JP2008070301A - Method and device for detecting disconnection position of power supply cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disconnection position detecting method and device of a power supply cable capable of detecting a disconnection part without moving a sensor along an electric wire with a relatively easy circuit. <P>SOLUTION: In the disconnection position detecting method and device of a double-core electric wire where two insulated conducting wires are adjacently arranged, the electric capacitance value between two conducting wires is measured from one end of each conducting wire included in the electric wire, the electric capacitance value between two conducting wires is measured from the other end of each conducting wire, and the disconnection part is calculated using the ratio between the electric capacitance values measured from both ends as the ratio of the length of the disconnection part to the overall length of the double-core electric wire of each side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for detecting a disconnection position of a power cable and an apparatus used therefor.

  As a method for detecting the disconnection position of the electric wire, a method of detecting the disconnection position by moving the sensor along the cable and using the electrolytic strength that changes at the disconnection point (for example, Patent Document 1 to Patent Document 3 below). In this case, one end of the disconnected cable is grounded, a high-frequency voltage is applied to the other end, a reference AC voltage is applied to one end of the conductive wire, and a reference is applied to the other end of the conductive wire. There are various aspects of the input signal, such as a method in which an inverted AC voltage whose phase is shifted by 180 degrees from the AC voltage is applied.

  In addition, when a pulse signal is applied to the wire, the current flowing in the wire is measured, the current waveform is compared with the reference current waveform, and the measured current waveform rise time and the time when the waveform difference occurs Based on the time interval, there is a technique (for example, Patent Document 4 below) for determining the distance from the current measurement location to the location where the disconnection occurs.

Japanese Patent Laid-Open No. 6-66872 Japanese Patent Laid-Open No. 9-292432 Japanese Patent Laid-Open No. 11-44728 JP 2006-23105 A

  Any of the above disconnection detection methods can be used to detect disconnection points such as electric wires of household electrical appliances that are secured for practical use and extension cables that are used to supply power from locations away from various electrical appliances. Although it is a method to detect, the methods described in Patent Document 1 to Patent Document 3 all involve complicated work of moving the sensor along the extension cable. In the method described in Patent Document 4, a circuit for generating a pulse signal and a circuit for detecting a time interval are required.

  The present invention has been made in view of the above circumstances, and a disconnection position detection method and apparatus for a power cable capable of detecting a disconnection point without moving the sensor along the electric wire with a relatively easy circuit. The purpose is to provide.

  The disconnection position detection method for a two-core electric wire according to the present invention made to solve the above-mentioned problem is a disconnection position detection method for a two-core electric wire in which two insulated wires are adjacently arranged, The electrical capacitance value between the two conductors is measured from one end of each conductor contained in the electric wire, the electrical capacitance value between the two conductors is measured from the other end of each conductor, The disconnection location is calculated by using the ratio of the capacitance values as the ratio of the length to the total length of the two-core electric wires on each side with the disconnection location as a boundary.

  The disconnection position detecting method for a three-core electric wire according to the present invention is a method for detecting a disconnection position of a three-core electric wire in which three insulated wires are arranged adjacent to each other in an equilateral triangle shape, and the electric wire includes From each end of each conducting wire, the electrical capacitance value measured between the three types of conducting wire pairs is measured while measuring the electrical capacitance value between three different conducting wire pairs obtained by selecting a pair of conducting wires from among the three conducting wires. The ratio of the maximum value and the minimum value is calculated as the ratio of the length from the one end to the disconnection location with respect to the total length of the three-core electric wire, and the disconnection location is calculated.

  The disconnection position detection device for a two-core electric wire according to the present invention made to solve the above-mentioned problem is a disconnection position detection device for a two-core electric wire in which two insulated wires are adjacently arranged, A sensor probe connected to both ends of each conducting wire included in the electric wire, an oscillating unit in which a CR multivibrator is configured to include an electric capacitance component detected through these sensor probes, and an output of the oscillating unit from the two An electric capacity value calculating unit for calculating an electric capacity value between the two conductive wires, and a boundary ratio calculating unit for calculating and outputting a ratio of the electric capacity values between the two electric wires detected from both ends of the electric wire. It is characterized by things.

  The disconnection position detecting device for a three-core electric wire according to the present invention is a disconnection position detecting device for a three-core electric wire in which three phase-insulated conductors are arranged adjacent to each other in an equilateral triangle shape. The CR multivibrator includes a sensor probe connected to one end of each of three different types of conductor pairs selected from a pair of conductors among the three conductors, and a capacitance component detected through these sensor probes. A configured oscillating unit; an electric capacitance value calculating unit that calculates an electric capacitance value between the three types of conductor pairs from an output of the oscillating unit; and a maximum value and a minimum electric capacitance value measured between the three types of electric wire pairs. And a boundary ratio calculating unit that calculates and outputs a ratio to the value.

