JPS61283882A - Locator for section struck by thunderbolt of aerial power transmission line - Google Patents

Abstract

PURPOSE:To enable accurate detection of a section struck by a thunderbolt in a power transmission line regardless of the magnitude and direction of a lightning current, by specifying one lightning current detector which the lightning current will reaches first among a plurality of lightning current detectors. CONSTITUTION:A plurality of lightning current detectors 3 are arranged separately along an overhead ground wire 2 of an aerial power transmission line 1. In these detectors 3, a lightning current signal obtained is connected to a decision circuit 4 through an optical fiber 6 to prevent malfunction caused by an electromagnetic induction noise. The decision circuit 4 is made up of a converter section for converting light signals fetched from the detectors 3 into electrical logic signals, a preference circuit for outputting a decision signal and an AND circuit. Then, as soon as any detector 3 detects a lightning current in case the power transmission line 1 is struck by a thunderbolt, detection information is sent to the decision circuit 4 through the optical fiber 6. The decision circuit 4 identifies one detector 3 which the lightning current reaches first among the detectors 3. Thus, it is possible to learn that the power transmission line 1 is struck by a thunderbolt at the point near the detector 3 thus identified.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lightning strike area locating device for an overhead power transmission line that detects the lightning strike itself that induces a flash accident that interrupts the power transmission system. Regarding what is being judged.

[Prior Art] Overhead power transmission lines or distribution lines are indispensable equipment for power transmission operations today, and accidents with these equipment can have a very serious impact on today's highly electrified society, and in some cases,
Social functions in all areas may be paralyzed.

Therefore, in order to protect overhead power lines etc. from lightning strikes,
Although overhead ground wires have been installed and highly reliable insulated support methods have been adopted to prevent lightning strikes and flash strikes, this has not yet completely eliminated lightning strikes and flash strikes.

Therefore, in the event that such an accident occurs on an overhead power transmission line or the like, the next best challenge is to quickly determine the location where the accident occurred.

Conventionally, the following three methods are mainly known as methods for detecting the location of a flash accident. In other words, ■Pulse radar method that sends out a high-frequency pulse immediately after an accident occurs and determines distance from the time it takes to receive the reflected wave at the accident point; ■Surge method that determines distance from the difference in arrival time of the accident surge to the measurement point. The reception method is an impedance method that locates the fault point from the voltage and current at the time of the fault. These so-called fault locators are used, and both of these methods determine the line length from the measurement point to the fault point and locate the fault location. I'm getting to know.

These conventional fault locators are detection systems that target flash accidents that cause grid interruptions, and do not detect the lightning strikes themselves that cause these accidents.

However, even if the power transmission system does not actually shut down, there is a risk that a lightning strike will cause serious damage to the power transmission line, which will have a significant impact on future reliability. Therefore, it is important to take measures to prevent future serious accidents by quickly detecting lightning strikes and conducting thorough inspections.

Therefore, conventional methods of detecting lightning strike points have been devised using such measures. That is, methods that detect lightning current flowing through overhead ground wires or steel towers and make judgments based on the magnitude of the lightning current (for example, Japanese Patent Application Laid-open No. 142479/1982), or methods that make judgments based on the direction in which the lightning current flows ( For example, Japanese Patent Application Publication No. 55-93067), and one that makes judgment based on both size and direction, for example, Japanese Patent Application Laid-Open No. 54-1077.
No. 80).

[Problems to be solved by the invention] However, depending on the line constant, it is not possible to clearly determine the location of a lightning strike based on the magnitude of the lightning current, and even from the direction of the lightning current, it is possible to determine the superposition of reflected back and forth waves from various parts of the transmission line. There was a problem that the lightning strike position could not be accurately determined due to the unavoidable influence of lightning.

[Object of the Invention] An object of the present invention is to provide a lightning strike section locating device for an overhead power transmission line that can accurately detect a lightning strike section of a power transmission line regardless of the magnitude or direction of lightning current by solving the above-mentioned conventional problems. The goal is to provide the following.

[Summary of the Invention] The configuration of the present invention in accordance with the above object is as follows.
As shown in the figure, a plurality of lightning current detectors 3 are arranged along an overhead ground wire 2 of an overhead power transmission line 1 and spaced apart from each other.

A determination circuit 4 is provided which determines which of the adjacent lightning current detectors the lightning current has reached first from the lightning current arrival information obtained from these lightning current detectors 3.

This makes it possible to identify the lightning current detector where the lightning current from a lightning strike quickly reached, and to know that there was a lightning strike on the power transmission line near the identified lightning current detector. .

[Example] An example of the present invention will be described below based on FIGS. 1 to 3.

