JP6485208B2 - Artificial ground fault test method and artificial ground fault test system - Google Patents

Description

  The present invention relates to an artificial ground fault test method and an artificial ground fault test system for measuring an artificial surge signal propagating through a transmission and distribution line.

  In order to prevent the expansion of damage caused by lightning strikes, ground faults, etc. in power facilities, surge countermeasures such as examination of optimum insulation levels are performed. In Patent Document 1 below, an automatic device that can automatically determine whether or not a ground fault direction relay or circuit breaker has normally operated when a ground fault occurs or an artificial ground fault occurs in a transmission and distribution line. A test system is described.

JP 2006-280024 A

  In order to provide surge countermeasures suitable for the voltage value of the surge signal in power equipment, etc., it is necessary to measure the waveform of the surge signal at a location away from the ground fault occurrence point and measure the voltage of the surge signal. desirable. However, since the propagation speed of the surge signal is fast, in an artificial ground fault test that artificially generates a ground fault, measure the voltage level of the surge signal that propagates in power equipment, etc., away from the place where the artificial ground fault occurs It can be difficult to do. In the equipment automatic test system described in Patent Document 1, the operation of the ground fault direction relay and breaker when an artificial ground fault is generated is determined, but the measurement of the surge waveform at a long distance is described. It has not been.

  An object of the present invention is to provide an artificial ground fault test method and an artificial ground fault test system capable of measuring an artificial surge signal propagating through a transmission and distribution line in an artificial ground fault test by solving the above problems. And

  An artificial ground fault test method according to an aspect of the present invention includes an artificial ground fault circuit breaker that switches between connection and disconnection between a transmission and distribution line and ground, and a surge signal that measures an artificial surge signal that propagates through the transmission and distribution line. An artificial ground fault test method having a measuring device, wherein a first time signal generator receives a radio wave including reference time information, and keeps the internal time information coincident with the reference time information at least once to measure time Outputs a first time signal to the artificial ground fault circuit breaker at a preset set time, and the artificial ground fault circuit breaker acquires the first time signal and connects the transmission / distribution line and the ground. A second time signal generation unit for receiving a radio wave including the reference time information and timing the time by matching the internal time information with the reference time information at least once; Based on time It outputs a time signal to the surge signal measuring device, wherein the surge signal meter, and a step of starting the measurement of the artificial surge signal to obtain the second time signal.

  According to this, the first time signal generation unit and the second time signal generation unit are based on the time that each internal time information is matched with the reference time information at least once and is timed with accurate internal time information. A first time signal and a second time signal are output. Generation of an artificial surge signal by the artificial ground fault circuit breaker connecting the transmission / distribution line and the ground is started with the first time signal as a trigger, and the start of measurement of the artificial surge signal triggers the second time signal. Started as. For this reason, the surge signal measuring device can measure an artificial surge signal propagating through the transmission and distribution line.

  As a preferred aspect of the present invention, the artificial ground fault circuit breaker connects the power transmission and distribution line and the ground when a predetermined switching time has elapsed from the time when the first time signal was acquired, and the surge The signal measuring device starts measuring the artificial surge signal at the time when the predetermined switching time has elapsed from the time when the second time signal is acquired. According to this, since the measurement time of the surge signal measuring device is shortened, the amount of data to be measured is reduced, and the artificial surge signal can be easily measured.

  As a desirable aspect of the present invention, the surge signal measuring instrument measures the artificial surge signal at a time when a predetermined delay time shorter than a propagation time of the artificial surge signal has elapsed since the time when the second time signal was acquired. To start. According to this, even if the measurement point of the artificial surge signal is away from the generation point of the artificial surge signal, the surge signal measurement is performed after a predetermined delay time considering the propagation time of the artificial surge signal has elapsed. The instrument is started to measure. For this reason, since the measurement time of the surge signal measuring device is shortened, the amount of data to be measured is reduced, and the artificial surge signal can be easily measured.

  As a desirable mode of the present invention, the surge signal measuring device stores information related to the waveform of the artificial surge signal in the surge signal storage unit. According to this, information such as a voltage value can be acquired from information related to the waveform of the artificial surge signal. In addition, since the measurement of the artificial surge signal is started using the second time signal as a trigger, the artificial surge signal can be measured using the surge signal storage unit having an appropriate storage capacity, and the measurement cost can be reduced. Can do.

  As a preferred aspect of the present invention, the first time signal generator and the second time signal generator are radio clocks. According to this, the internal time information of each of the first time signal generation unit and the second time signal generation unit coincides with the reference time information of the standard radio wave at least once, and the time is accurately measured. Moreover, it is easy to output the first time signal and the second time signal to the outside by using a radio timepiece.

