JPH073451B2 - Method of detecting lightning strike position in power transmission tower - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for detecting a lightning strike position in a power transmission tower, and more particularly to a method for detecting whether a lightning strike occurs on an overhead ground line or a power transmission line.

<< Prior Art >> As is well known, a transmission tower having a transmission line installed therein may be exposed to a lightning strike due to the high height of the tower and the fact that it is erected in a mountainous area.

For this reason, an overhead ground wire is installed at the top of the transmission tower to protect the transmission line from lightning strikes.

However, depending on the location and weather conditions of the transmission tower,
Direct hits to power lines due to failure to shield overhead ground lines and lightning strikes to the top of towers or overhead ground lines occur quite frequently.

Therefore, conventionally, in order to detect such a lightning strike, for example, as disclosed in JP-A-60-66617, a current sensor is installed in the power transmission tower, and the power transmission tower is hit by the lightning strike. The method of detecting the flowing lightning current was generally adopted.

However, such a conventional method has the problems described below.

<< Problems to be solved by the invention >> That is, the most important thing is to detect a lightning stroke that hits the power transmission line directly in the transmission tower where the overhead ground wire is installed at the top and the transmission line is installed below it. However, in the method of the above publication, only the current sensor is installed on the transmission tower, so even if the occurrence of lightning stroke can be detected, whether the lightning stroke hit the transmission line directly or occurred on the overhead ground wire. Perhaps there was a problem that the judgment could not be made.

For such a problem, a plurality of cameras focusing on the transmission line of the transmission tower and the overhead ground line are installed,
It has also been tested to activate this with a lightning bolt and take a picture to detect where on the power transmission tower the lightning strike occurred, but usually the lightning strikes are likely to occur in fog-prone areas. It was difficult to detect the position accurately because it overlapped with the present invention.The present invention has been made in view of such conventional problems. Is to provide a method that can be accurately identified.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention provides a power transmission tower comprising an overhead ground wire installed at the top and a power transmission line installed below the overhead ground wire. Between the overhead ground wire arm and the transmission line upper phase arm and between the transmission line lower phase arm and the ground, a current sensor is installed to detect a lightning current, and the current sensor is activated by the lightning stroke and the time of occurrence of the current sensor. Installed a lightning current recording device that records the direction of the lightning current flowing in, and a lightning strike occurred in either the overhead ground line or the power transmission line from the direction of the lightning current of the current sensor recorded in the lightning current recording device. It is characterized by detecting whether or not.

<Operation> According to the lightning strike position detection method configured as described above, the current sensors are installed between the overhead ground wire arm and the transmission line upper phase arm of the transmission tower, and between the transmission line lower phase arm and the ground, respectively. When a lightning strike hits a power line directly, the lightning currents flowing through these sensors are in different directions, while when a lightning strike occurs in an overhead ground wire, the lightning currents flowing through each sensor are in the same direction. Since the direction of the lightning current flowing through such a sensor and the time of occurrence are recorded in the lightning current recording device, it is possible to easily detect whether the lightning strike occurs in the power transmission line or the overhead ground wire.

Also, when a lightning stroke with different polarities occurs, the direction of the lightning current flowing through the current sensor differs depending on the polarity of the lightning stroke. When a lightning strike occurs, the directions are the same, so the position can be detected regardless of the polarity of the lightning strike.

<Example> Hereinafter, a preferred example of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show an embodiment of a method of detecting a lightning strike position in a power transmission tower according to the present invention.

In the power transmission tower 10 shown in the figure, a plurality of arms 12 are fixed in a stepwise manner in the vertical direction at intervals, and an overhead ground wire 14 is erected on the top arm 12 and three stages below the arm 12 are installed. arm
Each of the power transmission lines 18a to 12a includes a plurality of insulators 16
c is installed.

Then, the overhead ground wire 14 of the power transmission tower 10 and the uppermost power transmission line
A current sensor 20 is provided in each of the tower top 10a between 18a and the tower leg 10b between the lowest power transmission line 18c and the ground, and
A lightning current recording device 22 connected to this sensor 20 is installed.

Details of this current sensor 20 and lightning current recorder 22
Shown in the figure.

The current sensor 20 is the tower top of the transmission tower 10 in this embodiment.
It is composed of a Rogowski coil wound around the portion 10a or the tower leg portion 10b. When a lightning current flows through these portions 10a and 10b, a voltage corresponding to the magnitude is induced in the coil.

The lightning strike current recording device 22 is mainly composed of a so-called microcomputer, receives an output of the current sensor 20 via the input adjustment circuit 24 connected to the current sensor 20, and the input adjustment circuit 24, Peak hold circuit with polarity judgment to detect peak value with its polarity
26, a trigger generator 28 that outputs a trigger output when the output of the input adjustment circuit 24 is a predetermined value or more, a converter 30 that impedance-converts the output of the peak hold circuit 26, and an input via this converter 30. The AD converter 32 for digitally converting the output of the peak hold circuit 26, the time generator 34 and the storage means 36, and the trigger generator 28 are activated, and the output of the peak hold circuit 26 is passed through the AD converter 32. A CPU 38 is provided which stores the peak value of the lightning current and the time when the peak value of the polarity is generated and stored in the storage means 36.

