JP2017122666A - Lightning arrester leakage current detection method, lightning arrester leakage current detection device, and lightning arrester leakage current monitor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and accurately obtain a resistance component current of a lightning arrester, and to allow deterioration of the lightning arrester to be grasped at an early stage.SOLUTION: A lightning arrester leakage current detection device 30 includes a measurement unit 31, a storage unit 32, a removal unit 33, a waveform adjustment unit 34, a difference detection unit 35, and a current detection unit 36. The measurement unit 31 is configured to measure a total leakage current Io of a lightning arrester 10, and output currents of a reference waveform and a comparison waveform. The storage unit 32 is configured to store the reference waveform, and the removal unit 33 is configured to remove a high-order harmonic wave of the stored reference waveform and comparison waveform. The waveform adjustment unit 34 is configured to perform a waveform adjustment of a phase and an amplitude between the reference waveform and the comparison waveform after the high-order harmonic wave is removed. The difference detection unit 35 is configured to detect a difference between the reference waveform and the comparison waveform after the waveform is adjusted. The current detection unit 36 is configured to detect a resistance component current Ir of the lightning arrester 10 from the difference.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lightning arrester leakage current detection method, a lightning arrester leakage current detection device, and a lightning arrester leakage current monitoring device for diagnosing deterioration of a feeder arrester installed in, for example, a Shinkansen substation. .

FIG. 2 is a diagram showing the installation position of a general Shinkansen feeder.
In the Shinkansen, a trolley line 3 that supplies AC power to a pantograph of the train 1 is installed above the rail 2 through which the train 1 passes. A switching section (switching current sorting device) 4 of about 1 km is provided at a location where the different power sources of the trolley wire 3 are matched. The trolley wire 3 is supplied with electric power from, for example, a single transformer for an A power source (Auto-Transformer, hereinafter referred to as “AT”) 5-1 and an AT 5-2 for a B power source. In the feeder 6, the switching section 4 between the two ATs 5-1 and 5-2 is provided with two switching switches 7-1 and 7-2. Between the feeder 6 and the ground wire 8, a plurality of feeder arresters 10 (= 10-1 to 10-5) are connected.

  The switching section 4 is configured such that the power supplied to the switching section 4 is switched from the A power source to the B power source by the two switching switches 7-1 and 7-2 as the train 1 advances in the arrow direction. When a plurality of lightning arresters 10 do not pass a current at the feeding voltage E of the feeder 6 and the trolley wire 3 in a normal use state as in the case of an insulator, an excessive lightning surge voltage enters the feeder 6 and the trolley wire 3. By discharging to the grounding wire 8 side (this property is referred to as “nonlinear resistance characteristic”), it has a function of suppressing overvoltage and protecting dielectric breakdown of the device to be protected. In these lightning arresters 10, a discharge current may flow due to a surge voltage when the switching switch is operated.

  FIG. 3 is a diagram showing an equivalent circuit of the feeder arrester 10 in FIG.

  Most of the feeders 10 currently used are of the zinc oxide type gapless arrester type. The zinc oxide type gapless lightning arrester 10 has a structure in which a zinc oxide element is hermetically housed in an insulating insulator tube, and equivalently, a zinc oxide resistance element 11 (resistance value R) and a stray capacitance 12 (capacitance). It can be represented by a parallel circuit of value C). The resistance element 11 has a feature that the resistance value changes according to the applied voltage and the resistance value R also changes due to the deterioration of the resistance element 11. In the grounding circuit of the lightning arrester 10 connected between the feeder 6 and the grounding wire 8, the current that can be measured is the total leakage current Io that is the sum of the capacitance current Ic and the resistance current Ir. Note that V in FIG. 3 is a voltage between the feeder 6 and the trolley wire 3 and the ground wire 8 (hereinafter referred to as “lightning arrester voltage”).

  Conventionally, lightning arrester leakage current detection methods for Shinkansen feeders include the following methods (1) and (2).

(1) Lightning Arrester Leakage Current Detection Method The following two methods (a) and (b) are mainly known as the lightning arrester leakage current detection method for diagnosing the deterioration of the power line arrester 10. .

  (A) A method of counting the number of events of surge current flowing between the lightning arrester 10 and the grounding wire 8 by a counter (in other words, a method of grasping the number of discharges of the lightning arrester 10 by the number of operations of the counter).

  (B) A method of diagnosing the deterioration of the lightning arrester 10 by measuring the total leakage current Io flowing from the lightning arrester 10 and detecting the increase amount. In this method, when the lightning arrester 10 deteriorates, the total leakage current Io increases. Therefore, the increase of the total leakage current Io is detected to diagnose the deterioration of the lightning arrester 10.

  In the methods (a) and (b), the lightning arrester 10 operates even with a small surge voltage that does not affect deterioration (for example, a switching surge that is a surge voltage when the switching switch is operated). There is a case. In such a case, there is a problem in diagnostic accuracy in that the counter also counts its operation, and there is no clear relationship between the deterioration of the lightning arrester 10 and the number of operations of the counter. For this reason, it is considered that the method (b) is more effective for the deterioration diagnosis of the lightning arrester 10.

(2) Lightning Arrester Leakage Current Detection Method by Leakage Current Measurement As shown in FIG. 3, the total leakage current Io flowing between the lightning arrester 10 and the ground line 8 is the resistance current Ir flowing through the resistance element 11 of the lightning arrester 10, The electrostatic capacitance component current Ic flowing through the stray electrostatic capacitance 12 of the lightning arrester itself is a summed value.

  When the lightning arrester 10 deteriorates, the resistance value R of the resistance element 11 decreases and the resistance current Ir increases. As a result, since the total leakage current Io, which is the sum of the resistance current Ir and the capacitance current Ic, increases, the deterioration of the lightning arrester 10 can be diagnosed by observing the increase in the total leakage current Io. . However, the method of measuring the effective value of the total leakage current Io using a measuring instrument such as an AC ammeter and checking the increase amount has the following problems, and it is possible to detect the deterioration of the lightning arrester at an early stage. Can not.

  FIG. 4A is a vector diagram showing the total leakage current Io that flows when the lightning arrester 10 is normal. FIG. 4B is a vector diagram showing the total leakage current Io that flows when the lightning arrester 10 is deteriorated.

  4A and 4B, Io (1) rms is the effective value of the total leakage current Io when the arrester is normal, Iorms is the effective value of the total leakage current Io when the arrester is degraded, and ΔIr is the resistance current Ir when the arrester is degraded. The increase amount and ΔIo are the increase amount of the total leakage current Io when ΔIr increases.

  The effective value Io (1) rms of the total leakage current Io when the lightning arrester 10 is in a normal state is a sum of the resistance current Ir and the capacitance current Ic, and the capacitance current Ic is a resistance value. Since the phase is advanced by 90 ° with respect to the divided current Ir, it can be expressed as shown in FIG. 4A. Further, when the lightning arrester 10 is in a normal state, only a small amount of resistance current Ir flows (for example, about 10% of the capacitance current Ic), and most of the total leakage current Io is the capacitance current. Ic is occupied.

  On the other hand, as shown in FIG. 4B, when the lightning arrester 10 deteriorates, the resistance current Ir increases, and the total leakage current Io also increases to the effective value Iorms, but the increase amount ΔIr of the resistance current Ir increases. On the other hand, since the increase amount ΔIo of the total leakage current Io is very small, it is difficult to detect this when the lightning arrester 10 is slightly deteriorated. Therefore, in order to detect the deterioration of the lightning arrester 10 at an early stage, it is necessary to detect not the total leakage current Io but the increase amount ΔIr of the resistance current Ir.

  Therefore, conventionally, for the purpose of grasping the resistance current Ir, for example, various methods for detecting only the resistance current Ir component from the total leakage current Io (for example, the method (I) of Non-Patent Document 1, and The method (II)) of Patent Document 1 is considered.

(I) Method of Non-Patent Document 1 FIG. 5 is a diagram illustrating a detection image of the resistance current Ir described in Non-Patent Document 1.

  In the method of Non-Patent Document 1, the lightning arrester voltage V is measured in step S1, and at the same time, the total leakage current Io is measured in step S2. Then, in the next step S3, the capacitance component current is determined from the waveform of the lightning arrester voltage V. Determine the waveform of Ic. Next, after detecting the difference between the waveform of the total leakage current Io and the waveform of the capacitance-divided current Ic in step S4, the waveform of the resistance-divided current Ir is detected in step S5.