  According to the method for detecting a break position of an electric wire according to the present invention, a probe is connected to the end of the electric wire, for example, a terminal of an outlet or a plug, or an unprocessed start / end portion, along a wire with a relatively easy circuit. The disconnection location can be detected without moving the sensor. And even if it is in the apparatus, it can be made comparatively small and low-cost.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an electric wire break position detection method according to the present invention will be described below in detail with reference to the drawings together with an embodiment of an electric wire break position detection apparatus (hereinafter referred to as a position detection apparatus) used therefor.

  The position detection device shown in FIG. 1 is a disconnection position detection device (first embodiment) for a two-core electric wire 2 in which two insulated wires 1 and 1 are arranged adjacent to each other. A sensor probe 3 connected to both ends of each of the conducting wires 1 and 1 included in the electric wire 2; an oscillating unit 5 in which a CR multivibrator 4 is configured so as to include a capacitance component detected through the sensor probe 3; An electric capacitance value calculation unit 6 that calculates an electric capacitance value between the two conductors 1 and 1 from the output of the oscillation unit 5, and an electric capacitance between the two conductors 1 and 1 detected from both ends of the electric wire 2. A boundary ratio calculation unit 7 that calculates and outputs a ratio of values is provided.

  The sensor probe 3 in this example is provided in pairs for each end so as to detect an electric capacitance value from each end of an electric wire (hereinafter, referred to as a test electric wire 2) which is a detection target of disconnection (each It is also possible to adopt a form in which a pair of the two are grouped together and divided into two forks at the tip. Each sensor probe 3 is provided with an electrode 8 for electrical connection with the end of the conducting wire 1 included in the electric wire 2. The electrode 8 includes a needle shape (see FIGS. 1 and 2) inserted into both ends of each of the conductive wires 1 and 1 included in the test electric wire 2 or a terminal of a receptacle having a clamping function, or a terminal protruding from a plug. It is provided in a clip shape (a shape such as a so-called crocodile clip or a clip in a form in which a U-shaped hook portion sandwiches a conductive wire) or a shape that combines them.

  The CR multivibrator 4 constituting the oscillating unit 5 includes a capacitance component between the two conductors 1 and 1 constituting the test wire 2 as a capacitor for determining the time constant of the circuit (FIG. 1 (B ) And the symbol of the capacitor in FIG. 2B) to output a square wave. The circuit configuration may be appropriately designed according to the specifications of the test electric wire 2, but in practice, the two conductors 1 included in the test electric wire 2 having a length in the range of about 50 cm to several tens of meters. It is desirable to select a time constant that can detect a change in the disconnection position of about 5 cm to about 50 cm with a change in the output frequency with respect to the change in the capacitance component in the capacitance component over the entire length of 1.

  The electric capacity value calculation unit 6 counts the number of waves per unit time output from the oscillation unit 5 and derives the frequency f or the period T. In the CR multivibrator 4, the capacitance component included therein as a capacitor is proportional to the oscillation period T. Therefore, the derived cycle T can be regarded as the capacitance value equivalent to the capacitance component. .

  The boundary ratio calculation unit 7 is configured so that each of the test electric wires 2 obtained through the sensor probes 3 provided in pairs for each end in order to detect the capacitance value from each end of the electric test wire 2. The ratio of the electric capacity value from the end is output. When the length of the test electric wire 2 is known, the length from one end to the disconnection position can be calculated by inputting the length and multiplying the obtained ratio.

  In this example, a pair of the sensor probes 3 is provided for each end of the electric wire 2 to be tested, and each pair of sensor probes 3 (sensor probe pairs) includes a CR multivibrator 4. However, only one pair of the sensor probes is provided, the capacitance value is sequentially measured at each end, and the storage unit 9 that holds the capacitance value obtained in the previous and subsequent measurement is provided, and the electric recording recorded in the storage unit 9 is provided. A configuration that outputs a ratio of capacitance values is also possible. Further, even when two pairs of sensor probes 3 are provided, each sensor probe pair is configured by a single CR multivibrator without the CR multivibrator 4, and a terminal for connecting capacitance components of the CR multivibrator. A method may be adopted in which the sensor probe 3 connected to is switched by a switch for each sensor probe pair.

