JPS63243771A - Receiving apparatus for searching accident point - Google Patents

Abstract

PURPOSE:To prevent erroneous display due to noise and to detect noise input, by discriminating a receiving signal by a noise signal detection means and outputting a detection signal when said signal is a noise signal and outputting to trigger signal of a signal fixing means. CONSTITUTION:When loop antennae 4A, 4B receive continuous noise, signals are not inputted to the clock terminals of FF 15A, 15B from the AND circuit 20 of a noise signal detection means 16 and, therefore, said signals are not triggered and, before resetting, there is no change in an output state at the time and, after resetting, no output is issued. When short-term intermittent noise is inputted, a monomultivibrator 16 outputs a single pulse signal wherein a predetermined time length is added to the whole length of an intermittent noise signal and, therefore, when the time length of said pulse signal is longer than the output time length of a monomultivibrator 17, the signal corresponding to the noise signal is outputted from an AND circuit 19. By this method, a signal display device 13A performs no erroneous display by any noise signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a receiving device for detecting fault points, which applies high voltage pulse gold to detect all discharge fault points of an overhead power distribution line.

[Conventional technology]

0 as a receiving device for fault point detection of conventional overhead VL lines.
For example, there is a device that utilizes the "signal arrival direction detection device" disclosed in Japanese Patent Application Laid-Open No. 59-68678. This conventional method will be explained in detail with reference to Fig. 0.

Figure 8 is a block diagram of this receiving device for fault point exploration.
), (11 is an overhead distribution line that is thought to have had a ground fault, and (4 to (4B) are electromagnetic waves emitted by traveling current waves propagating from the point of the fault in this distribution line (1)). (5) is a receiving device;
It is connected to the upper antennas (4A) and (4B), respectively. Note that the waveform (I) in the figure is the power distribution i (1+ 'i
This shows the first wave of flowing fault current.

(9A), (9B) are antennas (4A), (4B)
The absolute value circuits (10A) and (10B) output a positive polarity voltage signal in response to signal input from the absolute value circuits (9A) and (9B), which output a single pulse of the required pulse width Td by the signal input from the absolute value circuits (9A) and (9B). The output monostable multivibrator, (1iAJ, (11B)) is a NAN with the entire flip-flop circuit connected to each other's input and output terminals.
It is a D circuit element.

(12A) and (12B) are inverters that completely invert the signal level of the input signal and output it; (13A) and (13
B) is a signal indicator.

Next, this operation will be explained.

I1. Antenna (4A) is more prominent than antenna (4B)]
Assuming that all of the above electromagnetic waves are received before the difference td, first the voltage signal output from the antenna (4AJ) is input to the absolute value circuit (9k), and the signal output from the absolute value circuit (9k) is input to the absolute value circuit (9k). monostable multivibrator (1
0A) outputs a single pulse of the required time width Td. By inputting this single pulse! l, NAND circuit element (11BJ t-interlock and this NAND
The output signal of the D circuit element (11A) is output for the time duration Td of the input signal, and the signal of the inverter (12A) is inverted and the signal indicator (13A) lights up to display the entire direction of the accident point.

Next, if the antenna (@) receives all of the electromagnetic waves and outputs a voltage signal, it will operate in the same way, but the above and (,
Because it is interlocked by the NAND circuit element (11B) μNAND NAND circuit element).

Signal display (13B, l is not input and does not light up.

[Problem that the invention seeks to solve]

However, according to the conventional devices above 9, in addition to regular electromagnetic waves generated by current traveling waves that propagate throughout the distribution line from the pJs failure point due to ground fault discharge, two examples are generated from nearby factories, private houses, and broadcasting equipment. There were problems such as receiving various kinds of foreign noise and displaying it incorrectly.

This invention was made in order to solve all of the above-mentioned problems, and detects persistent noise and intermittent noise that occurs intermittently in short cycles among foreign noise, and completely prevents false display. The purpose is to obtain a receiving device for accident point exploration that can be used.

