

[0032] <Findings> Next, the findings of the present inventors will be described with reference to FIG. The present inventors have investigated the relationship between the propagation distance, which is the distance along the electromagnetic wave propagation path from the occurrence position CP of partial discharge occurring inside the gas-insulated switchgear 100 to the sensor installation position, and the detection intensity, which indicates the magnitude of the detection value (e.g., voltage value) obtained when the electromagnetic wave is detected by the sensor. Here, the detection intensity is the crest value (maximum amplitude value) in the time-series data (hereinafter also referred to as waveform data) of the detection value obtained when the electromagnetic wave is detected. However, the detection intensity is not limited to the crest value, and may be, for example, the effective value or the peak-to-peak value of the waveform. FIG. 3 is a diagram showing an example of the relationship between the propagation distance and the detection intensity. In FIG. 3, R 2 is the coefficient of determination for the approximation curve 310 obtained by regression analysis from the points of the square shown in FIG.

[0033] As shown in Fig. 3, the detection strength decreases exponentially as the propagation distance increases. However, due to variations in the detection strength when detected by the sensor, the detection strength at a relatively long propagation distance may be higher than the detection strength at a relatively short propagation distance. Specifically, in Fig. 3, there are plot points at a propagation distance of about 10 m that have a higher detection strength than those at a propagation distance of about 6 to 7 m. Therefore, it can be seen that there is a possibility of erroneous determination of the location CP of the partial discharge occurrence by only comparing the magnitude relationship of the detection strength.

[0034] On the other hand, the present inventors have found that it is possible to determine whether the location of the partial discharge is the busbar accommodating space or the branch line accommodating space based on the frequency spectrum of the signal waveform of the electromagnetic wave received by the sensor installed in the branch line accommodating space. In detail, a simulated signal, such as a pulse signal, simulating the electromagnetic wave caused by the partial discharge is generated in the busbar accommodating space or the branch line accommodating space. For example, when the above-mentioned simulated signal is generated in the branch line accommodating spaces 180a to 180d, it is possible to generate it by using one of the sensors 190c to 190f as shown in FIG. 4. This simulated signal is detected by each sensor installed in the branch line accommodating space, and the frequency spectrum of the signal is obtained by frequency analysis of the waveform data obtained when the simulated signal is detected by any one of the sensors 190a to 190f by FFT (Fast Fourier Transform). FIG. 4 is a diagram showing an example of the configuration of a test device for obtaining the frequency spectrum of the above-mentioned waveform data.

[0035] A pulse generator 410 is connected to one of the sensors 190a to 190f. FIG. 4 illustrates a state in which the pulse generator 410 is connected to the sensor 190f. An oscilloscope 420 is connected to all the sensors 190a to 190f. As described above, the sensors 190a to 190f are equipped with UHF antennas. A simulation signal is output from the pulse generator 410 to the sensor 190f connected to the pulse generator 410, and the sensor 190f transmits the simulation signal. The oscilloscope 420 acquires waveform data corresponding to the simulation signal received by the sensors 190a to 190e other than the sensor 190f connected to the pulse generator 410, and the analysis PC 430 performs frequency analysis to obtain a frequency spectrum for each of the sensors 190a to 190e. The frequency spectrum is obtained as described above by changing the sensor connected to the pulse generator 410 (i.e., the sensor that transmits the simulation signal).

[0036] 5A and 5B are diagrams showing a first and second example of the frequency spectrum of the above-mentioned waveform data. In Fig. 5A and Fig. 5B, the unit of the spectrum intensity (intensity of the frequency spectrum) is made dimensionless ([-] on the vertical axis indicates that the unit is made dimensionless). 5A, frequency spectrum 510 (solid line) is the frequency spectrum of waveform data corresponding to the simulation signal received by sensor 190d when the sensor transmitting the simulation signal is sensor 190c installed in branch line accommodating space 180a. Frequency spectrum 520 (dashed line) is the frequency spectrum of waveform data received by sensor 190d when the sensor transmitting the simulation signal is sensor 190b installed in busbar accommodating space 170b.

[0037] 5B, frequency spectrum 530 is the frequency spectrum of the waveform data received by sensor 190e when the sensor transmitting the simulation signal is sensor 190f installed in branch line accommodating space 180d. Frequency spectrum 540 is the frequency spectrum of the waveform data received by sensor 190e when the sensor transmitting the simulation signal is sensor 190b installed in busbar accommodating space 170b.

[0038] In FIG. 5A, the distance between sensor 190c on the transmission side of the simulation signal and sensor 190d on the reception side, which was used when frequency spectrum 510 was obtained, is approximately twice the distance between sensor 190b on the transmission side of the simulation signal and sensor 190d on the reception side, which was used when frequency spectrum 520 was obtained, but there is no significant difference in the maximum value of the spectral intensity in the frequency spectrum.

[0039] In addition, in FIG. 5B, the distance between sensor 190f on the transmission side of the simulation signal and sensor 190e on the reception side, which was used when frequency spectrum 530 was obtained, is approximately 1.4 times the distance between sensor 190b on the transmission side of the simulation signal and sensor 190e on the reception side, which was used when frequency spectrum 540 was obtained, but there is no significant difference in the maximum value of the spectral intensity in the frequency spectrum.

[0040] 5A, comparing the distributions of frequency spectra 510 and 520, it can be seen that frequency spectrum 510 has fewer peaks with high spectral intensity in the frequency band of 850 MHz or more and 1100 MHz or less compared to other frequency bands among the frequency bands included in the electromagnetic waves generated by partial discharge, and the peaks with high spectral intensity are concentrated in the region below 850 MHz. On the other hand, frequency spectrum 520 has a smaller distribution bias between the frequency band of 850 MHz or more and 1100 MHz or less and other frequency bands than frequency spectrum 510, and it can be seen that peaks with high spectral intensity occur over a wide range.

[0041] 5B, comparing the distributions of frequency spectra 530 and 540, it can be seen that frequency spectrum 530 has fewer peaks with high spectral intensity in the frequency band of 650 MHz or more and 1100 MHz or less compared to other frequency bands among the frequency bands contained in the electromagnetic waves generated by partial discharge, and the peaks with high spectral intensity are concentrated in the region below 650 MHz. On the other hand, frequency spectrum 540 has a smaller distribution bias between the frequency band of 650 MHz or more and 1100 MHz or less and other frequency bands than frequency spectrum 530, and it can be seen that peaks with high spectral intensity occur over a wide range.

[0042] Frequency spectra 510 and 530 are frequency spectra when the sensors transmitting the simulation signals are sensors 190c and 190f installed in branch line accommodating spaces 180a and 180d, respectively. On the other hand, frequency spectra 520 and 540 are frequency spectra when the sensor transmitting the simulation signal is sensor 190b installed in busbar accommodating space 170b.