That is, the relationship between the electrostatic capacity divided current Ic (instantaneous value ic), resistance divided current Ir (instantaneous value ir), and total leakage current Io (instantaneous value io) of the lightning arrester 10 can be expressed by the following equation (1). it can.
io = ir + ic (1)

From the equation (1), the resistance current ir can be expressed by the following equation (2).
ir = io-ic (2)
Further, the electrostatic capacity divided current ic can be expressed by the following equation (3).
ic = C (dv / dt) (3)

Therefore, from the equations (2) and (3), the resistance current ir can be expressed by the following equation (4).
ir = io−C (dv / dt) (4)

  In the method of Non-Patent Document 1, the above equation is applied to obtain the waveform of the electrostatic capacity divided current Ic from the waveform of the lightning arrester voltage V. By subtracting, the waveform of the resistance current Ir is detected.

  FIG. 6 is a diagram showing an image of voltage measurement actually used in the measurement in FIG.

  As described above, the method of Non-Patent Document 1 requires the measurement of the lightning arrester voltage V to detect the resistance current Ir. However, since the lightning arrester voltage V is high, it is dangerous and difficult to directly measure a voltmeter in parallel between the trolley wire 3 and the ground G. Usually, since the potential difference between the rail 2 and the ground G is approximately 100 V or less, it can be considered as an equipotential. Therefore, the lightning arrester voltage V between the trolley wire 3 and the ground G and the voltage Vtn between the trolley wire 3 and the rail 2 Are equivalent values.

  Therefore, actually, the voltage Vtr stepped down by the existing instrument transformer (hereinafter referred to as “Tr”) 13 is measured, and the trolley wire 3 and the rail that are equivalent to the lightning arrester voltage V are measured using this voltage Vtr. By obtaining the waveform of the voltage Vtn between the two, a voltage waveform necessary for detecting the resistance current Ir is obtained.

(II) Method of Patent Document 1 FIG. 7 is a configuration diagram illustrating the lightning arrester leakage current detection device described in Patent Document 1.

  In this lightning arrester leakage current detection device, a detector 22 is connected in series to the zinc oxide lightning arrester 10 connected between the power transmission line 21 and the ground G. The detector 22 detects the total leakage current Io flowing through the lightning arrester 10. At a connection point between the lightning arrester 10 and the detector 22, an analog / digital (hereinafter referred to as “A / D”) converter 23, a central processing unit (hereinafter referred to as “CPU”) 24a, and a memory 24b as a storage device. A one-chip microcomputer (hereinafter referred to as “microcomputer”) 24 having a digital display 25 and a digital display 25 are connected in series.

  FIG. 8 is a diagram showing a detection image of the resistance current Ir using the lightning arrester leakage current detection device of FIG.

  In the detection image of FIG. 8, in step S <b> 11, the total leakage current Io is measured by the detector 22, and the measurement result is converted into a digital signal by the A / D converter 23 and given to the microcomputer 24. In step S12, the microcomputer 24 performs a plurality of processes on the total leakage current Io after the digital signal conversion, thereby generating a waveform of the capacitance current Ic. Next, the microcomputer 24 takes the difference between the waveform of the capacitance divided current Ic and the waveform of the total leakage current Io stored in the memory 24b in step S13, and in step S14, the waveform of the resistance divided current Ir. Is detected and displayed on the digital display 25.

  That is, in the detection method of FIG. 8, the total leakage current Io is measured, and a plurality of processes are performed on the measured waveform of the total leakage current Io to generate a waveform of the capacitance current Ic. The resistance current Ir is detected by taking the difference between the waveform of the capacitance current Ic and the waveform of the total leakage current Io.

FIG. 9 is a flowchart showing specific processing of the method of FIG.
In the method of FIG. 8 using the lightning arrester leakage current detection device of FIG. 7, the processes of steps S10 to S14 are performed.

  First, in step S10, the relationship between the phase difference between the fundamental wave component of the total leakage current Io and the capacitance current Ic and the degree of distortion is stored in the memory 24b in FIG. In step S11, the detector 22 measures the total leakage current Io, and the A / D converter 23 converts the measurement result into a digital signal.

  In step S12 (= S12a to S12h) of the processing of the CPU 24a for generating the electrostatic capacity divided current Ic from the total leakage current Io, the fundamental wave component and the harmonic component of the total leakage current Io are calculated in step S12a. In step S12b, the degree of distortion of the total leakage current Io is calculated. In step S12c, the phase difference between the total leakage current Io and the capacitance current Ic is calculated. In step S12d, the peak value of the capacitance current Ic is calculated. In step S12e, a reference phase in which the instantaneous value of total leakage current Io and the peak value of capacitive leakage current Ic are equal is detected, and in step S12f, the phase is adjusted to match the phase of total leakage current Io with the reference phase. In step S12g, the peak value of the total leakage current Io subjected to the phase adjustment is adjusted to coincide with the peak value of the capacity leakage current Ic. In step S12h, a waveform of the capacitance divided current Ic is generated. Thereafter, in step S13, the difference between the total leakage current Io and the capacitance current Ic is detected, and in step S14, the resistance current Ir is detected.

  In the method of Patent Document 1, unlike the method of Non-Patent Document 1, since the resistance current Ir is detected only by measuring the total leakage current Io, it is not necessary to measure the lightning arrester voltage V.

Japanese Patent Laid-Open No. 10-2923

Railway Research Institute report (June 2012 issue) "Development of lightning arrester for Shinkansen feeder circuit" 2011 IEICE Industrial Application Conference (September 2011) No. 3-46 “Adequacy of AC power surge arrester deterioration management method”

  However, the conventional methods of Non-Patent Document 1 and Patent Document 1 have the following problems (I) and (II).

(I) Problems of Non-Patent Document 1 (Problems of FIGS. 5 and 6)
In the method of Non-Patent Document 1, it is necessary to simultaneously measure the waveform of the total leakage current Io and the waveform of the lightning arrester voltage V in order to detect the resistance current Ir. However, as described above, since it is difficult to measure the lightning arrester voltage V, actually, a necessary voltage waveform is obtained from the Tr 13 installed at a position about 100 m away from the lightning arrester 10. For this reason, the measuring device must be connected to both the lightning arrester grounding G side and the Tr13 side, and accordingly, the wiring becomes very long, and it takes time to secure the wiring route.

  Further, the voltage Vtr obtained from the Tr 13 is obtained by stepping down the voltage Vtn generated between the trolley line 3 and the rail 2, and is strictly different from the lightning arrester voltage V generated between the trolley line 3 and the ground G. Is different. For this reason, there is a possibility that some errors occur in the final measurement result.

(II) Problems of Patent Document 1 (Problems of FIGS. 7 to 9)
In the method of Patent Document 1, the resistance current Ir can be detected only by measuring the total leakage current Io, and the measurement of the lightning arrester voltage V is not required. However, there are many processes (steps S12a to S12h in FIG. 9) required when generating the waveform of the capacitance-divided current Ic from the waveform of the total leakage current Io, and the program incorporated in the microcomputer 24 becomes complicated. Further, in order to process a complicated program, a high-performance microcomputer 24 is required, which increases the design cost.

  A lightning arrester leakage current detection method according to the present invention is connected between a power supply path and a ground line, and discharges a surge voltage entering the power supply path to the ground line to protect the protection target device. A method of detecting a total leakage current of the lightning arrester for a lightning arrester represented by a parallel circuit of elements and stray capacitances, comprising: a total leakage current measurement storage process; a total leakage current measurement process; and the total leakage current High-order harmonic elimination processing, total leakage current waveform adjustment processing, total leakage current difference detection processing, and resistance component current detection processing in the total leakage current.

  Here, in the all-leakage current measurement storage process, when the lightning arrester is in a normal state and flows through the stray capacitance and the resistance element at a predetermined time based on time information. The total leakage current obtained by adding up the resistance component current is measured, and the current of the reference waveform is obtained and stored in advance. In the total leakage current measurement process, the total leakage current of the lightning arrester is measured at a predetermined time on any day based on the time information, and a current having a comparative waveform is output.

