JPS6176019A - Branch power line fault area location device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a fault locator for power transmission lines with branches, and unlike conventional fault locators which cannot be applied to lines with branches, It relates to something that can be applied to railroad tracks and allows for accurate location.

[Prior Art] Overhead power transmission lines are indispensable equipment for today's power transmission operations, and accidents involving these equipment can have a very serious impact on today's highly electrified society, and in some cases, can cause social damage in all areas. Function may become paralyzed.

Therefore, in order to protect overhead power transmission lines from lightning strikes, etc., overhead ground wires are installed, and extremely reliable insulation support methods are adopted to prevent lightning strikes. It has not yet been possible to completely eliminate flashover accidents. Therefore, in the event that such an accident occurs on an overhead power transmission line, the next best challenge is to quickly determine the location where the accident occurred.

Conventionally, the methods for detecting the location of an accident have been: ■ Pulse radar method, which sends out a high-frequency pulse immediately after the accident occurs and determines the distance based on the time it takes to receive the reflected wave at the accident point; ■
So-called fault locators are used, such as the surge reception method that locates the distance from the difference in arrival time of the fault surge to the measurement point, and the impedance method that locates the fault point location from the voltage and current at the time of the fault. The location of the accident can be determined by finding the track length to the point.

[Problems to be Solved by the Invention] However, although the above-mentioned conventional fault locator does not have any problems on power transmission lines without branches, when applied to power transmission lines with branches, reflections at each branch point may affect the received signal. There was a problem in that accurate orientation was difficult because of the overlap.

Therefore, there has been a strong desire to develop a technology that can accurately locate which transmission line an accident has occurred at a branch point of a power transmission line.

[Purpose of the Invention] The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to solve branch power transmission line accidents in which it is possible to accurately locate the transmission line section where an accident has occurred in a power transmission line with branches. The objective is to obtain a section locating device.

SUMMARY OF THE INVENTION] The configuration of the present invention in accordance with the above object is to provide current detection means such as a current transformer on the overhead ground wire of each power transmission line branching from the branch point at a branch point of an overhead power transmission line, A light-emitting means with rectification such as an LED is connected to the output of this current detection means, and the light-emitting information of each light-emitting means is led to a locating circuit via an optical fiber, and this locating circuit collects information from each overhead ground wire that differs depending on the section where the accident occurred. It is characterized in that the direction of the power transmission line where a flashover accident, lightning accident, etc. has occurred is determined by processing the light emission information. This makes it possible to locate which power transmission line an accident has occurred on, without being affected by disturbance noise such as electromagnetic induction or reflection at each branch point.

[Example] An example of the present invention will be described below based on FIGS. 1 and 2.

FIG. 1 is a configuration diagram showing a preferred embodiment of a branch power line accident section locating device according to the present invention. As shown in the figure, 1 is an overhead power transmission line with three branches, 2 is an overhead ground wire extending in three directions from branch point J, 3 is a steel tower electrically connected to overhead ground wire 2 at branch point J, and 4 is This is an insulator that mechanically connects the overhead power transmission line 1 to the steel tower 3. Each overhead ground wire extends in three directions2.
2. A current transformer 5 serving as a current detection means is installed near the branch point J in 2.
6.7 is provided to detect alternating current fault currents flowing through each overhead ground wire 2 due to flash faults, lightning strikes, etc. 5.6.7 Each current transformer installed near the branch point
Light-emitting diodes 8 and 9 as light-emitting means are connected to the secondary winding output of
．． 10 are connected. These light emitting diodes 8, 9
．． In the illustrated example, the connection direction of 10 is such that it emits light when the current flows toward the branch point J, and does not emit light when the current flows from the branch point J.

That is, the light emitting diode 11 emits light only by either the positive or negative AC output of the current transformer 12 due to its rectifying property.

FIG. 2 shows a connection circuit configuration between the current transformer 12 and the light emitting diode 11. As shown in FIG. In the figure, R1 is a resistor that dissipates electric power as thermal energy, R2, RE, and R4 are voltage step-down resistors, and Gap is a gear presta for discharging.
ZnO is a zinc oxide surge absorber to reduce damage such as dielectric breakdown.