[0043] When the sensor transmitting the simulation signal is installed in branch line accommodating space 180a, 180d, the bias in the distribution of frequency spectra such as frequency spectra 510, 530 shown in Figures 5A and 5B becomes significantly larger, whereas when the sensor transmitting the simulation signal is installed in busbar accommodating space 170b, the bias in the distribution of frequency spectra such as frequency spectra 520, 540 shown in Figures 5A and 5B becomes smaller. This tendency was the same regardless of the combination of the sensor transmitting and the sensor receiving the simulation signal.

[0044] From the above, the inventors have discovered that when a partial discharge occurs in the branch line accommodating spaces 180a-180d, a relatively large bias occurs in the distribution of the frequency spectrum based on the waveform data output from the sensors 190a-190f, whereas when a partial discharge occurs in the bus bar accommodating spaces 170a-170b, the bias occurring in the distribution of the frequency spectrum of the waveform data output from the sensors 190a-190f becomes relatively smaller.

[0045] Therefore, for example, if the frequency spectrum of the waveform data output from one sensor selected from the sensors 190a-190f is deemed to have a bias in the distribution of the frequency spectrum, the partial discharge occurrence position CP is determined to be the branch line accommodating space 180a-180d, and if not, the partial discharge occurrence position CP is determined to be the bus line accommodating space 170a-170b, and the partial discharge occurrence position CP can be located. Here, the actual partial discharge occurrence position CP is a limited space of the bus line accommodating spaces 170a-170b (bus lines 120a-120b) and the branch line accommodating spaces 180a-180d (branch lines 130a-130d). However, the interruption of power by the disconnectors 140a-140d and the circuit breakers 150a-150d is performed in units of the bus line accommodating spaces 170a-170b or the branch line accommodating spaces 180a-180d. Therefore, if it is possible to locate the partial discharge occurrence position CP in units of the bus bar accommodating spaces 170a to 170b or the branch line accommodating spaces 180a to 180d, there will be no practical problem.

[0046] Whether or not the distribution of the frequency spectrum is considered to be biased is determined based on, for example, a result of comparison between an analysis value of the frequency spectrum in a high frequency band higher than the specified frequency and an analysis value of the frequency spectrum in a low frequency band lower than the specified frequency. Here, a frequency value that can determine whether or not the distribution of the frequency spectrum of the waveform data output from the sensors 190a to 190f has a bias, such as a peak being biased toward the low frequency band side (or the high frequency band side) compared to the high frequency band side (or the low frequency band side), is set as the specified frequency. For example, the specified frequency may be set to a frequency value near the center of the entire distribution of the frequency spectrum caused by the electromagnetic wave of partial discharge (excluding noise parts) obtained through experiments or the like. Alternatively, a frequency value that can determine the presence or absence of the occurrence of partial discharge may be selected and set as the specified frequency from the difference in the distribution of the frequency spectrum obtained according to the presence or absence of the occurrence of partial discharge through experiments or the like. The specified frequency may also be set according to various conditions such as the internal structure and installation state of the target gas-insulated switchgear.

[0047] In this embodiment, the prescribed frequency is selected from a range (650 MHz to 850 MHz) with the upper and lower limits of 850 MHz and 650 MHz being the upper limit values ​​of the frequency band where peaks with high spectrum intensity are concentrated in the frequency spectrum 510, 530 based on the waveform data output from the sensors 190c, 190f. The prescribed frequency may be, for example, 650 MHz or 850 MHz, or 750 MHz, which is the average value of these. The upper limit value of the high frequency band may be set as the prescribed frequency. The upper limit value of the high frequency band on the higher frequency side than the prescribed frequency may be, for example, 1100 MHz or 1050 MHz depending on the value assumed as the upper limit value of the frequency band included in the electromagnetic waves generated by partial discharge.

[0048] The analysis value of the frequency spectrum may be, for example, an integral value. Alternatively, the analysis value of the frequency spectrum may be a ratio of the number of peaks whose spectral intensity exceeds a threshold in a high frequency band higher than a specified frequency to the total number of peaks in the frequency spectrum in all frequency bands, or a ratio of the number of peaks whose spectral intensity exceeds a threshold in a low frequency band lower than a specified frequency to the total number of peaks in the frequency spectrum in all frequency bands.

[0049] <Partial discharge position locating device> 6 is a diagram showing an example of a functional configuration of the partial discharge locating device 600. The hardware of the partial discharge locating device 600 is realized by using, for example, an information processing device (computer) equipped with a processor, a storage device such as a main storage device or an external storage device, and various interfaces, or dedicated hardware. The partial discharge locating device 600 may also include various signal processing circuits. The partial discharge locating device 600 may also include a spectrum analyzer.

[0050] The partial discharge position locating device 600 is a device for locating a position CP of a partial discharge occurring inside the gas-insulated switchgear 100. As shown in FIG. 6, the partial discharge position locating device 600 includes a detection value acquiring unit 610, a storage unit 620, a detector 630, a waveform data acquiring unit 640, and a locating unit 650, and is configured to be able to locate the position of a partial discharge when the partial discharge occurs. In this embodiment, the partial discharge position locating device 600 further includes an output unit 660. Each of these functional units will be described. Note that the function of the storage unit 620 may be included in a device other than the partial discharge position locating device 600. In this case, the partial discharge position locating device 600 accesses the storage unit 620 by communicating with the other device.

[0051] <<Detection value acquisition unit 610, storage unit 620>> The detection value acquisition unit 610 acquires detection values ​​detected by one or more sensors 190 installed in the gas-insulated switchgear 100 and stores them in the storage unit 620. In this embodiment, the detection value acquisition unit 610 acquires detection values ​​detected by each sensor 190 (sensors 190a to 190f) at a specified sampling period in a predetermined acquisition order. The detection value acquisition unit 610 identifies the sensor 190 that detected the detection value based on the acquisition order of the detection value. The detection value acquisition unit 610 stores (accumulates) the detection value detected by each sensor 190 in a storage area for each sensor 190 set in the storage unit 620 (such as an external storage device, which is an example of hardware constituting the storage unit 620). It is not necessary for the detection value acquisition unit 610 to acquire the detection values ​​in the predetermined acquisition order. For example, the detection value may be transmitted to the partial discharge position locating device 600 with information identifying the sensor 190 added thereto. In this case, the detection value acquisition unit 610 identifies the sensor 190 that detected the detection value based on the information added to the detection value.

