JPH02276976A - Method and device for locating accident point of power transmission line or the like - Google Patents

Abstract

PURPOSE:To locate the accident point by detecting and calculating the observation point arrival time difference between an electromagnetic wave and an oscillatory wave which are propagated on the line. CONSTITUTION:A magnetic sensor 7 and a vibration sensor 8 are coupled with the power transmission line 1 nearby a power source 2, and a converter 9 which converts their outputs into voltage signals and a counting circuit 10 which detects the arrival time difference from its outputs are provided. Then if an accident occurs at an electric accident position 4, its electromagnetic wave 5 and elastic wave 6 are propagated on the power transmission line 1 and detected by the sensors 7 and 8 respectively. The numerals of the propagation speeds of both the waves have a difference of five digits, so the detection time difference between both the waves is measured to accurately detect the distance from the observation point 11 to the electric accident position 4.

Description

[Detailed Description of the Invention] [Industrial Application Fields] -t! The present invention relates to a method and device for locating accident points on power transmission lines and the like.

[Prior art] To locate the fault point on a power transmission line, mark both ends with A.

For example, if a surge sensor S is installed at the B end of the power transmission line B, and a surge occurs due to a lightning strike or the like on a phase at a point C on AB, the surge sensor S at the B end will detect the first wave between the lines. The accident point can be found by observing the line wave and the second wave reflected at end A, finding the difference in arrival time, and calculating this using the propagation speed of the surge. It is generally difficult to detect this, so normally a master station and a slave station are installed at both ends of A and 8, and if a surge occurs in a phase at point C on AB, this surge will be detected at the A end. By calculating the time difference between the time of arrival at end B and the time of arrival at end B, the accident point can be located from this.Based on this principle,
Many methods have been proposed for locating accident points.

This method detects only electrical surges and measures time differences, so high measurement accuracy is required.

On the other hand, there is an optical CT fault area locating method that uses 0PGW (overhead ground wire with built-in optical fiber) and mainly targets multi-branch transmission lines, and a cable fault area locating method that uses optical magnetic field sensors (e.g. BSO), etc. .

In these accident area locating methods, the locating accuracy is determined by the sensor installation interval, and in order to increase the accuracy, it is necessary to increase the number of sensors, but the disadvantage is that increasing the number of sensors increases the overall cost.

[Problems to be Solved by the Invention] As described above, the present invention uses any of the above methods to determine the surge detection area and locate the accident area using the arrival time difference of electric surges and a large number of sensors. This provides an accident point location method that can also be applied.

Means for Solving Problem c] In the above method of calculating the arrival time difference of electric surges, it is necessary to calculate the arrival times of electric surges that propagate in both directions from the accident point to a predetermined position. The time difference between electric surges at a given location is also extremely small. For this reason, highly accurate measurement is required, so in the present invention, we focus on the fact that when an electrical accident occurs, elastic waves are generated in addition to electrical surges (electromagnetic waves), which propagate through power transmission lines, and we observe both of these waves. The present invention provides a method and a device for locating the accident point based on the point passing time difference.

The present invention will be explained below with reference to the basic configuration diagram shown in FIG.

In the figure, 1 indicates the power transmission line, 2 indicates the power supply, 3 indicates the load, and 4
indicates the location of an electrical fault, for example, the location of a ground fault that occurred on a power transmission line. Note that in this example, only one phase is shown.

The fault current that occurs at the electrical fault location 4 and propagates is shown as 5, the elastic wave that occurs at the electrical fault location 4 and propagates through the power transmission line 1 is shown as 6, and the magnetic field sensor 7 and vibration sensor 8 are located near the power source 2. It is connected to the power transmission line 1 to detect the fault current 5 and the elastic wave 6, and inputs the output signals from the magnetic field sensor 7 and vibration sensor 8 to a converter 9 that converts them into appropriate voltage signals. The output is input to a counting circuit 10 which detects the arrival time difference of the magnetic waves based on the input.

With the above configuration, when an electrical accident occurs at the electrical accident location 4, electromagnetic waves and elastic waves propagate through the power transmission line 1.

Figure 2 shows electromagnetic waves (a) and elastic waves (b) generated at electrical accident location 4 in Figure 1, and electromagnetic wave propagation and elastic wave propagation at observation point ■1 where magnetic field sensor 7 and vibration sensor 8 are installed. delayed electromagnetic wave (a') and elastic wave (b'
) are shown respectively.

If the propagation speed of electromagnetic waves is Y15, then N Va= 3 X
IOam/S1 elastic wave metal (solid) propagation speed v8
Then, since V6=approximately 3 X l03 m/s, which is a 5-digit difference, at the observation point 11, the difference time t between the detection time of the current signal by the magnetic field sensor 7 and the detection time of the vibration signal by the vibration sensor 8 By measuring , the distance from the observation point 11 to the electrical accident point 4 can be calculated using V6 and t.

[Embodiment FIG. 3 shows an embodiment of the present invention. This example is an example in which the located accident point position is transmitted to a remote monitoring point using an optical fiber with a built-in 0PGW.

