JP3527432B2 - Slave station, surge detection time locating method, failure location system, and failure location method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slave station, surge detection time locating method, fault point locating system and fault point locating method. More specifically, a slave station and a surge detection time locating method capable of obtaining an accurate surge detection time without increasing the frequency of erroneous detection, and a fault point locating system and a fault point capable of accurately locating a failure point. Regarding orientation method.

[0002]

2. Description of the Related Art Conventionally, when a failure occurs in a straight transmission line or distribution line without branching (hereinafter collectively referred to as "transmission and distribution line"), the breakdown occurs. There is a method of obtaining a fault position on a power transmission and distribution line from a difference in surge detection time between two slave stations sandwiching a location (Japanese Patent Publication No. 63-51274, etc.).
In this method, the localization accuracy of the time when the surge is detected at the slave stations at both ends (hereinafter referred to as "surge detection time") affects the localization accuracy of the failure position.

On the other hand, regarding the detection of the surge, when the surge voltage and the surge current exceed a certain threshold,
It is said to have detected a surge. The lower the voltage and current thresholds, the more accurately (initially) the rising time of the surge waveform can be captured, but usually noise is generated in the voltage and current of the power transmission and distribution lines. , If the threshold value is set too low, false detection of surge due to noise will occur frequently. For this reason, the threshold value for recognizing the occurrence of the surge is set to a certain high level so that noise is not erroneously detected. Therefore, "surge detection"
Will be performed after a certain time has elapsed after the surge waveform rises.

The surges received by the two slave stations having the fault point may have different waveforms due to propagation loss in the power transmission and distribution lines. In such a case, as shown in FIG. 6, in the slave station whose surge waveform is more crushed, the rise time of the surge becomes longer,
"Surge detection" will be delayed. For this reason,
Accurate fault location cannot be performed based on the difference in surge detection times of the slave stations across the fault point.

There is a two-potential method as a method for correcting the elapsed time due to the threshold value being set to a high level and obtaining a more accurate "surge detection time". As shown in FIG. 7, this is a straight line at two points (points that exceed a certain set reference level L1, L2) in the graph of the surge waveform when the horizontal axis represents time and the vertical axis represents voltage. And the line (time) at which the straight line intersects the 0 level of the voltage, that is, the horizontal axis is referred to as “surge detection time T”.

That is, in the two-potential method, after the voltage or current of the transmission and distribution line exceeds a certain reference level, it rises as it is, and when the next reference level is exceeded, those two levels and the voltage curve are The approximate straight line of the voltage curve is drawn by connecting the intersection points of, and the point at which the approximate straight line intersects the 0 level of the voltage is the surge detection time T. With respect to the dual potential method, various improved inventions and improved inventions have been filed (Japanese Utility Model Application Laid-Open No. 58-28219, Japanese Patent Application Laid-Open No. 8-015362, etc.).

[0007]

However, as described above, there is noise in the voltage and current of the power transmission and distribution line, and when relatively large noise is generated or when noise is superimposed on the surge waveform, In some cases, the voltage or current of the power transmission / distribution line once drops after exceeding the above-mentioned first reference level L1. In such a case, as shown in FIG. 8, the "intersection between the next reference level L2 and the voltage curve" and the "intersection between the first reference level L1 and the voltage curve" may be connected by a straight line. The voltage detection curve does not become an accurate approximate straight line of the voltage curve, and the calculated surge detection time T deviates from the desired realistic time Tr.

The present invention solves such a problem, and a slave station and a surge detection time locating method capable of obtaining an accurate surge detection time without increasing the frequency of erroneous detection, and an accurate method. An object is to provide a fault point locating system and a fault point locating method capable of locating a fault location.

[0009]

The invention according to claim 1 is
A slave station installed on a power transmission / distribution line and locating a detection time of a surge voltage or a surge current due to a failure that occurs at any part of the power transmission / distribution line, and at least from the current time to a time point traced back for a fixed time. The past voltage or current waveform of the power transmission and distribution line is stored and updated, and the surge certification level, which is the reference level for surge certification and is set higher than the noise level, and the start point of the surge waveform are set. A surge waveform start level which is a reference level for determining and is set lower than the surge approval level, and when the voltage or current of the transmission and distribution line exceeds the surge approval level, The stored waveform is traced back from the time when the surge certified level is exceeded, and the time when the voltage or current first exceeds the surge waveform start level is detected by surge detection. A slave station, characterized by the time.