  An artificial ground fault test system according to an aspect of the present invention includes an artificial ground fault circuit breaker that switches between connection and disconnection between a transmission and distribution line and ground, and a surge signal that measures an artificial surge signal that propagates through the transmission and distribution line. A measuring device, a first time signal generator for receiving a radio wave including reference time information, and measuring time by matching internal time information with the reference time information at least once; and a radio wave including the reference time information. And a second time signal generator for measuring the time by matching the internal time information with the reference time information at least once, and the first time signal generator at a preset time A first time signal is output to the artificial ground fault circuit breaker, and the artificial ground fault circuit breaker acquires the first time signal and starts connection between the transmission and distribution line and the ground, and the second time The signal generator The second time signal is output to the surge signal measuring instrument based time, the surge signal measurement device obtains the second time signal to start the measurement of the artificial surge signal.

  According to this, the first time signal generation unit and the second time signal generation unit are based on the time that each internal time information is matched with the reference time information at least once and is timed with accurate internal time information. A first time signal and a second time signal are output. The generation of the artificial surge signal by the artificial ground fault circuit breaker connecting the transmission / distribution line to the ground is started with the first time signal as a trigger, and the start of the measurement of the artificial surge signal is started with the second time signal as a trigger. Be started. For this reason, the surge signal measuring device can measure an artificial surge signal propagating through the transmission and distribution line.

  According to the artificial ground fault test method and the artificial ground fault test system according to one aspect of the present invention, it is possible to measure an artificial surge signal propagating through a transmission and distribution line in an artificial ground fault test.

Drawing 1 is a mimetic diagram showing composition of an artificial ground fault test system concerning an embodiment. FIG. 2 is a block diagram showing the configuration of the surge signal measuring device. FIG. 3 is a flowchart for explaining the artificial ground fault test method of the artificial ground fault test system according to the embodiment. FIG. 4 is a timing chart for explaining the artificial ground fault test method. FIG. 5 is a timing chart for explaining the artificial ground fault test method according to the first modification. FIG. 6 is a timing chart for explaining the artificial ground fault test method according to the second modification. FIG. 7 is a timing chart for explaining the artificial ground fault test method according to the third modification.

  Hereinafter, embodiments of an artificial ground fault test method and an artificial ground fault test system according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. Moreover, the method, apparatus, and modification example described in this embodiment can be arbitrarily combined within the scope obvious to those skilled in the art.

(Artificial ground fault test system)
Drawing 1 is a mimetic diagram showing composition of an artificial ground fault test system concerning an embodiment. The artificial ground fault test system 1 of the present embodiment includes an artificial ground fault circuit breaker 31 connected to the first branch point 10a of the transmission and distribution line 10 and a first branch point 10b connected to the second branch point 10b of the transmission and distribution line 10. A surge signal measuring instrument 20 and a second surge signal measuring instrument 21 connected to the third branch point 10 c of the transmission and distribution line 10 are provided. The artificial ground fault test system 1 further includes a first radio clock 30a, a second radio clock 30b, which output time signals to the artificial ground fault circuit breaker 31, the first surge signal measuring instrument 20, and the second surge signal measuring instrument 21, respectively. A third radio timepiece 30c is provided.

  In the present embodiment, the transmission and distribution line 10 includes electric lines such as power transmission lines and distribution lines. Artificial ground fault occurrence point A where the artificial ground fault circuit breaker 31 is provided, first measurement point B where the first surge signal measuring device 20 is provided, and second measurement point C where the second surge signal measuring device 21 is provided. Each may be a power facility such as a power plant of a power company, a substation, or a steel tower that supports a transmission line. The artificial ground fault occurrence point A, the first measurement point B, and the second measurement point C are provided at positions separated from each other by a long distance (for example, several kilometers to several tens of kilometers or more).

  The artificial ground fault circuit breaker 31 is provided between the transmission / distribution electric line 10 and the ground (ground) 35, and switches between connection and disconnection between the transmission / distribution electric line 10 and the ground (ground) 35. The artificial ground fault circuit breaker 31 includes a first circuit breaker 32, a second circuit breaker 33, and an opening / closing drive unit 34. When the second circuit breaker 33 is turned on (closed), the opening / closing drive unit 34 drives the first circuit breaker 32 to be turned on (closed). The opening / closing drive unit 34 can use, for example, a solenoid coil that switches between ON (closed) and OFF (open) of the first circuit breaker 32 by electromagnetic force. In addition, the opening / closing drive part 34 is not limited to this, You may mechanically switch ON (close) and OFF (open) of the 1st circuit breaker 32. FIG.