FIG. 1 shows a lightning strike area locating device for an overhead power transmission line according to the present invention. 1 is an overhead power transmission line, 5 is a transmission line tower, and 2 is an overhead ground wire, and this overhead ground wire 2 is provided with a lightning current detector 3. The lightning current detector 3 is connected to the overhead ground wire 2 near each tower.
A plurality of (three in this embodiment) are arranged along the line.

These lightning current detectors 3 are connected to a determination circuit 4 via an optical fiber 6 to transmit the obtained lightning current signal in order to prevent malfunctions due to electromagnetic induction noise. This determination circuit 4 has a function of determining which of the adjacent lightning current detectors 3 the lightning current has reached first.

Here, the central steel tower 5 is called the steel tower S, and the steel towers on both sides are called the adjacent steel towers R and L, and the lightning is installed near the steel tower. Lightning current detector 3.3 with signals from Ii current detector 3 provided on the left and right sides of 51
Let the signals from R and fl be respectively r and fl.

Figure 2 shows the circuit configuration of the lightning current detector 3.
is a lightning current detection coil, and information on the lightning current flowing through the overhead ground wire 2 detected by this coil is voltage-limited by a Zener diode 8 and then guided to a light emitting diode 11 through a full-wave rectifier circuit 10 constituted by a diode 9. It is designed to extract optical signals from this.

Therefore, lightning current information is voltage-limited to an appropriate value by the Zener diode 8, so it is accurately transmitted regardless of the size of the lightning current, and is full-wave rectified by the full-wave rectifier circuit 10, so the lightning current information is Transmitted regardless of direction.

Moreover, since the lightning current energy is used as the transmission energy, the lightning current detector does not require an external power source.

FIG. 3 shows a determination circuit 4 that determines lightning current arrival information from each lightning current detector 3 that has been optically transmitted through an optical fiber 6.
This figure shows the circuit configuration of .

The determination circuit 4 includes a converter 12. 1st. second priority circuit 13,
14. It is composed of an AND circuit 15.

The converter 12 receives optical signals s, r, j! extracted from three lightning current detectors arranged in sequence. It is comprised of three photoelectric converters 16 that photoelectrically convert each signal into an electrical logic signal (N electrical signal).

The first priority circuit 13 uses an AND circuit 18 to AND the lightning electric signal r, which is one of the outputs of the photoelectric conversion section, and the second latch output inverted by the NOT circuit 17, and outputs the AND output to the first priority circuit 13. The latch circuit 19 outputs a judgment signal R corresponding to the lightning electric signal r, and this judgment signal R is connected to the latch circuit 19 of
The inverted output inverted by the OT circuit 17 and the lightning electric signal S which is the second output of the photoelectric conversion section delayed by the delay circuit 20
The AND circuit 18 performs an AND operation, and the AND output is led to the second latch circuit 21 which outputs the second latch output, and outputs one of the judgment signals $1 corresponding to the lightning electric signal S. It has become.

Note that the delay circuit 20 described above is similar to the delay circuit 20 described later.
Similarly, the own tower information is delayed by the optical transmission delay time from the adjacent towers R and L required for m current arrival information to reach the judgment circuit 4, and the subsequent processing is given simultaneity to improve detection accuracy. It is for.

Further, the second priority circuit 14 uses an AND circuit 18 to AND the lightning electric signal S delayed by the delay circuit 20 and the fourth latch output inverted by the NOT circuit 17.
The AND output is led to the third latch circuit 22 to output another judgment signal S2 corresponding to the lightning electric signal S, and an inverted output obtained by inverting this output S2 by the NOT circuit 17 and a photoelectric conversion section. A fourth latch circuit 2 which outputs the fourth latch output by AND circuit 18 with the lightning electric signal 1 which is the third output of 12.
3 to output a judgment signal corresponding to the snow electricity signal l.

The determination circuit 4 is configured by connecting an AND circuit 24 that outputs the AND output of the two tower determination signals S1 and S2 taken out from the first and second priority circuits 13 and 14.

Now, in the above configuration, when there is a lightning strike on the power transmission line 1 and the lightning current detector 3 detects M current, the detection information reaches the determination circuit 4 through the optical fiber 6. Lightning current arrival information S, r, which has reached the judgment circuit 4
j! After each is converted into an electrical logic signal by the photoelectric converter 12, the latch circuit is set to "H" level through the AND circuit 18, but this latch output is inverted by the NOT circuit 17 and sent to another adjacent AND circuit 18. , one of the adjacent latch circuits in the priority circuit goes to "H" first.
When it reaches the II level, input to the other latch circuit is prohibited, so even if a lightning electric signal is input later than the other latch circuit, that latch circuit will not go to the "H" level.

That is, the priority circuit blocks lightning current information that arrives with a time delay.