[0052] <<Detection Unit 630>> The detection unit 630 detects the presence or absence of the occurrence of partial discharge in the gas insulated switchgear 100 based on detection values ​​detected by one or more sensors 190 out of one or more sensors 190 installed in the gas insulated switchgear 100. The detection unit 630 only needs to acquire detection values ​​for each sensor 190 within a range necessary for detecting the occurrence of partial discharge, for example by determining at least a part of the multiple sensors 190 as monitoring targets, and may acquire detection values ​​of all sensors 190 or may acquire detection values ​​of a part of sensors 190. In this embodiment, the detection unit 630 includes a first intensity acquisition unit 631 and a sensor determination unit 632.

[0053] <<<First Intensity Acquisition Unit 631>>> The first intensity acquisition unit 631 acquires the detection intensity of each sensor 190 (190a to 190f). This detection intensity is not particularly limited as long as it indicates the magnitude of the detection value detected by the sensor 190. For example, it may be the detection value itself (instantaneous value) of each sensor 190, or it may be a statistical value calculated based on a plurality of instantaneous values, such as an average value of instantaneous values ​​in a specified period. Alternatively, as already described, the detection intensity may be a crest value obtained from waveform data or its statistical value. In this embodiment, the detection intensity acquired by the first intensity acquisition unit 631 is an instantaneous value. Moreover, the first intensity acquisition unit 631 is adapted to acquire the detection intensity for each sensor based on one or more detection values ​​stored in the storage unit 620.

[0054] <<<Sensor determination unit 632>>> The sensor determination unit 632 determines whether or not the detection intensity acquired by the first intensity acquisition unit 631 exceeds a threshold for each detection intensity of the sensors 190 (190a to 190f). If there is at least one sensor 190 whose detection intensity exceeds the threshold, it can be determined that electromagnetic waves have been detected inside the gas insulated switchgear 100, and it is determined that a partial discharge has occurred in the gas insulated switchgear 100. On the other hand, if there is no sensor 190 whose detection intensity exceeds the threshold, it is determined that a partial discharge has not occurred in the gas insulated switchgear 100.

[0055] The threshold value may be determined, for example, as follows. That is, the minimum value of the detection strength output from each sensor 190 (190a to 190f) when a partial discharge occurs is checked in advance, and a value equal to or greater than the checked minimum value of the detection strength is set as the threshold value. The threshold value may be set individually for each sensor 190 (190a to 190f), or the same value may be set for all sensors 190 (190a to 190f).

[0056] Furthermore, when there is one sensor 190 whose detection strength exceeds the threshold, the sensor determination unit 632 determines the space in which the sensor 190 is installed among the bus bar accommodating spaces 170a to 170b and the branch line accommodating spaces 180a to 180d as the partial discharge occurrence position CP.

[0057] <<Waveform data acquisition unit 640>> The waveform data acquiring unit 640 acquires waveform data of one or more sensors 190 from one or more sensors 190 installed in the gas-insulated switchgear 100. The waveform data acquiring unit 640 may acquire waveform data for each sensor 190 within a range required for locating the partial discharge occurrence position CP, and may acquire waveform data for all sensors 190 or may acquire waveform data for some sensors 190. When acquiring waveform data for multiple sensors 190, each waveform data may include detection values ​​in the same time period, or at least one waveform data may include detection values ​​in a time period different from other waveform data. Moreover, the waveform data may include data of multiple detection values ​​constituting at least one period of the waveform. The waveform data acquiring unit 640 acquires the necessary waveform data by acquiring multiple detection values ​​from the storage area for each sensor 190 in the storage unit 620. In this embodiment, the waveform data acquiring unit 640 is activated when the sensor determining unit 632 determines that there are two or more sensors 190 whose detection strength exceeds the threshold.

[0058] <<Orientation section 650>> The locating unit 650 locates a position CP of a partial discharge occurring inside the gas insulated switchgear 100, based on at least one of the waveform data for each sensor 190 acquired by the waveform data acquiring unit 640. In this embodiment, the locating unit 650 includes a frequency spectrum acquiring unit 651, a frequency spectrum determining unit 652, a second intensity acquiring unit 653, and an identifying unit 654. In this embodiment, the locating unit 650 is activated after the sensor determining unit 632 determines that there are two or more sensors whose detection intensity exceeds the threshold value, and further, the waveform data acquiring unit 640 acquires the waveform data.

[0059] <<<Frequency spectrum acquisition unit 651>>> The frequency spectrum acquisition unit 651 calculates and acquires the frequency spectrum of the waveform data acquired by the waveform data acquisition unit 640. For example, FFT is used to calculate the frequency spectrum. In this embodiment, the frequency spectrum acquisition unit 651 selects one of the sensors 190 whose detection intensity is determined by the detection unit 630 (sensor determination unit 632) to be greater than the threshold value from among the multiple sensors 190c-190f installed in the branch line accommodating spaces 180a-180d, and calculates and acquires the frequency spectrum of the waveform data of the selected sensor 190. When there are multiple sensors 190 whose detection intensity is determined by the detection unit 630 (sensor determination unit 632) to be greater than the threshold value among the multiple sensors 190c-190f installed in the branch line accommodating spaces 180a-180d, the frequency spectrum acquisition unit 651 calculates and acquires the frequency spectrum of the waveform data of the sensor 190 whose detection intensity is the largest acquired by the first intensity acquisition unit 631, for example. However, the present invention is not limited to this embodiment, and the frequency spectrum acquisition unit 651 may acquire the frequency spectrum of waveform data of the sensor 190 whose detection strength is not the maximum. For example, the frequency spectrum acquisition unit 651 may acquire the frequency spectrum of waveform data of the sensor 190 whose detection strength is closest to a detection strength preset as a detection strength corresponding to the occurrence of partial discharge.

[0060] <<<Frequency spectrum determination unit 652>>> The frequency spectrum determination unit 652 determines whether the location CP of a partial discharge occurring inside the gas-insulated switchgear 100 is a bus bar accommodating space 170a-170b of one or more unit units 110 (110a-110d) or a branch line accommodating space 180a-180d of one or more unit units 110 (110a-110d) based on the presence or absence of bias in the distribution of the frequency spectrum of the waveform data acquired by the frequency spectrum acquisition unit 651.

[0061] In the present embodiment, the frequency spectrum determination unit 652 determines that the partial discharge occurrence position CP is the bus bar accommodating space 170a-170b when a frequency distribution condition indicating that the distribution of the frequency spectrum of the waveform data acquired by the frequency spectrum acquisition unit 651 can be regarded as having no bias is satisfied, and determines that the partial discharge occurrence position CP is the branch line accommodating space 180a-180d when the frequency distribution condition is not satisfied.