Here, "the time when the voltage or current first exceeds the surge waveform start level retroactively" means
Along the time axis direction, the time at which the voltage or current exceeds the surge waveform start level at the end, that is, at the time closest to the time at which the surge approval level is exceeded. The "surge detection time" is the time at which the slave station receives and detects a surge voltage or surge current due to a failure that occurs at any part of the power transmission and distribution line.

According to a second aspect of the present invention, in a slave station arranged on a power transmission / distribution line, a surge for locating a detection time of a surge voltage or a surge current due to a failure occurring at any part of the power transmission / distribution line. It is a detection time locating method, and is a surge certification level that is a reference level for certifying surges and is set higher than the noise level, and a reference level for defining the start point of the surge waveform, which is the surge certification level. The surge waveform start level that is set lower than the above is defined, and the waveform of the past voltage or current of the power transmission and distribution line from at least the current time to a time traced back by a fixed time is stored and updated, and the power transmission and distribution is performed. When the line voltage or current exceeds the surge approval level, the stored voltage is traced back from the time when the surge approval level is exceeded. Is a surge detection time locating method of the SD time the first time beyond the surge waveform starting level current.

The invention according to claim 3 is the surge detection time locating method according to claim 2, wherein the waveform of the past voltage or current is stored as a discrete value sampled at regular intervals, and the surge is recorded. The surge detection time is defined as the sampling time next to the sampling time at which the sample value first falls below the surge waveform start level as far back as the time when the certified level is exceeded.

Here, the "next" means "the first one following the direction of the time axis". That is, when the sample value below the surge waveform start level exceeds the surge waveform start level, the "surge detection time" is set. In addition, for example, a surge detection time locating method in which "sampling time at which the sample value first falls below the surge waveform start level" is defined as "surge detection time" is also conceivable. If the sampling interval is sufficiently small with respect to the required accuracy of time, such a method will not cause any inconvenience.

According to a fourth aspect of the present invention, the slave station 1 is installed in the power transmission / distribution line and transmits the information of the surge detection time to the master station 2.
And a master station 2 for locating a failure point based on the information of the surge detection time, wherein the slave station 1 has at least the time from the present time to a time traced back by a fixed time. The past voltage or current waveform of the power transmission and distribution line is stored and updated, and the surge certification level, which is the reference level for surge certification and is set higher than the noise level, and the start point of the surge waveform are set. A surge waveform start level which is a reference level for determining and is set lower than the surge approval level, and when the voltage or current of the transmission and distribution line exceeds the surge approval level, The stored waveform is traced back from the time when the surge approval level is exceeded, and the time when the voltage or current first exceeds the surge waveform start level is defined as the surge detection time. A fault point location system, characterized by transmitting to the master station 2 via a communication network detection time.

This fault point locating system can also be embodied as follows. That is, the slave station 1 that is installed on the power transmission and distribution line and transmits the information of the surge detection time to the master station 2, and the master station 2 that locates the failure point based on the information of the surge detection time.
And a fault point locating system including:
Is a surge detector 13 and a surge information transmitter 14b.
The surge detecting means 13 includes surge waveform storing means 136 and surge recognizing means.

The surge waveform storage means 136 is provided.
Stores and updates the past voltage or current waveforms of the power transmission and distribution line from at least the current time to a time traced back by a certain time, and the surge recognizing means can store the past waveforms in the past in accordance with the request of the surge recognizing means. It conveys the information of the voltage or current waveform of.

The surge certifying means is a surge certifying level which is a reference level for certifying a surge and is set higher than a noise level, and a reference level for defining a start point of a surge waveform. The surge waveform start level set lower than the level is stored, and when the voltage or current of the power transmission and distribution line exceeds the surge approval level, the surge waveform storage unit 136 stores the past voltage or current. The information on the waveform is received, and the stored waveform is traced back from the time when the surge approval level is exceeded, and the time when the voltage or current first exceeds the surge waveform start level is defined as the surge detection time. To the surge information transmitting means 14b.

Then, the surge information transmitting means 14b.
Transmits the surge detection time to the master station 2 through the communication network. The failure point locating system according to the fourth aspect may be configured as described above.