ZD is a Zener diode for constant voltage, and D is a diode for protecting the light emitting diode LED11. By providing multiple stages of circuit elements between the current transformer 12 and the light emitting diode 11 in this way, the high current generated in the secondary winding output of the current transformer 12 is sequentially attenuated, and the light emitting diode 11 in the final stage is A current within the specifications is allowed to flow through the terminal.

Each light emitting diode 8.9.10 has an optical fiber 13.1
3.13 is optically coupled, and the light emission output is transmitted through this optical fiber, leading to a location circuit 14 that locates the direction of the faulty power transmission line based on this light emission output. This location circuit 14, which mainly consists of logic circuits, is different from optical circuits and is affected by noise emitted from power transmission lines, etc., so it should be installed at a location sufficiently far away from the power transmission line 1 or shielded to prevent the effects of noise. It is desirable to avoid this.

The locating circuit 14 first connects each fiber 13° 13 .
13 converts the optical signal into an electrical signal and outputs a normal rotation output A, 8.
Three optical/electrical converters 15°16, 17 that obtain C, three NOT circuits 18, 19° 20 that invert these outputs and obtain inverted outputs A, B, and C, and these positive and inverted outputs. Four AND circuits 21, 2 that perform logical product and obtain a logical product output
2,23°24. AND circuit 21 of these
teeth.

The configuration is such that a logical output is obtained when A, B, and C are all HF1, and similarly, the AND circuit 22 is configured so that only A is H11.
When only B is H'', the AND circuit 23
The D circuit 24 is configured to obtain a logical output when only C is "H''.Next, the location circuit 14 optically transmits the parallel logical signal outputs from the four AND circuits 25 at the subsequent stage. The optical transmission device 26 has an optical transmission device 26 that converts the serial electrical signal into a serial signal, and a light emitting element 27 that converts the serial electrical signal of the optical transmission device 26 into an optical signal.

In this way, the location circuit 14 inputs the optical information obtained from the three overhead ground wires 2゜2.2, converts this optical information into an electrical signal, performs arithmetic processing, and outputs the processing result again as an optical signal. However, this optical output signal is transmitted through an optical fiber 28, guided to an optical fiber in an optical fiber composite overhead ground wire (OPGW) 29 integrated with the overhead ground wire 2, and transmitted to a remote control point. It looks like this.

Now, the operation of the above configuration will be explained.

Now, assuming that a flash fault occurs in the direction of the transmission lines [I], [I], [I[[] shown in Figure 1 and the tower 3 itself (this is the [01 section)], the power source The light emission status of each light emitting diode 8°9.10 in each half period of the waveform is as shown in Table 1.

Table 1: Light emission status of light emitting diodes This is due to the following reasons. In other words, in the section [o, ] where a flash fault occurs in the tower 3 itself, when the phase is positive, the fault current flowing upward through the tower 3 is shunted from the branch point J to the three overhead ground wires 2, 2.2. Since the current flows out, none of the light emitting diodes 8, 9, and 10 emit light, but when the phase is opposite, the ground 30 becomes negative? The fault currents flowing through each of the overhead ground wires 2.2.2 flow toward the branch point J, join together, and flow downward through the tower 3, so that all the light emitting diodes 8.9.10 emit light. [I] If a flash fault occurs in the section, the ground faulted power transmission line 1. Earth 30° steel tower 3. A closed circuit is formed with the overhead ground wire 2 on the grounded power transmission line 1,
An alternating current fault current will flow through this open circuit, but when it is in the positive phase, that is, the overhead ground 12 forming an open circuit
When the voltage of tower 3 and other 2
Since the main overhead ground wire 2.2 ([II] and [I[[] sections) is at ground potential, the fault current flowing through the overhead ground wire 2 in the [■] section flows toward branch point J. , flows out to the steel tower 3 and the other two overhead ground wires 2.2. Therefore, [I]
Only the diode 8 in the section will emit light, and the diodes 9 and 10 in the other sections will not emit light.