[0062] More specifically, in this embodiment, the aforementioned specified frequency is 750 MHz. The first frequency band is 750 MHz to 1100 MHz, and the second frequency band is 400 MHz to 1100 MHz. In this embodiment, the frequency distribution condition is set such that the ratio of the integral value (area) of the frequency spectrum of the waveform data in the first frequency band to the integral value (area) of the frequency spectrum of the waveform data in the second frequency band is equal to or greater than a threshold value.

[0063] The threshold value may be determined, for example, as follows. That is, by using the test equipment (pulse generator 410, oscilloscope 420, and analysis PC 430) shown in Fig. 4, the frequency spectrum of the waveform data corresponding to the simulation signal received by the sensors 190c-190f installed in the branch line accommodating spaces 180a-180d is obtained by changing the combination of the sensor on the transmitting side and the sensor on the receiving side of the simulation signal. For each of the frequency spectra thus obtained, the ratio of the integral value of the frequency spectrum of the waveform data in the first frequency band to the integral value of the frequency spectrum of the waveform data in the second frequency band is calculated, and a value equal to or greater than the minimum value of the calculated ratio is set as the threshold value. The threshold value is, for example, 0.4.

[0064] <<<Second Intensity Acquisition Unit 653>>> The second intensity acquisition unit 653 acquires the detection intensity (described above) of each sensor 190 that is determined to have detected an electromagnetic wave by at least the above-mentioned detection unit 630 in any of the accommodation spaces (busbar accommodation spaces 170a to 170b or branch line accommodation spaces 180a to 180d) determined by the above-mentioned frequency spectrum determination unit 652. In this embodiment, the detection intensity is a peak value, and the second intensity acquisition unit 653 calculates the detection intensity for the necessary sensor 190 based on the detection value of each sensor 190 stored in the storage unit 620. However, the present invention is not limited to this embodiment. The detection intensity acquired by the second intensity acquisition unit 653 may be of the same type as the detection intensity acquired by the first intensity acquisition unit 631. In this case, the calculation result of the first intensity acquisition unit 631 may be stored in a predetermined storage area of ​​the storage unit 620, and the second intensity acquisition unit 653 may acquire the detection intensity of the necessary sensor 190 from the storage area.

[0065] That is, the above-mentioned first intensity acquisition unit 631 acquires the detection intensity of each sensor 190 (190a to 190f) in order to detect the presence or absence of occurrence of partial discharge in the gas insulated switchgear 100. On the other hand, the second intensity acquisition unit 653 acquires the detection intensity of each sensor 190 (190a to 190b, 190c to 190f) for each of the bus bar accommodating spaces 170a to 170b or each of the branch line accommodating spaces 180a to 180d in accordance with the determination result by the frequency spectrum determination unit 652.

[0066] Specifically, when the frequency spectrum determining unit 652 determines that the partial discharge occurrence position CP is the bus bar accommodating spaces 170a to 170b, the second intensity acquiring unit 653 acquires the detection intensities of the sensors 190a to 190b installed in the bus bar accommodating spaces 170a to 170b and determined by the sensor determining unit 632 that the detection intensities exceed the threshold value. On the other hand, when the frequency spectrum determining unit 652 determines that the partial discharge occurrence position CP is the branch line accommodating spaces 180a to 180d, the second intensity acquiring unit 653 acquires the detection intensities of the sensors 190c to 190f installed in the branch line accommodating spaces 180a to 180d and determined by the sensor determining unit 632 that the detection intensities exceed the threshold value. The second intensity acquiring unit 653 may be configured to acquire the detection intensities of all the sensors installed in any of the accommodating spaces (the bus bar accommodating spaces 170a to 170b or the branch line accommodating spaces 180a to 180d) determined by the frequency spectrum determining unit 652.

[0067] <<<Specific part 654>>> The identifying unit 654 identifies the occurrence position CP of the partial discharge occurring inside the gas insulated switchgear 100 based on the result of the determination by the frequency spectrum determining unit 652 and the detection intensity acquired by the second intensity acquiring unit 653. In other words, the identifying unit 654 identifies one sensor 190 that is closest to the occurrence position CP of the partial discharge. Specifically, when a plurality of sensors detect electromagnetic waves in any of the accommodation spaces (the bus bar accommodation spaces 170a to 170b or the branch line accommodation spaces 180a to 180d) determined by the frequency spectrum determining unit 652, the identifying unit 654 determines the sensor that exhibits the maximum detection intensity as the sensor that is closest to the occurrence position CP of the partial discharge, and when only one sensor detects the electromagnetic waves, the identifying unit 654 determines that sensor as the sensor that is closest to the occurrence position CP of the partial discharge, and identifies the accommodation space in which the determined sensor is installed as the space in which the occurrence position CP of the partial discharge exists.

[0068] In this embodiment, when the frequency spectrum determination unit 652 determines that the partial discharge occurrence position CP is the busbar accommodating space 170a-170b, and the second intensity acquisition unit 653 acquires multiple detection intensities as the detection intensities of the sensors 190a-190b installed in the busbar accommodating spaces 170a-170b whose detection intensities are determined by the sensor determination unit 632 to exceed a threshold value, the identification unit 654 determines the busbar accommodating space in which the sensor showing the maximum detection intensity is installed among the busbar accommodating spaces 170a-170b as the partial discharge occurrence position CP.

[0069] On the other hand, when the frequency spectrum determination unit 652 determines that the partial discharge occurrence position CP is the busbar accommodating space 170a-170b, and the second intensity acquisition unit 653 acquires one detection intensity as the detection intensity of the sensor among the sensors 190a-190b installed in the busbar accommodating spaces 170a-170b whose detection intensity is determined by the sensor determination unit 632 to exceed the threshold value, the identification unit 654 determines the busbar accommodating space in which the sensor is installed as the partial discharge occurrence position CP without comparing the detection intensities.

[0070] Furthermore, when the frequency spectrum determination unit 652 determines that the partial discharge occurrence position CP is the branch wire accommodating space 180a-180d, and the second intensity acquisition unit 653 acquires a plurality of detection intensities as the detection intensities of the sensors 190c-190f installed in the branch wire accommodating spaces 180a-180d whose detection intensities are determined by the sensor determination unit 632 to exceed a threshold value, the identification unit 654 determines that the branch wire accommodating space in which the sensor showing the maximum detection intensity is installed among the branch wire accommodating spaces 180a-180d is the partial discharge occurrence position CP.

[0071] On the other hand, when the frequency spectrum determination unit 652 determines that the partial discharge occurrence position CP is the branch wire accommodating space 180a-180d, and the second intensity acquisition unit 653 acquires one of the detection strengths of the sensors 190c-190f installed in the branch wire accommodating spaces 180a-180d whose detection strength is determined by the sensor determination unit 632 to exceed the threshold, the identification unit 654 determines the branch wire accommodating space in which the sensor is installed as the partial discharge occurrence position CP without comparing the detection strengths.