  In the high-order harmonic removal processing, high-order harmonics (that is, unnecessary components to be removed such as high-frequency noise) between the reference waveform and the comparison waveform stored in the total leakage current measurement storage processing are respectively removed. To do. In the total leakage current waveform adjustment process, the phase and amplitude of the reference waveform after the removal of the higher-order harmonics and the comparison waveform after the removal of the higher-order harmonics are adjusted. In the total leakage current difference detection process, a difference between the reference waveform after the waveform adjustment and the comparison waveform after the waveform adjustment is detected. Furthermore, in the resistance component current detection process, the resistance component current is detected from the difference.

  A lightning arrester leakage current detection device of the present invention is connected between a power supply path and a ground line, and discharges a surge voltage entering the power supply path to the ground line to protect the protection target device. A device that detects the total leakage current of the lightning arrester with respect to a lightning arrester represented by a parallel circuit of elements and stray capacitances, a total leakage current measuring unit, a total leakage current storage unit, and a high in the total leakage current A second harmonic elimination unit, a total leakage current waveform adjustment unit, a total leakage current difference detection unit, and a resistance current detection unit in the total leakage current.

  Here, the total leakage current measuring unit is a case where the lightning arrester is in a normal state and at a predetermined time based on time information, a capacitance component current flowing through the stray capacitance and a resistance flowing through the resistance element. Measure the total leakage current summed with the divided current, output the current of the reference waveform, and further measure the total leakage current of the lightning arrester at the predetermined time on any day based on the time information To output the current of the comparison waveform. The total leakage current storage unit stores the reference waveform.

  The high-order harmonic removal unit removes high-order harmonics (that is, unnecessary components to be removed such as high-frequency noise) between the reference waveform and the comparison waveform stored in the total leakage current storage unit. . The total leakage current waveform adjustment unit adjusts the phase and amplitude of the reference waveform after the removal of the higher-order harmonics and the comparison waveform after the removal of the higher-order harmonics. The total leakage current difference detection unit detects a difference between the reference waveform after the waveform adjustment and the comparison waveform after the waveform adjustment. Furthermore, the resistance component current detection unit detects the resistance component current from the difference.

  Then, in the total leakage current waveform adjustment unit, the reference waveform in a range where the resistance current does not occur in the reference waveform after the removal of the higher order harmonics and the comparison waveform after the removal of the higher order harmonics. The phase adjustment and the amplitude adjustment of the reference waveform and the comparison waveform are performed so that the difference between the reference waveform and the comparison waveform is minimized.

  Furthermore, the lightning arrester leakage current monitoring device of the present invention includes the lightning arrester leakage current detection device, a time information transmission unit that transmits the time information, and a transmission unit that transmits information stored in the total leakage current storage unit to the outside. And.

  According to the lightning arrester leakage current detection method, the lightning arrester leakage current detection device, and the lightning arrester leakage current monitoring device of the present invention, the resistance component current of the lightning arrester can be obtained simply and accurately. Furthermore, since it is considered that there is a large correlation between the deterioration of the lightning arrester and the resistance component current, it is possible to catch the deterioration of the lightning arrester at an early stage based on the obtained resistance current and the like.

FIG. 1 is a schematic configuration diagram showing a lightning arrester leakage current detection device 30 in Embodiment 1 of the present invention. FIG. 2 is a diagram showing the installation position of a general Shinkansen feeder. FIG. 3 is a diagram showing an equivalent circuit of the feeder arrester 10 in FIG. FIG. 4A is a vector diagram showing the total leakage current Io that flows when the lightning arrester 10 is normal. FIG. 4B is a vector diagram showing the total leakage current Io that flows when the lightning arrester 10 is deteriorated. FIG. 5 is a diagram illustrating a detection image of the resistance current Ir described in Non-Patent Document 1. FIG. 6 is a diagram showing an image of voltage measurement actually used in the measurement in FIG. FIG. 7 is a configuration diagram showing the lightning arrester leakage current detection device described in Patent Document 1. As shown in FIG. FIG. 8 is a diagram showing a detection image of the resistance current Ir using the lightning arrester leakage current detection device of FIG. FIG. 9 is a flowchart showing the processing of the method of FIG. FIG. 10 is a diagram showing the reference waveform SW and the comparison waveform CW measured by the total leakage current measuring unit 31. As shown in FIG. FIG. 11 is a diagram illustrating the reference waveform SW (1) and the comparative waveform CW (1) after the removal of high-order harmonics. FIG. 12A is a diagram showing a reference waveform SW (1) and a comparative waveform CW (1) before phase adjustment. FIG. 12B is a diagram illustrating the reference waveform SW (2) and the comparison waveform CW (2) after phase adjustment. FIG. 13A is a diagram illustrating the reference waveform SW (2) and the comparison waveform CW (2) before amplitude adjustment. FIG. 13B is a diagram illustrating the reference waveform SW (3) and the comparison waveform CW (3) after amplitude adjustment. FIG. 14 is a diagram illustrating a difference waveform DW between the reference waveform SW (3) and the comparison waveform CW (3). FIG. 15 is a flowchart showing a lightning arrester leakage current detection method in the lightning arrester leakage current detection device 30 of FIG. FIG. 16 is a diagram illustrating a simulation circuit for a lightning arrester leakage current. FIG. 17A is a diagram showing an actually measured waveform of the total leakage current Io of the lightning arrester for the Shinkansen substation with respect to the feeding voltage E. FIG. FIG. 17B is a diagram showing the performance of the lightning arrester for the Shinkansen feeder line. FIG. 18A is a diagram showing the performance of a lightning arrester for an AC electric railway substation (feeder side). FIG. 18B is a diagram showing the protection performance of the zinc oxide lightning arrester. FIG. 19: is a schematic block diagram which shows the lightning arrester leakage current detection apparatus in Example 2 of this invention. FIG. 20 is a schematic configuration diagram illustrating a lightning arrester leakage current monitoring apparatus according to Embodiment 3 of the present invention. FIG. 21 is a functional block diagram illustrating a configuration example of the lightning arrester leakage current monitoring device of FIG.

  Modes for carrying out the present invention will become apparent from the following description of the preferred embodiments when read in light of the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Configuration of Example 1)
FIG. 1 is a schematic configuration diagram showing a lightning arrester leakage current detection device 30 in Embodiment 1 of the present invention.

  The lightning arrester leakage current detection device 30 is a device that detects the leakage current of the lightning arrester 10 similar to the conventional lightning arrester 10. The lightning arrester 10 is connected between a trolley wire 3 as a power supply path and a ground wire 8, and discharges a surge voltage entering the trolley wire 3 to the ground wire 8 to protect the protection target device. Are represented by a parallel circuit of the resistance element 11 and the stray capacitance 12. The resistance value of the resistance element 11 is R, and the capacitance value of the stray capacitance 12 is C.

  The ground wire 8 is provided with a total leakage current measuring unit 31. The total leakage current measuring unit 31 includes the electrostatic capacity divided current Ic flowing through the stray electrostatic capacitance 12 and the resistance element 11 at a predetermined time based on the time information IT given from the outside when the lightning arrester 10 is in a normal state. The total leakage current Io obtained by adding together the resistance current Ir flowing through the current is measured, the current of the reference waveform SW is output, and further, at the predetermined time on any day based on the time information IT, The total leakage current Io is measured and the current of the comparison waveform CW is output, and is constituted by a current transformer (hereinafter referred to as “CT”).

  The total leakage current measurement unit 31 is connected to a storage unit 32 as a total leakage current storage unit and a high-order harmonic removal unit 33, and further to the high-order harmonic removal unit 33, the total leakage current waveform A waveform adjustment unit 34 as an adjustment unit, a difference detection unit 35 as a total leakage current difference detection unit, and a resistance current detection unit 36 are connected.

  The storage unit 32 stores the reference waveform SW and the like measured by the total leakage current measurement unit 31, and a high-order harmonic removal unit 33 is connected to the output side. The high-order harmonic removal unit 33 removes high-order harmonics (that is, high-frequency noise and the like) between the reference waveform SW stored in the storage unit 32 and the comparison waveform CW measured by the total leakage current measurement unit 31. Unnecessary components) are removed, and the reference waveform SW (1) and the comparison waveform CW (1) after high-order harmonics are removed are output. A waveform adjusting unit 34 is connected to the output side. Yes.