[Means to solve all problems]

The receiving device for accident point exploration according to the present invention includes a time difference signal output means for outputting a pair of signals having a nine time difference according to an output signal of an antenna, and a time difference between the input signals. A signal time difference amplifying means for expanding and outputting the signal to a predetermined time difference or more, and inputting all the output signals of the time difference signal output means, determining whether the input signal is a regular input signal or noise, and responding to the regular input signal or the noise signal. noise signal detection means for outputting a signal corresponding to the normal input signal; and a signal fixing means for self-holding and outputting a first-arrival signal corresponding to the direction of the accident point that is triggered by the output signal corresponding to the normal input signal and being output from the signal time difference expansion means. It has the means and everything.

[Effect]

The receiving device for accident point exploration according to the present invention expands the minute time difference of the input signal from the time difference signal output means to a predetermined time difference or more by the signal time difference expansion means, and outputs the result.
The noise signal detection means determines whether the input signal from the time difference signal output means is a noise or a regular input signal depending on whether the time length of the input signal is longer or shorter than a predetermined time, and based on the appearance or appearance of the noise signal detection, it is determined whether the input signal is a noise or a regular input. Full signal output.

All the signal fixing circuits are triggered by the output signal corresponding to this regular input, and at this time, all of the first layer signals corresponding to the fault point direction of the first distribution line being outputted from the signal time difference expansion means are self-maintained by this signal fixing circuit. and output it.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Note that the same reference numerals as in the conventional example indicate the same or corresponding parts. In Figure 1, (1) is an imaginary arrangement where a discharge ground fault is likely to occur! On the line.

There is a power outage. +31 is the faulty equipment that caused the discharge ground fault connected to the unknown B point of this layout KHm.

(2) is a high M voltage pulse application means (voltage applying device) that intermittently generates high M voltage pulses, and is
By applying one high voltage pulse, the distribution line 111' (i-charges. (4A) and (4A)
B) is the above arrangement! It is an electromagnetic wave detection antenna that detects electromagnetic waves emitted by traveling current waves propagating from all fault points on 1 flll.1 Usually, a loop antenna is used and the distance is set at an appropriate distance.
For example, they are installed on the roof of a car (7) in series with the direction of travel of the car (7), with a distance of (m) between them.

(8) is this 1' pair of antennas (4A), (4B)
This is a receiving device that determines the direction of the accident point from the arrival time difference t(i) of the signals received at the antenna (4k).

(4B) via coaxial cables (6A) and (6B), respectively, and is mounted on the vehicle (7).

Note that waveform (I) in the figure indicates the first wave of fault current flowing through the distribution line (1).

FIG. 2 is a block diagram of the receiving device (8).

(9) Time difference signal output means for inputting all the output signals of the antennas (4A) and (4B) and outputting two signals having a time difference; in this embodiment, it is used as an input signal! It is comprised of absolute value circuits (9A) and (9B) that always output a positive polarity voltage signal regardless of the polarity of this input signal.

αl is a signal time difference amplifying means υ which magnifies and outputs the minute time difference td i of the output signal of the time difference signal output means (9) beyond a predetermined time difference, and a pair of monostable multivibrators (10AJ, (10B)); A pair of NAND circuit elements (11A,) fully configured as a flip-flop circuit
.

(11B). σe inputs all the output signals of the time difference signal output means (9), determines whether this input signal is a noise signal or a regular input signal based on the ground fault discharge at the fault point, and detects the noise signal or signal detection means. A monostable multivibrator (16A) with a retrigger function that outputs a single pulse signal with a time length T1, which is a predetermined length of time plus the time length of the above input signal, and this monostable multivibrator (16k). A monostable multivibrator that is triggered by the rising edge of the leading edge of the output pulse signal of the monostable multivibrator (10K) and outputs a single pulse signal of a predetermined time period Te that is p shorter than the output pulse time Td of the monostable multivibrator (10B). A vibrator r1η, a monostable multivibrator u8 that is triggered by the falling edge of the output pulse of this monostable multivibrator η and outputs a single pulse of a predetermined time width Ts, and this monostable multivibrator α ladder. Zener circuit element 1 which receives the output pulse signal of the monostable multivibrator (16k) as its input! J, and the above monostable multivibrator Q
8 output pulse signal and the above monostable multivibrator (
16A) is input to the inverted output pulse signal of *FM.