The invention according to claim 5 is the fault point locating system according to claim 4, wherein the master station 2 is one of a pair of slave stations sandwiching a fault point of the transmission and distribution line network. Based on the surge detection time t1 of the station, the surge detection time t2 of the other slave station, the propagation speed v of the surge, and the length L of the power transmission / distribution line between the slave stations, The distance L1 on the power transmission and distribution line from the slave station to the above-mentioned fault point is calculated by the equation L1 = (L + (t1
-T2) * v) / 2.

The invention according to claim 6 is the fault point locating system according to claim 4, wherein the master station 2 has the surge detection time t of the slave station closest to the power source end of the power transmission and distribution line network.
1, the surge detection time t2 of the slave station at the end of the power transmission and distribution line network, the propagation speed v of the surge, and the length L of the power transmission and distribution line between the slave stations, based on the power source end side. The distance L1 on the power transmission and distribution line from the slave station of the
(T1−t2) × v) / 2, and further, the surge detection time t3 of one of the pair of slave stations sandwiching the failure point obtained by the above calculation and the surge detection time of the other slave station. Based on the surge detection time t4, the propagation speed v of the surge, and the length L'of the power transmission / distribution line between the pair of slave stations, the power transmission / distribution line from the one slave station to the failure point is The distance L3 of
It is obtained from (L ′ + (t3−t4) × v) / 2.

The invention according to claim 7 is the fault point locating system according to any one of claims 4 to 6, wherein the past voltage or current waveform is a discrete value sampled at regular intervals. The surge detection time is stored at a sampling time next to the sampling time at which the sample value first falls below the surge waveform start level, which is traced back from the time when the surge approval level is exceeded.

The invention according to claim 8 is a fault point locating method for locating a fault point based on information of surge detection times at two or more slave stations arranged on a power transmission and distribution line. It is a procedure.

(1) To determine the surge approval level, which is a reference level for approval of surge and is set higher than the noise level, and the start point of the surge waveform for each slave station arranged on the power transmission and distribution line And a surge waveform start level that is set to be lower than the surge approval level, the waveform of the past voltage or current of the power transmission and distribution line from at least the current time to a time traced back by a fixed time. When the voltage or current of the power transmission and distribution line exceeds the surge approval level, the stored waveform is traced back from the time when the surge approval level is exceeded and the voltage or current is first stored. The time when the surge waveform start level is exceeded is the surge detection time.

(2) The surge detection time t1 of one slave station of the power transmission and distribution line network, the surge detection time t2 of another slave station, the propagation speed v of the surge, and the distance between the slave stations. Based on the length L of the power transmission and distribution line, and the distance L1 on the power transmission and distribution line from the one slave station to the fault point, the equation L1 = (L + (t
1-t2) × v) / 2.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [Examples] (1) Configuration of Fault Point Locating System As shown in FIG. 1, this fault point locating system includes a slave station 1 installed on each tower or telephone pole of a power transmission and distribution line, and a business office of an electric power company. It is composed of a parent station 2 installed in a branch office and locating a failure point based on information from the child station 1.

(A) Slave station The slave station 1 has a GPS antenna 111 as shown in FIG.
, GPS receiver 112, oscillation circuit 121, reference clock 122, time synchronization correction circuit 123, and ZCT131
(Zero-phase current transformer), a filter circuit 132, a surge signal detection circuit 133, a surge detection time holding circuit 134,
Surge waveform recording circuit 136 and central processing unit 141
And a communication interface 142.

Then, the ZCT 131 and the filter circuit 13
2, the surge signal detection circuit 133, the surge detection time holding circuit 134, the surge waveform recording circuit 136, and a part of the central processing unit 141 correspond to “surge detection means 13” in the claims. Further, the central processing unit 141 and the communication interface 142 correspond to "surge information transmitting means 14b" in the claims.

And, as a similar concept, GPS
The antenna 111 and the GPS receiver 112 are collectively referred to as "GP
The oscillation circuit 12 can be regarded as "S receiving means".
1 and the reference clock 122 and the time synchronization correction circuit 123 can be collectively regarded as "time measuring means 12". Each component will be described below.