  The waveform adjustment unit 34 adjusts the phase and amplitude of the reference waveform SW (1) after the high-order harmonic removal output from the high-order harmonic removal unit 33 and the comparison waveform CW (1). The phase adjustment unit 34a and the amplitude adjustment unit 34b are configured. The phase adjustment unit 34a adjusts the phase of the reference waveform SW (1) after removal of the higher-order harmonics and the comparison waveform CW (1), and the amplitude adjustment unit 34b is connected to the output side. . The amplitude adjustment unit 34b performs amplitude adjustment of the reference waveform SW (2) after phase adjustment and the comparison waveform CW (2).

  In such a waveform adjustment unit 34, a range in which the resistance current Ir does not occur in the reference waveform SW (1) after removal of the higher-order harmonics and the comparison waveform CW (1) (for example, the comparison waveform CW (1)). The reference waveform SW (1) and the comparison waveform CW (1) so that the difference between the reference waveform SW (1) and the comparison waveform CW (1) is minimized in the range of 30% to 80% of the peak value. The phase and amplitude of the waveform are adjusted. A difference detector 35 is connected to the output side of the amplitude adjuster 34b.

  The difference detection unit 35 detects a difference between the reference waveform SW (3) after amplitude adjustment and the comparison waveform CW (3) and outputs a difference waveform DW. A resistance current detection unit is provided on the output side. 36 is connected. The resistance component current detector 36 detects the resistance component current Ir from the differential waveform DW.

(Principle of the lightning arrester leakage current detection method of Example 1)
In the conventional method of Non-Patent Document 1 shown in FIG. 5 and the method of Patent Document 1 shown in FIG. 8, the difference between the waveform of the total leakage current Io and the waveform of the capacitance-divided current Ic in the lightning arrester 10 of FIG. By adopting, resistance current Ir is detected. However, since there is the above-described problem, in order to solve this, the lightning arrester leakage current detection method of the first embodiment stores the waveform of the total leakage current Io (reference waveform SW) when the lightning arrester 10 is in a normal state. By taking the difference between the waveform of the total leakage current Io (comparison waveform CW) measured at an arbitrary date and time after that and the reference waveform SW (that is, the difference between the total leakage current waveforms), the resistance current Ir The waveform is detected.

  As described above, the lightning arrester leakage current detection method of the first embodiment detects the resistance current Ir by taking the difference between the reference waveform SW and the comparison waveform CW. However, the reference waveform SW and the comparison waveform are simply detected. Only by taking the difference from CW, the high-order harmonic component included in both waveforms, the difference in the lightning arrester voltage V applied to the lightning arrester 10, and the like are affected, and the resistance current Ir cannot be accurately detected. Therefore, before taking the difference between both waveforms, detection accuracy is improved by performing high-order harmonic elimination processing and waveform adjustment processing as total leakage current waveform adjustment processing consisting of phase adjustment processing and amplitude adjustment processing. .

(Lightning Arrester Leakage Current Detection Processing of Example 1)
FIG. 10 is a diagram showing the reference waveform SW and the comparison waveform CW measured by the total leakage current measuring unit 31, and FIG. 11 shows the reference waveform SW (1) and the comparison waveform CW (1) after removal of the higher harmonics. FIG. 12A shows a reference waveform SW (1) before phase adjustment and a comparison waveform CW (1), and FIG. 12B shows a reference waveform SW (2) and comparison waveform CW (2) after phase adjustment. FIG. FIG. 13A is a diagram showing the reference waveform SW (2) and the comparison waveform CW (2) before amplitude adjustment, and FIG. 13B is a diagram showing the reference waveform SW (3) and the comparison waveform CW (3) after amplitude adjustment. Further, FIG. 14 is a diagram showing a differential waveform DW (that is, a waveform of the resistance current Ir) between the reference waveform SW (3) and the comparison waveform CW (3). 10 to 14, the horizontal axis represents time (ms), and the vertical axis represents current (mA).

  FIG. 15 is a flowchart showing a lightning arrester leakage current detection method in the lightning arrester leakage current detection device 30 of FIG. Hereinafter, processing (steps S20 to S25) of the lightning arrester leakage current detection method will be described with reference to the flowchart of FIG.

(1) Measurement storage processing as total leakage current measurement storage processing (step S20)
As a preliminary preparation, the waveform of the total leakage current Io is measured by the total leakage current measuring unit 31 at a predetermined time based on the time information IT when the lightning arrester 10 shown in FIG. The SW current is stored in the storage unit 32 in advance. The measured reference waveform SW is shown in FIG.

  In measuring the reference waveform SW at the total leakage current Io, in order to obtain accurate waveform data, as shown in FIG. 2, it is desirable to acquire the waveform in a time zone where the train 1 is not present. Measure at a predetermined time based on IT.

(2) Total leakage current measurement process (step S21)
At the predetermined time on any day based on the time information IT, the total leakage current measuring unit 31 measures the comparison waveform CW of the total leakage current Io. This comparison waveform CW is shown in FIG.

  The measurement of the comparison waveform CW in the total leakage current Io is performed, for example, once a day. However, in order to obtain accurate waveform data, the comparison waveform CW may be measured at the same predetermined time based on the time information IT. desirable.

  The waveform of FIG. 10 is obtained as follows, as shown in FIGS. 16, 17A and 17B. Conventionally, since lightning arrester leakage current is not constantly monitored, data indicating the tendency and process of lightning arrester deterioration has not been obtained. Therefore, a circuit for simulating the following lightning arrester deterioration is configured and the processing flow of the first embodiment is described.

FIG. 16 is a diagram illustrating a lightning arrester leakage current simulation generation circuit 40.
The simulation generating circuit 40 includes a voltage adjusting transformer 41 to which an AC voltage (AC 100 V, 50 Hz) is applied on the primary side, and an insulating transformer 42 (connected to the secondary side of the voltage adjusting transformer 41 ( Primary 100V / secondary 100V). The lightning arrester voltage V output from the secondary side of the insulation transformer 42 is applied to the simulated feeder line arrester 10A. The lightning arrester 10A includes a varistor 11A (V _1mA ; 120V) as a voltage limiting element corresponding to the resistance element 11, a capacitor 12A (0.022 μF) corresponding to the stray capacitance 12, and a switch 43. Yes.

  FIG. 17A is a diagram illustrating an actual measurement waveform of the total leakage current Io of the lightning arrester for the Shinkansen substation with respect to the feeding voltage E, as described in Non-Patent Document 2. Furthermore, FIG. 17B is a figure which shows the performance of the lightning arrester for Shinkansen feeder lines.

  The waveform of FIG. 10 is obtained by the simulation generation circuit 40 of FIG. The constants of the capacitor 12A constituting the simulation generating circuit 40 and the characteristics of the varistor 11A are selected so that a leakage current equivalent to that of a feeder lightning arrester used in the Shinkansen substation (a porcelain insulator type) flows. Has been.

(3) Higher harmonic removal processing (step S22)
The high-order harmonic removal unit 33 removes high-order harmonic components from the reference waveform SW stored in the storage unit 32 and the measured comparison waveform CW, thereby minimizing waveform distortion.

  Methods for removing higher-order harmonic components include, for example, a method using moving average processing and a method using Fourier analysis using a digital filter. In the first embodiment, for example, a three-point simple moving average process is repeated 100 times by a method using a moving average process to remove high-order harmonic components. FIG. 11 shows the reference waveform SW (1) and the comparative waveform CW (1) after this high-order harmonic removal.

(4) Waveform adjustment processing as total leakage current waveform adjustment processing (step S23)
In step S23, in order to adjust the waveforms of the reference waveform SW (1) and the comparative waveform CW (1) after high-order harmonic removal by the waveform adjustment unit 34, the phase adjustment unit 34a performs phase adjustment in step S23a. In the next step S23b, amplitude adjustment processing is performed by the amplitude adjustment unit 34b.