[0072] <<Output Unit 660>> The output unit 660 generates operation signals for the disconnectors 140a-140d and the circuit breakers 150a-150d in accordance with the partial discharge occurrence position CP located by the location unit 650, and outputs the signals to the gas insulated switchgear 100 or a control device (not shown) that controls the operation of the gas insulated switchgear 100.

[0073] When the partial discharge occurrence position CP located by the location unit 650 is a busbar accommodation space, the output unit 660 generates and outputs an operation signal indicating to open all circuit breakers connected to all branch lines connected to the busbar accommodated in the busbar accommodation space and then to open all disconnectors connected to the branch lines.

[0074] For example, it is assumed that the partial discharge occurrence position CP located by the location unit 650 is the bus bar accommodation space 170a (bus bar 120a) and all of the disconnectors 140a to 140d are connected to the electric wires 131a to 131d. In this case, the output unit 660 generates and outputs an operation signal indicating that the disconnectors 140a to 140d are to be disconnected from the electric wires 131a to 131d after all of the circuit breakers 150a to 150d are opened. The output unit 660 may also generate and output an operation signal indicating that the circuit breakers 150a to 150d are to be closed after the circuit breakers 140a to 140d are connected to the electric wires 132a to 132d. These two operation signals may be combined into one operation signal. Furthermore, in the case where the disconnectors 140a-140d are disconnectors with a loop opening and closing function, the output unit 660 may, for example, generate and output an operation signal indicating that the disconnectors 140a-140d should be disconnected from the electric wires 131a-131d after connecting the disconnectors 140a-140d to the electric wires 132a-132d (i.e., after connecting the disconnectors 140a-140d to both the electric wires 131a-131d and 132a-132d).

[0075] However, the functions of the output unit 660 are not limited to those described above. For example, instead of the above-mentioned control device or together with the above-mentioned control device, the output unit 660 may be connected to a notification device (not shown) capable of notifying the manager of the located partial discharge occurrence position CP, such as a display or speaker of a manager terminal, and may output the located partial discharge occurrence position CP to the notification device (not shown). In addition, the output unit 660 may output information capable of identifying a disconnecting switch or a circuit breaker to be operated. This enables the manager to quickly grasp the occurrence of a partial discharge and its occurrence position CP, and enables the circuit breaker or the disconnecting switch to be operated manually.

[0076] In the following description, the above-described operation of the disconnectors 140a-140d and the circuit breakers 150a-150d to disconnect the busbar 120a or 120b from loads (not shown) connected to the branch lines 130a-130d is also referred to as disconnecting the busbar from the power system.

[0077] Also, for example, it is assumed that the partial discharge occurrence position CP located by the location unit 650 is the branch line accommodating space 180d (branch line 130d) and the disconnector 140d is connected to the electric wire 131d or 132d. In this case, after opening the circuit breaker 150d, the output unit 660 generates and outputs an operation signal indicating that the disconnector 140d is to be disconnected from the electric wires 131d and 132d.

[0078] In the following description, by operating the disconnector 140a, 140b, 140c, or 140d and the circuit breaker 150a, 150b, 150c, or 150d as described above, a load (not shown) connected to the branch line 130a, 130b, 130c, or 130d is disconnected from the bus bars 120a to 120b, which is also referred to as disconnecting the load from the power system.

[0079] <Operation flow chart> Next, an example of a partial discharge locating method using the partial discharge locating device 600 described above will be described with reference to the flowchart in Fig. 7. Note that at least a part of the partial discharge locating method may be performed manually without using the partial discharge locating device 600.

[0080] First, in step S701, the detection value acquisition unit 610 acquires detection values ​​detected by each sensor 190 (sensors 190a to 190f) and stores them in the storage unit 620. In this embodiment, the detection value acquisition unit 610 identifies the sensor 190 that detected the detection value, and stores (accumulates) the detection values ​​detected by each sensor 190 (sensors 190a to 190f) in a storage area for each sensor 190. Next, in step S702, the first intensity acquisition unit 631 acquires, based on the stored information in the storage unit 620, the detection intensity of each of the sensors 190 (190a to 190f) determined as a monitoring target.

[0081] Next, in step S703, the sensor determination unit 632 determines whether or not there is a sensor whose detection intensity obtained in step S702 exceeds the threshold value. If there is no sensor whose detection intensity exceeds the threshold value as a result of this determination (NO in step S703), partial discharge has not occurred inside the gas-insulated switchgear 100, and the process according to the flowchart in FIG. 7 ends.

[0082] On the other hand, if there is a sensor whose detection strength exceeds the threshold (YES in step S703), the process of step S704 is executed. In step S704, the sensor determination unit 632 determines whether the number of sensors whose detection strength exceeds the threshold acquired in step S702 is one. If the result of this determination is that the number of sensors whose detection strength exceeds the threshold is one (YES in step S704), the process of step S705 is executed.

[0083] In step S705, the sensor determination unit 632 determines, among the bus bar accommodating spaces 170a to 170b and the branch line accommodating spaces 180a to 180d, the space in which the sensor whose detection intensity is determined to exceed the threshold in step S704 is installed, as the partial discharge occurrence position CP.

[0084] Next, in step S706, the output unit 660 generates an operation signal according to the space determined in step S705, and outputs the operation signal to the gas insulated switchgear 100 or a control device that controls the operation of the gas insulated switchgear 100. Then, the disconnectors 140a to 140d and the circuit breakers 150a to 150d perform operations according to the operation signal.

[0085] For example, when the partial discharge occurrence position CP determined in step S705 is the bus bar accommodation space 170a or 170b, the output unit 660 generates an operation signal indicating that the bus bar 120a or 120b is to be disconnected from the power system. When the partial discharge occurrence position CP determined in step S705 is the branch line accommodation space 180a, 180b, 180c, or 180d, the output unit 660 generates an operation signal indicating that a load (not shown) connected to the branch line accommodation space is to be disconnected from the power system. In addition, an operation signal such as an operation signal for the disconnector 140 may be generated to disconnect the unit 110 forming the branch line accommodation space in which the partial discharge occurrence position CP has been determined from the bus bar (the same applies to S717 described later). When the process of step S706 is completed, the process according to the flowchart of FIG. 7 is completed.

[0086] In the above-mentioned step S704, if it is determined that the number of sensors whose detection strength exceeds the threshold is not one (NO in step S704), the number of sensors whose detection strength exceeds the threshold is two or more. In this case, the process of step S707 is executed. In step S707, the sensor determination unit 632 determines whether or not the sensors whose detection strength exceeds the threshold acquired in step S702 include the sensors 190c-190f installed in the branch line accommodating spaces 180a-180d. In FIG. 7 and the following description, the sensors 190c-190f installed in the branch line accommodating spaces 180a-180d are also referred to as load side sensors. In addition, the sensors 190a-190b installed in the bus bar accommodating spaces 170a-170b are also referred to as bus bar side sensors.