(A) As shown in the figure, the power transmission line 1 is suspended via a plurality of steel towers I4 and insulators 16. However, only one phase is required.

Further, the 0PGW 13 is suspended at the top of the steel tower 14.

As shown in the diagram, the steel tower I jumped over the bridge of the steel tower 14.
An OPCW junction box 12 is attached to the 0PGW junction box 12, and an optical fiber 15 is drawn out from the 0PGW junction box 12 and connected to a counting circuit 10 attached to a steel tower 14. As shown in FIG. 3(b), 17 is a composite sensor comprising the magnetic field sensor 7, vibration sensor 8, and converter 9 shown in FIG. The composite sensor 17 itself is held at the end of the insulator 16, the vibration sensor 8 and the magnetic field sensor 7 are coupled to the power transmission line 1, and the power transmission line 1 is stopped by the insulator 16.

The electromagnetic waves and elastic waves propagated from the accident point detected by the magnetic field sensor 7 and vibration sensor 8 in the composite sensor 17 are converted into appropriate voltage signals by the converter 9, and then converted into optical signals and sent to the counting circuit IO. A counting circuit 1O calculates the arrival time difference between the magnetic wave and the elastic wave.
The accident point is located from this time difference, converted into an optical signal,
Although not shown, it is transmitted to a monitoring position.

FIG. 4 shows an example in which a sensor detects the accident point and sends a signal to a transmitter on the tower side. The composite sensor 18 includes a magnetic field sensor 7, a vibration sensor 8, a converter 9, as well as a transmitter and an antenna, and transmits a detection signal wirelessly between the antennas of a receiver 19 installed on the side of the steel tower 14. It is also possible to use a method in which the calculation is performed using a counting circuit built into the controller, and the result is transmitted to the monitoring position via the optical fiber I5.

FIG. 5 shows an example of sensor arrangement in a method of locating the accident point using electromagnetic waves propagating through N0PGW or ordinary overhead ground wires in the event of an accident.

As shown, a magnetic field sensor 7, a vibration sensor 8, a transducer 9
A composite sensor 20 including the following is attached to the 0PGW 13. When an insulator flash fault occurs on the power transmission line 1 as shown in the diagram, or when a lightning strike occurs on 0PGWI3,
Since electromagnetic waves and elastic waves propagate to the 0PGl 113, they are detected by the composite sensor 20.

For signal transmission to the monitoring point, the method described with reference to FIG. 3 can be used.

Although the application to power transmission lines has been described above, the present invention can be applied to branched power transmission line sections, and can also be applied to overhead distribution line sections.

FIG. 6 shows an embodiment of the present invention in a power cable.

The magnetic field sensor 7 and the vibration sensor 8 are coupled at the joint portion 22 of the power cable 21, and the output signal thereof is converted into a fault point position signal via a converter 9 in a counting circuit 1O, and transmitted to a monitoring point.

[Effects of the Invention] According to the present invention, as is clear from the above description, if a measurement point is placed at one end of an overhead power transmission line, distribution line, or power cable line in a predetermined orientation section, trouble points can be avoided. Orientation can be achieved.

The present invention uses electromagnetic wave propagation and elastic wave propagation from the accident point, and the difference in propagation speed is large.Therefore, the time difference between the arrival of both waves at the measurement point is generally large. No precision counter required.

Furthermore, unlike the conventional optical CT accident area locating method which can only locate the accident area, it is possible to locate the accident point.

The cost of the accident point locating system is also low.

[Brief explanation of drawings]

FIG. 1 shows a basic configuration diagram of the present invention, and FIG. 2 is an explanatory diagram of the evaluation method using the configuration shown in FIG. FIG. 3(A) shows an example of application of the present invention to a power transmission line.
Figure a) shows a partial view of figure (a). FIG. 4 shows an example in which wireless communication is used for signal transmission in the embodiment of FIG. 3. FIG. 5 shows an embodiment in which the present invention is applied to 0PGW. FIG. 6 shows an embodiment of the application of the power cable of the present invention. 1...Power transmission line, 2...Power source, 3...Load, 4...
- Accident position, 7... Magnetic field sensor, 8... Vibration sensor, 9... Converter, 10... Counting circuit, 11... Observation point, 12... Connection box, 13... 0PGW, +
5... Optical fiber, 16... Insulator, 21... Electric cable, 22... Joint part. 10℃

Claims (2)

[Claims] (1) A method for locating accident points on power transmission lines, etc., which is characterized by determining the distance to the accident point from the difference in arrival time at an observation point between electromagnetic waves and elastic waves that occur during an electrical accident and propagate in a solid body. (2) A magnetic field sensor and a vibration sensor that detect electromagnetic waves and elastic waves that occur during an electrical accident and propagate in a railway line, and calculate the arrival time difference between the electromagnetic waves and elastic waves, and calculate the time difference and the propagation of the elastic waves in solids. An accident point locating device for power transmission lines, etc., characterized by comprising a counting circuit that determines the distance to the accident point from the speed.