  First, in the phase adjustment process of step S23a, the phase is adjusted by setting the position where the difference between the reference waveform SW (1) and the comparison waveform CW (1) is minimum as the place where both waveforms are in phase. However, since the lightning arrester is approximately approximated as a capacitive load before discharge, the total leakage current phase and the voltage phase differ by 90 °, and therefore the maximum voltage is applied to the resistance element near the zero cross of the total leakage current waveform. As a result, the lightning arrester instantaneously discharges (resistance value decreases), and the waveform is distorted. That is, since the resistance current Ir is generated in the vicinity of the zero cross (the current waveform is distorted), if the difference is taken in the entire waveform including the distorted portion, the phase cannot be matched well. . Therefore, it is necessary to take the difference between both waveforms in a range where the resistance current Ir does not occur (other than the regions A1 and A2).

  12A and 12B are waveforms based on a model of a lightning arrester for a Shinkansen substation feeder line (a porcelain insulator tube type). In FIG. 12A and FIG. 12B, A1 and A2 of the round frames are regions where the resistance current Ir is generated, a thick solid line with a current value of 0.4 mA is a 50% line of the comparative waveform peak value, and B in the hatched portion is B A difference area between the reference waveforms SW (1) and SW (2) and the comparison waveforms CW (1) and CW (2), and a period H is a difference comparison range of both waveforms.

  As shown in regions A1 and A2 of FIG. 12A, the resistance current Ir is generated only near the zero cross (0 mA) in both the reference waveform SW (1) and the comparison waveform CW (1). Therefore, for example, the reference waveform SW (1) is compared with the reference waveform SW (1) in the period H that is the difference comparison range between the two waveforms with reference to the 50% line of the comparison waveform peak value drawn with a thick solid line with a current value of 0.4 mA By taking the difference (shaded area B) of the waveform CW (1) (only the part where the peak value is 50% or more), the influence of the resistance current Ir component can be minimized. FIG. 12B shows the reference waveform SW (2) and the comparison waveform CW (2) when the phase is adjusted so that the area of the difference (region B) is minimized.

  Next, in the amplitude adjustment process of step S23b, the amplitude of the reference waveform SW (2) after phase adjustment and the comparison waveform CW (2) are matched by the amplitude adjustment unit 34b.

  The lightning arrester voltage V changes due to the influence of the load current and the like, and the total leakage current value Io also changes accordingly. Therefore, the amplitudes of the reference waveform SW (2) and the comparison waveform CW (2) may be different. However, the amplitude fluctuation of the total leakage current Io due to the change in the lightning arrester voltage V is irrelevant to the deterioration of the lightning arrester 10. Therefore, it is necessary to remove the amplitude fluctuation of the total leakage current Io due to the change in the lightning arrester voltage V by combining the amplitudes of both waveforms. For this reason, amplitude adjustment processing is performed.

  FIG. 13A and FIG. 13B are waveforms based on a model of a lightning arrester for a bullet train substation (a porcelain insulator type) as in FIGS. 12A and 12B. In FIG. 13A and FIG. 13B, A1 and A2 in the round frames are regions where the resistance current Ir is generated, a thick solid line with a current value of 0.4 mA is a 50% line of the comparative waveform peak value, and B in the hatched portion is B A difference area between the reference waveforms SW (2) and SW (3) and the comparison waveforms CW (2) and CW (3), and a period H is a difference comparison range of both waveforms.

  As a method of adjusting the amplitude, for example, there is a method of adjusting the amplitude of the reference waveform SW (2) so that the difference between the two waveforms is minimized. However, since the resistance current Ir is generated in the vicinity of the zero cross (the current waveform is distorted), the amplitude cannot be matched well if a difference is taken in the entire waveform including the distorted portion. . Therefore, it is necessary to take a difference between both waveforms in a range where the resistance current Ir is not generated (other than the regions A1 and A2). For example, as shown in FIGS. 13A and 13B, the resistance component current Ir component is adjusted by adjusting the amplitude so that the difference (region B) between the two waveforms is minimized in the period H that is the difference comparison range between the two waveforms. Can be minimized.

  In addition, the appropriate level of the waveform comparison area | region shown by FIG. 12A, FIG. 12B, FIG. 13A, and FIG. 13B changes with kinds of lightning arrester. The waveforms shown in FIGS. 12A, 12B, 13A, and 13B are modeled on a lightning arrester for a bullet train substation (electric porcelain insulator type). In this case, 50% or more is used as described above. Good results have been obtained by using the comparison region.

FIG. 18A is a diagram showing the performance of a lightning arrester for an AC electric railway substation (feeder side). Furthermore, FIG. 18B is a figure which shows the protection performance in the zinc oxide type lightning arrester displayed on the JEC-217 specification of the Japanese Electrotechnical Committee (JEC).
FIG. 18A shows the types (one example) of power line arresters used in a substation of an AC electric railway. Since the region where the resistance current Ir is generated varies depending on the type of arrester (including differences in the insulator material) including those shown in FIGS. 18A and 18B, it is necessary to appropriately set the comparison region in consideration of this characteristic. Yes. The present inventor has found that good results can be obtained by setting a comparison region in a range where the comparative waveform peak value is 30% to 80%.

(5) Difference detection processing as total leakage current difference detection processing (step S24)
In the difference detection process of step 24, the difference detection unit 35 detects the difference between the reference waveform SW (3) after amplitude adjustment and the comparison waveform CW (3) to obtain the difference waveform DW.

(6) Resistance current detection process (step S25)
In the resistance component current detection process in step S25, the resistance component current detection unit 36 detects the waveform of the resistance component current Ir from the differential waveform DW, as shown by a round frame in FIG.

(Modification of Example 1)
In the first embodiment, the following modifications (a) to (d) may be made.

  (A) In FIG. 1, the comparison waveform CW measured by the total leakage current measurement unit 31 is temporarily stored in the storage unit 32, and then the reference waveform stored in the storage unit 32 by the high-order harmonic removal unit 33. High-order harmonics of SW and the comparison waveform CW stored in the storage unit 32 may be respectively removed.

  (B) In FIG. 1, the reference waveform SW (1) and the comparison waveform CW (1) after removal of the higher harmonics are temporarily stored in the storage unit 32, and then stored by the waveform adjustment unit 34. Waveform adjustment between the waveform SW (1) and the comparison waveform CW (1) may be performed.

  (C) In FIG. 1 and FIG. 15, in the waveform adjustment processing of step S23 by the waveform adjustment unit 34, the phase adjustment may be performed after the amplitude adjustment, thereby obtaining the same waveform adjustment result as described above. It is done.

  (D) In FIG. 15, the reference waveform SW may be prepared by storing a waveform from which higher-order harmonic components have been removed in advance at the stage of the measurement storage process in step S20. In this case, only the high-order harmonics of the comparison waveform CW are removed in the high-order harmonic removal process of step S22.

(Effect of Example 1)
In the first embodiment, the following advantages (effects) (1) to (3) are obtained as compared with the methods and apparatuses of the conventional Non-Patent Document 1 and Patent Document 1.

(1) Comparison with the conventional non-patent document 1 In the conventional non-patent document 1, in order to detect the resistance current Ir, in addition to the waveform of the total leakage current Io, it is difficult to measure the lightning arrester voltage V. The waveform of the lightning arrester voltage V is a bottleneck. On the other hand, in the method of the first embodiment, the reference waveform SW and the comparison waveform CW necessary for detecting the resistance current Ir are both data obtained from the total leakage current Io, and other lightning arrester voltages V, etc. This data is not required, so the measurement work can be performed easily.

  The connection between the “measuring instrument” and the “instrument transformer located away from the lightning arrester”, which was essential in the conventional non-patent document 1, is no longer necessary, reducing the labor of wiring work when performing measurement. it can.

  Further, in the method requiring the measurement of the lightning arrester voltage V as in the conventional non-patent document 1, it is difficult to directly measure the lightning arrester voltage V, and an equivalent voltage waveform of another system must be substituted. Since it was not obtained, there may be some error in the accuracy of the measurement result. On the other hand, in the first embodiment, since the substitute data is not used, the resistance current Ir can be detected with high accuracy.