[0087] If the result of this determination is that there is no load-side sensor among the sensors whose detection strength exceeds the threshold (YES in step S707), the only sensor whose detection strength exceeds the threshold is sensor 190a or 190b installed in busbar accommodating spaces 170a to 170b. In this case, the process of step S712 described below is executed. On the other hand, if there is a load-side sensor among the sensors whose detection strength exceeds the threshold (NO in step S707), the process of step S708 is executed. In step S708, the sensor determination unit 632 determines whether there is a busbar side sensor (sensor 190a to 190b) among the sensors whose detection strength obtained in step S702 exceeds the threshold.

[0088] If the result of this determination is that there is no bus-side sensor among the sensors whose detection strength exceeds the threshold (NO in step S708), the only sensors whose detection strength exceeds the threshold are the load-side sensors. In this case, the process of step S715 described below is executed. On the other hand, if there is a bus-side sensor among the sensors whose detection strength exceeds the threshold (YES in step S708), the sensors whose detection strength exceeds the threshold include the bus-side sensor and the load-side sensor. In this case, the process of step S709 is executed.

[0089] In step S709, the waveform data acquiring unit 640 acquires waveform data based on the detection values ​​stored in the storage unit 620 in step S701. In this embodiment, among the load side sensors whose detection strength exceeds the threshold, the waveform data of the load side sensor whose detection strength is the largest is acquired. Note that, if there is only one load side sensor whose detection strength exceeds the threshold, the waveform data acquiring unit 640 acquires the waveform data of that load side sensor.

[0090] Next, in step S710, the frequency spectrum acquisition unit 651 calculates and acquires the frequency spectrum of the waveform data of the load side sensor acquired in step S709. Next, in step S711, the frequency spectrum determining unit 652 determines whether or not the distribution of the frequency spectrum of the waveform data of the load side sensor acquired in step S710 satisfies a frequency distribution condition.

[0091] A specific example of the frequency distribution condition is that the ratio of the integral value of the frequency spectrum in the second frequency band of 400 MHz to 1100 MHz to the integral value of the frequency spectrum in the first frequency band of 750 MHz to 1100 MHz is 0.4 or more. As described with reference to Fig. 5A and Fig. 5B, when such a frequency distribution condition is satisfied, the occurrence position CP of the partial discharge occurring inside the gas insulated switchgear 100 is the bus bar accommodating spaces 170a to 170b (see frequency spectra 520 and 540). On the other hand, when the frequency distribution condition is not satisfied, the occurrence position CP of the partial discharge occurring inside the gas insulated switchgear 100 is the branch wire accommodating spaces 180a to 180d (see frequency spectra 510 and 530).

[0092] As a result of the determination in step S711, if the distribution of the frequency spectrum of the waveform data of the load side sensor acquired in step S710 does not satisfy the frequency distribution condition (NO in step S711), the process of step S715 described later is executed. On the other hand, as a result of the determination in step S711, if the distribution of the frequency spectrum of the waveform data of the load side sensor acquired in step S710 satisfies the frequency distribution condition (YES in step S711), the process of step S712 is executed. As described above, even if it is determined in step S707 that there is no load side sensor among the sensors whose detection strength exceeds the threshold (YES in step S707), the process of step S712 is executed. In step S712, the second intensity acquisition unit 653 acquires the detection strength of the bus side sensor whose detection strength is determined to exceed the threshold in step S702.

[0093] Next, in step S713, the identifying unit 654 determines one of the bus-bar accommodating spaces in which the bus-bar side sensor is installed as the bus-bar accommodating space, based on the detection strength of the bus-bar side sensor acquired in step S712, as the partial discharge occurrence position CP. If a plurality of detection strengths are acquired in step S712 as the detection strengths of the bus-bar side sensors whose detection strengths are determined to exceed the threshold, the identifying unit 654 determines the bus-bar accommodating space in which the bus-bar side sensor exhibiting the maximum detection strength is installed among the bus-bar accommodating spaces 170a-170b as the partial discharge occurrence position CP. On the other hand, if one detection strength is acquired in step S712 as the detection strength of the bus-bar side sensor whose detection strength is determined to exceed the threshold, the identifying unit 654 determines the bus-bar accommodating space in which the bus-bar side sensor is installed as the partial discharge occurrence position CP.

[0094] Next, in step S714, the output unit 660 generates an operation signal indicating that the busbar accommodated in the busbar accommodating space determined in step S713 is to be disconnected from the power grid, and outputs the operation signal to the gas insulated switchgear 100 or a control device that controls the operation of the gas insulated switchgear 100. When the process of step S714 ends, the process according to the flowchart in FIG.

[0095] As described above, in step S708, if it is determined that the bus-side sensor is not among the sensors whose detection intensity exceeds the threshold (NO in step S708), or in step S711, if it is determined that the distribution of the frequency spectrum of the waveform data satisfies the frequency distribution condition (NO in step S711), the process of step S715 is executed. In this case, the occurrence position CP of the partial discharge occurring inside the gas-insulated switchgear 100 is any one of the branch wire accommodating spaces 180a to 180d.

[0096] In step S715, the second intensity acquisition unit 653 acquires the detection intensity of the load-side sensor whose detection intensity has been determined to exceed the threshold in step S702. Next, in step S716, the identifying unit 654 determines one of the branch line accommodating spaces in which the load side sensor is installed as the branch line accommodating space, based on the detection strength of the load side sensor acquired in step S715, as the partial discharge occurrence position CP. If a plurality of detection strengths are acquired in step S715 as the detection strengths of the load side sensors whose detection strengths are determined to exceed the threshold, the identifying unit 654 determines the branch line accommodating space in which the load side sensor showing the maximum detection strength is installed, among the branch line accommodating spaces 180a to 180d, as the partial discharge occurrence position CP. On the other hand, if one detection strength is acquired in step S712 as the detection strength of the load side sensor whose detection strength is determined to exceed the threshold, the identifying unit 654 determines the branch line accommodating space in which the load side sensor is installed as the partial discharge occurrence position CP.

[0097] Next, in step S717, the output unit 660 generates an operation signal indicating that the load connected to the branch line accommodating space determined in step S716 is to be disconnected from the power system, and outputs the operation signal to the gas insulated switchgear 100 or a control device that controls the operation of the gas insulated switchgear 100. When the process of step S717 ends, the process according to the flowchart of Fig. 7 ends. Regarding the above-mentioned steps S706, S714, and S717, when this method is performed manually, the above operation signal is generated by manually operating a control device.