(I) ZCT 131 (zero-phase current transformer) This is attached to the steel tower of the power transmission and distribution line, detects a surge signal (surge current) generated at the time of failure, and sends it to the filter circuit 132. When detecting a surge voltage as a surge signal, a voltage detector such as PT or PD is used. (Ii) Filter circuit 132 Unnecessary commercial frequency signal components other than the surge signal are removed from the signal detected by the ZCT 131, only the surge signal is passed, and sent to the surge signal detection circuit 133 and the surge waveform recording circuit 136. (Iii) Surge signal detection circuit 133 The level of the surge signal is detected, and when the signal level exceeds the surge certified level, it is determined that a surge has occurred and a time holding signal is output to the surge detection time holding circuit 134. At the same time, the surge waveform recording stop signal is sent to the surge waveform recording circuit 1.
Output to 36.

(Iv) Surge detection time holding circuit 134 When the time holding signal is output from the surge signal detection circuit 133, the time of the reference clock 122 at that time is held, and it is set as the initial value of the surge detection time and the central processing unit 141 is set. Output to. (V) Surge waveform recording circuit 136 A surge signal waveform received from the filter circuit 132 is converted into digital data by an A / D converter on the basis of the sampling signal received from the oscillation circuit 121, and the data is recorded in an endless structure. (For example, a ring memory) is constantly recorded and updated. When the surge signal recording stop signal is received from the surge signal detection circuit 133, the recording of the waveform is stopped, and the surge signal waveform that has been recorded until that time is held in the waveform recording memory and is output to the central processing unit 141.

(Vi) GPS antenna 111 and GPS receiver 112 The GPS antenna 111 receives a radio wave from a GPS satellite and sends it to the GPS receiver 112. Then, the GPS receiver 112 extracts the information of the standard time held by the GPS satellite from the radio wave as a synchronization signal and outputs it to the time synchronization correction circuit 123. (Vii) Time synchronization correction circuit 123 According to the synchronization signal output from the GPS receiver 112,
The time of the reference clock 122 is synchronized with the standard time of the GPS satellite.

(Viii) Reference clock 122 The reference time is output to the surge detection time holding circuit 134. (Ix) Oscillation circuit 121 Outputs a reference time signal for measuring time to the reference clock 122. The waveform sampling signal synchronized with the reference time signal is output to the surge waveform recording circuit 136.

(X) Central processing unit 141 From the surge detection time initial value output from the surge detection time holding circuit 134 and the surge signal waveform output from the surge waveform recording circuit 136, immediately before the surge detection time initial value. When the voltage exceeds the surge waveform start level, the time is specified as the surge detection time and transmitted to the master station 2 via the communication interface 142. (Xi) Communication Interface 142 Relays communication signals between the central processing unit 141 and the public network so that the central processing unit 141 can communicate with the master station 2 using the public network.

Note that the slave station 1 has a G
It is also possible to identify its own position based on PS radio waves and send that information to the master station.

(B) Master Station Further, as shown in FIG. 3, the master station 2 includes a communication interface 21, an auxiliary storage device 222, and a central processing unit 2.
3, a CRT 241, a printer 242, and a keyboard 25.

Here, the communication interface 21 is a slave station position information receiving means 2 for receiving the position information from each slave station.
1a or the slave station surge information receiving means 21b for receiving the information on the surge detection time from each slave station. Then, the central processing unit 23 serves as a power transmission and distribution line map information creating unit 23a that creates power transmission and distribution line map information based on the position information of the slave station, and also a fault that locates the failure position based on the surge detection time. Position specifying means 23c
Can be positioned as

Further, the auxiliary storage device 222 can be positioned also as a map information storage means, and the CRT 241 can be used.
The printer 242 can be positioned as a power transmission / distribution line diagram information output unit that outputs the orientation result. And
The keyboard 25 can be positioned as an input means. Each component will be described below.

(I) Communication interface 21 Relays communication signals with the slave station 1. That is, the signal sent from the slave station 1 via the public communication line is converted and passed to the central processing unit 23.

(Ii) Central processing unit 23 (personal computer etc.) Each slave station 1, 1, 1 ,. ． ． The position information and the surge detection time sent from are received via the communication interface 21, and the failure point locating process described later is performed. The fault point obtained by the fault point locating process is transmitted to the CRT 241 together with the transmission / distribution line diagram data stored in the auxiliary storage device 222.
Alternatively, it is output to the printer 242.

