JP2006058066A - Method for calculating surge propagation velocity in fault location system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To find a surge propagation velocity to be used for fault location with higher precision, and perform the location of a fault point with high precision. <P>SOLUTION: The surge propagation velocity for performing location of a fault point is calculated by executing processing consisting of a first step for selecting a plurality of pairs of combinations composed of each one pair of substations being in a relation of arrangement interposing a fault section between, and a second step for calculating surge arrival time at each substation from data on a surge waveform received from each substation, and calculating a surge propagation velocity at which the variations of located fault positions in each combination become minimum by data on surge arrival time at each substation in each selected combination and each length of transmission/distribution lines between the substations stored beforehand in a storage means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for calculating a surge propagation speed in a failure point locating system for locating a failure point position when a failure such as a ground fault occurs in a transmission / distribution electric line.

  Conventionally, as a system for locating fault points such as ground faults that occur in transmission and distribution lines, multiple slave stations that detect surge currents or surge voltages are placed in the transmission and distribution lines, and GPS (Global Positioning System) time signals are used. The surge signal arrival time (hereinafter referred to as “surge arrival time”) is specified in each synchronized slave station, and the surge arrival time specified in each slave station is transmitted to the master station. There is one in which a failure point is determined based on a difference in surge arrival time between a pair of slave stations sandwiched (for example, Patent Document 1).

JP 2000-258487 A (pages 5 to 7, FIGS. 1 to 3)

When performing the fault point location calculation, the surge propagation speed v is required as an essential parameter.
Conventionally, as the surge propagation speed v, a method of using a surge propagation speed obtained from a ground fault other than the transmission / distribution line as a constant, or as proposed in the following Patent Document 2, There is a method of using the one calculated based on the transmission / distribution line length between a pair of slave stations that do not sandwich the point and the surge arrival time at the slave stations.

JP 2001-133504 A (FIG. 5)

  However, in the method proposed in Patent Document 2, the influence of the ground capacitance of power transmission / distribution equipment arranged in various places, the high-frequency component of the surge voltage or surge current that attenuates along the transmission / distribution line If a large error is included in the surge arrival time detected by one of the pair of slave stations due to the influence of the above, there is a problem that a large error occurs in the fault location result.

  An object of the present invention is to provide a method for calculating a surge propagation speed in a fault location system that can obtain a surge propagation speed used for fault location with higher accuracy.

In order to solve the above-mentioned problems, the present invention detects the direction of the accident by comparing the phase of the zero-phase voltage and the zero-phase current at the time of occurrence of the accident in the transmission and distribution line, and the data indicating the detection result and the surge waveform is stored in the master station. A plurality of slave stations to be transmitted, and a master station that identifies a fault section based on data of an accident direction received from each of the slave stations, and determines a fault location based on surge waveform data of the slave station sandwiching the fault section; A method for calculating a surge propagation speed in a fault location system comprising:
The master station is
A first step of selecting a plurality of pairs of a pair of slave stations in an arrangement relationship across the failure section, and calculating a surge arrival time at each slave station from surge waveform data received from each slave station; Surge propagation speed that minimizes variation in fault location in each combination based on surge arrival time between slave stations in each selected combination and transmission / distribution line length data between the slave stations stored in the storage means in advance And a second propagation step for calculating a surge propagation speed for locating the failure point.

  According to the present invention, the surge propagation speed used for fault location can be determined with higher accuracy. Thereby, it becomes possible to pinpoint a failure point with high accuracy using the calculated surge propagation speed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of a failure point locating system for locating a failure point in a transmission / distribution electric line using the surge propagation velocity calculation method of the present invention.
The fault location system according to the present embodiment is installed in the transmission / distribution line 10, and has a plurality of slave stations a to d that monitor and detect the zero-phase current and zero-phase voltage of the transmission and distribution line, and the slave stations a to The master station 2 is configured to receive data based on the detection result of d and to determine the location of the failure point x based on the data.