αS is triggered by the output signal corresponding to the normal input signal of the noise signal detection means σG, that is, the AND circuit element quantity signal, and at that time, a signal that self-holds and outputs the output signal of the signal time difference expansion means Ql. The fixing means is a pair of reset terminal type D type positive edge trigger one-way flip-flop circuit elements (hereinafter referred to as D
- arranged with flip-flop circuit elements) (15A),
(1sB). Note that the D-flip-flop circuit elements (15A) and (15B) are connected to the terminal T.
(When the signal input to the clock input terminal rises, the signal at the input terminal at that point in time) is self-maintained and output from terminal Q. Even if the signal at the terminal changes thereafter, the signal at the input terminal remains unchanged. As long as there is no change (rise) in the input signal of T, the output state does not change and is held until a reset signal is input to terminal i.C) 1) is the above M■ circuit α
It is a monostable multipipulator that takes the output pulse of 9 as input, and when the leading edge of this person chi g rises, the terminal Q! ll Single pulse full output. (c) is a signal display that inputs all the output pulse signals of the monostable multivibrator Cυ and displays the input of noise signals, (c) shows the upper hpi D-flip-flop circuit elements (15A), (15B) all reset This is a manual reset switch that provides a signal to

Next, the operation will be explained. In Fig. 1, the hypothetical arrangement M in a power outage state, the proboscis (1) is
Jf, device) (2) is charged by applying a high voltage pulse gold, and when the fault equipment (3) is caused to discharge due to a ground fault, the ground fault current due to the photoelectric charge of the above arrangement JL Katsufil will reach the fault point B.
flow into. The rise of the second wave of the transient current in this ground fault discharge is generally extremely steep, and
propagates from fault point B in the direction of charge point A and in the direction of counter charge point C as a traveling current wave.

A pair of antennas (4A), (4B) and a receiving device (8
) A fully loaded truck (7) moves directly under the overhead wiring line m from the control point A toward the opposite power point side C, on this wiring W, 1.
(2) When located at any point between the energizing point A and the fault point B, the current traveling wave propagating through the distribution line (1) When the emitted 11Lm wave is received by the above antennas (4A) and (4B), the antenna (4A) on the accident point B side receives it first, and the other antenna (4B) i'l: Time Mtd
Only delayed reception. When the vehicle (7) is located on the opposite side C from the accident point B, the antenna (4A),
(4B) receives the above electromagnetic wave, the antenna (4B) on the side of the accident point B receives it before the other antenna (4AJ) by a time difference td. Therefore, the above pair of antennas (4A) and (4B) ), the direction of arrival of the traveling current wave can be determined by determining which one first received the electromagnetic waves emitted by the traveling current wave propagating from the fault point.
In other words, the direction of the accident point can be detected. The direction of the fault point can be detected every time the power applying device (2) applies a high voltage pulse intermittently.

As mentioned above, a car (7) equipped with antennas (4K), (4B, L and a receiver (8)) runs from all energizing points (2) along the overhead distribution system while detecting the direction of the accident point. if.

The antenna that receives the TM waves first is the antenna (4A
) to the antenna (4B), it becomes possible to search for ground fault point B.

Next, the operation of the noise signal detection means σe in the receiving device (8) of FIG. 2 will be explained. FIG. 3 is a time chart at the input and output terminals of the noise signal detection means tLfi in FIG.
B) shows the case where a noise signal is input.

Note that noise signals include very short noises such as Q, 1 ms at the output stage of loop antennas (4A) and (4B).
There are various types of noise, such as the following, persistent noise that lasts for a long time, and noise that intermittent in short cycles. A case where noise detection is performed regarding intermittent noise (for example, one that occurs intermittently with a period of less than 0.5 ms) is shown as gold.

When the normal signal shown in Fig. 3 (A) is input to the noise signal detection means αe, that is, the loop antenna (4 to 4 shown in Fig. 3 (A)) receives the electromagnetic waves emitted from the distribution line.
When the full signal shown in Ao is output, the monostable multivibrator (16A) is activated by inputting the signal shown in Figure 3 (A) AI output from the absolute value circuit (9A) to terminal B. , H-rigged, terminal Q
As shown at 210s in FIG. 3(A), a predetermined time Tf(
For example, 0.5 ms) long time pulse signal Ti
(For example, 0.6 ms) 'z High output, the output signal from terminal Q is input to terminal B of monostable multivibrator aD.