(Iii) Auxiliary storage device 222 (such as a hard disk) Each slave station 1, 1, 1 ,. ． ． The surge detection time and position information sent from the device, the fault point calculated by the central processing unit 23 and the power transmission and distribution line diagram data necessary for the processing in the central processing unit 23 are recorded and saved. Here, the transmission / distribution line diagram data includes position data of electric poles and towers, distance data between electric poles (towers), and the like. (Iv) Printer 242 In accordance with an instruction from the central processing unit 23, the power transmission and distribution line diagram data sent from the central processing unit 23 and the result of locating a fault point are printed.

(V) CRT 241 In accordance with an instruction from the central processing unit 23, the transmission / distribution line diagram sent from the central processing unit 23 and the result of fault location are displayed. (Vi) Keyboard 25 (input means) Input drawing data and the like necessary for creating a power transmission and distribution line diagram. Here, the drawing data includes position data of electric poles and steel towers, distance data between electric poles (steel towers), and the like.

(2) Processing in the fault point locating system In the following, the procedure for identifying the fault location when a fault occurs in the power transmission / distribution line will be described. First, in (a), the orientation of the surge detection time in the slave station will be described, and in (b), the orientation of the failure point in the parent station will be described.

(A) Surge detection time in slave station In the central processing unit 141 of the standard station 1 of the slave station, the surge signal exceeds the surge approval level in order to reduce the difference in surge detection time due to the difference in rise time of surge signals. The initial value of surge detection time, which is set as the predetermined time, is corrected to obtain the surge detection time. Below, the procedure of locating the surge detection time in the central processing unit 141 of the slave station 1 will be described.

(Procedure 1) Surge detection time holding circuit 134
The initial value of the surge detection time is received, and the surge waveform data is received from the surge waveform recording circuit 136 in the form of discrete values (see FIGS. 2 and 4). (Procedure 2) The waveform data (discrete value) is traced sequentially from the initial value of the surge detection time in chronological order, and the signal levels of the waveform data are compared until the signal level becomes equal to or lower than the surge waveform start level (see FIG. 4). (Procedure 3) When the signal level of the waveform data reaches the surge waveform start level, multiply the sampling interval by (“the number of times traced back to that signal-1”)
It is subtracted from the initial value of the surge detection time and used as the surge detection time (see FIG. 4).

(B) Locating a fault point in the master station The principle and procedure for locating a fault point in the central processing unit 23 of the master station 2 will be described below. First, in (i), the principle of the fault location will be described, and then in (ii), the procedure will be described.

(I) Principle of locating a fault point FIG. 5 shows a principle diagram of locating a fault point. When a ground fault occurs between the slave stations, a traveling wave (surge) occurs as shown in FIG. Assuming that the propagation speed v of the traveling wave propagating in the power transmission and distribution line is constant, the distance at which the traveling wave is detected by the slave station and the slave station is the distance L1 from the fault occurrence point to each slave station. It will be proportional to L2.

That is, if the length L of the power transmission / distribution line between the slave station and the slave station is known and the time difference detected by the slave station and the slave station can be accurately detected, as shown in FIG. Calculation formula “L1 = (L + (t1−t2) × v) /
2 ”, the distance L1 from the slave station to the failure point can be obtained.

In the fault point locating system of the present embodiment, the length L of the power transmission / distribution line between the slave stations (the slave station at the power source end and the slave station at the terminal end) whose surge time difference is examined is calculated and stored in advance. There is something. That is, regarding the adjacent slave stations, the distance between the two is determined based on the position information (latitude, longitude, altitude) of the slave stations, assuming that the power transmission and distribution lines are almost straight. Can be calculated.

Regarding the distance between non-adjacent slave stations, the length of the power transmission / distribution line between the slave stations can be calculated by adding the lengths of the power transmission / distribution lines between the adjacent slave stations existing therebetween. L can be obtained.

(Ii) Fault location procedure The central processing unit 23 of the master station 2 preliminarily sets the length of the power transmission and distribution line between the slave station closest to the power source end and the slave station at each end of the power transmission and distribution line network. S is calculated and stored. Then, the central processing unit 23 uses the slave station 1 closest to the power source end on the power transmission and distribution line.
And the slave station 1 closest to the ends of the trunk line and the branch line are selected, and the failure point is located from the difference in surge detection time of both slave stations.

