KR101865295B1

KR101865295B1 - Apparatus for detecting cable failure place

Info

Publication number: KR101865295B1
Application number: KR1020170053791A
Authority: KR
Inventors: 김경수; 이범구
Original assignee: 김경수
Priority date: 2017-04-26
Filing date: 2017-04-26
Publication date: 2018-06-07

Abstract

According to an embodiment of the present invention, there is provided a signal processing apparatus comprising: a detection signal generating unit generating a detection signal to be injected into a cable; A detection signal injection unit connected to the detection node of the cable for injecting the detection signal generated by the detection signal generation unit without interrupting the power of the cable; A defect direction determining signal injecting unit injecting a defect direction determining signal different from the detecting signal to a point of a sub node spaced apart in a left or right direction of the detecting node; A reflection signal receiving unit for receiving a reflection signal reflected from the merit of the cable; A reflection signal processing unit for removing noise from the received reflection signal and performing signal processing; And detecting a defect position distance by comparing the transmitted detection signal with the reflected signal reflected from the cable, and detecting the arrival time of the reflected signal due to the injection of the detection signal, And a defective position determination unit for determining a defective position direction by comparing the arrival time of the defective position.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cable fault location detecting apparatus,

The present invention relates to a cable fault location detecting device, and more particularly, to a cable fault location detecting device for detecting a fault location such as disconnection or short circuit of a cable.

Cable cabling systems are used in all fields ranging from military weapons systems such as air defense weapons systems and fighters to civilian industries such as buildings, factories, nuclear power, automobiles, ships, aircraft, have.

Defects (short circuit, contact failure, breakage, disconnection, etc.) of cable wiring system may cause important functions of military and civil electrical / electronic facilities to be lost or cause system malfunction, power outage, fire occurrence and information loss, It can cause enormous damage such as disruption and can threaten public safety.

According to the 2011 National Statistical of Electrical Disaster Statistics of the National Emergency Management Agency and the Korea Electrical Safety Corporation, the majority (20.6%) of electric fires are generated in wiring and wiring equipment, and 21.3% of electrical equipment accidents are related to cable wiring. The technology of detecting and locating cause and location more than cable early is playing an important role in preventing safety accident and reducing enormous damage. Therefore, it is necessary to detect the main cause of the cable fault and develop the technology for the location tracking technology, thereby preventing the accident.

In the prior art, there are a sound detection method for measuring an ultrasonic wave or an audible frequency region by discharging in case of a cable fault, an insulation resistance measurement method for measuring a leakage current by converting the insulation value by supplying DC power in a power failure state Various cable fault diagnosis and position detection techniques such as a partial discharge measurement method for measuring a discharge phenomenon of a defect are used.

However, most of the conventional techniques have been conducted after the cable is disconnected, so that there is a fear of interruption of facility operation, cable damage, initial failure or intermittent fault detection, maintenance time and cost It took a lot of time.

The present applicant has proposed a cable fault position detection apparatus 10 and a system (hereinafter, referred to as " system ") that can be applied in an uninterrupted state in which a specific transmission signal is inserted into a cable in an uninterrupted state, Korean Patent No. 10-1516403).

In Korean Patent No. 10-1516403, a detection signal is generated and transmitted to a cable for detecting a cable defect position, and a defective point is detected by receiving a signal reflected therefrom.

However, as shown in FIG. 1, a detection signal transmitted for detecting a cable fault position is branched at a branch point and transmitted in a left direction and a right direction. If a reflected signal reflected at a defect point on the cable is received as shown in FIG. 2 There is a problem that it is unknown whether the position of the defect point exists on the left side of the bifurcation point or on the right side of the bifurcation point based on the bifurcation point.

In order to solve such a problem, the present applicant has implemented a filter having a branch point as shown in Fig. 3 and branching the detection signal from the left and right of the filter to transmit the detected defect position (see Patent Document 10-1602407 ).

However, in this case, there is an inconvenience that a filter must be buried separately in the cable, and there is a problem of an increase in the detection cost.

Korean Patent No. 10-1516403

SUMMARY OF THE INVENTION It is an object of the present invention to provide a means for detecting a cable fault location using a single detection signal.