The slave stations a to d include a voltage / current sensor 3 that detects a zero-phase voltage and a zero-phase current of the transmission / distribution electric line 10. Further, a GPS receiver (not shown) that receives a time signal from the GPS satellite 11 and a data communication device (not shown) with the master station 2 are provided.
The slave stations a to d detect the fault direction by phase comparison between the zero-phase voltage and the zero-phase current when the fault occurs in the transmission / distribution electric line 10 and transmit the detection result to the master station 2. Further, the zero-phase voltage and zero-phase current surge waveform data detected by the voltage / current sensor 3 are transmitted to the master station 2 together with a time stamp generated in synchronization with the time signal from the GPS satellite 11.
As the slave stations a to d, those described in Japanese Patent Application No. 2002-295801 filed earlier by the applicant of the present application can be used, and thus detailed description thereof will be omitted. In short, each of the slave stations a to d only needs to have a function of transmitting data indicating an accident direction and a surge waveform to the master station 2 when an accident occurs in the transmission and distribution line 10.

The master station 2 identifies the failure section based on the detection data indicating the accident direction received from each of the slave stations a to d and the system connection information. Further, a plurality of combinations of a pair of slave stations having an arrangement relationship across the failure section as a specific result are selected, and surge arrival times t _{a to} t _d detected from surge waveform data received from the slave stations in the selected combinations. And the surge propagation speed v that minimizes the variation (or standard deviation) of the fault location in each combination based on the data of the transmission / distribution line length between the slave stations stored in advance in the internal storage device. Failure in each combination based on the difference in surge arrival times t _{a to} t _d between the slave stations in the combination of the selected surge propagation velocity v and the selected plurality of pairs of slave stations and data on the transmission / distribution line length between the slave stations A point x is calculated, and a value obtained by averaging the calculated failure points is output as a failure point location.

As shown in FIG. 2, the master station 2 includes a data communication device 21, a controller (CPU) 22, a storage device 23, and an input / output device 24. The data communication device 21 performs data communication with the slave stations a to d. The controller 22 is constituted by a CPU, and a program for performing the following processing is stored in the memory 220.
(1) Accident information collection processing 221 for sending a transmission result of detection results to the slave stations a to d and collecting data of detection results of accident directions and surge arrival times;
(2) A failure section determination process for identifying a failure section based on the data of the accident direction detection result received from the slave stations a to d and the system connection information;
(3) Surge arrival time calculation processing 223 for calculating the surge arrival time from the surge waveform data received from the slave stations a to d and the time stamp.
(4) Surge propagation speed calculation processing 224 for calculating the surge propagation speed v based on the data of the surge arrival time in the slave stations a to d and the data of the transmission / distribution cable length between the slave stations,
(5) Fault location process 225 for locating the fault point x based on the calculated surge propagation velocity v
As shown in FIG. 3, the line length data 231 between the slave stations and the system connection information 232 are previously input from the input / output device 24 and stored in the storage device 23.
Further, surge waveform data 233, accident direction data 234 received from each slave station, and surge arrival time data 235 calculated from the surge waveform data are stored.

With the above configuration, a method of calculating the surge propagation speed used for locating the failure point position during a ground fault in the transmission / distribution electric line will be described.
First, the failure section is specified by the data indicating the accident direction and the system connection information 232 stored in the storage device 23. Since the process of specifying the failure section is out of the scope of the present invention, detailed description is omitted. And below, the case where the system of a transmission-and-distribution electric wire path is one system is demonstrated as a representative.
In the present invention, as shown in FIG. 5, when it is determined that the failure between the slave stations b and c of the transmission and distribution line 10 is a failure section, a combination of a pair of slave stations in an arrangement relationship sandwiching the failure section Select multiple pairs.
That is, combinations such as slave stations bc, bd, ac, and ad are selected. Then, each combination is determined based on the surge arrival times t _{a to} t _d of the slave stations in the selected combinations and the data L _ab , L _bc , and L _cd of the transmission and distribution line lengths between the slave stations stored in the storage device 23 in advance. The surge propagation velocity v that minimizes the variation in the failure point location positions x ₁ , x ₂ , x ₃ , x ₄ is calculated.

Substituting the number of combinations n = 4 in FIG. 5 into <Calculation Formula 1>, the following <Calculation Formula 2> is obtained.