That is, the central processing unit 23 detects the surge detection time t1 of the slave station on the power source end side, the surge detection time t2 of the slave station on the end side, the propagation speed v of the surge, and power transmission / distribution between both slave stations. Based on the line length L and the line length L, the distance L1 on the power transmission and distribution line from the slave station on the power source end side to the position (failure point) at which the power transmission and distribution line has failed is calculated by the formula L1 = (L + (t1 -T2) ×
v) / 2. However, v is 150 to 300 m / μ considering the case of an overhead line and the case of a cable distribution line.
s. This v is more preferably 250 to 300 m / μs.

If there are slave stations 1 and 1 which sandwich the fault point near the fault point, the fault point is re-oriented from the difference in surge detection time of those slave stations. The reliability of orientation can be improved. Regarding this fault point locating procedure, the operator may manually give a necessary instruction to the central processing unit 23 each time to perform the fault point locating process, or the central processing unit 23 automatically processes it. You may program it so that you can.

In this case, an accurate time difference cannot be detected unless the times of the reference clocks of the slave stations at both ends are synchronized, but here, as described above, the standard time sent from the GPS satellite and each By synchronizing the times of the reference clocks of the slave stations, the time of each slave station is synchronized.

(III) Display of Fault Occurrence Point The central processing unit 23 of the master station 2 notifies the operator of the fault occurrence point when the fault point is located, so that the power transmission and distribution line stored in the auxiliary storage device 222 is displayed. The graphic information and the localized failure point are displayed on the screen of the CRT 241. In addition, the printer 242 can be used to print them according to the operator's request.
To print from.

(3) Operation of the fault point locating system The slave station 1 is attached to an electric pole (steel tower) that supports the power transmission and distribution line, and is operated continuously for 24 hours so that it can be detected whenever a fault occurs. The master station 2 may be installed, for example, in a branch or a sales office of a power company, and may be operated only while an operator is present. It may be time driving.

(4) Effect of the fault point locating system The fault point locating system of this embodiment determines the fault point from the difference in arrival time of surge signals of the slave stations located on both sides (power source end and terminal end) of the fault point. Specify the position (distance from the slave station to the position of the failure point). Therefore, the fault point can be located quickly and accurately.

[Others] The present invention is not limited to those shown in the above examples, and various modifications can be made within the scope of the present invention depending on the purpose and application. For example, when transmitting information from a child station to a parent station, a mobile phone, PH
S, a public communication line may be used, or a dedicated line (metal cable, optical fiber, wireless, etc.) provided on the power transmission / distribution line may be used.

The map data in the power transmission / distribution line diagram information is not limited to the one recorded in the auxiliary storage device, but may be recorded in another recording medium such as a CD-ROM or a DVD. Good. Alternatively, the map data may be downloaded from a server of a WWW site that operates a map information system on the Internet or retrieved online. If the data is downloaded from the server via the Internet or taken out online, the latest map information can always be obtained without the need to keep the map information independently.

[0059]

In the slave station according to claim 1, the surge detection time locating method according to claim 2, the fault point locating system according to claim 4, and the fault point locating method according to claim 9, there are provided: The surge is certified based on whether the voltage or current exceeds the surge certified level that is set higher than the noise level, and the surge waveform start point, that is, the surge detection time, is set at the surge waveform start level that is set lower than that. Orient. That is, different reference levels are set for the approval of the surge and the approval of the starting point of the surge waveform.

Therefore, the surge waveform start level can be set low so that the time delay of surge detection can be sufficiently reduced. Therefore, it is possible to prevent the erroneous detection due to noise and reduce the time delay of the surge detection. In addition, since the surge waveform start level can be set low, even if the surge waveform received by each slave station is deformed due to propagation loss in the transmission and distribution lines, the surge detection time at each slave station will be similar. Can be accurately located. That is, there is little variation in the surge detection time caused by the difference in the rise time of the surge received by each slave station.

Since the stored surge waveform is traced from the back after the current or voltage exceeds the surge approval level, the surge detection time can be accurately measured even when there is a preceding surge as shown in FIG. Can be oriented.

In the surge detection time locating method according to the third aspect and the fault point locating system according to the seventh aspect, since the past waveforms are stored as discrete values, the storage capacity required for the storage device is small. And the location of the surge detection time and the location of the failure point are accurate.