  According to the position detection apparatus having the above-described configuration, the electrical capacitance value between the two conductors 1 and 1 is measured from one end of each conductor 1 and 1 included in the test electric wire 2 and each conductor 1 and 1 is measured. The electrical capacitance value between the two conducting wires 1 and 1 is measured from the other end of the wire, and the ratio of the electrical capacitance values measured from both ends is determined to be a two-core electric wire on each side with the broken wire as the boundary (test wire 2) Thus, it is possible to implement a method for detecting a broken position of an electric wire by calculating the broken portion as a ratio of the length to the total length of the wire.

  The example shown in FIG. 2 is a three-core electric wire (test object) formed by arranging three phase-insulated conductors 1, 1, 1 adjacent to each other in a regular triangle shape (constant spacing between adjacent conductors). A position detecting device (second embodiment) of the electric wire 2), wherein a pair of conducting wires 1, 1 are selected from among the three conducting wires 1, 1, 1 included in the electric wire 2 to be tested. A sensor probe 3 having an electrode 8 for electrical connection to one end of each of three different types of conducting wire pairs, and a CR multivibrator 4 is configured so as to include capacitance components detected through these sensor probes 3 The oscillating unit 5, the capacitance value calculating unit 6 that calculates the capacitance between the three types of conductor pairs from the output of the oscillating unit 5, and the maximum value of the capacitance value measured between the three types of conductor pairs A boundary ratio calculation unit 7 that calculates and outputs a ratio to the minimum value is provided.

  In the example, two or three sensor probes 3 are provided to detect the capacitance value from the end of the electric wire 2 to be tested (the two or three are grouped together and bifurcated at the tip or It may be divided into three parts.) Each sensor probe 3 is provided with an electrode 8 for electrically connecting to the end of the conducting wire 1 included in the electric wire 2 to be tested. As in the first embodiment, the electrode 8 has a needle shape inserted into both ends of each of the conducting wires 1, 1, 1 contained in the electric wire 2 to be tested, or a terminal of an outlet having a clamping function, or a plug It is provided in the shape of a clip that holds the protruding terminal or a shape that combines them.

  The CR multivibrator 4 constituting the oscillating unit 5 uses the capacitance component obtained from one end of each of the three types of conductor pairs consisting of the three conductors 1, 1, 1 constituting the test electric wire 2 at the time of the circuit. A square wave is output as a capacitor for determining a constant. The points to be noted when configuring the circuit are the same as those of the CR multivibrator 4 in the first embodiment described above, and the aspect of the capacitance value calculation unit 6 is also described in the first embodiment. This is the same as the electric capacity value calculation unit 6 in FIG.

  When the three sensor probes 3 are provided, the boundary ratio calculation unit 7 includes one end of each of three types of conductor pairs (three conductors 1, 1, 1) constituting the test electric wire 2 ( A storage unit that sequentially measures electric capacitance values obtained from each of the sensor probes 3, 3, and 3 from an end serving as a reference for measurement (hereinafter referred to as a measurement end) and holds the electric capacitance value obtained in the measurement. 9 is provided, the magnitudes of the capacitance values recorded in the storage unit 9 are compared, and the ratio between the maximum capacitance value and the minimum capacitance value is output. When the length of the electric wire 2 to be tested is known, the length from the measurement end to the disconnection position can be calculated by inputting the length and multiplying the obtained ratio.

  In this example, three sensor probes 3 are provided, and a CR multivibrator 4 is provided for each of the three types of sensor probe pairs including the sensor probes 3, 3, 3. Only two sensor probes 3 for individually measuring the capacitance component are provided, and two from the measurement end of each of the three types of conductor pairs consisting of the three conductors 1, 1, 1 constituting the test electric wire 2. The capacitance values obtained through the sensor probes 3 and 3 are sequentially measured, and a storage unit 9 for holding the capacitance values obtained in the previous and subsequent measurements is provided, and the capacitance value recorded in the storage unit 9 is stored. A configuration may be adopted in which the size is compared and the ratio between the maximum electric capacity value and the minimum electric capacity value is output. Further, even when three sensor probes 3 are provided as in the example, each of the three types of sensor probe pairs consisting of the sensor probes 3, 3, 3 is not provided with a CR multivibrator 4, but a single CR multi A method may be adopted in which the sensor probe 3 configured by a vibrator and connected to the capacitance component connection terminal of the CR multivibrator is switched by a switch for each sensor probe pair.

