JPH068841B2 - Receiver for accident point exploration - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver for accident point search for applying a high voltage pulse to search for a discharge ground fault point on an overhead distribution line.

[Conventional technology]

As a conventional receiving device for detecting an accident point of an overhead distribution line, there is one using a "signal arrival direction detecting device" disclosed in, for example, JP-A-59-68678. This conventional device will be described with reference to the drawings.

Figure 4 is a block diagram of the receiver for this accident point exploration. (1) is an overhead distribution line that seems to have a discharge-induced ground fault, and (4A) and (4B) are this distribution line (1). An electromagnetic wave detection antenna for detecting an electromagnetic wave generated by a current traveling wave propagating from the accident point above, (5) is a receiving device, and is connected to the antennas (4A) and (4B), respectively. The waveform (I) in the figure shows the first wave of the fault current flowing through the distribution line (1).

(9A) and (9B) are absolute value circuits that output a positive voltage signal by inputting signals from the antennas (4A) and (4B),
(10A), (10B) are the absolute value circuits (9A), (9B)
A monostable multivibrator that outputs a single pulse with a required pulse width Td by inputting a signal from (11A), (11
B) is a NAND circuit element in which the input and output terminals are connected to each other to form a flip-flop circuit. (12A),
(12B) is an inverter that inverts the signal level of the input signal and outputs it, and (13A) and (13B) are signal indicators.

Next, this operation will be described.

Now, the antenna (4A) has a time difference td from the antenna (4B).
Assuming that the electromagnetic wave is received first, the voltage signal output from the antenna (4A) is first input to the absolute value circuit (9A), and monostable by the signal output from this absolute value circuit (9A). The multivibrator (10A) outputs a single pulse having a required time width Td. By the input of this one-shot pulse, the NAND circuit element (11B) is interlocked, and the output signal of this NAND circuit element (11A) is output for the time width Td of the input pulse, and the signal is inverted by the inverter (12A) Turn on the indicator (13A) and display the direction of the accident point. Then, the antenna (4
Similarly, when B) receives the electromagnetic wave and outputs a voltage signal, as described above, the NAND circuit element (11B) is interlocked by the NAND circuit element (11A). It is not driven during. That is, the minute reception time difference td between the two antennas (4A) and (4B) is expanded to an arbitrary time difference Td at the output stage of the two NAND circuits, and the late arrival signal is input to the NAND circuit (11B). The output time is usually very small (td) and the signal indicator (13B) does not light up.

[Problems to be solved by the invention]

However, in the conventional receiver for detecting an accident point configured as described above, in addition to the electromagnetic wave generated by the traveling current wave propagating through the overhead distribution line due to the ground fault discharge at the accident point, the surrounding building However, there was a problem in that the reflected wave caused by the noise and the external noise generated when the switch was opened and closed in the vicinity were received and displayed incorrectly.

The present invention has been made to solve the above-mentioned problems, and by identifying and displaying the fault point direction by a plurality of intermittently received signals, the fault point of an overhead distribution line can be reliably identified. The purpose of the present invention is to obtain a receiver for accident point exploration that can be searched for.

[Means for solving problems]

The receiver for detecting an accident point according to the present invention counts an input pulse signal indicating the direction of the accident point for each direction of the overhead distribution line, and a pair of counters for outputting the signal at a predetermined count or more, and this pair of counters. A pair of counter resetting means for resetting the other by starting the counting of one of them, a pair of signal holding means for inputting the output signals of the pair of counters respectively and outputting the signals by self-holding, and this pair of signal holding One of the means comprises a pair of self-holding reset means for resetting the other when starting self-holding, and a signal processing means for outputting a signal for confirming the correctness in the direction of the accident point indicated by the output signal of the signal holding means. It was done.

[Action]

In the receiver for self-point searching according to the present invention, when the signal indicating the same direction is continuously input to the counter a predetermined number of times or more, the signal holding means outputs the signal indicating the accident point direction, which is the opposite of this. Even if the signal indicating the direction is input, if it is less than the predetermined number of times, the signal output indicating the direction of the accident point retains the previous state, and instead, the signal processing means outputs a signal for confirming the correctness of the direction of the accident point. Is output.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. The same reference numerals as in the conventional example indicate the same or corresponding parts.