In the fault point locating system according to claims 4 and 5, since the master station is provided, the fault point is evaluated by the master station based on the information of the surge detection time from each slave station. You can Moreover, since the master station is provided separately from the slave stations provided in the transmission and distribution line network, the equipment of each slave station can be made simple and compact by leaving the fault location function to the master station equipment. it can. In the fault point locating system according to the fourth and fifth aspects, since the slave station can accurately determine the surge detection time, the master station can accurately determine the fault point.

In the fault location system according to the fifth aspect, the fault position of the power transmission and distribution line network can be easily estimated based on the surge detection times of the two slave stations.

In the fault point locating system according to the sixth aspect, first, the position of the fault point is roughly calculated between the power source terminal and the terminal, and further, the pair of slave stations sandwiching the fault point position obtained by the calculation. The position of the failure point is recalculated. Therefore, by recalculating the position of the fault point between the slave stations having a short distance, it is possible to reduce the influence of an error due to propagation loss or the like in the transmission and distribution line when locating the fault point. That is, the position of the failure point can be accurately located.

According to the fault location method of claim 8,
The surge detection time of the slave station can be accurately located, and the fault position of the power transmission and distribution line network can be located easily and accurately based on the surge detection time. That is,
Since the delay of the surge detection time from the start of the actual reception of the surge can be reduced, the error in the fault point localization due to the difference in the rise time of the surge signal in each slave station can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between a master station and a slave station of a fault location system.

FIG. 2 is an explanatory diagram of each component of a slave station.

FIG. 3 is an explanatory diagram of each component of the master station.

FIG. 4 is an explanatory diagram of a method of locating a surge detection time.

FIG. 5 is an explanatory diagram showing the principle of identifying a failure point in an unbranched section.

FIG. 6 is an explanatory diagram showing a shift in surge detection time due to a difference in surge waveform.

FIG. 7 is an explanatory diagram of a dual potential method.

FIG. 8 is an explanatory diagram of a two-potential method when there is a preceding surge.

[Explanation of symbols]

1; slave station, 11; GPS receiving means, 111; GPS antenna, 112; GPS receiver, 12; timing means, 12
1; Oscillation circuit, 122; Reference clock, 123; Time synchronization correction circuit, 13; Surge detection means, 131; ZCT (zero phase current transformer), 132; Filter circuit, 133; Surge signal detection circuit, 134; Surge detection Time keeping circuit, 136;
Surge waveform recording circuit, 14b; surge information transmitting means, 1
41; central processing unit, 142; communication interface, 2; master station, 21; communication interface, 21a;
Slave station position information receiving means, 21b; Slave station surge information receiving means, 22; Map information storage means, 221; CD-ROM drive, 222; Auxiliary storage device, 23; Central processing unit,
23a; transmission and distribution line diagram information creating means, 23b; failure section specifying means, 23c; failure position specifying means, 24; transmission and distribution line drawing information output means, 241; CRT, 242; printer, 25; keyboard (input means).

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-8-21864 (JP, A) JP-A-52-66307 (JP, A) JP-A-8-15362 (JP, A) JP-A 52- 66308 (JP, A) JP-A-7-113837 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01R 31/08-31/11 H02J 13/00 301

Claims (8)