  According to the position detection device having the above-described configuration, the three conductors 1 are formed from one end of each conductor 1 including a three-core electric wire 2 formed by arranging three insulated wires adjacent to each other in an equilateral triangle shape. , 1, and 1 to select the pair of conductors 1 and 1, respectively, and measure the capacitance values between the three different types of conductor pairs, and the maximum value of the capacitance values measured between the three types of conductor pairs. And the minimum value as a ratio of the length from the one end to the broken portion with respect to the total length of the three-core electric wire 2, the method for detecting the broken position of the electric wire can be implemented.

  For example, in a commercially available vinyl captyre cord or rubber captyre cord, the electric capacity per 1 m of electric wire is about 100 pF to 150 pF. When the disconnection position of a two-core test electric wire with specifications similar to this is detected using the first embodiment, the capacitance value between the two conductors measured from one end is a value corresponding to 1000 pF. Yes, when the capacitance value between the two conductors measured from the other end is a value corresponding to 4000 pF, a disconnection occurs at a ratio of 20% to the total length from the one end, which is the ratio between them. It is thought that.

  On the other hand, when the disconnection position of the three-core test electric wire having a specification similar to this is detected using the second embodiment, the capacitance value between the first conductor pair is a value corresponding to 5000 pF, When the capacitance value between the second conductor pair is a value corresponding to 1000 pF and the capacitance value between the third conductor pair is a value corresponding to 1000 pF, the ratio of the minimum value to the maximum value is It is considered that a disconnection occurs at a position of 20% from a certain measurement end to the total length.

  As described above, the existence of the method and apparatus for detecting the disconnection position of the power cable according to the present invention prolongs the service life of various electric devices having long electric wires and relatively easily restores the disconnection accident at the work site. By being able to do so, the waste of time due to inadequate equipment is also eliminated, contributing to the realization of efficient operation.

(A): It is explanatory drawing which shows an example of the electric wire which uses the disconnection position detection method of the electric wire by this invention, (B): It is a block diagram which shows 1st embodiment of the disconnection position detection apparatus of the electric wire by this invention. . (A): It is explanatory drawing which shows an example of the electric wire which uses the disconnection position detection method of the electric wire by this invention, (B): It is a block diagram which shows 2nd embodiment of the electric wire break position detection apparatus by this invention. .

Explanation of symbols

1 lead wire, 2 electric wire, 3 sensor probe, 4 multivibrator,
5 Oscillator, 6 Electric capacitance value calculator, 7 Boundary ratio calculator, 8 Electrode, 9 Memory,

Claims (4)

A method for detecting a disconnection position of a two-core electric wire formed by arranging two phase-insulated conductors adjacent to each other,
The electrical capacitance value between the two conductors is measured from one end of each conductor contained in the electric wire, the electrical capacitance value between the two conductors is measured from the other end of each conductor, A method for detecting a disconnection position of an electric wire, wherein the ratio of the capacitance value is calculated as a ratio of the length to the total length of the two-core electric wire on each side with the disconnection portion as a boundary. A method for detecting a broken position of a three-core electric wire in which three insulated wires are arranged adjacent to each other in an equilateral triangle shape,
From one end of each conducting wire included in the electric wire, each of the electric capacitance values between three different types of conducting wire pairs selected from a pair of conducting wires among the three conducting wires is measured, and between the above three types of conducting wire pairs A wire breakage position detection method for calculating the breakage location as a ratio of the measured maximum value and minimum value of the capacitance value to a total length of a three-core electric wire having a length from the one end to the breakage location. A disconnection position detecting device for a two-core electric wire in which two conductors that are phase-insulated are arranged adjacent to each other,
A sensor probe connected to both ends of each conducting wire included in the electric wire, an oscillating unit in which a CR multivibrator is configured to include an electric capacitance component detected through these sensor probes, and an output of the oscillating unit from the two An electric capacity value calculating unit for calculating an electric capacity value between the two conductive wires, and a boundary ratio calculating unit for calculating and outputting a ratio of the electric capacity values between the two electric wires detected from both ends of the electric wire. Wire breakage position detection device. A disconnection position detecting device for a three-core electric wire in which three conductors insulated in phase are arranged adjacent to each other in a regular triangle shape,
A sensor probe that is connected to one end of each of three different pairs of conductors obtained by selecting a pair of conductors from the three conductors included in the wire, and a capacitance component detected through these sensor probes is included. An oscillation unit in which a CR multivibrator is configured, an electric capacitance value calculation unit that calculates an electric capacitance value between the three types of conductor pairs from the output of the oscillation unit, and an electric capacitance value measured between the three types of conductor pairs An apparatus for detecting a breakage position of an electric wire, comprising: a boundary ratio calculation unit that calculates and outputs a ratio between a maximum value and a minimum value.

Images