[0098] <Summary> As described above, in this embodiment, the partial discharge position locating device 600 locates the position of a partial discharge that occurs in the gas insulated switchgear 100 having one or more units 110 (110a-110d) formed therein with bus bar partial spaces 171a-174a, 171b-174b in which the bus bars 120a-120b are partially accommodated and branch line accommodating spaces 180a-180d in which the branch lines 130a-130d branched from the bus bars 120a-120b are accommodated. At that time, the partial discharge position locating device 600 acquires waveform data that is the detection result of an electromagnetic wave generated when a partial discharge occurs, by at least one sensor 190 installed in the gas insulated switchgear 100. Then, the partial discharge position locating device 600 acquires a frequency spectrum of the acquired waveform data, and determines whether the space in which the partial discharge occurrence position CP exists is within the busbar accommodation space 170a-170b formed by the busbar partial spaces 171a-174a, 171b-174b of one or more unit units 110 (110a-110d) or within any of the branch line accommodation spaces 180a-180d of one or more unit units 110 (110a-110d) based on the presence or absence of bias in the distribution of the acquired frequency spectrum. The frequency spectrum is obtained for each waveform data of the sensors 190a-190f, and the bias in the distribution of the frequency spectrum can be obtained without performing a comparison for a plurality of sensors. Therefore, the partial discharge occurrence position CP can be located with high accuracy without using an expensive sensor as a sensor for detecting partial discharge, installing a large number of sensors for detecting partial discharge, or imposing a large calculation load, and the partial discharge occurrence position CP can be located with high accuracy at a lower cost.

[0099] Moreover, in this embodiment, the sensors 190c-190f are installed in the branch line accommodating spaces 180a-180d. Therefore, the degree of bias in the distribution of the frequency spectrum of the waveform data of the sensors 190c-190f clearly differs depending on whether the partial discharge occurrence position CP is in the bus bar accommodating spaces 170a-170b or the branch line accommodating spaces 180a-180d (see frequency spectra 510, 520, 530, 540). Therefore, the partial discharge occurrence position CP can be located with high accuracy at low cost.

[0100] Furthermore, in this embodiment, when electromagnetic waves are detected by two or more sensors 190 based on the presence or absence of bias in the distribution of the frequency spectrum, the partial discharge position locating device 600 identifies the occurrence position CP of the partial discharge based on the detection intensity of the electromagnetic waves detected by each of the two or more sensors 190. Therefore, the occurrence position CP of the partial discharge can be determined with high accuracy using a relatively simple logic.

[0101] In this embodiment, the partial discharge position locating device 600 detects the occurrence of partial discharge based on the presence or absence of the sensor 190 whose detection intensity of the waveform data exceeds a threshold, and acquires the frequency spectrum of the waveform data when the occurrence of partial discharge is detected. Therefore, even if it is not possible to determine whether the partial discharge occurrence position CP is the bus bar accommodating spaces 170a-170b or the branch wire accommodating spaces 180a-180d by only comparing the detection intensity of the waveform data with the threshold, it is possible to determine whether the partial discharge occurrence position CP is the bus bar accommodating spaces 170a-170b or the branch wire accommodating spaces 180a-180d based on the frequency spectrum of the waveform data.

[0102] In this embodiment, the frequency distribution condition is determined based on a comparison between an analysis value of a frequency spectrum in a high frequency band higher than a specified frequency and an analysis value of a frequency spectrum in a low frequency band lower than a specified frequency, and determines whether the distribution of the frequency spectrum is biased. Therefore, the bias of the distribution of the frequency spectrum can be quantitatively evaluated. Moreover, by making the analysis value an integral value, the analysis value can be set to a value that appropriately and easily reflects the degree of bias of the distribution of the frequency spectrum.

[0103] <Modification> As in this embodiment, it is preferable to install one sensor 190a-190f in each of the busbar accommodating spaces 170a-170b and the branch line accommodating spaces 180a-180d, since the number of sensors can be just right. However, the number of sensors 190a-190f is not limited. A plurality of sensors may be installed in one busbar accommodating space 170a-170b, or a plurality of sensors may be installed in one branch line accommodating space 180a-180d. In addition, if it is determined that the partial discharge occurrence position CP is in the busbar accommodating spaces 170a-170b or the branch line accommodating spaces 180a-180d, it is not necessary to install sensors in all of the busbar accommodating spaces 170a-170b and the branch line accommodating spaces 180a-180d, in which case it is not necessary to determine which of the busbar accommodating spaces 170a-170b and the branch line accommodating spaces 180a-180d the partial discharge occurrence position CP is in. In addition, in the present embodiment, the case where waveform data output from all the sensors 190a to 190f is acquired is exemplified. However, it is not necessary to acquire waveform data output from all the sensors 190a to 190f. For example, if it is not necessary to determine which of the busbar accommodating spaces 170a to 170b and the branch line accommodating spaces 180a to 180d the partial discharge occurrence position CP is in, it is not necessary to acquire waveform data output from the sensors 190a to 190b installed in the busbar accommodating spaces 170a to 170b. Also, for example, if the number of busbar accommodating spaces is one, it is not necessary to acquire waveform data output from the sensors 190a to 190b installed in the busbar accommodating spaces.

[0104] In addition, in the present embodiment, the frequency distribution condition is exemplified as a condition indicating that the distribution of the frequency spectrum of the waveform data is not biased. However, as long as the condition is a comparison between an analysis value of the frequency spectrum in a high frequency band on the higher frequency side than the specified frequency and an analysis value of the frequency spectrum in a low frequency band on the lower frequency side than the specified frequency, the frequency distribution condition does not necessarily have to be the condition described in the present embodiment. For example, the frequency distribution condition may be a condition indicating that the distribution of the frequency spectrum of the waveform data is biased. In addition, the frequency distribution condition may be that the ratio of the integral value of the frequency spectrum in the high frequency band on the lower frequency side than the specified frequency to the integral value of the frequency spectrum in the low frequency band on the higher frequency side than the specified frequency is equal to or greater than a threshold value or equal to or less than a threshold value.

[0105] In the present embodiment, the case where waveform data and a frequency spectrum are acquired when the occurrence of a partial discharge is detected by the detection unit 630 is exemplified. However, this is not necessarily required. For example, the waveform data and the frequency spectrum may be acquired regardless of whether the occurrence of a partial discharge is detected. In this case, for example, the occurrence of a partial discharge may be detected based on the waveform data.