(57) [Claims] 1. A slave station installed on a power transmission and distribution line, for locating a detection time of a surge voltage or a surge current due to a failure occurring at any part of the power transmission and distribution line, which traces back at least a certain time from the current time. The past voltage or current waveform of the power transmission / distribution line up to the specified time is stored and updated, and the surge certification level that is set as the reference level for surge certification and higher than the noise level, and surge And a surge waveform start level which is a reference level for determining the start point of the waveform and is set lower than the surge approval level, and the voltage or current of the power transmission and distribution line exceeds the surge approval level. When the stored waveform is traced back from the time when the surge approval level is exceeded, the voltage or current first exceeds the surge waveform start level. A slave station that sets the time as the surge detection time. 2. A surge detection time locating method for locating a detection time of a surge voltage or a surge current due to a failure occurring at any part of the power transmission and distribution line in a slave station arranged on the power transmission and distribution line. The surge approval level is set higher than the noise level, which is the reference level for certifying the surge, and the reference level is set lower than the surge approval level, which is the reference level for defining the start point of the surge waveform. Surge waveform start level is defined, and the past voltage or current waveform of the power transmission and distribution line from at least the current time to a time traced back by a certain time is stored and updated, and the voltage or current of the power transmission and distribution line is When the surge approval level is exceeded, the stored waveform is traced back from the time when the surge approval level is exceeded, and the voltage or current is A surge detection time location method in which the surge detection time is the time when the surge waveform start level is exceeded. 3. The past voltage or current waveform is stored as a discrete value sampled at regular intervals, and the sample value first traces the surge waveform start level backward from the time when the surge approval level is exceeded. The surge detection time locating method according to claim 2, wherein the sampling time next to the sampling time which is lower than the sampling time is set as the surge detection time. 4. A slave station (1) which is installed on a power transmission / distribution line and transmits surge detection time information to a master station (2), and a master station (which determines a fault point based on the surge detection time information ( 2) and
In the fault point locating system, the slave station (1) stores and updates a past voltage or current waveform of the power transmission and distribution line at least from a current time to a time traced back a fixed time, A surge certification level that is set as a reference level for certifying surges and higher than the noise level, and a surge waveform that is set as a reference level for defining the start point of the surge waveform and that is set lower than the surge certification level. When the voltage or current of the power transmission and distribution line exceeds the surge approval level, the stored waveform is traced back to the voltage or current from the time when the surge approval level is exceeded. The time when the current first exceeds the surge waveform start level is set as the surge detection time, and the surge detection time is transmitted to the master station (2) through the communication network. Fault point location system according to claim. 5. The master station (2) detects the surge detection time t1 of one slave station of a pair of slave stations sandwiching the fault point of the power transmission and distribution line network and the surge detection time of another slave station. Time t2
And the propagation speed v of the surge and the length L of the power transmission / distribution line between the slave stations, the distance L1 on the power transmission / distribution line from the one slave station to the fault point is calculated by the equation L1. = (L + (t1-t
The fault point locating system according to claim 4, which is obtained from 2) × v) / 2. 6. The master station (2) has the surge detection time t1 of the slave station closest to the power source end of the power transmission and distribution line network and the surge detection time t2 of the slave station at the end of the power transmission and distribution line network. ,
Propagation speed v of surge and length L of power transmission / distribution line between the slave stations
Based on the above, the distance L1 on the power transmission and distribution line from the slave station on the power source end side to the fault point is calculated by the equation L1 = (L + (t1-t
2) × v) / 2, and further, the surge detection time t3 of one slave station of the pair of slave stations sandwiching the failure point position obtained by the above calculation, and the surge detection of another slave station. Time t4 and surge propagation speed v
And the length L ′ of the power transmission / distribution line between the pair of slave stations, the distance L3 on the power transmission / distribution line from the one slave station to the fault point is calculated by the formula L3 = (L ′ + (T3-t4) xv) / 2
The fault point locating system according to claim 4, which is obtained from the above. 7. The past voltage or current waveform is stored as a discrete value sampled at regular time intervals, and the sample value first starts from the surge waveform starting from the time when the surge approval level is exceeded. 7. The fault point locating system according to claim 4, wherein the sampling time next to the sampling time below the level is the surge detection time. 8. A fault point locating method for locating a fault point on the basis of information of surge detection times at two or more slave stations arranged on a power transmission and distribution line, which is (1) arranged on a power transmission and distribution line. For each slave station, the surge approval level is set higher than the noise level, which is the reference level for approval of surge, and the reference level for defining the start point of the surge waveform, which is lower than the surge approval level. The surge waveform start level to be set is defined, and the past voltage or current waveform of the power transmission and distribution line from at least the current time to a time traced back by a fixed time is stored and updated, and the voltage of the power transmission and distribution line is updated. Alternatively, when the current exceeds the surge approval level, the stored waveform is traced back from the time when the surge approval level is exceeded, and the voltage or current is first the surge wave. The time at which the start level is exceeded is defined as the surge detection time, and (2) the surge detection time t1 of one slave station of the transmission and distribution line network, the surge detection time t2 of another slave station, and the propagation of surge. Based on the speed v and the length L of the power transmission / distribution line between the slave stations, the distance L1 on the power transmission / distribution line from the one slave station to the fault point is calculated by the formula L1 = (L +
A failure point locating method characterized by obtaining from (t1−t2) × v) / 2.