The monostable multivibrator αD is triggered by the rising edge υ of the input pulse signal, and the third capacitor (
b) A predetermined time width Tc as shown in c4 (for example, 1 m)
s), and this pulse signal is input to terminal A of the monostable multivibrator 0&. The monostable multivibrator αυ is activated by the falling edge of the input signal for a predetermined time period T as shown in Fig. 3 from the terminal Q.
r pulse signal is output, and this output pulse signal is AND
Circuit element σ■.

(branch) respectively.

A low level pulse signal is input from the terminal Q of the monostable multivibrator (16k) to the other input terminal of the AND circuit element (■), but in the case of a regular signal input, the time width T1 of this output pulse is as above. Monostable multivibrator (because it is shorter than the output pulse width Tc of 17+,
The AND circuit element outputs the same signal as the output pulse signal of the monostable multivibrator α, as shown in FIG. 308. This signal is an output signal corresponding to the regular input signal and is inputted to the clock terminal T of the D-Noritsubu flop circuit element (15AJ, (15B)), and the D-flip-flop circuit element (15A),
(15B) is moved by f'Il+. A high level signal from the terminal Q of the monostable multivibrator (16A) is input to the other input terminal of the NAND circuit element α, but, contrary to the case of the AND circuit element
There is no output from the ND circuit element 119 as shown in FIG. 3 C6, therefore the monostable multivibrator C11 does not operate, and the noise signal indicator 2 does not light up as shown in FIG. 2 07.

In addition, when a noise signal shown in Fig. 3 is input, that is, a loop antenna (4A
) outputs a signal as shown in Figure 3 (B) Ao, the monostable multivibrator (16A) with retrigger function, which is retriggered every time the input signal rises, outputs a signal as shown in Figure 3 (B) Ao. It is triggered by the rise of the first wave of the output signal of the absolute value circuit (9A) as shown in FIG. From terminal Q and terminal Q, respectively, as shown in Figure 3 (b) C2# C5, from the input signal time r width (1 ms or more) to a predetermined time (for example, 0.5 ms)
) Long time pulse signal Ti (for example, 1.5 ms
above) Full output. AND circuit element t19. 3 (b) C after a predetermined time Tc from the monostable multivibrator σg in the same way as when a regular signal is input.
A pulse signal having a time width 'rr as shown in FIG. 5 is input, but at the time when this pulse signal is input.

The AND circuit element α9 outputs a noise detection signal which is the same as the output pulse signal of the monostable multivibrator αEnoki as shown in C6 of FIG. 3(B). By inputting this signal, a pulse signal with a time width as shown in FIG. 3 (b) C7 is output from the monostable multivibrator Q11,
When this signal is input, the noise signal indicator (■) lights up for an arbitrarily settable time Tn.

Show noise input. On the other hand, the above AND circuit element (2
On the contrary to CO child +11, from the AND circuit element tile, Figure 3 (b)
As shown in cB, the normal input detection signal is not output.

Next, the operation of the receiving device (8) shown in FIG. 2 will be explained with reference to FIG. 4. Figure 4 shows the input terminal An of the receiver @t81.

A time chart at the input/output terminals of each circuit block from BQ to signal indicators (13A) and (13B) is shown for the case where a regular signal is input. here.

Assuming that the electromagnetic wave emitted by the traveling current wave from the fault point on the distribution line is received by the loop antenna (France) earlier than the loop antenna (with a time difference of ta (for example, 10 ers)), 4A), (4B
) signal input to the inverter (12A), (12B
) The operation of each circuit block up to the signal output is the same as the conventional one shown in FIG.
, (4B) and the time difference signal output means (9) The output signals of the absolute value circuits (9A) and (qB) that all constitute the time difference signal output means (9) are as shown in Figure 4. Monostable multivibrator (10, AJ, (10B) and NAN comprising TD metal and signal time difference amplification means aG)
The output signals of the D circuit elements (11A) and (11B) are as shown in FIG.
) is expanded to a time difference of Td at the output stage. The output signals of the NAND circuit elements (11A) and (IIB) are inverted by the inverters (12A) and (12B), and the signals shown in FIG. (15
A).

It is input to the terminal (15B). The time width Td (for example, 10 ms) of the output pulse signal of the monostable multivibrator (10A) l (10B) is set longer than the time length Tc of the output pulse signal of the monostable multivibrator αη of the noise signal detection circuit. Because I do.