  A first circuit breaker 32, a resistor 36, and a ground (ground) 35 are connected to the first branch point 10 a of the transmission / distribution electric line 10 through the branch line 11. When the artificial ground fault circuit breaker 31 is turned on (closed), the first circuit breaker 32 is turned on (closed), and the power distribution line 10 and the ground (ground) 35 are connected. Thereby, the power transmission and distribution line 10 is grounded, and a ground fault occurs artificially. When the transmission / distribution line 10 is grounded, a transient artificial surge signal is generated in the transmission / distribution line 10.

  The first surge signal measuring device 20 and the second surge signal measuring device 21 measure an artificial surge signal propagating through the transmission and distribution line 10. The first surge signal measuring device 20 is connected to the branch line 12 connected to the second branch point 10 b of the transmission and distribution line 10 via the transformer 15. The second surge signal measuring device 21 is connected to the branch line 13 connected to the third branch point 10 c of the transmission and distribution line 10 via the transformer 16. As the first surge signal measuring instrument 20 and the second surge signal measuring instrument 21, for example, an oscilloscope or a data logger can be used.

  FIG. 2 is a block diagram showing the configuration of the surge signal measuring device. The first surge signal measuring instrument 20 includes a filter circuit 20A, a surge signal detection unit 20B, a surge signal storage unit 20C, and a control unit 20D. Although FIG. 2 illustrates the configuration of the first surge signal measuring instrument 20, the second surge signal measuring instrument 21 can also have the same configuration.

  The filter circuit 20A removes unnecessary frequency signal components other than the artificial surge signal from the signal input to the first surge signal measuring instrument 20, and allows only the artificial surge signal to pass through. The surge signal detection unit 20B determines that an artificial surge signal has been input when the voltage value of the input signal is equal to or greater than a predetermined value. For example, the surge signal detection unit 20B outputs the time information when the artificial surge signal is input to the control unit 20D. The surge signal storage unit 20C converts the artificial surge signal that has passed through the filter circuit 20A into digital data with a predetermined sampling period (for example, 0.5 μs or more and 1.0 μs or less) by an A / D converter (not shown) or the like. Convert and store the waveform of the artificial surge signal. The surge signal storage unit 20C is a hard disk, RAM, ROM, or the like.

  The control unit 20D controls the start and stop of the storage operation of the surge signal storage unit 20C. The control unit 20D acquires the second time signal Vb of the second radio timepiece 30b, and causes the surge signal storage unit 20C to start storing the waveform of the artificial surge signal using the second time signal Vb as a trigger. Further, the control unit 20D stops the storage operation of the surge signal storage unit 20C after a predetermined time has elapsed since the time when the artificial surge signal was input based on the time information input from the surge signal detection unit 20B. May be.

  The first radio clock 30a, the second radio clock 30b, and the third radio clock 30c each receive a radio wave including reference time information by an antenna (not shown), and make the internal time information coincide with the reference time information. To time. The radio wave including the reference time information is a long wave standard radio wave (long wave band JJY: East Japan 40 kHz long wave standard radio wave, West Japan 60 kHz long wave standard radio wave). The first radio clock 30a, the second radio clock 30b, and the third radio clock 30c receive the long wave standard radio wave, decode the encoded reference time information superimposed on the long wave standard radio wave, and generate time information. The internal time information is corrected based on the decoded time information. The correction of the internal time information is performed once or twice a day, for example. You may perform correction | amendment of internal time information each time before implementation of an artificial ground fault test. The internal time information is time information measured by a so-called quartz clock such as a crystal oscillation circuit built in each of the first radio clock 30a, the second radio clock 30b, and the third radio clock 30c.

  Each of the first radio clock 30a, the second radio clock 30b, and the third radio clock 30c has a time measuring unit (not shown) for measuring time and a set time storage unit (not shown) for storing a preset set time. And a time signal output unit (not shown) for outputting a time signal at the set time stored in the set time storage unit. Using an alarm function that outputs a time signal at a set time, the first radio clock 30a, the second radio clock 30b, and the third radio clock 30c are respectively a first time signal Va, a second time signal Vb, and a first time signal. 3 Time signal Vc is output at a preset time.