When the phase is negative, that is, the overhead ground wire 2 forms a closed circuit.
When the voltage of It flows out onto the overhead ground wire 2 in section [I] where this occurs. Therefore, no accident occurred this time [II], [
The light emitting diode 9.10 in the I[I] section emits light, and the [1
] The light emitting diodes 8 in the section do not emit light.

Based on the same principle, if a flash fault occurs in the section [II], only the light emitting diode 9 in the section [ffl will emit light when the phase is positive, and when the phase is negative, the light emitting diode 9 in the section [II] and [1] will emit light. The light emitting diodes 8 and 10 of 1 emit light.In addition, in the interval [II[], when the phase is positive, only the light emitting diodes 10 in the interval [I[[1] emit light, and when the phase is negative, [II and [II
]II light emitting diode 8°9 emits light.

In this way, each section [0], [I, [■].

89.10 Light-emitting diodes installed on each overhead ground wire 2.2.2 in the event of a separate accident on [I[[]
There is a regularity in the light emission situation, and this is detected by the optical/electrical converter 15.
．． If expressed as a truth table based on the outputs A, B, and C of 16.17, it will be as shown in Table 2.

Table 2 Truth table for light emission Therefore, in the locating circuit 14 that obtains light information from the overhead ground wire 2.2.2, three NOT circuits 18°19.20 are provided and the optical/electrical converter 15.16 Obtain the inverted output of ゜17 and use this to create A.

AND circuit 2 that outputs logic output when B and C are all “H”
1. By providing four AND circuits 22, 23, and 24 that output a logical output only when A, B, and C are each at H''', it is possible to logically locate the section where the accident occurred based on the above-mentioned light emission situation. It can be known from the optical output signal of the circuit 14. That is, in the accident in the [O] section, AND
Three AND circuits 22, 23, and 24 excluding circuit 21 [
II, [II], [II[] output is constantly “
L'°, a pulse corresponding to the [O] specific output phase change of the AND circuit 21 is output, and this pulse is sent to the control point by the optical fiber in the optical fiber composite overhead ground wire (OPGW) 29. Learn about the accident in section 01. Similarly, [I
In an accident in section I, [I[], [II[], A
Each of the ND circuits 22, 23, and 24 [II, [II].

Since the [II[] outputs each output a pulse, accidents in each section can be known.

In this case, the detection signal obtained from the alternating current fault current flowing through the overhead ground wire 2 due to the fault is the detection signal obtained from the light emitting diode 1.
Since only one of the positive and negative signals is taken out due to the rectification properties of 1, there is no possibility that the reflection at the branch point J will be superimposed on the signal. In addition, the detection signal is transmitted to the light emitting diode 11.
converts it into an optical signal, and sends it to the location circuit 1 via an optical fiber 13.
4, unlike the case where it is transmitted directly as an electric signal, malfunctions due to disturbance noise such as electromagnetic induction are less likely to occur.In particular, since it is optically coupled, it can be used as a detection point for ground potential rise in the event of an accident and as a location circuit 14. It is also possible to avoid the risk of circuit damage due to a large potential difference.

Although the main body of the locating circuit 14 is an electric circuit and is easily affected by disturbance noise, the locating circuit 14 can be easily located by extending the optical fiber 13 and separating the locating circuit 14 to a point where it is no longer under the influence of noise, or by shielding it. The circuit 14 itself can be protected from noise. In addition, the location circuit 14 does not care about the so-called analog information such as the absolute current 1n or the phase difference itself,
Since it has a simple logic circuit configuration using only 0N10FF digital information, the overall device structure is simple and inexpensive.

Furthermore, since the output of the location circuit 14 is taken out as an optical signal, it is possible to accurately transmit the location results to remote control points using the optical fiber composite overhead ground wire (○PGW) 29, which is currently being developed and put into practical use. Can be sent.

In the above embodiment, a branch power transmission line extending in three directions from the branch point J has been described, but the present invention can also be applied to a multi-branch power transmission line or a two-branch power transmission line.