The D-flip-flop circuit element (1) is activated by the output signal corresponding to the normal input as shown in FIG.
At the time when 5A) and (15B) are triggered, only this D-flip-flop circuit element (15A) has a high level signal input to its input terminal, so this input signal is fully held and the terminal Q A continuous signal as shown in Fig. 4 A5 is outputted from the signal display (13A, )'
i Lights up to indicate the direction of the accident point.

The above D-flip-flop circuit element (15A,),
(Even if a new signal is input to the terminal, the output state from terminal Q of 15B will not change unless there is a change in the rising edge of the new input signal to terminal T, and as shown in Figure 4, 09) From the reset switch @ at the time 're.

This will continue until the terminal 5 reset signal is input.

Next, when the loop antennas (4A) and (4B) receive a persistent noise signal (for example, one that lasts for 1 ms or more), the above-mentioned normal signal input is but when a noise signal is input.

As already mentioned, the D-flip-flop circuit element (1
Since no signal is input to the clock terminal T of (5A) and (15B), this D-flip-flop circuit element (1
5A) and (15s) are not triggered, the output state at that time will not change if it is before reset, and will not be output after reset. Therefore, the signal indicator (13A),
(13B) will not be displayed incorrectly.

In addition, if an intermittent noise signal is input with a short period, for example, if pulse noise No. .

Since a single pulse signal is output by adding the predetermined time T to the total length of the intermittent noise signal, the time length T1 of this pulse signal is longer than the output pulse time length of the monostable multi-byte break a71. If it's long.

All signals corresponding to the noise signal are output from the AND circuit element ti. That is, the signal indicator (13A) operates in the same way as when the above-mentioned persistent noise signal is input.

(13BJ will not display incorrect information.

Figure 5 shows another embodiment, in which the loop antenna (4) is installed so that the normal direction of its antenna surface is perpendicular to the traveling direction of the car (7) on which it is mounted and parallel to the ground. Consists of one antenna.

The time difference signal output means (9) includes an inverting amplifier (24A) that amplifies and outputs the output signal of the loop antenna (41) and outputs the signal after amplifying and inverting the polarity, and the output signal of this inverting amplifier (24A) has all the polarities inverted amplifying means (2) consisting of an inverting amplifier (24B) for outputting the signal; and the above-mentioned inverting amplifier (24A).

This embodiment differs from the embodiment shown in FIG. 2 in that it is constructed with a pair of half-wave rectifying means (26A) and (26B) for half-wave rectifying the output signal of (24B) and outputting the resultant signal.

In the embodiment of FIG. 5, from the fault point (31 to the overhead power distribution 1
(lli) When the electromagnetic waves emitted by the propagating current traveling wave are received by the loop antenna (4), the polarity of the first wave of the output voltage of the loop antenna (41) is added to the traveling direction of the current traveling wave. The time difference signal output means (9) is connected to the loop antenna 14.
) is input, the direction of the fault point is determined from the polarity of the first wave of this input signal, and of the two signals with a time difference, the signal corresponding to the direction of the fault point of the overhead distribution line is output first. do. That is, the amplification means (to) inputs the output signal of the loop antenna (4), outputs two signals with different polarities, and converts these signals to the half-wave rectification means (26A).
This method takes advantage of the fact that by half-wave rectifying and outputting each of (2+SB), a time difference of 1A, which is the period of the output signal of the loop antenna (4), inevitably occurs between these two output signals. So, the above loop antenna (4
) If the polarity of the -th wave of the output signal of ) is negative, the time difference signal is outputted from the half-wave rectifying means (26A), and vice versa, if it is positive, the time difference signal is outputted earlier than the half-wave rectifying means (26B). .

Therefore, this receiving device (8) also operates in the same manner as the embodiment shown in FIG. 2, and the same effects can be obtained.

Moreover, FIG. 6 shows yet another embodiment.

As in the embodiment shown in FIG. 5, all fault point directions of the overhead IwL line (11) are determined based on the polarity of the first wave of the output voltage of the loop antenna (4), but the zero time difference signal output means (9
) Width increasing means c! of the embodiment shown in FIG. The difference from the embodiment shown in FIG. 5 is that the inverting amplifier (24B) of No. 4 is provided with a time difference amplifying means (lGi) as follows. That is, the signal time difference in this embodiment is Expansion means a value is.