In FIG. 1, (14) inputs the time difference signal output from the pair of NAND circuit elements (11A) and (11B) in the preceding stage, outputs only the first-arrival signal by itself, and outputs the latter-arrival signal. This is a first-arrival signal holding means for blocking, which uses a pair of D-type negative edge trigger type flip-flop circuit elements with reset terminals (hereinafter referred to as D-flip-flop circuit elements) (14A) and (14B) respectively. Is connected to the other input terminal D, and
It is configured by using the clock terminal as an input terminal. (15) is an OR circuit element which receives the output of the pair of D-flip-flop circuit elements, and (16) is triggered in synchronization with the operation of the first-arrival signal holding means (14) and, after a predetermined time Te, holds this first-arrival signal. Automatic reset signal generating means for outputting a signal for resetting the means (14), connected in series with the output signal of the OR circuit element (15) as an input
It is composed of a single monostable multivibrator (16A), (17), and has a relationship with the first-arrival signal holding means (14) so that it outputs a single-shot pulse corresponding to the first-arrival signal among the input signals. There is. (18) is a signal arrival direction discriminating circuit which receives the output signal of the first-arrival signal holding means (14) and outputs a signal when the same signal is continuously input a predetermined number of times or more. A circuit block diagram is shown.

In FIG. 2, (20A) and (20B) are a pair of counters that count the input pulse signal and output the signal at a predetermined count or more. In order to count the rising edge of the leading edge of the input pulse signal, the signal is output from the terminal Q ₁ at the start of counting, that is, at the first counting, and the terminal is at a predetermined count number (for example, 2 to 6) or more. Q _N
To output the signal from. (21A) and (21B) are a pair of counter reset means for resetting the other by starting the counting of one of the pair of counters (20A) and (20B). It is composed of a monostable multivibrator that receives the output signal from each terminal Q ₁ and outputs a single pulse.
The output signal of this low level voltage is the AND circuit element (30
B), (30A) through the other counter (20
Input to the reset terminal of B) and (20A). (twenty two
A) and (22B) are a pair of signal holding means for inputting the output signals from the terminals Q _{N of the} counters (20A) and (20B), and holding and outputting them, respectively. A pair of monostable multivibrator (23A), which outputs a single pulse triggered by the rising edge of
B) and this pair of monostable multivibrates (23
A) and (23B), which are set by low-level voltage output signals from the terminals (A) and (23B), respectively, and are composed of a pair of RS flip-flop circuit elements (24A) and (24B) which self-hold and output. The low-level voltage output signals of the pair of monostable multivibrators (23A) and (23B) are respectively connected to the reset terminals of the other RS flip-flop circuit elements (23B) and (23A) at the AND circuit element (31B). , (31A), whereby a pair of self-holding reset means for resetting the self-holding of one of the pair of signal holding means (22A), (22B) when the self-holding of the other is started. Are configured. (25) is a state in which no signal is output from the terminals Q _{N of the} counters (20A) and (20B), the signal holding means (22A),
(22B) is a signal processing means for outputting a signal when the signal is being output from any one of (22B).
Inverters (26A) and (26B) for inverting and outputting the output signals of (A) and (20B), respectively, and this inverter (26
AND circuit elements (27A) and (27B) that receive the output signals of A) and (26B) and the output signals of the RS flip-flop circuit elements (24A) and (24B), respectively, and the AND circuit element (27A). ), (27B) and the OR circuit element (28) which receives the output signal. (29
In A), (29B), and (29C), since the output signals of the signal processing means (25) and the pair of signal holding means (22A) and (22B) are continuous signals, these output signals are output. An AND which is provided for the purpose of converting the input signals of the counters (20A) and (20B) into the same pulse signal, and which receives the output signals of these output signals and the OR circuit element (15) as inputs. It is a circuit element. (13A), (13
B) and (13C) are signal display means, (13A) and (13B).
Is a signal indicator indicating the direction of the accident point, and (13C) is a signal indicator indicating the correctness. (19) is a manual reset switch for simultaneously resetting the counters (20A), (20B) and the RS flip-flop circuit elements (24A), (24B). A low level reset signal from the manual reset switch (19). Is an AND circuit element (30A),
Counter (20A), (20B) through (30B), A
It is inputted to the reset terminals of the RS flip-flop circuit element through the ND circuit elements (31A) and (31B), respectively.