When obtaining the failure point x in the failure section of FIG. 5, surge arrival times t _{a to} t between the slave stations in the combination of the surge propagation velocity v calculated by <Calculation Formula 2> and the selected plurality of pairs of slave stations. calculating a fault point x ₁ ~x ₄ in each combination based on the TD line length of data between _d differences and child station, and outputs the average value of the calculated fault point as a fault point locating position.

そして、故障点より電源側直近の子局（図６（ａ）の場合、子局a）からの標定ｘを＜計算式４＞の計算結果を用いて、次の＜計算式５＞により算出する。ｘは故障点を挟む２通りの子局間で各々標定したｘ１とｘ２の平均値とする。

As shown in FIG. 6A, when the number of combinations n is n = 2 and the orientation is performed by a total of three slave stations, one on the power source side and two on the load side, the above-described <Calculation Formula 1> The propagation velocity v is calculated by the following <calculation formula 4> in which n = 2 is substituted for.

Then, the orientation x from the slave station closest to the power supply side from the failure point (slave station a in the case of FIG. 6A) is calculated by the following <Calculation Formula 5> using the calculation result of <Calculation Formula 4>. To do. x is an average value of x1 and x2 each determined between two slave stations sandwiching the failure point.

In addition, as shown in FIG. 6B, when the number of combinations n is n = 2 and the orientation is performed by three slave stations a to c in total, that is, two units on the power source side and one unit on the load side, propagation is performed. The speed v is obtained by the above-described <Calculation Formula 4>. However, each variable is as follows.

Next, the orientation x from the slave station closest to the power supply side (in this case, the slave station b) from the failure point is calculated by the above <Calculation Formula 5> using the calculation result of <Calculation Formula 4>. Incidentally, _{x 1} and _{x 2} unlike in the case of FIG. 6 (a) is as follows.

As described above, in the present embodiment, a plurality of pairs of a pair of slave stations having an arrangement relationship across the failure section are selected, and surge arrival times t _{a to} t _d of the slave stations in the selected combinations are selected. And the surge transmission speed v that minimizes the variation of the fault location in each combination is calculated from the data of the transmission / distribution line length between the slave stations stored in advance in the internal storage device 23, and the calculated surge propagation speed The failure point x in each combination is calculated based on the difference in surge arrival times t _{a to} t _d between the slave stations in the combination of v and the selected plurality of pairs of slave stations and data on the transmission / distribution line length between the slave stations. Since the average value of the calculated failure points is output as the failure point location, even if an error is included in the surge arrival time detected by one slave station, the failure point location result is incorrect. It can be reduced.

For example, when the failure point x in the failure section as shown in FIG. 5 is determined by the conventional method, the calculation formula is as shown in the following <Calculation Formula 6>.

When the fault points are determined by the conventional method and when the method of the present invention is used, the results of the determination when no error is included in the surge arrival time detected by each slave station are as follows.
In this case, when the distance L between slave stations, the failure point position x from the slave station b, and the surge arrival time t of each slave station are as shown in Table 1 below, the surge propagation speed v of each method The calculation result of the fault location x is as shown in “Table 2”. However, L and t are set so that v is constant at 300 [m / μs] between each slave station, and t represents the arrival time tc of the slave station c as a reference (0 μs).
As shown in Table 2, when t does not include an error, both methods show accurate orientation.

「表３」から明らかなように、本発明による標定方法では１つの子局が検出したサージ到達時刻に誤差が含まれていたとしても、標定精度が良いことが分かる。 Next, “Table 3” shows the results of comparison of the orientation accuracy when the error Δt _b is included in the surge arrival time t _b of the slave station b in “Table 1”.

As is apparent from “Table 3”, it can be seen that the orientation method according to the present invention has good orientation accuracy even if an error is included in the surge arrival time detected by one slave station.

When the value of the surge propagation speed calculated by the surge propagation speed calculation method according to the present invention is used, in principle, the accuracy of the orientation result increases as the number of combinations of slave stations increases. However, if some of the results x ₁ , x ₂ , x ₃ ,... Calculated by each combination show extremely distant values, adopting them may reduce the accuracy of the orientation results. There is. In such a case, it is desirable to exclude those indicating extremely distant standard values, and to obtain only the standard value x within the allowable variation range.