A method of detecting the lightning strike position of the power transmission tower 10 using the current sensor 20 and the lightning strike current recording device 22 configured as described above will be described below.

FIG. 3 shows two cases when the positive pole lightning strike A occurs in the transmission tower 10.

The same figure (a) shows the case where the lightning strike A directly hits the power transmission line 18a, and the same figure (b) shows the case where the lightning strike A occurs on the overhead ground line 14 (including the case where it directly hits the top of the power transmission tower 10). Are shown respectively.

First, when the lightning strike A directly hits the power transmission line 18a, this is + polarity, so at the top 10a of the power transmission tower 10, the overhead ground wire 1
Lightning current B flows toward the 4 side, and tower leg 10b
Then, the lightning current C shunted toward the surface side flows.

On the other hand, when the lightning strike A occurs on the overhead ground wire 14, the lightning currents D and E in the same direction toward the ground side flow in the tower top portion 10a and the tower leg portion 10b of the power transmission tower 10.

In this case, on the tower leg 10b side, the directions C and E of the lightning currents for the two cases of the lightning strike A are the same, but on the tower top 10a side, the case where the lightning strike A directly hits the transmission line 18a and the overhead ground line 14 It is in the opposite direction to the case when it occurs in the
The directions are different.

The peak values of the lightning currents B, C, D and E for the lightning strike A and their directions are detected by the current sensor 20 and stored in the storage means 36 of the lightning current recording device 22 together with the time of occurrence. Therefore, after a lapse of a certain period of time, if the printer 40 or the display device 42 is connected to the lightning current recording device 22 and the direction of the lightning current of the lightning A generated during the period is compared with the time of occurrence, the lightning A is It is determined whether the power transmission lines 18a to 18c of the power transmission tower 10 have been directly hit or the lightning strike A has occurred on the overhead ground wire 14.

When the polarity of the lightning strike A is negative, a lightning strike current flows in the direction shown by the broken line in FIG. 3, and the direction is opposite to that in the case of positive polarity lightning at each current sensor 20. Since the sensor 20 at the top 10a of the transmission tower 10 has the same direction as that of the positive polarity lightning stroke, the lightning stroke position of the transmission tower 10 can be detected even for negative polarity lightning strokes.

Further, in the above-mentioned embodiment, the digital type mainly composed of the microcomputer is exemplified as the lightning current recording device 22, but the practice of the present invention is not limited to this, and the lightning stroke detected by the current sensor 20 is not limited thereto. It is also possible to use another type of recording device as long as it is activated by recording the direction of the lightning current and its generation time.

<Effects of the Invention> As described in the above embodiments, according to the method for detecting the lightning strike position in the power transmission tower according to the present invention, whether the lightning strike directly hits the power transmission line or occurred on the overhead ground line,
It is possible to make a reliable judgment without being affected by weather conditions and regardless of the type of polarity of lightning stroke.

[Brief description of drawings]

FIG. 1 is a front view of a power transmission tower to which the method of the present invention is applied, and FIG.
The figure is a connection block diagram of a current sensor and a recording device used in the same method, and FIG. 3 is an explanatory diagram showing a state of occurrence of lightning stroke in the transmission tower shown in FIG. 10 …… Transmission tower 10a …… Tower top 10b …… Tower legs 14 …… Overhead ground line 18a ～ c …… Transmission line 20 …… Current sensor 22 …… Lightning strike current recorder

Claims (2)

[Claims] 1. A power transmission tower comprising an overhead ground wire installed on the top and a power transmission line installed below the overhead ground wire, wherein a space between the overhead ground wire arm and the upper phase arm of the power transmission line of the power transmission tower and a lower part of the power transmission line. Between each of the phase arm and the ground, a current sensor is installed to detect a lightning current, and a lightning current recording device is installed which records the direction of the lightning current that is activated by the lightning and flows to the current sensor with the time of occurrence. A method for detecting a lightning stroke position in a transmission tower, comprising detecting, from the direction of the lightning current of the current sensor recorded in the lightning current recording device, whether the lightning strike occurs in the overhead ground wire or the power transmission line. . 2. The current sensor comprises a Rogowski coil, and the lightning strike current recording apparatus comprises a peak hold circuit with polarity determination for obtaining the peak value of the lightning strike current detected by the Rogowski coil together with its polarity, and this peak hold. An AD converter for digitally converting the output of the circuit, and a microcomputer for controlling the peak hold circuit and the AD converter, the microcomputer has a time signal generation unit inside or outside, and, The power transmission according to claim 1, further comprising a storage unit that captures an output of a peak hold circuit via the AD converter and stores a peak value and a polarity of the lightning current together with an occurrence time thereof. Method of detecting lightning strike position in steel tower.