(2) Comparison with Conventional Patent Document 1 When the method of the first embodiment and the conventional patent document 1 are compared, the resistance current Ir can be detected only by measuring the total leakage current Io. Then it is the same. However, if FIG. 15 showing the method of the first embodiment is compared with FIG. 9 showing the method of the conventional patent document 1, the number of processes required until the resistance current Ir is detected is greatly different. As is apparent from FIGS. 15 and 9, it can be seen that the detection of the resistance current Ir by the method of the first embodiment is much less processing than the method of the conventional Patent Document 1. This is because, in the method of the first embodiment, the entire leakage current waveform is smoothed and matched with the reference waveform, and the resistance current component is obtained from the difference. This is because the processing is simplified by matching in the portion excluding the “portion”. Therefore, for example, when the steps of FIG. 15 are processed using a processor such as a microcomputer, the first embodiment can simplify the program incorporated in the processor.

  As described above, in the first embodiment, since the processing necessary for detecting the resistance current Ir is simple and small, it is relatively easy to create a program to be incorporated into the processor. As a result, the contents of the program are simplified, so that the lightning arrester leakage current detection device 30 can be configured by a general-purpose processor rather than a high-performance processor, and the cost can be reduced.

(3) Other effects The lightning arrester 10 may be deteriorated when a surge voltage is applied to decrease the resistance value R of the resistance element 11 and increase the resistance current Ir, and to install the lightning arrester 10 outdoors. Therefore, it can be considered that the resistance value R of the resistance element 11 decreases and the resistance current Ir increases due to the intrusion of moisture or the like. In the first embodiment, even when the resistance current Ir is increased due to intrusion of moisture or the like, it can be detected easily and accurately.

(Configuration of Example 2)
FIG. 19: is a schematic block diagram which shows the lightning arrester leakage current detection apparatus in Example 2 of this invention.

  The lightning arrester leakage current detection device 50 according to the second embodiment is configured so that digital processing can be easily performed with respect to the lightning arrester leakage current detection device 30 of FIG.

  The lightning arrester leakage current detection device 50 according to the second embodiment includes a total leakage current measurement unit 51 similar to the total leakage current measurement unit 31 according to the first embodiment provided on the ground line 8 of the lightning arrester 10. The total leakage current measuring unit 51 includes a high-order harmonic removal unit 52, an A / D conversion unit 53 corresponding to the high-order harmonic removal unit 32 of the first embodiment, and a total leakage corresponding to the storage unit 32 of the first embodiment. A storage unit 54 as a current storage unit, a waveform adjustment unit 55 as a total leakage current waveform adjustment unit corresponding to the waveform adjustment unit 34 of the first embodiment, and a total leakage current difference detection unit corresponding to the difference detection unit 35 of the first embodiment And a resistance component current detection unit 57 corresponding to the resistance component current detection unit 36 of the first embodiment are connected.

  The total leakage current measuring unit 51 measures the waveform of the total leakage current Io of the lightning arrester 10 at a predetermined time based on the time information IT given from the outside when the lightning arrester 10 is in a normal state. The current of the reference waveform SW as a result is output, and further, the waveform of the total leakage current Io is measured at a predetermined time on any day based on the time information IT, and the current of the comparison waveform CW as the measurement result is obtained. Output. The total leakage current measuring unit 51 includes, for example, a CT that detects the total leakage current Io, a control unit that captures the output current of the CT, and the like, and a high-order harmonic removal unit 52 is connected to the output side. Yes.

  The high-order harmonic removal unit 52 removes the high-order harmonics of the current of the reference waveform SW and the current of the comparison waveform CW output from the total leakage current measurement unit 51, respectively, and the reference after the removal of the high-order harmonics The current of the waveform SW (1) and the current of the comparison waveform CW (1) are output. An A / D conversion unit 53 is connected to the output side of the high-order harmonic removal unit 52, and a storage unit 54 is connected to the A / D conversion unit 53.

  The A / D conversion unit 53 converts the current of the reference waveform SW (1) after removal of the high-order harmonics into a digital signal to obtain reference waveform data Dsw (1), and the comparison waveform after removal of the high-order harmonics The current of CW (1) is converted into a digital signal to obtain comparison waveform data Dcw (1), and these reference waveform data Dsw (1) and comparison waveform data Dcw (1) are stored in the storage unit 54. is there.

  The storage unit 54 stores reference waveform data Dsw (1), comparison waveform data Dcw (1), the time information IT, the predetermined time, and the like, and is configured by a semiconductor memory or the like. A waveform adjustment unit 55 and a resistance current detection unit 57 are connected to the storage unit 54.

  The waveform adjustment unit 55 includes a phase adjustment unit 55a and an amplitude adjustment unit 55b.

  The phase adjustment unit 55a adjusts the phase of the reference waveform data Dsw (1) after removal of the higher-order harmonics stored in the storage unit 54 and the comparison waveform data Dcw (1). The phase adjustment unit 55a is, for example, a range in which the resistance current Ir does not occur in the reference waveform data Dsw (1) and the comparison waveform data Dcw (1) after the removal of higher harmonics (for example, the comparison waveform Dcw (1)). The reference waveform data Dsw so that the difference between the reference waveform data Dsw (1) and the comparison waveform data Dcw (1) is minimized in the range of 30% to 80% (preferably 50% or more) of the peak value of. The phase of (1) and comparison waveform data Dcw (1) is adjusted. An amplitude adjustment unit 55b is connected to the output side of the phase adjustment unit 55a.

  The amplitude adjusting unit 55b adjusts the amplitude of the reference waveform data Dsw (2) and the comparison waveform data Dcw (2) after phase adjustment. The amplitude adjustment unit 55b, for example, in the reference waveform data Dsw (2) after the phase adjustment and the comparison waveform data Dcw (2), a range in which the resistance current Ir does not occur (for example, the peak value of the comparison waveform Dcw (2)). 30% to 80% (preferably 50% or more) of the reference waveform data Dcw (2) and the reference waveform data Dsw (2) so that the difference between the reference waveform data Dcw (2) and the comparison waveform data Dcw (2) is minimized. And the amplitude of the comparison waveform data Dcw (2). A difference detector 56 is connected to the output side of the amplitude adjuster 55b.

  The difference detection unit 56 detects the difference between the reference waveform data Dsw (3) after amplitude adjustment and the comparison waveform data Dcw (3) and outputs the difference waveform data Ddw. A current detection unit 57 is connected. The resistance current detector 57 has a function of detecting the resistance current waveform data Dir of the resistance current Ir from the differential waveform data Ddw and storing the resistance current waveform data Dir in the storage unit 54.

(Operation of Example 2)
First, in order to obtain the reference waveform SW, the total leakage current measuring unit 51 detects the total leakage current Io that always flows through the ground line 8 of the lightning arrester 10 at a predetermined time based on the time information IT. A total leakage current waveform (ie, reference waveform SW) for at least one cycle is extracted from the total leakage current Io. The extracted reference waveform SW is subjected to smoothing processing by the high-order harmonic removal unit 52 to remove high-order harmonic components. The reference waveform SW (1) after the removal of the higher-order harmonics is converted into a digital signal by the A / D converter 53, and the reference waveform data Dsw (1) is generated. The generated reference waveform data Dsw (1) is stored in the storage unit 54 together with the time information IT.

  Next, in order to obtain the comparison waveform CW, the total leakage current measurement unit 51 causes all currents that constantly flow through the ground line 8 at a predetermined time on any day (for example, once a day) based on the time information IT. The leakage current Io is detected, and a total leakage current waveform (that is, a comparison waveform CW) for at least one cycle is extracted from the detected total leakage current Io. The extracted higher-order harmonic component is removed from the extracted comparison waveform CW by the smoothing process by the higher-order harmonic removal unit 52. The comparison waveform CW (1) after the removal of the higher-order harmonics is converted into a digital signal by the A / D converter 53 to generate comparison waveform data Dcw (1). The generated comparison waveform data Dcw (1) is stored in the storage unit 54 together with the time information IT.

  The reference waveform data Dsw (1) and the comparison waveform data Dcw (1) stored in the storage unit 54 are matched in phase by phase adjustment by the phase adjustment unit 55a in the waveform adjustment unit 55. The amplitudes of the reference waveform data Dsw (2) and the comparison waveform data Dcw (2) after the phase adjustment are adjusted by the amplitude adjustment by the amplitude adjustment unit 55b in the waveform adjustment unit 55. The difference detection unit 56 takes a difference between the reference waveform data Dsw (3) and the comparison waveform data Dcw (3) after amplitude adjustment, and generates difference waveform data Ddw of the difference waveform DW. The resistance-divided current waveform data Dir is detected by the resistance-divided current detection unit 57 from the generated difference waveform data Ddw. The detected resistance current waveform data Dir is stored in the storage unit 54 together with the time information IT.