FIG. 4 is a flowchart showing a procedure in which the controller 22 in the master station 2 calculates the surge propagation speed v and uses the calculated surge propagation speed v to locate the failure point x.
In FIG. 4, the controller 22 is waiting for accident information to arrive from a predetermined reference slave station (for example, one slave station close to the power supply side). (Data indicating direction and surge waveform) is received (step 41), the accident information collecting process 221 transmits a transmission command to the other slave stations in the system, and the accident information detected by each slave station. (Surge waveform, accident direction) are collected (step 42). The collected accident information is stored in the storage device 23 as surge waveform data 233 of each slave station and accident direction data 234 detected by each slave station. The surge waveform data 233 includes time stamp data.

Next, the failure section determination processing 222 reads the accident direction data 234 detected by each slave station from the storage device 23, and determines the failure section from the accident direction data 234 and the system connection information 232. Further, the surge arrival time at each slave station is calculated from the surge waveform data 233 received from each slave station, and stored in the storage device 23 (step 43).
Next, the surge propagation speed calculation processing 223 selects a plurality of combinations of a pair of slave stations having an arrangement relationship across the failure section (step 44), the line length 231 between the selected slave stations, the surge arrival time. Is read from the storage device 23 (step 45).

Next, the surge propagation velocity v is calculated by substituting into the surge propagation velocity computation formula (step 46). For example, when using accident information detected by four slave stations sandwiching a failure section as illustrated in FIG. 5, the line length between slave stations and the surge arrival time between slave stations are expressed in <Calculation Formula 2> described above. Substituting the difference data, the surge propagation velocity v is calculated.
Next, the data of the difference in surge propagation speed v, the selected line length between slave stations, and the surge arrival time is substituted into the fault location calculation formula to calculate and output the fault point x (step 47). For example, when the accident information detected by four slave stations sandwiching the failure section as illustrated in FIG. 5 is used, the failure point x is calculated by the above-described <Calculation Formula 3>. The calculated failure point x is displayed on a display constituting the input / output device 24 or printed out from a printer.

In the above description, the number of slave stations used for calculating the surge propagation velocity v is 3 or 4. However, it goes without saying that the present invention is not limited to this, and the combination of slave stations is: What is necessary is just two or more pairs.
In addition, the transmission / distribution line length data that each slave station is monitoring is input in advance from the input / output device 24, but the location information of each slave station detected by the GPS receiver is transmitted to the master station, thereby The line length between the slave stations may be calculated and used.

It is a block diagram which shows schematic structure of the failure point location system which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the main | base station in FIG. It is a figure which shows the example of the data stored in the memory | storage device of a master station. It is a flowchart which shows the procedure of the failure point location process in a master station. It is a figure explaining the combination (the number of slave stations = 4) of a slave station in the case of calculating a surge propagation speed. It is a figure explaining the combination (the number of slave stations = 3) of a slave station in the case of calculating a surge propagation speed.

Explanation of symbols

a to d Slave station 2 Master station 3 Voltage / current sensor 10 Transmission and distribution line 11 GPS satellite x Failure point 21 Data communication device 22 Controller (CPU)
23 Storage device 24 Input / output device 221 Accident information collection processing 222 Accident section determination processing 223 Surge arrival time calculation processing 224 Surge propagation speed calculation processing 225 Fault location processing

Claims (1)

A plurality of slave stations that detect the direction of the accident by phase comparison of zero-phase voltage and zero-phase current at the time of the occurrence of an accident in the transmission and distribution line, and transmit the detection result and data indicating the surge waveform to the master station, and each of the slave stations Surge propagation speed in a fault location system consisting of a master station that identifies faulty sections from accident direction data received from the master station and locates fault points based on surge waveform data of slave stations that sandwich the fault section The calculation method of
The master station is
A first step of selecting a plurality of combinations of a pair of slave stations in an arrangement relationship across the failure section;
The surge arrival time at each slave station is calculated from the surge waveform data received from each slave station, the surge arrival time between the slave stations in each of the selected combinations and the transmission between the slave stations stored in advance in the storage means. A second step of calculating a surge propagation speed that minimizes the variation of the fault location in each combination based on the distribution line length data;
A method for calculating a surge propagation speed in a fault location system, wherein a surge propagation speed for locating a fault location is calculated.

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