  The first radio timepiece 30a outputs the first time signal Va to the artificial ground fault circuit breaker 31, and the artificial ground fault circuit breaker 31 acquires the first time signal Va and turns on the first circuit breaker 32 (closed). Start the operation. The second radio timepiece 30b outputs the second time signal Vb to the first surge signal measuring device 20, and the first surge signal measuring device 20 starts measuring the artificial surge signal using the second time signal Vb as a trigger. The third radio timepiece 30c outputs the third time signal Vc to the second surge signal measuring device 21, and the second surge signal measuring device 21 starts measuring the artificial surge signal using the third time signal Vc as a trigger.

  As described above, the artificial ground fault test system 1 of the present embodiment includes the artificial ground fault circuit breaker 31 that switches between connection and disconnection between the transmission / distribution line 10 and the ground (ground) 35, and the transmission / distribution line 10. The first surge signal measuring device 20 and the second surge signal measuring device 21 that measure the artificial surge signal to be propagated, and the radio wave including the reference time information are received, and the internal time information is matched with the reference time information at least once. A first time signal generator (first radio timepiece 30a) that measures time, and receives a radio wave including reference time information, and measures time by matching the internal time information at least once with the reference time information. And a time signal generator (second radio clock 30b and third radio clock 30c). The first time signal generator (first radio timepiece 30a) outputs the first time signal Va to the artificial ground fault circuit breaker 31 at a preset time. The second time signal generator (the second radio clock 30b and the third radio clock 30c) converts the second time signal Vb and the third time signal Vc to the first surge signal measuring device 20 and the second time signal at a time based on the set time. Each is output to the surge signal measuring device 21. The artificial ground fault circuit breaker 31 acquires the first time signal Va and starts the connection between the transmission / distribution electric line 10 and the ground (ground) 35. The first surge signal measuring instrument 20 and the second surge signal measuring instrument 21 are The second time signal Vb and the third time signal Vc are acquired, and the measurement of the artificial surge signal is started.

  The artificial ground fault test system 1 according to the present embodiment receives a radio wave having reference time information, and makes the first radio timepiece as a time signal generator that measures the time by matching the internal time information with the reference time information at least once. 30a, the second radio clock 30b, and the third radio clock 30c are used. Therefore, it is possible to output the first time signal Va, the second time signal Vb, and the third time signal Vc based on the time counted by the accurate internal time information. Generation of an artificial surge signal due to the artificial ground fault circuit breaker 31 connecting the transmission and distribution line 10 to the ground (ground) 35 is started with the first time signal Va as a trigger. Further, the measurement of the artificial surge signal is started with the second time signal Vb and the third time signal Vc as triggers. For this reason, the distance between the artificial ground fault occurrence point A and the first measurement point B and the distance between the artificial ground fault occurrence point A and the second measurement point C are long distances (for example, several kilometers to several tens of kilometers or more). Even if it is a case, the 1st surge signal measuring device 20 and the 2nd surge signal measuring device 21 can measure the artificial surge signal which propagates a power transmission and distribution line.

  Since the propagation speed of the artificial surge signal is fast, if the second time signal Vb and the third time signal Vc are not used as triggers for starting the measurement of the first surge signal measuring device 20 and the second surge signal measuring device 21, Perform measurements over a long period of time before and after the occurrence of the ground fault, and reliably measure the artificial surge signal. As described above, the sampling period for acquiring the waveform of the artificial surge signal is about 0.5 μs or more and 1.0 μs or less, and is stored in the surge signal storage unit 20C (see FIG. 2) when the measurement time becomes long. The amount of data increases.

  According to the artificial ground fault test system 1 of the present embodiment, the first time signal Va, the second time signal Vb, and the third time signal Vc are output based on the time counted by the accurate internal time information. The An artificial surge signal is generated by the artificial ground fault circuit breaker 31 using the first time signal Va as a trigger. Further, the measurement of the first surge signal measuring device 20 and the second surge signal measuring device 21 is started using the second time signal Vb and the third time signal V as triggers. Therefore, it is suppressed that the measurement time of the 1st surge signal measuring device 20 and the 2nd surge signal measuring device 21 becomes long. For this reason, an increase in storage capacity can be suppressed, and an increase in cost of the artificial ground fault test system 1 is suppressed. In addition, since the increase in the amount of data to be measured is suppressed, the time and cost required for data processing are reduced.

  In addition, in this embodiment, although two places, the 1st measurement point B and the 2nd measurement point C, are provided as a measurement location of the artificial surge signal, it is not limited to this, and is a single measurement location. Alternatively, three or more measurement points may be provided.

(Artificial ground fault test method)
Next, the artificial ground fault test method of the artificial ground fault test system 1 according to the embodiment will be described. FIG. 3 is a flowchart for explaining the artificial ground fault test method of the artificial ground fault test system according to the embodiment. FIG. 4 is a timing chart for explaining the artificial ground fault test method.