A pair of D-flip-flop circuit elements (27A) connected to each output terminal to the input terminal of the other.

(27B) and this D-flip-flop pixel element (2
7A), (27B) A monostable multivibrator that outputs a pulse signal triggered by the rising edge of the output pulse signal of the monostable multivibrator (16A). (to), an OR circuit element (2) which inputs the output pulse signals of both this monostable multivibrator Kanji and the monostable multivibrator αG, and the falling edge of the trailing edge of the output signal of this OR circuit element. It consists of a monostable multivibrator (to) that outputs a pulse signal.

The entire operation of the receiving device (8) in FIG. 6 will be explained according to the time chart in FIG. 7.

First, the operation in the case of normal signal input as shown in Fig. 7 (A) will be explained.
According to the signal output as shown in Ao, the amplification means CI'
The inverting amplifier (24k) and the non-inverting amplifier (2) comprising the 41'i output amplified signals with different polarities as shown in Fig. 7(a) A, , and B1, and the half-wave rectifying means (
2, half-wave rectification and waveform shaping are performed at (26B), and the particular output signal shown in FIG.
B) are respectively input to clock terminals T. but,
The output signals of the half-wave rectifying means (26A) and (26B) are connected to the antenna (41) with a time difference of 1A between the periods of the output signals.
Since the signal of the half-wave rectifier (26A) corresponding to the direction of the accident point is output first at a2, Fig. 7 (a) A4,
As shown in B4<D-flip-flop circuit element (27
Only AJ self-retains and outputs the first-arrival signal, and the subsequent D-
As well as being input to the terminal of the flip-flop circuit element (15A).

The other circuit element (27B) is all interlocked to block output from this circuit element (27B). Above mentioned flip-flop circuit elements (15A), (15B)
is the same as the embodiment shown in FIG.
In synchronization with the signal output of A), after a predetermined time Tc, the AND circuit element of the noise signal detection circuit aS is activated by the input signal shown in FIG.

As shown in FIG. 7(a) A5 and B5, all input signals at the terminals are held and output. On the other hand, a monostable multivibrator (to) is a monostable multivibrator (16
The output pulse signals of A and l are input, and triggered by the rising edge of the leading edge of this pulse signal, a predetermined time width T? A pulse signal like C1o in FIG. 7(a) is inputted to the monostable multivibrator (to) via the OR circuit element (g). Monostable multivibrator (to)
is retriggered by the falling edge of the trailing edge of this input pulse signal, and outputs a signal as shown in FIG. 7(a) C11, and the D
- It is input to each reset terminal R of the flip-flop circuit elements (27A) and (27B), and this circuit element (
27A), (27B) 'I reset.

Note that the output pulse signal of the monostable multivibrator (16A) is also input to the above example of the OR circuit element, but the time width T1 of this pulse signal is the same as that of the monostable multivibrator (c) in the case of a regular input signal. Since it is shorter than Tf in the output pulse signal of , it is ignored.

It was a cabinet. The time width Tf of the pulse signal is set longer than the predetermined time width Tc of the output pulse of the monostable multivibrator αD before resetting the D-flip-flop circuit elements (27A) and (27B).

The above D-flip-flop circuit element (15A), (
15B,) is activated (seratono).

The operation in the case of a noise signal input shown by the arrow and the mouth in FIG.
, (27B) is the same as in the case of normal signal input as shown in FIG.

However, in the case of a noise signal input, for the same reason as in the embodiment shown in FIG.
Since the signal output of the circuit element mill is not outputted as shown in Figure T, extension No. C8, the D-flipflop circuit elements (15A) and (15B) do not operate, and the signals in Figure 1 (B) A5 and B5 do not operate. No signal is output as shown.

On the other hand, when a noise signal is input, the time length T1 of the output pulse signal of the monostable multivibrator (16A) is often larger than the time width Tt of the output pulse signal of the monostable multivibrator 2, and in this case, The D-flip-flop circuit elements (27A) and (27B) are reset after a time Ti that is a predetermined time longer than the time width of the noise signal.