[0106] As described above, the gas-insulated switchgear is not limited to the gas-insulated switchgear 100 shown in Fig. 1A to Fig. 1C. The reason why the bias in the distribution of the frequency spectrum of the waveform data differs depending on whether the partial discharge occurs in the busbar accommodating space or the branch line accommodating space is that the propagation distance of the electromagnetic wave, the structures present in the propagation path of the electromagnetic wave, and the shape of the propagation path of the electromagnetic wave differ depending on whether it is the busbar accommodating space or the branch line accommodating space.

[0107] In the gas-insulated switchgear 100 exemplified in this embodiment, if the waveform data of the load-side sensor is selected to obtain the frequency spectrum, the degree of bias in the distribution of the frequency spectrum of the waveform data of the sensors 190c-190f can be clearly different depending on whether the partial discharge occurrence position CP is the busbar accommodating space 170a-170b or the branch wire accommodating space 180a-180d, which is preferable. However, when the partial discharge position locating device 600 of this embodiment is applied to a gas-insulated switchgear having a structure in which the degree of bias in the distribution of the frequency spectrum of the waveform data of the busbar side sensor is clearly different depending on whether the partial discharge occurrence position CP is the busbar accommodating space 170a-170b or the branch wire accommodating space 180a-180d, the frequency spectrum may be obtained by selecting the waveform data of the busbar side sensor.

[0108] The above-described embodiment of the present invention can be realized by a computer executing a program. A computer-readable recording medium having the program recorded thereon and a computer program product such as the program can also be applied as an embodiment of the present invention. Examples of the recording medium that can be used include a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a non-volatile memory card, and a ROM. The embodiment of the present invention can be realized by a PLC (Programmable Logic Controller) or dedicated hardware such as an ASIC (Application Specific Integrated Circuit). Furthermore, the above-described embodiments of the present invention are merely examples of the implementation of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0109] 1. Partial discharge location system 100 Gas Insulated Switchgear (GIS) 110(110a~110d) Unit 120a~120b bus bar 130a~130d Branch line 140a~140d Disconnector 150a~150d Circuit breaker 160a~160d Cable Head 170a~170b Bus bar accommodation space 171a~174a Subspace for bus bar 171b~174b Subspace for bus bar 180a~180d Branch line accommodation space 190(190a~190f) Sensor 210 Insulating spacer 310 Approximation curve of the relationship between detection strength and propagation distance 410 Pulse Generator 420 Oscilloscope 430 Analysis PC 510~540 Frequency spectrum 600 Partial discharge position locating device 610 Detection value acquisition unit 620 Storage section 630 Detection Unit 631 First Strength Acquisition Section 632 Sensor Judgment Unit 640 Waveform Data Acquisition Unit 650 Orientation section 651 Frequency spectrum acquisition unit 652 Frequency spectrum judgement unit 653 Second Strength Acquisition Section 564 Specific part 660 Output section CP Partial discharge occurrence position

Claims

1. A partial discharge location locating device for locating a location of a partial discharge occurring in a gas-insulated switchgear having one or more units formed therein with a busbar partial space for partially accommodating a busbar and a branch line accommodating space for accommodating a branch line branched from the busbar, the device comprising: at least one sensor that is installed in at least one of the busbar partial space and the branch line accommodating space of the gas-insulated switchgear and detects electromagnetic waves generated when the partial discharge occurs; a waveform data acquisition unit for acquiring waveform data that is a detection result of the electromagnetic wave; a location unit that determines a location where the partial discharge occurs based on the waveform data, The orientation unit includes: a frequency spectrum acquisition unit for acquiring a frequency spectrum of the waveform data; If there is no bias in the distribution of the frequency spectrum, it is determined that the space in which the partial discharge occurs is within a busbar accommodation space formed by the busbar partial spaces of the one or more unitary units; a frequency spectrum determining unit that, when there is a bias in the distribution of the frequency spectrum, determines that the space in which the partial discharge occurs is within the branch line accommodating space of one of the one or more units; A partial discharge location device comprising:

2. The partial discharge location locating device according to claim 1 , wherein the sensor is installed in the branch line accommodating space.

3. The gas-insulated switchgear is provided with a plurality of the sensors, The orientation unit includes: an intensity acquisition unit that acquires a detection intensity of the electromagnetic wave detected by the sensor; 3. The partial discharge location location device according to claim 2, further comprising an identification unit that, when the electromagnetic waves are detected by two or more sensors installed in the space determined by the frequency spectrum determination unit, determines the sensor that shows the maximum detection strength of the electromagnetic waves detected by each of the two or more sensors as the sensor closest to a partial discharge occurrence position, and identifies the partial discharge occurrence position within the space based on a position corresponding to the sensor.

4. A detection unit that detects the occurrence of the partial discharge based on the presence or absence of the sensor in which the detected intensity of the electromagnetic wave exceeds a threshold for determining the occurrence of the electromagnetic wave, The frequency spectrum acquisition unit is 4. The partial discharge location device according to claim 1, further comprising: a waveform data acquisition unit that acquires a frequency spectrum of the waveform data acquired by the waveform data acquisition unit when the occurrence of the partial discharge is detected by the detection unit.

5. The frequency spectrum determination unit is If a value corresponding to the ratio of the number of peaks in the frequency spectrum is taken as an analysis value, 5. The partial discharge location device according to claim 1, wherein the device determines whether or not the distribution of the frequency spectrum is biased based on a result of a comparison between an analysis value of the frequency spectrum in a high-frequency band that is higher than a specified frequency and an analysis value of the frequency spectrum in a low-frequency band that is lower than the specified frequency.

6. The partial discharge location locating device according to claim 5 , wherein the analysis value is an integral value of the frequency spectrum.

7. A partial discharge location locating method for locating a location of a partial discharge occurring in a gas insulated switchgear having one or more units formed therein with a busbar partial space for partially accommodating a busbar and a branch line accommodating space for accommodating a branch line branched from the busbar, comprising: a waveform data acquiring step of acquiring waveform data as a detection result of an electromagnetic wave generated when a partial discharge occurs, using at least one sensor that is installed in at least one of the busbar partial space and the branch wire accommodating space of the gas-insulated switchgear and detects an electromagnetic wave generated when the partial discharge occurs; and a location step of locating a location of the partial discharge based on the waveform data, The orientation step includes: a frequency spectrum acquisition step of acquiring a frequency spectrum of the waveform data; If there is no bias in the distribution of the frequency spectrum, it is determined that the space in which the partial discharge occurs is within a busbar accommodation space formed by the busbar partial spaces of the one or more unitary units; a frequency spectrum determination step of determining, when there is a bias in the distribution of the frequency spectrum, that the space in which the partial discharge occurs is within the branch line accommodation space of any of the one or more units; A partial discharge location method comprising:

8. A program for causing a computer to function as each unit of the partial discharge position locating device according to any one of claims 1 to 6.

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