Next, this operation will be described. Fig. 3 shows a time chart at the input and output ends of the signal arrival direction discrimination circuit (18), which will be described below together with this figure. Electromagnetic waves emitted by the current traveling wave propagating through the overhead distribution line from the ground fault point. Is received by the loop antennas (4A) and (4B) and is output as expanded time difference signals from the output terminals A ₃ and B _{3 of} the NAND circuit elements (11A) and (11B). It is the same as the conventional example. Now, assuming that the accident point is on the side of the antenna (4A), and the antenna (4A) receives from (4B) with a minute time difference td (eg, 10ns), the NAND circuit element (11A) causes a time difference Td (eg, 10ms). It is enlarged and the signal is output first. The output signal of the NAND circuit element (11A) sets the D-flip-flop circuit element (14A) to self-hold and output a high level signal from the terminal Q, and a low level output signal from the terminal to the other D- Since the flip-flop circuit element (14B) is interlocked, even if a late arrival signal is input to the terminal of the D-flip-flop circuit element (14B) with a time difference of Td, it is not output from the terminal Q. The output signal of the D-flip-flop circuit element (14A) is input to the monostable multivibrator (16A) via the OR circuit element (15), and the monostable multivibrator (16A) is driven by the leading edge of the input signal. It is triggered to output a single pulse with a time length Te and input to the monostable multivibrator (17). This monostable multivibrator (17) is triggered by the trailing edge of the trailing edge of the input signal to output a low-level voltage single-shot pulse signal, which is output to the D-flip-flop circuit element (14A).
Input to the terminal of (14B) and
Reset A) and (14B). As a result, the preceding difference signal holding means (14) has a time length Te corresponding to the first arrival input signal.
A single pulse signal (for example, 1 sec) is output, and the output of the late arrival signal is blocked. This output signal is input to the signal arrival direction discrimination circuit (18), and the operation of the signal arrival direction discrimination circuit (18) will be described with reference to FIG. In Figure 2, the output pulse signal of counter above to the input terminal T of the (20A) D-flip-flop circuit elements (14A) is, as shown in FIG. 3 A _4, the period Tp (e.g. 2se
Assuming continuous input at c), from the output terminal Q ₁ of this counter (20A), as shown in Fig. 3 D ₁ in synchronism with the leading edge of the first input pulse signal. The signal is output and the monostable multivibrator (21A) triggered by the rising edge of the leading edge of this signal is shown in Fig. 3D.
_As shown in ₂ , a low level single pulse signal is output, and this signal is input to the terminal of the counter (20B) through the AND circuit element (30B) and reset. The counter (20A) counts the number of times of rising of the pulse signal input to the terminal T, and outputs a signal from the output terminal Q _N when the number of times reaches a predetermined number. This predetermined number can be set arbitrarily, the here is set to twice, the output signal from the output terminal Q _N of the counter (20A) is as shown in FIG. 3 A _5, to the counter (20A) Is output in synchronization with the rising edge of the second input signal. Monostable multivibrator (23) of the signal holding means (22A)
A) is triggered by the rise of the leading edge of the output signal of this counter (20A), as shown in FIG. 3 A ₆ outputs a single pulse signal of the low level voltage, R-S flip-flop circuit element by the output signal (24A) is set, and outputs a continuous signal such shown in FIG. 3 a ₇ to self-holding, the signal is inputted to the aND circuit element (29A). From OR circuit element (15) to the other input terminal of the AND circuit element (29A), since the input signal and the same signal of the signal i.e. counter terminal A ₄ (20A) is input, the AND circuit element The output signal of (29A) is the third
As shown in FIG. A _8, output from the signal corresponding to 2 shots th input signal of the counter (20A) shown in FIG. 3 A _4, the fault point direction is input the signal annunciator in (13A) indicate. The output signal of the monostable multivibrator (23A) passes through an AND circuit element (31B),
The other R-SS flip-flop circuit element (24B)
Is input to the terminal, although reset the circuit element (24B), the counter (20B) at this time is Fig. 3 B ₄
No signal input as shown in, the although connexion Figure 3 B _5,
B _6, as shown in B ₇ counter (20B), a monostable multivibrator (23B), R-S flip-flop circuit elements (24B) does not output any signal, the signal indicator (13B) the third Fig B No signal is displayed as it is not input as shown in ₈ . Further, since the counter (20A) outputs a signal at this point, the inverter (26A) which receives this output signal inverts and outputs as a low level signal, and the AND circuit element (which receives this signal as an input ( 27A) does not output as shown in D ₆ of FIG. Similarly, the RS flip-flop circuit element (24
No signal is output from B), so this circuit element (24
No output is made from the AND circuit element (27B) which receives the output signal of B) as shown in FIG. 3E ₆ . Therefore, an OR circuit element (28) which receives the output signals of these AND circuit elements (27A) and (27B), that is, signal processing means
(25) does not output a signal as shown in FIG. 3 C _7, slave connexion annunciator (@ 13 C) is not displayed because it is not entered as shown in Figure 3 C _8.