  First, the first radio clock 30a, the second radio clock 30b, and the third radio clock 30c receive the long wave standard radio wave and acquire reference time information (time information) included in the long wave standard radio wave (step S11). The first radio clock 30a, the second radio clock 30b, and the third radio clock 30c perform correction to match the internal time information with the reference time information. Thereby, the internal time information of each of the first radio clock 30a, the second radio clock 30b and the third radio clock 30c is synchronized (step S12).

The first radio clock 30a, a second radio clock 30b and the third radio clock 30c, the first time signal Va, the time _{t a} for outputting the second time signal Vb, and the third time signal Vc is set in advance, information of the time t _a are stored in the respective setting time storage unit (not shown). Thus, a set time of time t _a is described above in the present embodiment. The first radio clock 30a, using an alarm function, and outputs the preset time t _a, the first time signal Va into an artificial ground fault interrupter 31. The second radio clock 30b is at time _{t a,} and outputs a second time signal Vb, which is synchronized with the first time signal Va to the first surge signal measuring instrument 20. The third wave clock 30c is the time _{t a,} and outputs a third time signal Vc which is synchronized with the first time signal Va to the second surge signal measuring instrument 21 (step S13). As shown in FIG. 4, the first time signal Va, the second time signal Vb, and the third time signal Vc are simultaneously output at _a preset time ta.

  The artificial ground fault circuit breaker 31 shown in FIG. 1 is turned on (closed) when the first time signal Va is input to the second circuit breaker 33, and the driving operation of the opening / closing drive unit 34 is started. The first circuit breaker 32 is turned on (closed) by the driving operation of the opening / closing drive unit 34, and the first branch point 10a of the power distribution line 10 is electrically connected to the ground (ground) 35 (FIG. 3, Step S14). As a result, the transmission / distribution line 10 is grounded and a ground fault is artificially generated, and a transient artificial surge signal is generated in the transmission / distribution line 10 when the transmission / distribution line 10 is grounded.

Here, as shown in FIG. 4, artificial ground fault interrupter 31, when the first time signal Va is input to the time t _a, the time t _b the time Delta] t ₁ from the time t _a has passed, the first The circuit breaker 32 (see FIG. 1) is turned on (closed), and the power transmission / distribution line 10 is grounded. Time Δt ₁ (= t _b −t _a ) is a switching time required for the switching operation of the opening / closing drive unit 34, the first circuit breaker 32, and the second circuit breaker 33. The switching time Δt ₁ of the artificial ground fault circuit breaker 31 is a time determined by the breaking method and the driving method of the artificial ground fault circuit breaker 31 and is, for example, about 30 μs or more and 100 μs or less.

The information of the switching time Δt ₁ is input to the first surge signal measuring device 20 and the second surge signal measuring device 21 in advance before starting the artificial ground fault test, and is stored in a storage unit (not shown) included in the control unit 20D. The The first surge signal measuring device 20, when the second time signal Vb is input, the second time signal Vb from the time t _a which is input, the time t for the switching time Delta] t ₁ artificial ground fault interrupter 31 has elapsed _{In b} , the measurement of the artificial surge signal is started. Similarly, the second surge signal measuring instrument 21, the third time signal Vc is input from time t _a to the third time signal Vc is input, the switching time Delta] t ₁ artificial ground fault interrupter 31 is passed to the time _{t b,} to start the measurement of the artificial surge signal (Fig. 3, step S15). In FIG. 4, when the first surge signal measuring device 20 is ON, the surge signal storage unit 20C (see FIG. 2) is storing the input signal. This shows the state where the memory is stopped. Similarly, the second surge signal measuring device 21 indicates that the signal is being stored when it is ON, and indicates that the signal is stopped when it is OFF.

Artificial surge signal generated at time t _b in artificial locations絡発cloth point A (see FIG. 1) is inputted from the second branch point 10b propagates the TD line 10 to the first surge signal measuring instrument 20, a surge signal The waveform of the artificial surge signal is stored in the storage unit 20C (FIG. 3, step S16). As described above, the artificial surge signal is converted into digital data at a predetermined sampling period and stored.

  Similarly, the artificial surge signal propagating through the transmission / distribution line 10 is input to the second surge signal measuring device 21 from the third branch point 10c, and the waveform of the artificial surge signal is stored in a surge signal storage unit (not shown). .