Therefore, among the signals from the adjacent lightning current detectors 3, only the output of the priority circuit which arrived earlier in time is obtained at the "H" level. In this case, as can be seen from the table below, if lightning strikes near the adjacent right steel tower R in the S-R section or near the adjacent left steel tower in the L-8 section, neither of the priority circuits 13 and 14 will be struck. Since the “H” level is output, the judgment signals S1 and S2 are sent to the AND circuit 24.
are input and ANDed to unify the output, and ensure that only one output terminal is at the "H" level. In particular, when the output of the ANC circuit 24 becomes "H" level, it can be determined whether or not there has been a lightning strike near the steel tower.

Table〉Logic table of judgment circuit However, ■, ■, ■ indicate the order in which the signals arrive. means.

In the above table, combinations such as ■■■ and ■■■ are excluded because they do not physically exist. When snow falls on the power transmission line 1, the lightning current detector 3 closest to the lightning strike point detects the lightning current before the others, and the detection time increases as the distance from the lightning current detector 3 increases. Become slow. Therefore, when detecting lightning current from the lightning current detectors 3 arranged sequentially, for example, when there is a lightning strike in the vicinity of the first one, the second one is detected after the first one, and the second one is skipped. This is because it will not be detected third.

As is clear from the table above, the three outputs R of the determination circuit 4
, S, and L, it is possible to determine in which section the lightning struck, and furthermore, which steel tower in that section the lightning struck.

In this way, according to this embodiment, the determination is not based on the magnitude of the lightning current or the direction of flow, but rather on which of the adjacent lightning currents the M current has reached first, so the line constant It may not be possible to determine the exact location of the lightning strike, or
In addition, there is no possibility that the determination cannot be made due to the superposition of reflected round waves from various parts of the power transmission line.

In the above embodiment, the information of the lightning current detector 3 is sent through the optical fiber 6, but the optical fiber 6 is
i! ! Combined overhead ground wire (OPGW) integrated with 112
You may also use

Furthermore, although the case is shown in which lightning current detectors 3 are installed at three locations on the overhead ground wire 2, it is also possible to install more lightning current detectors 3 to extend the detection section.

Furthermore, the determination circuit 4 shown in FIG. 3 is not limited to this circuit configuration, and in short, the determination circuit 4 shown in FIG.
Detects which side of the lightning current has arrived first,
It is only necessary to be able to determine where the lightning has struck based on this detection information, and any circuit that can make such a determination may be used.

[Effects of the Invention] In short, according to the present invention, one lightning current detector to which a lightning current has quickly arrived is identified from among a plurality of lightning current detectors, and the transmission near the identified lightning current detector is Il! Since it is possible to know that the I circuit has been struck by lightning, it is possible to accurately detect the section of the power transmission line struck by lightning, regardless of the magnitude or directionality of the lightning current. Therefore, it exhibits an excellent effect of preventing serious accidents on power transmission lines.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing a preferred embodiment of the lightning strike area locating device for an overhead power transmission line according to the present invention; the second reason is a circuit diagram showing details of the lightning current detector shown in FIG. 1; The same figure is a circuit diagram showing details of the determination circuit. In the figure, 1 is an overhead power transmission line, 2 is an overhead ground wire, 3 is a lightning current detector, and 4 is a determination circuit.

Claims (4)

[Claims] (1) Determine which of the multiple lightning current detectors installed apart from each other along the overhead ground wire of the overhead power transmission line or adjacent lightning current detectors the lightning current reaches first. 1. A lightning strike area locating device for an overhead power transmission line, comprising: a determination circuit. (2) A lightning strike area locating device for an overhead power transmission line as set forth in claim 1, wherein the lightning current detector and the determination circuit are connected by an optical fiber. (3) The lightning current detector includes a current detection coil that detects lightning current flowing through an overhead ground wire, a rectifier circuit that full-wave rectifies the current detected by the coil, and converts the rectified output of the rectifier circuit into an optical signal. 3. A lightning strike area locating device for an overhead power transmission line according to claim 2, characterized in that the device comprises a light emitting diode. (4) The above-mentioned judgment circuit outputs the optical signals extracted from the three lightning current detectors arranged in sequence to the first, second, and third lightning current detectors.
a converter for converting into a lightning electrical signal, and first and second output terminals corresponding to the input terminals of the first and second lightning electrical signals, and a converter that compares the two lightning electrical signals and converts them. A first priority circuit that outputs a determination signal to an output terminal corresponding to the input terminal that arrived earlier, and second and third output terminals that correspond to the input terminals of the second and third lightning electric signals. a second priority circuit that compares the two lightning electrical signals and outputs a determination signal to an output terminal corresponding to the input terminal that reached earlier among them; A of the judgment signals taken out together from the second output terminal of the priority circuit
4. The lightning strike area locating device for an overhead power transmission line according to claim 3, further comprising an AND circuit for taking out an ND output.