That is, in this embodiment, the timing for resetting the D-flip-flop circuit elements (27A) and (27B), which fully hold and output the first-arriving signal and completely block the output of the second-arriving signal, is the same as that of the regular input signal. In this case, the D-flip-flop circuit elements (15A) and (15B) in the subsequent stage are set and the output signal of the circuit element (27A) or (27B) is self-held and output after a predetermined period of time.

In the case of noise signal input, this occurs a predetermined time after the input of the noise signal ends.

Furthermore, in the signal time difference expanding means σG and signal fixing means α$ in the embodiment shown in FIG. It is clear that a similar effect can be obtained by using a flip-flop circuit element for J-. In addition, when using a negative edge trigger type one-type D type or J- type flip-flop circuit element in the embodiment shown in FIG. A similar effect can be obtained by inserting an inverter.

Furthermore, the amplifying means C consisting of the inverting amplifier (24A) and the non-inverting amplifier (24A) shown in FIG. 6 can be used in place of the amplifying means Q4 of the embodiment shown in FIG. Conversely, the same result can be obtained even if the amplifying means 34 consisting of the two inverting amplifiers (24A) and (24B) shown in the fifth factor is used in place of the amplifying means (c) shown in FIG. It is clear that the effect can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the noise signal detecting means completely determines whether the input signal received by the antenna is a regular signal or a noise signal, and if the signal is a regular signal, a corresponding signal is output and the signal is output. The fixing means is triggered, and at that point, it self-holds and outputs the first signal indicating the direction of the accident point inputted from the signal time difference expansion means in the previous stage, but if it is a noise signal, it is output as a corresponding signal, i.e., noise. In addition to outputting all of the detection signals, the trigger signal of the signal fixing means is not output in full and this signal fixing means is configured to be inoperative, so that it is possible to prevent incorrect display of the device due to the input of noise signals, and also to prevent all of the input of noise signals. It has the effect of detecting a monkey.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram illustrating the concept of a receiving device for accident point exploration according to the present invention, and FIG. 2 is a block diagram showing an embodiment of the receiving device for accident point exploration according to the present invention. 3 and 4 are time charts showing the operation of the input and output terminals of the receiving device shown in FIG. 2, and FIGS. 5 and 6 are respectively showing different embodiments of the receiving device for fault point investigation. FIG. 7 is a time chart showing the operation of the input and output terminals of the receiving device shown in FIG. 6, and FIG. 8 is a block diagram showing the entire conventional receiving device. In the figure, (1) is the overhead distribution line, (2) is the high voltage pulse application means (power charging device), +31 is the ground fault equipment,
14+. (4A, 3, (4B) is a loop antenna, (8) is a receiving device. (9) is a time difference signal output means, σO is a signal time difference expansion means, (L9 is a signal fixing means, and 1η is a noise signal detection means. In Figure 9, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An antenna that receives electromagnetic waves emitted by current traveling waves from the fault point of the overhead distribution line, a time difference signal output means that outputs a time difference signal based on the output signal of this antenna, and a predetermined time difference between the output signals of the time difference signal output means. A signal time difference amplifying means for expanding and outputting a signal larger than the time difference of , inputs the output signal of the time difference signal output means, determines whether this input signal is noise or a normal signal, and corresponds to a signal corresponding to noise or a normal signal. a signal fixing means that is triggered by an output signal corresponding to the normal signal of the noise signal detection means and that self-holds and outputs the first-arrival signal outputted by the signal time difference expansion circuit. A receiving device for accident point exploration, characterized by comprising: (2) The noise signal detection means includes a first monostable multivibrator with a retrigger function that is triggered by a voltage change in the input signal and outputs a pulse signal for a predetermined time longer than the time length of the input signal; a second monostable multivibrator that outputs a pulse signal with a predetermined time width shorter than the time difference between the output signals of the signal time difference amplification means by a voltage change at the leading edge of the output pulse signal of the stable multivibrator or the signal time difference amplification means; a third monostable multivibrator that outputs a pulse signal based on a voltage change at the trailing edge of the output pulse signal of the second monostable multivibrator; a first AND circuit that inputs the output pulse signal of the stable multivibrator and outputs a signal corresponding to the noise input; an output pulse signal of the third monostable multivibrator; and an output of the first monostable multivibrator. A second AND that inputs an inverted signal of the pulse signal and outputs a signal corresponding to the normal signal.
2. A receiving device for accident point exploration according to claim 1, comprising a circuit.