  The surge signal detection unit 20B (see FIG. 2) determines that an artificial surge signal has been input when the voltage value of the input signal is equal to or greater than a predetermined value. The surge signal detection unit 20B outputs information on the time when the artificial surge signal was input to the control unit 20D, and the control unit 20D detects the surge signal storage unit after a predetermined time has elapsed from the input time of the artificial surge signal. A stop signal is output to 20C. Upon receiving the stop signal, the surge signal storage unit 20C stops storing the artificial surge signal and ends the measurement of the artificial surge signal (step S17 in FIG. 3).

As described above, in the artificial ground fault test method of the present embodiment, the first radio timepiece 30a that receives a radio wave including reference time information and keeps the internal time information coincident with the reference time information at least once to measure the time is as follows. , and outputs a first time signal Va into an artificial ground fault interrupter 31 in a time t _a which is set in advance. The artificial ground fault circuit breaker 31 acquires the first time signal Va, starts the connection between the transmission / distribution electric line 10 and the ground (ground) 35, and turns the artificial ground fault circuit breaker 31 ON (closed) (step S14). ). The second radio clock 30b for counting a time to coincide at least once as a reference time information the internal time information by receiving a radio wave including the reference time information, the second time signal Vb second time t _a which is set in advance 1 output to the surge signal measuring device 20. The first surge signal measuring device 20 acquires the second time signal Vb and starts measuring the artificial surge signal (step S15). Further, the third radio timepiece 30 c outputs the third time signal Vc to the second surge signal measuring device 21. The second surge signal measuring device 21 acquires the third time signal Vc and starts measuring the artificial surge signal.

According to this, each of the first radio clock 30a, the second radio clock 30b, and the third radio clock 30c has its internal time information matched at least once with the reference time information, and is timed with accurate internal time information. Based on the time t _a (set time), the first time signal Va, the second time signal Vb, and the third time signal Vc are output. Using the first time signal Va as a trigger, the artificial ground fault circuit breaker 31 connects the power transmission and distribution line 10 and the ground (ground) 35 to generate an artificial surge signal. In addition, the measurement of the artificial surge signal is started using the second time signal Vb and the third time signal Vc as triggers. For this reason, the 1st surge signal measuring device 20 and the 2nd surge signal measuring device 21 can measure the artificial surge signal which propagates the power transmission and distribution line 10 reliably.

In artificial ground fault testing method of the present embodiment, an artificial ground fault interrupter 31, the time t _a which has obtained the first time signal Va, the time t _b the predetermined switching time Delta] t ₁ has elapsed, TD line 10 And ground (ground) 35 are connected. The first surge signal measuring device 20 starts measuring the artificial surge signal at a time t _b when _a predetermined switching time Δt ₁ has elapsed from the time ta when the second time signal Vb is input. Similarly, the second surge signal measuring instrument 21, from the time t _a third time signal Vc is input at time t _b the predetermined switching time Delta] t ₁ has elapsed, starts measuring the artificial surge signal.

According to this, TD line 10 and the ground (ground) 35 and is connected artificial surge signal from the time the time t _b generated, measurement is started. Therefore, compared with the case where the measurement is started from the time t _a second time signal Vb is input, the measurement time of the first surge signal measuring instrument 20 and the second surge signal measuring instrument 21, the predetermined switching time Delta] t ₁ Only shortened. For this reason, the amount of data to be measured is reduced, and the storage capacity of the surge signal storage unit 20C can be reduced. Further, since the amount of data to be measured is suppressed, the waveform of the artificial surge signal can be easily analyzed, and the time and cost required for data processing are reduced. Therefore, an artificial surge signal can be easily measured.

  Further, the second measurement point C where the second surge signal measuring device 21 is provided is provided at a position farther from the artificial ground fault occurrence point A than the first measurement point B. For this reason, the voltage value of the artificial surge signal propagating to the second measurement point C may be lower than that of the artificial ground fault occurrence point A and the first measurement point B. By measuring the reduced artificial surge signal by the artificial ground fault test method and the artificial ground fault test system 1 of the present embodiment, it is measured, for example, in a power plant such as a power company, a substation, or a steel tower. It is possible to provide an appropriate surge countermeasure facility for the voltage value of the surge signal. Therefore, it is not necessary to provide excessive facilities for surge countermeasures, and the cost required for surge countermeasures in power facilities can be reduced.

(First modification)
FIG. 5 is a timing chart for explaining the artificial ground fault test method according to the first modification. In the timing chart of the artificial ground fault test shown in FIG. 4, the first surge signal measuring device 20 and the second surge signal measuring device 21 start measurement from the same time t _b , whereas in the first modification example. The artificial ground fault test method is different in that the first surge signal measuring device 20 and the second surge signal measuring device 21 start measuring artificial surge signals at different times.