The injection of the detection signal and the injection of the defect direction judgment signal can be performed with a time difference.

When the arrival time of the reflection signal due to the detection signal injection due to the defect of the cable is faster than the arrival time of the reflection signal due to the defect direction determination signal injection, the defect position determination unit determines that the sub- The direction in which the defect is located can be grasped as the defect position direction.

When the arrival time of the reflected signal due to the defect of the cable is faster than the arrival time of the reflected signal due to the defect direction determination signal injection, when the sub node is located in the left direction of the detection node, If the arrival time of the reflection signal due to the insertion of the detection signal due to the defect of the cable is slower than the arrival time of the reflection signal due to the injection of the defect direction determination signal, the defect position direction can be determined as the left direction.

When the arrival time of the reflected signal due to the defect of the cable is higher than the arrival time of the reflected signal due to the defect direction determination signal injection, If the arrival time of the reflection signal due to the insertion of the detection signal due to the defect of the cable is slower than the arrival time of the reflection signal due to the injection of the defect direction determination signal, the defect position direction can be determined as the right direction.

And the defect direction determination signal has the same signal form as the detection signal.

The reflection signal processing unit includes a noise removing filter for removing noise included in the reflected signal, an amplifier for amplifying the output, and an analog-to-digital converter for converting the analog signal into a digital signal.

According to the embodiment of the present invention, even if a detection signal is injected into any one point of the cable, the direction can be accurately detected in addition to the distance of the defect position on the basis of the injection point of the detection signal.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a cable fault position detector according to the prior art;
2 is a diagram showing a reflected signal reflected at a defect point on a cable;
3 shows a cable fault position detector according to the prior art;
Figs. 4 and 5 are conceptual diagrams for explaining a defect position detection principle of a cable fault position detection apparatus with improved transmission pulse signal distortion. Fig.
6 is a block diagram of a configuration of a cable fault location detecting apparatus according to an embodiment of the present invention;
FIG. 7 is a diagram showing a state in which a defect direction judgment signal is injected into a cable from the left side of a detection node in addition to a detection signal according to an embodiment of the present invention. FIG.
FIG. 8 is a diagram showing a state in which a defect direction judgment signal other than a detection signal is injected into a cable from the right side of a detection node according to an embodiment of the present invention. FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to achieve them, will be apparent from the following detailed description of embodiments thereof taken in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. And the present invention is only defined by the scope of the claims. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Figs. 4 and 5 are conceptual diagrams for explaining a defect position detection principle of the cable fault position detection device 10 with improved transmission pulse signal distortion. Fig.

The basic principle of the laser is used to detect the defect position (cable cutting position, etc.) of the cable. As shown in Fig. 4, the distance R = (C x t) / 2 to the target can be obtained. R is the target distance, C is the speed of light (3 × 10 ⁸ m / s), and t is the round trip time. Referring to FIG. 5, when the signal is reflected from the defect position and the reflection time is analyzed, the position of the defect position is detected . For example, as shown in FIG. 5, when the received reflection signal has the same form as the transmitted pulse signal, it is determined that the defect position is open circuit. Further, when the received reflection signal has a reverse form of the transmitted pulse signal, it is determined that the defect position is short-circuited.

The cable serves to supply a power signal or a communication signal and is installed in the ground. In the case of this embodiment, a cable for supplying electric power to the street lamp is described as an example, and the power line may be generally 220 V of 60 Hz or the like.

The load connected to the cable is not limited to the street lamp, but may be a variety of loads, for example, power cables used in military weapons systems (missile weapons systems, fighters, submarines, etc.) and civilian (power, aircraft, . That is, the cable can be implemented as a power / signal complex type cable that is responsible for communication besides power. Communication lines can be largely divided into analog and digital communication. Analog communication has various frequencies and signal levels. Digital communication, baud rate, signal level and protocol can be used in various ways. Hereinafter, the frequency of the electric power operated by the cable and the frequency of the communication are referred to as the operating frequency.

On the other hand, a detection signal transmitted for cable fault position detection is branched at the branch point and transmitted in the left direction and the right direction. If a reflection signal reflected from a defect point on the cable is received, There is a problem that it exists on the left side of the fork or on the right side of the fork.