(Modification of Example 2)
In the waveform adjustment unit 55, the phase adjustment unit 55a and the amplitude adjustment unit 55b may be replaced, and the amplitude adjustment may be performed first, and then the phase adjustment may be performed later.

(Effect of Example 2)
According to the lightning arrester leakage current detection device 50 of the second embodiment, there are substantially the same effects as in the first embodiment. Furthermore, since the digital processing can be easily performed, program control by a processor such as a microcomputer can be performed.

  A third embodiment of the present invention relates to a lightning arrester leakage current monitoring device including the lightning arrester leakage current detection device 50 of the second embodiment.

(Configuration of Example 3)
FIG. 20 is a schematic configuration diagram illustrating a lightning arrester leakage current monitoring apparatus according to Embodiment 3 of the present invention. In FIG. 20, elements common to those in FIG. 19 showing the second embodiment are denoted by common reference numerals.

  The lightning arrester leakage current monitoring device according to the third embodiment includes the lightning arrester leakage current detection device 50 according to the second embodiment, a time information transmission unit 110, and a data transmission unit 120 as a transmission unit.

  The lightning arrester leakage current detection device 50 is connected to a CT71 for measuring total leakage current and a CT91 for measuring surge current provided on the ground line 8 of the lightning arrester 10. The CT 71 for measuring total leakage current measures the total leakage current Io that always flows from the lightning arrester 10 to the ground line 8 and outputs a current corresponding to the total leakage current Io. The surge current measuring CT 91 measures the surge current Is flowing from the trolley wire 3 through the lightning arrester 10 to the ground wire 8 when a lightning surge occurs, and outputs a current corresponding thereto.

  The lightning arrester leakage current detection device 50 controls the storage unit 54 for storing the detected waveform data and the like, and controls the access (read / write) of data to the storage unit 54 to process the detected waveform data and manage the time information IT. And a control unit 60 that performs the above. The control unit 60 is constituted by a processor such as a microcomputer, for example.

  The time information transmission unit 110 continues to transmit the latest time information IT to the control unit 60, and includes, for example, a GPS (Global Positioning System) module that transmits time information and the like. The data transmission unit 120 transmits the storage data Dm stored in the storage unit 54 to a distant place. For example, the data transmission unit 120 includes a wifi (Wireless Fidelity) module which is one of wireless LAN (Local Area Network) standards. Has been.

  FIG. 21 is a functional block diagram showing a specific configuration example of the lightning arrester leakage current monitoring device of FIG.

  The control unit 60 in the lightning arrester leakage current detection device 50 includes a reference waveform data acquisition unit 70 and a comparative waveform data acquisition unit 80 connected to the CT 71 for measuring total leakage current, and a surge connected to the CT 91 for measuring surge current. A current waveform data acquisition unit 90 and a resistance current waveform data acquisition unit 100 connected to the storage unit 54 are included.

  The reference waveform data acquisition unit 70 acquires reference waveform data Dsw (1) from the output current of the CT 71, and includes an amplifier (hereinafter referred to as “amplifier”) 72, a high-order harmonic removal unit 52a, and an A / A It has a D converter 53a.

  The amplifier 72 is a circuit that amplifies the output current of the CT 71 and outputs the current of the reference waveform SW, and a high-order harmonic removal unit 52a is connected to the output side. Similarly to the high-order harmonic removal unit 52 in FIG. 19, the high-order harmonic removal unit 52a removes the high-order harmonics of the current of the reference waveform SW output from the amplifier 72 and removes the high-order harmonics. The current of the later reference waveform SW (1) is output, and an A / D converter 53a is connected to the output side. Similarly to the A / D conversion unit 53 in FIG. 19, the A / D conversion unit 53a converts the current of the reference waveform SW (1) after the removal of the higher-order harmonics into a digital signal and converts the reference waveform data Dsw (1 ) And a storage unit 54 is connected to the output side.

  The comparison waveform data acquisition unit 80 acquires the comparison waveform data Dcw (1) from the output current of the CT 71, and includes an amplifier 82, a high-order harmonic removal unit 52b, and an A / D conversion unit 53b. Yes.

  The amplifier 82 is a circuit that amplifies the output current of the CT 71 and outputs the current of the comparison waveform CW, and a high-order harmonic removal unit 52b is connected to the output side. Similarly to the high-order harmonic removal unit 52 in FIG. 19, the high-order harmonic removal unit 52b removes high-order harmonics from the current of the comparison waveform CW output from the amplifier 82, thereby removing the high-order harmonics. The current of the later comparison waveform CW (1) is output, and an A / D converter 53b is connected to the output side. Similarly to the A / D conversion unit 53 in FIG. 19, the A / D conversion unit 53b converts the current of the comparison waveform CW (1) after the removal of the higher-order harmonics into a digital signal and compares the comparison waveform data Dcw (1 ) And a storage unit 54 is connected to the output side.

  The surge current waveform data acquisition unit 90 acquires surge current waveform data Dis from the output current of the CT 91, and includes a level conversion unit 92, a polarity conversion unit 93, and an A / D conversion unit 94.

  The level conversion unit 92 is a circuit that converts the level of the output current of the CT 91, and a polarity conversion unit 93 is connected to the output side. The polarity conversion unit 93 is a circuit for aligning the polarity of the output current of the level conversion unit 92 (for example, a circuit for converting the output current to a positive polarity when the output current is a negative polarity and aligning all the positive polarity). An A / D converter 94 is connected to the output side. The A / D conversion unit 94 converts the output current of the polarity conversion unit 93 into a digital signal and outputs surge current waveform data Dis, and a storage unit 54 is connected to the output side.

  The resistance-divided current waveform data acquisition unit 100 is based on the reference waveform data Dsw (1) and the comparative waveform data Dcw (1) after the removal of the higher-order harmonics stored in the storage unit 54. The current waveform data Dir is acquired and stored in the storage unit 54. This resistance-divided current waveform data acquisition unit 100 is similar to that in FIG. 19, the waveform adjustment unit 55 including the phase adjustment unit 55 a and the amplitude adjustment unit 55 b, the difference detection unit 56, and the resistance-division current detection unit 57. ,have.

  The time information IT output from the time information transmission unit 110 is stored in the storage unit 54 under the control of the control unit 60. The data transmission unit 120 has a function of transmitting the storage data Dm read from the storage unit 54 under the control of the control unit 60 to a distant place.

(Operation of Example 3)
In the lightning arrester leakage current monitoring apparatus according to the third embodiment, the operation (I) at the time of obtaining the reference waveform, the operation (II) at the time of obtaining the comparison waveform, and the operation (III) at the time of detecting the surge current will be described.

(I) Operation at Reference Waveform Acquisition Similar to the second embodiment, the CT 71 constantly connects the ground line 8 connected to the lightning arrester 10 at a predetermined time based on the time information IT transmitted from the time information transmission unit 110. A flowing total leakage current Io is detected, and a total leakage current waveform (ie, reference waveform SW) for at least one cycle is extracted from the detected total leakage current Io.

  The extracted reference waveform SW is amplified by the amplifier 72 in the reference waveform data acquisition unit 70, and then the high-order harmonic component is removed by the smoothing process by the high-order harmonic removal unit 52a. The reference waveform SW (1) after the removal of the higher-order harmonics is converted into a digital signal by the A / D converter 53a to generate reference waveform data Dsw (1). The generated reference waveform data Dsw (1) is stored in the storage unit 54 together with the time information IT obtained from the time information transmission unit 110.

  The reference waveform data Dsw (1) stored in the storage unit 54 and the storage data Dm of the time information IT are transmitted to the far side through the data transmission unit 120.

(II) Operation during acquisition of comparison waveform As in the second embodiment, at a predetermined time on any day (for example, once a day) based on the time information IT transmitted from the time information transmission unit 110 by CT71. Then, the total leakage current Io that always flows through the ground line 8 is detected, and the total leakage current waveform (that is, the comparison waveform CW) for at least one cycle is extracted from the detected total leakage current Io.