As shown in FIG. 5, the first surge signal measuring device 20 starts measurement at time t _c when the delay time Δt ₂ has elapsed from time t _b when the artificial ground fault circuit breaker 31 is turned on (closed). . The second surge signal measuring device 21 starts measurement from time t _c when the first surge signal measuring device 20 starts measurement, and at time t _d when the delay time Δt ₃ has elapsed.

The delay time Δt ₂ and the delay time Δt ₃ are set corresponding to the time during which the artificial surge signal propagates through the transmission / distribution line 10 shown in FIG. The distance from the first branch point 10a to the second branch point 10b of the transmission and distribution line 10 is L1, the distance from the second branch point 10b to the third branch point 10c is L2, and the propagation speed of the artificial surge signal is v. To do. The propagation time Δt _s1 of the artificial surge signal from the first branch point 10a to the second branch point 10b is Δt _s1 = L1 / v, and the propagation of the artificial surge signal from the second branch point 10b to the third branch point 10c. The time Δt _s2 is Δt _s2 = L2 / v.

The delay time Δt ₂ shown in FIG. 5 is set to a time shorter than the propagation time Δt _s1 , and the delay time Δt ₃ is set to a time shorter than the propagation time Δt _s2 . Thus, the first surge signal measuring device 20 is, from the time t _a second time signal Vb is input, passes the switching time Delta] t ₁ artificial ground fault interrupter 31 and than the propagation time Delta] t _s1 The measurement of the artificial surge signal is started at time t _c when a short predetermined delay time Δt ₂ has elapsed. The second surge signal measuring instrument 21, from the time t _a third time signal Vc is input, the switching time Delta] t ₁ artificial ground fault interrupter 31, a predetermined delay time Delta] t _2, a predetermined delay time to start the measurement of the artificial surge signal at the time t _d of a Delta] t ₃ has elapsed.

The delay time Δt ₂ and the delay time Δt ₃ are times set in advance based on the propagation length calculated from the line length of the transmission / distribution electric line 10 and the propagation speed of the artificial surge signal, and the first surge signal measurement. And the second surge signal measuring device 21.

According to the artificial ground fault test method of this modification, the measurement time of the first surge signal measuring instrument 20 and the second surge signal measuring instrument 21 is shortened in consideration of the time for the artificial surge signal to propagate through the transmission and distribution line 10. can do. Therefore, the amount of data measured by the first surge signal measuring device 20 is reduced by the delay time Δt ₂ , and the amount of data measured by the second surge signal measuring device 21 is reduced by the delay time Δt ₂ and the delay time Δt. Decrease by ₃ total hours. Therefore, the storage capacity of the first surge signal measuring instrument 20 and the second surge signal measuring instrument 21 can be reduced. Also, the stored artificial surge signal data can be easily processed. Therefore, an artificial surge signal can be easily measured.

(Second modification)
FIG. 6 is a timing chart for explaining the artificial ground fault test method according to the second modification. In the artificial ground fault test method according to the second modification shown in FIG. 6, the first surge signal measuring device 20 and the second surge signal measuring device 21 start measurement without providing a delay time. With the first surge signal measuring device 20 to start the measurement at time t _a which is the second time signal Vb is input, the second surge signal measuring instrument 21 measures the time t _a which is the third time signal Vc is input Start.

In this case, although the amount of data to be measured increases, the error in the switching time Δt ₁ of the artificial ground fault circuit breaker 31 and the error in the propagation times Δt _s1 and Δt _{s2 in which} the above-described artificial surge signal propagates through the transmission and distribution line 10 Even when this occurs, the first surge signal measuring device 20 and the second surge signal measuring device 21 can reliably measure the artificial surge signal.

(Third Modification)
FIG. 7 is a timing chart for explaining the artificial ground fault test method according to the third modification. The artificial ground fault test method according to the third modification shown in FIG. 7 is different in that the first time signal Va, the second time signal Vb, and the third time signal Vc are output at different times.

The first radio clock 30a, the time t _a which outputs a first time signal Va is set in advance, information of the time t _a is stored in the setting time storage unit (not shown). The second radio clock 30b, the time t _c for outputting the second time signal Vb is set in advance, information of the time t _c is stored in the setting time storage unit (not shown). The third radio clock 30c is set time t _d for outputting the third time signal Vc in advance, information of the time t _d is stored in the setting time storage unit (not shown).

The second radio clock 30b, based on the time _{t a,} a time _{t c} which preset switching time Delta] t ₁ and the delay time Delta] t ₂ has elapsed, and outputs a second time signal Vb. The third radio clock 30c, based on the time _{t a,} preset switching time Delta] t _1, the time _{t d} has elapsed delay time Delta] t ₂ and the delay time Delta] t _3, and outputs a third time signal Vc.