In order to solve the problem of the direction information of such a defect point, the cable defect position detecting apparatus 10 of the present invention further injects a defect direction judgment signal in addition to the detection signal injection as shown in FIG. 6 to 8 will be described below in detail.

FIG. 6 is a block diagram of a cable fault location detecting apparatus 10 according to an embodiment of the present invention. FIG. 7 is a block diagram of a cable fault location detecting apparatus 10 according to an embodiment of the present invention. FIG. 8 is a diagram illustrating a state in which a defect direction determination signal in addition to a detection signal is injected into a cable from the right side of a detection node according to an embodiment of the present invention

6, the cable defect position detecting apparatus 10 using the single detection signal of the present invention includes a detection signal generating unit 110, a detection signal injecting unit 120, a defect direction determining signal injecting unit 130, A reflection signal receiving unit 140, a reflection signal processing unit 150, and a defect position determination unit 160. [

The detection signal generation unit 110 performs a function of generating various detection signals injected into the cable. The detection signal generator includes a frequency determination module (not shown) for determining the frequency of the detection signal, a waveform generator for generating a detection signal having a frequency inputted through the frequency determination module, A digital-to-analog converter for converting the input signal, and an output variable amplification module (not shown) for amplifying the converted signal. For reference, in the drawings of the embodiment of the present invention, a square wave is exemplified as an example of a detection signal, but it will be obvious that various pulse signals such as a triangle wave may be applicable instead of a square wave.

The detection signal injection unit 120 transmits the detection signal generated by the detection signal generation unit 110. [ The detection signal injecting unit 120 is connected to a cable and performs a function of injecting a detection signal generated by the detection signal generating unit 110 into the cable in a state in which the power of the cable is not cut off, that is, in an uninterrupted state. For example, an inductive coupler may be used as the uninterruptible signal injection unit. Therefore, the detection signal injection unit 120 of the present invention is connected to the detection node N of the cable, and transmits the detection signal generated by the detection signal generation unit 110 to the detection node N ) In an uninterrupted state.

The defect direction determination signal injection unit 130 injects a defect direction determination signal distinguishable from the detection signal to a point of the sub node S spaced apart in either the left or right direction of the main node. So that the injection of the detection signal and the injection of the defect direction judgment signal are injected with a time difference. It is preferable that the defect direction determination signal has the same signal form as the detection signal. The defect direction determination signal and the detection signal must have the same signal intensity and signal shape so that the influence of other variables can be minimized when determining the defect location direction according to the arrival time comparison of the reflection time.

7, the sub node S to which the defect direction determination signal is injected may be located on the left side of the detection node N, or the sub node S to which the defect direction determination signal is injected, And may be located on the left side of the detection node N as shown in Fig.

The reflection signal receiving unit 140 receives the reflection signal of the detection signal reflected from the defect point of the cable in accordance with the injection of the detection signal. And receives a reflection signal of a defect direction judgment signal reflected from a defect point of the cable in accordance with injection of the defect direction judgment signal.

The reflection signal processing unit 150 performs a function of removing noise and performing signal processing on the received reflection signal. The reflection signal processing unit 150 includes a noise removing filter for removing noise included in the reflected signal, an amplifier for amplifying the output, and an analog-to-digital converter for converting the analog signal into a digital signal.

The defect position determination unit 160 compares the detection signal transmitted and injected into the cable with the reflection signal reflected from the defect point of the cable to determine the defect position distance. And performs a function of determining a defect position by comparing a transmitted detection signal with a reflection signal reflected from a defect point of the cable. The time difference between the transmitted detection signal and the reflected signal is measured, and the distance to the defect point is measured. For example, when a detection signal is transmitted as a detection signal, a type of a defect of the cable can be grasped by using a form of a reflection signal that is reflected and received by the pulse signal. This is because the shape of the reflected signal differs depending on the kind of defect. For example, as shown in FIG. 5, when the received reflection signal has the same form as the transmitted pulse signal, it is determined that the defect position is open circuit. Further, when the received reflection signal has a reverse form of the transmitted pulse signal, it is determined that the defect position is short-circuited.

In addition, the defect position determination unit 160 of the present invention compares the arrival time of the reflection signal due to the detection signal injection and the arrival time of the reflection signal according to the defect direction determination signal injection to grasp the defect position direction.