Next, as shown in A ₄ and B ₄ in FIG. 3, the fourth input signal was input to the counter (20B) (terminal B ₄ ) and then to the counter (20A) (terminal A ₄ ) again. Assuming that, as in the case described above, the output signal from the terminal Q ₁ of this counter (20B) as shown in FIG. 3 E ₁ causes the monostable multivibrator (21B) to move to FIG. 3 E ₂ . Output a low level single pulse as shown,
This signal is input to the terminal of the counter (20A) through the AND circuit element (30A), and this counter (20A)
Reset. However, since the input signal to the counter (20B) is only one shot, this counter (20B)
There is no signal output from the terminal Q _{N of} B), and the signal indicator (13
B) does not display. On the other hand, the above counter (20
A) is reset and the signal output from the terminal Q _N is stopped, but the RS flip-flop circuit element (24A) is the third
Continuing the output of self-hold signal as shown in FIG. A _7, annunciator (13A) continues the display as shown in Figure 3 A _8. Incidentally, the stop signal output of the counter (20A), the signal as the AND circuit element (27A) shown in FIG. 3 _{D 6} is output, OR circuit element (28), via the AND circuit element (29C) is input by displaying annunciator a (@ 13 C) such signals Figure 3 C ₈ is annunciator in (@ 13 C),
It is displayed that the signal display (13A) is not "accurate".

Next, as shown in Fig. 3 A ₄ and B ₄ , the counter (20
When the 5th and 6th signals are continuously input to A),
Since the fifth shot th input signal is the first input signal after reset, which resets the counter (20B) from the terminal to Q ₁ the counter (20A). Since the sixth input signal is the second signal after reset, a signal is output from the terminal Q _N of the counter (20A), and this output signal causes a single pulse from the monostable multivibrator (23A). Although it is output, the RS flip-flop circuit element (24A) is already in the set state, and the signal indicator (13A) continues to display. However, due to the output from the terminal Q _N of the counter (20A), the AND circuit element (27A) stops the signal output as shown in D ₆ of FIG. 3, and accordingly, the signal indicator (13C) displays the third signal. The display is stopped as shown in FIG. C ₈ .