  The extracted comparison waveform CW is amplified by the amplifier 82 in the comparison waveform data acquisition unit 80, and then the high-order harmonic component is removed by the smoothing process by the high-order harmonic removal unit 52b. The comparison waveform CW (1) after the removal of the higher-order harmonics is converted into a digital signal by the A / D conversion unit 53b to generate comparison waveform data Dcw (1). The generated comparison waveform data Dcw (1) is stored in the storage unit 54 together with the time information IT.

  The reference waveform data Dsw (1) and the comparison waveform data Dcw (1) stored in the storage unit 54 are the phase in the waveform adjustment unit 55 in the resistance current waveform data acquisition unit 100 as in the second embodiment. The phase is adjusted by the phase adjustment by the adjustment unit 55a. The amplitudes of the reference waveform data Dsw (2) and the comparison waveform data Dcw (2) after the phase adjustment are adjusted by the amplitude adjustment by the amplitude adjustment unit 55b in the waveform adjustment unit 55.

  The difference detection unit 56 takes a difference between the reference waveform data Dsw (3) and the comparison waveform data Dcw (3) after amplitude adjustment, and generates difference waveform data Ddw of the difference waveform DW. The resistance-divided current waveform data Dir is detected by the resistance-divided current detection unit 57 from the generated difference waveform data Ddw. The detected resistance current waveform data Dir is stored in the storage unit 54 together with the time information IT.

  The comparison waveform data Dcw (1), the resistance current waveform data Dir, and the storage data Dm of the time information IT stored in the storage unit 54 are transmitted to a long distance through the data transmission unit 120.

(III) Operation at Surge Current Detection For example, when an excessive lightning surge voltage is generated between the trolley wire 3 and the ground G, the lightning arrester 10 is discharged and the surge current Is flows through the ground wire 8. The surge current Is flowing through the ground line 8 is measured by CT91. The measured surge current waveform ISW is level-converted by the level converter 92 and then polarity-converted by the polarity converter 93 in the surge current waveform data acquisition unit 90.

  The polarity-converted current waveform is converted into a digital signal by the A / D converter 94 to generate surge current waveform data Dis. The generated surge current waveform data Dis is stored in the storage unit 54 together with the time information IT transmitted from the time information transmission unit 110.

  The surge current waveform data Dis stored in the storage unit 54 and the storage data Dm of the time information IT are transmitted to the distant place through the data transmission unit 120.

(Modification of Example 3)
Similarly to the modification of the second embodiment, in the waveform adjustment unit 55, the phase adjustment unit 55a and the amplitude adjustment unit 55b are replaced, and the amplitude adjustment is performed first, and the phase adjustment is performed later. Also good.

(Effect of Example 3)
According to the lightning arrester leakage current monitoring device of the third embodiment, there are the same effects as in the second embodiment. Further, since the deterioration of the lightning arrester 10 and the resistance current Ir are considered to have a large correlation, the deterioration of the lightning arrester 10 can be easily and early detected based on the obtained resistance current waveform data Dir and the like. become. As a result, damage to the lightning arrester can be prevented in advance, and as a result, failure of the power system due to damage to the lightning arrester can also be prevented. Therefore, stable operation of equipment can be realized.

DESCRIPTION OF SYMBOLS 3 Trolley line 8 Grounding line 10 Lightning arrester 11 Resistance element 12 Stray electrostatic capacitance 30, 50 Lightning arrester leakage current detection device 31, 51 Total leakage current measurement part 32, 54 Storage part 33, 52 Higher order harmonic removal part 34, 55 Waveform Adjustment unit 34a, 55a Phase adjustment unit 34b, 55b Amplitude adjustment unit 35, 56 Difference detection unit 36, 57 Resistance current detection unit 60 Control unit 70 Reference waveform data acquisition unit 80 Comparison waveform data acquisition unit 90 Surge current waveform data acquisition unit 100 resistance current waveform data acquisition unit 110 time information transmission unit 120 data transmission unit

Claims (6)

A parallel circuit of a non-linear resistance element and stray capacitance is connected between a power path and a ground line, and discharges a surge voltage entering the power path to the ground line to protect the protection target device. For the arrester represented
A lightning arrester leakage current detection method for detecting the total leakage current of the arrester,
When the lightning arrester is in a normal state and at a predetermined time based on the time information, the total leakage current obtained by adding the capacitance current flowing through the stray capacitance and the resistance current flowing through the resistance element is added. Measuring and storing the current of the reference waveform to obtain and store in advance all leakage current measurement,
A total leakage current measurement process for measuring the total leakage current of the lightning arrester at a predetermined time based on the time information and outputting a current of a comparison waveform;
High-order harmonic elimination processing in the total leakage current for respectively removing high-order harmonics of the reference waveform and the comparison waveform stored in the total leakage current measurement storage processing;
A total leakage current waveform adjustment process for adjusting the phase and amplitude of the reference waveform after removal of the high-order harmonics and the comparison waveform after removal of the high-order harmonics; and
A total leakage current difference detection process for detecting a difference between the reference waveform after the waveform adjustment and the comparison waveform after the waveform adjustment;
From the difference, a resistance current detection process in the total leakage current for detecting the resistance current, and
A lightning arrester leakage current detection method comprising: In the lightning arrester leakage current detection method according to claim 1,
In the total leakage current measurement storage process,
Store in advance after removing the higher harmonics of the reference waveform,
In the high-order harmonic removal processing,
Removing only the higher harmonics of the comparison waveform;
The lightning arrester leakage current detection method characterized by the above-mentioned. In the total leakage current waveform adjustment process,
The difference between the reference waveform and the comparison waveform is minimized in a range where the resistance current does not occur in the reference waveform after the removal of the higher harmonics and the comparison waveform after the removal of the higher harmonics. The lightning arrester leakage current detection method according to claim 1, wherein the waveform adjustment of the phase and the amplitude of the reference waveform and the comparison waveform is performed as described above. A parallel circuit of a non-linear resistance element and stray capacitance is connected between a power path and a ground line, and discharges a surge voltage entering the power path to the ground line to protect the protection target device. For the arrester represented
A lightning arrester leakage current detection device for detecting the total leakage current of the arrester,
When the lightning arrester is in a normal state and at a predetermined time based on the time information, the total leakage current obtained by adding the capacitance current flowing through the stray capacitance and the resistance current flowing through the resistance element is added. Measuring and outputting a current of a reference waveform, and further measuring the total leakage current of the lightning arrester at a predetermined time based on the time information and outputting a current of a comparison waveform A current measurement unit;
A total leakage current storage unit for storing the reference waveform;
A high-order harmonic removal unit in the total leakage current that respectively removes high-order harmonics of the reference waveform and the comparison waveform stored in the total leakage current storage unit;
A total leakage current waveform adjustment unit for adjusting the phase and amplitude of the reference waveform after the removal of the higher harmonics and the comparison waveform after the removal of the higher harmonics; and
A total leakage current difference detection unit for detecting a difference between the reference waveform after the waveform adjustment and the comparison waveform after the waveform adjustment;
From the difference, a resistance component current detection unit in the total leakage current for detecting the resistance component current,
Have
In the total leakage current waveform adjustment unit,
The difference between the reference waveform and the comparison waveform is minimized in a range where the resistance current does not occur in the reference waveform after the removal of the higher harmonics and the comparison waveform after the removal of the higher harmonics. As described above, the lightning arrester leakage current detection device performs the waveform adjustment of the phase and the amplitude of the reference waveform and the comparison waveform. A lightning arrester leakage current detection device according to claim 4,
A time information transmitter for transmitting the time information;
A transmission unit for transmitting information stored in the total leakage current storage unit to the outside;
A lightning arrester leakage current monitoring device comprising: The lightning arrester leakage current monitoring device according to claim 5, further comprising:
A surge current measuring unit that measures a surge current flowing from the power source path to the ground line through the lightning arrester when the surge voltage is generated;
Surge current waveform data is obtained by performing level conversion and polarity conversion on the surge current measured by the surge current measurement unit, and together with the time information received from the time information transmission unit, the surge current waveform data A surge current waveform data acquisition unit to be stored in the total leakage current storage unit;
A lightning arrester leakage current monitoring device comprising:

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