When the arrival time of the reflection signal due to the detection signal injection due to the defect of the cable is faster than the arrival time of the reflection signal due to the injection of the defect direction judgment signal, the defect position judgment unit 160 judges, The direction in which the sub node S of the cable to which the cable 130 is connected is located in the defect position direction.

As shown in FIG. 6, when the sub node S is located on the left side of the main node, the arrival time of the reflected signal due to the detection signal injection due to the defect of the cable is smaller than the arrival time of the reflected signal If it is earlier than the arrival time, the defect position direction is determined as the rightward direction. Also, when the arrival time of the reflection signal due to the detection signal injection due to the defect of the cable is slower than the arrival time of the reflection signal due to the defect direction judgment signal injection, the defect position direction is determined as the leftward direction.

As shown in FIG. 7, when the sub node S is located on the right side of the main node, the arrival time of the reflected signal due to the detection signal injection due to the defect of the cable is smaller than the arrival time of the reflected signal If it is earlier than the arrival time, the defective position direction is determined to be the leftward direction. Further, when the arrival time of the reflection signal due to the detection signal injection due to the defect of the cable is slower than the arrival time of the reflection signal due to the defect direction judgment signal injection, the defect position direction is determined as the right direction.

Therefore, even if a detection signal is injected into any one point of the cable, it is possible to accurately detect the direction in addition to the distance of the defect position based on the injection point of the detection signal.

The embodiments of the present invention described above are selected and presented in order to assist those of ordinary skill in the art from among various possible examples. The technical idea of the present invention is not necessarily limited to or limited to these embodiments Various changes, modifications, and other equivalent embodiments are possible without departing from the spirit of the present invention.

110:
120: detection signal injection unit
130: Defect direction determination signal injection unit
140: reflection signal receiver
150: reflection signal processing unit
160: Defect position determination unit

Claims

A detection signal generator for generating a detection signal injected into the cable;
A detection signal injection unit connected to the detection node of the cable for injecting the detection signal generated by the detection signal generation unit without interrupting the power of the cable;
A defect direction determining signal injecting unit injecting a defect direction determining signal different from the detecting signal to a point of a sub node spaced apart in a left or right direction of the detecting node;
A reflection signal receiving unit for receiving a reflection signal reflected from the merit of the cable;
A reflection signal processing unit for removing noise from the received reflection signal and performing signal processing; And
The defect location distance is determined by comparing the transmitted detection signal with the reflected signal reflected from the cable, and the arrival time of the reflection signal due to the detection signal injection and the arrival time of the reflection signal due to the defect direction determination signal injection And a defective position determining unit for determining a defective position direction by comparing the arrival times,
The defect location determination unit may determine,
When the arrival time of the reflection signal due to the defect of the cable is shorter than the arrival time of the reflection signal due to the defect direction determination signal injection, And detecting a cable defect position using the single detection signal.

The method according to claim 1,
Wherein the detection signal is injected and the injection of the defect direction judgment signal is injected with a time difference.

The method according to claim 1,
When the arrival time of the reflected signal due to the defect of the cable is faster than the arrival time of the reflected signal due to the defect direction determination signal injection, when the sub node is located in the left direction of the detection node, If the arrival time of the reflected signal due to the injection of the detection signal due to the defect of the cable is slower than the arrival time of the reflected signal due to the injection of the defect direction judgment signal, the direction of the defect position is determined as the leftward direction, or
When the arrival time of the reflected signal due to the defect of the cable is higher than the arrival time of the reflected signal due to the defect direction determination signal injection, When the arrival time of the reflection signal due to the insertion of the detection signal due to the defect of the cable is slower than the arrival time of the reflection signal due to the injection of the defect direction judgment signal, the defect position direction is determined as the rightward direction The cable defect position detection device using the single detection signal.

The method according to claim 1,
Wherein the defect direction determination signal has the same signal form as the detection signal.

The method according to claim 1,
The reflection signal processing unit,
An amplifier for amplifying an output, and an analog-to-digital converter for converting an analog signal into a digital signal, characterized by comprising: a noise elimination filter for eliminating noise included in a reflection signal;