Further, the location circuit 14 of the above embodiment has its logic circuit set to NO.
Although the circuit configuration is made up of the T circuit 31 and the AND circuit 25, the present invention is not limited to this.
OR circuit, NANDAND circuit CLUSIVE-OR
Of course, it is also possible to configure it with other logic circuits such as circuits. Furthermore, it is also possible to carry out the orientation by a program using a microcomputer or the like, which is particularly advantageous when locating a multi-branch power transmission line.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) By configuring the structure so that accident information is extracted as an optical signal rather than an electric signal from each overhead ground wire where fault current flows, which varies depending on the accident section, electric! ! It is possible to prevent malfunctions and failures due to inductive disturbances, ground potential rises, etc., so it is possible to prevent an accident from occurring on any of the power transmission lines with branches.

It is possible to accurately locate the fish.

(D) Since the light-emitting means emits light according to either the positive or negative detection output of the current detection means, only a signal in one direction is detected as accident information, so reflections at branch points may be superimposed on the detection signal. Since there will be no more
It is possible to accurately locate the fault section of the power transmission line.

(3) Since the location circuit can be a logic circuit, the structure of the entire device can be simplified and made inexpensive.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a preferred embodiment of the branch power line fault section locating device according to the present invention, and FIG. 2 is a partially detailed diagram of FIG. 1, which is a connection circuit diagram of a current transformer and a light emitting diode. It is. In the figure, 1 is a power transmission line, 2 is an overhead ground wire, 5.6°7, and 12 is a current transformer, which is an example of current detection means, 8.9,
10 and 11 are light emitting diodes which are examples of light emitting means;
13 is an optical fiber. 14 is a location circuit, 18, 19, 20 and 31 are N07 circuits, and 21, 22, 23, 24 and 25 are AND circuits. Patent Applicant Hitachi Cable Co., Ltd. Representative Patent Attorney Nobuo Kinutani Procedure? Hosho (self-proposal) October 12, 1980 Manabu Shiga, Director General of the Patent Office 1, Indication of the case, Patent Application No. 1987-195713 2,
Name of the invention Branch power line accident section locating device (512) Hitachi Cable Co., Ltd. 4 Agent postal code 105 1-6-7-5 Atago, Minato-ku, Tokyo Date of amendment order (voluntary) 7 Contents of amendment (1) Ming! 10, page 7, line 8, "gear prestor" has been corrected to "gap arrester." (V Corrected l'-A, B, CJ on page 8, line 10 as rA. B, CJ. (3) Changed [Ukeya (, s'b It's easy, though," he corrected.

Claims (5)

[Claims] (1) A current detection means for detecting an alternating current fault current flowing in the overhead ground wire of each power transmission line due to a flash fault accident, lightning accident, etc. in a fault section locating device for a power transmission line with branches;
A light emitting means that emits light according to either the positive or negative detection output of the current detection means, an optical fiber that transmits the light emitting output of the light emitting means, and light emitted information from each overhead ground wire that is output from the optical fiber and differs depending on the accident section. A branch power line accident section locating device comprising: a locating circuit for locating the direction of the power transmission line where the flash fault, lightning accident, etc. occurred based on the above. (2) The branch power transmission line fault section locating device according to claim 1, wherein the current detection means is a current transformer provided on an overhead ground wire of each power transmission line. (3) The branch power transmission line fault section locating device according to claim 2, wherein the light emitting means is a light emitting element having rectifying properties and connected to a secondary winding output of a current transformer. (4) A patent claim characterized in that the light emitting element is connected to the secondary winding output of the current transformer such that the light emitting element has a polarity that emits light when a fault current flows toward a branch point of the overhead ground wire. Branch power line accident section locating device as described in item 3. (5) The above-mentioned locating circuit forms an AND output of a NOT circuit that forms an inverted output from the transmission output of the optical fiber according to the number of branches, and the inverted output of the inversion circuit and the above-mentioned transmission output that is not inverted. and an AND circuit, and is configured to locate the direction of a power transmission line where a flashover accident, lightning accident, etc. has occurred from the output of this AND circuit. Branch power line fault section locating device.