The first surge signal measuring device 20 starts measurement from the time t _c when the second time signal Vb is input, and the second surge signal measuring device 21 is measured from the time t _d when the third time signal Vc is input. To start.

According to this, the switching time Δt ₁ , the delay time Δt _2, and the delay time Δt ₃ until the first surge signal measuring device 20 and the second surge signal measuring device 21 start measurement are the second radio timepiece 30b and It is controlled on the third radio timepiece 30c side. Therefore, it is possible to suppress the occurrence of a shift in the measurement start time due to errors in the timers of the first surge signal measuring device 20 and the second surge signal measuring device 21, and to measure the artificial surge signal reliably.

  The embodiment and each modification described above can be changed as appropriate. For example, a radio timepiece is exemplified as a time signal generating device that generates a time signal, but the present invention is not limited to this, and a GPS (Global Positioning System) timepiece may be used. The GPS clock includes an antenna that receives a signal (GPS signal) from a satellite of the global positioning system, a time correction unit that corrects the current time measured by the digital clock circuit based on time information included in the GPS signal, A time signal output unit for outputting a time signal at a set time;

DESCRIPTION OF SYMBOLS 1 Artificial ground fault test system 10 Transmission / distribution electric line 10a 1st branch point 10b 2nd branch point 10c 3rd branch point 11, 12, 13 Branch line 15, 16 Transformer 20 1st surge signal measuring device 20A Filter circuit 20B Surge signal detection Section 20C Surge signal storage section 20D Control section 21 Second surge signal measuring instrument 30a First radio clock 30b Second radio clock 30c Third radio clock 31 Artificial ground fault circuit breaker 32 First circuit breaker 33 Second circuit breaker 34 Opening and closing drive Part 35 Grounding
36 resistance A artificial ground fault occurrence point B first measurement point C second measurement point Va first time signal Vb second time signal Vc third time signal

Claims (6)

An artificial ground fault test method comprising an artificial ground fault circuit breaker that switches between connection and disconnection between a transmission / distribution line and ground, and a surge signal measuring device that measures an artificial surge signal propagating through the transmission / distribution line. ,
A first time signal generation unit that receives a radio wave including reference time information and keeps the internal time information coincident with the reference time information at least once to measure the time, and outputs a first time signal at a preset set time. Outputting to the artificial ground fault circuit breaker, the artificial ground fault circuit breaker acquiring the first time signal and starting the connection between the transmission and distribution line and the ground;
A second time signal generation unit that receives a radio wave including the reference time information and keeps the internal time information coincident with the reference time information at least once, and measures the time based on the set time. Outputting a signal to the surge signal measuring device, and the surge signal measuring device acquires the second time signal and starts measuring the artificial surge signal. The artificial ground fault circuit breaker connects the power distribution line and the ground when a predetermined switching time has elapsed from the time when the first time signal was acquired,
2. The artificial ground fault test method according to claim 1, wherein the surge signal measuring device starts measuring the artificial surge signal at a time when the predetermined switching time has elapsed from a time when the second time signal is acquired.   The said surge signal measuring device starts the measurement of the said artificial surge signal at the time when the predetermined delay time shorter than the propagation time of the said artificial surge signal passed from the time which acquired the said 2nd time signal. The artificial ground fault test method according to claim 2.   The artificial ground fault test method according to any one of claims 1 to 3, wherein the surge signal measuring device stores information related to a waveform of the artificial surge signal in a surge signal storage unit.   The artificial ground fault test method according to any one of claims 1 to 4, wherein the first time signal generation unit and the second time signal generation unit are radio timepieces. An artificial ground fault circuit breaker that switches between connection and disconnection between the transmission / distribution line and ground,
A surge signal measuring device for measuring an artificial surge signal propagating through the transmission and distribution line;
A first time signal generator for receiving radio waves including reference time information, and counting time by matching internal time information with the reference time information at least once;
A second time signal generator for receiving a radio wave including the reference time information and measuring the time by matching the internal time information with the reference time information at least once;
The first time signal generator outputs a first time signal to the artificial ground fault breaker at a preset set time, and the artificial ground fault breaker acquires the first time signal and transmits the first time signal. Start the connection between the distribution line and the ground,
The second time signal generating unit outputs a second time signal to the surge signal measuring device at a time based on the set time, and the surge signal measuring device acquires the second time signal and generates the artificial surge signal. Artificial ground fault test system to start measuring.

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