Next, assuming that a pulse signal is input to the counter (20B) as shown in A ₄ and B ₄ in FIG. 3 from the 7th input, the 7th input signal, that is, the counter (20B)
The counter (20A) is reset by the first input signal after the reset of B). At this point, the signal indicator (13A) continues to display, but at the same time, the signal indicator (13C) is displayed, indicating that the indication on the signal indicator (13A) is not "accurate". Next, the signal is output from the terminal Q _N of the counter (20B) by the signal input of the 8th, that is, the second input after resetting to the counter (20B), and the monostable multivibrator (23B) outputs a single-shot pulse signal. Output, RS flip-flop circuit element (24B)
Is set to output a self-holding signal and RS
Results flip-flop circuit elements (24A) is reset, the signal indicator as shown in FIG. 3 _{A 8 ~C} 8 (13
A) and (13C) are turned off, and the signal indicator (13B) is turned on instead, and the direction of the accident point is correctly displayed.

That is, the signal indicators (13A) and (13B) display the signal as the correct direction only when the pulse signals indicating the same direction are continuously input a predetermined number of times (two times in this example) or more, and the predetermined number of times or less ( The direction of signal display does not change with the signal input indicating the opposite direction (once in this example). But the third
The signal display (13C) indicates that the signal display is not "accurate".

In the above embodiment, a pair of counters (20A), (20B)
When one of the pair of signal holding means (22A) and (22B) is outputting a signal in the state where the signal is not output by the signal processing means (25), the signal processing means (25) outputs the signal and outputs the signal. Input to the signal indicator (13C), and the signal indicator (13A),
The case of displaying that the accident point direction display by any of (13B) is not "accurate" has been described, but the signal processing means for outputting a signal when any of the pair of counters (20A), (20B) outputs a signal. If a signal indicator (13
C) can display a signal in response to the input of this output signal to indicate that the accident point direction display by any of the signal indicators (13A) and (13B) is "accurate". The signal processing means in this case is the same as the signal processing means (25) of the above-described embodiment except the inverters (26A), (26B) and the AN.
D circuit elements (27A) and (27B) are omitted and the counter (20
It can be constructed by directly connecting the output terminals of A) and (20B) to the input terminals of the OR circuit element (28).

〔The invention's effect〕

As described above, according to the present invention, when the signal indicating the same direction is continuously input a predetermined number of times or more, the signal indicating the fault point direction is output and the signal indicating the opposite direction is input. However, if the number of times is less than the predetermined number of times, the signal output indicating the direction of the accident point retains the previous state, and instead, a signal for confirming the correctness of the direction of the accident point is output, so that the surrounding construction There is an effect that it is possible to prevent erroneous display due to reception of reflected waves from objects and other external noises, and to easily search for fault points on overhead distribution lines.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the receiver for detecting accident points according to the present invention, FIG. 2 is a block diagram showing an example of the signal arrival direction discriminating circuit in FIG. 1, and FIG. 3 is shown in FIG. FIG. 4 is a block diagram showing a conventional receiver for detecting an accident point, which is a time chart showing the operation at the input / output end of the signal arrival direction discrimination circuit shown in FIG. In the figure, (1) is an overhead distribution line, (4A) and (4B) are loop antennas, (8) is a receiver, (18) is a signal arrival direction discrimination circuit, (20A) and (20B) are counters, (21A ),
(21B) is a counter reset means, (22A), (22
B) shows a signal holding means, and (25) shows a signal processing means. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An aerial distribution system that receives electromagnetic waves emitted from the distribution line and displays the direction of the accident point by intermittently applying a high voltage pulse to the aerial distribution line in the power failure state to cause a ground fault discharge at the accident point. In a receiving device for detecting an accident point of an electric wire, a signal indicating the direction of the accident point is counted for each direction of the distribution line, and a pair of counters that outputs the signal at a predetermined count or more, one of the pair of counters is counted. A pair of counter reset means for resetting the other at the start,
A pair of signal holding means for inputting the output signals of the pair of counters respectively and self-holding and outputting a signal indicating the fault point direction of the distribution line, and the other of the pair of signal holding means at the start of self-holding And a signal processing means for outputting a signal for confirming the correctness of the accident point direction indicated by the output signal of the signal holding means.