Live Wire Notification System

Abstract

This invention provides a live-line detection system that can determine the presence or absence of live lines within a power transmission system in a manner different from conventional magnetic field detection methods. [Solution] A live wire detection system for detecting the presence or absence of a live wire in a power transmission system having at least an insulating connection part B, comprising at least one dielectric 10 connected in series with an insulating plug 400 constituting the insulating connection part B, and a notification unit 20 capable of notifying the presence or absence of a live wire by a voltage induced in at least one of the dielectric 10. The notification unit 20 can employ methods such as using a light-emitting element, a switching circuit, or a signal transmitter. In addition, a voltmeter 30 and a calculation unit 40 may be provided to calculate the internal voltage value of the insulating connection part B from the voltage waveform of the dielectric 20, or to separate the vibration waveform from the voltage waveform and calculate the vibration value.

Description

[Technical Field]

[0001] The present invention relates to a live-line detection system for detecting the presence or absence of a live line in a power transmission system having at least an insulating connection portion. [Background Art]

[0002] In power transmission systems including extra-high voltage lines or high-voltage lines, periodic inspections specified by the Electricity Business Act are carried out. In this context, electric shock accidents caused by accidentally touching live parts have occurred. Normally, most periodic inspections are on-site visual inspections. However, since it is difficult to visually judge whether an inspection object is energized or not, workers may unintentionally approach or contact the object during work, leading to accidents. As a countermeasure against this problem, magnetic field detection type live line alarms described in the following Patent Document 1 and Non-Patent Document 1 have been used. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2002-260120 [Non-Patent Documents]

[0004] [Non-Patent Document 1] "Live Line Approach Alarm" https: / / www.hasegawa-elec.co.jp / archives / voltage-detector_cate / alarm [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] One object of the present invention is to provide a means capable of grasping the presence or absence of a live line in a power transmission system in a mode different from that of the conventional magnetic field detection type. [Means for Solving the Problem]

[0006] The present invention, made to solve the above problems, is a live-line detection system for detecting the presence or absence of a live wire in a power transmission system having at least an insulated connection portion, wherein the insulated connection portion has at least an insulator, a shielding electrode, an internal electrode, an open port, and an insulating plug, and one or more dielectrics connected in series with the insulating plug, The device is characterized by comprising at least a notification unit capable of notifying whether a wire is live or not based on a voltage induced in at least one of the aforementioned dielectrics. Furthermore, in the present invention, the notification unit can also be configured with a light-emitting element. Furthermore, the present invention also allows the notification unit to be configured as a signal transmitter. Furthermore, the present invention also allows the notification unit to be configured with a switching circuit. Furthermore, the present invention may also be configured to further include a voltmeter for acquiring the voltage waveform of the dielectric, and a calculation unit for calculating the internal voltage value and / or vibration value of the insulating connection part from the voltage waveform of the dielectric. [Effects of the Invention]

[0007] According to the present invention, it is possible to determine the presence or absence of live lines within a power transmission system in a manner different from conventional magnetic field detection methods. [Brief explanation of the drawing]

[0008] [Figure 1] Basic configuration diagram of the live-line notification system according to Example 1. [Figure 2] Basic configuration diagram of the live-line notification system according to Example 2. [Figure 3] A diagram illustrating the separation of voltage waveforms. [Figure 4] A schematic diagram showing the overall configuration of the live-line notification system according to Example 3. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Examples]

[0010] <1>Basic Configuration (Figure 1) The live line notification system A according to the present invention is a system for detecting the presence or absence of a live line in a power transmission system including an extra-high voltage line or a high voltage line. The live line notification system A according to the present invention comprises at least one or more dielectrics 10 and a notification unit 20. Hereinafter, details of each part and an example of the calculation method will be described.

[0011] <2>Insulated Connection Part (Figure 1) The insulated connection part B is a member to which power cables and power equipment constituting the power transmission system are connected. In the present invention, the type of the insulated connection part B is not particularly limited, and particularly includes termination connection parts and intermediate connection parts used in extra-high voltage lines or high voltage lines. In the embodiment, an example of a termination connection part of a power cable will be described as the insulated connection part B. As shown in Figure 1, the insulated connection part B is broadly divided into a charged part B1 and an insulating part B2. A more specific configuration of the charged part B1 and the insulating part B2 will be described in Example 3 described later.

[0012] <3>Dielectric (Figure 1) The dielectric 10 is a member for inducing a voltage by the internal voltage of the insulated connection part B. The dielectric 10 forms a series circuit by being connected in series with the insulated connection part B, more specifically, an insulating member (insulating part B2) constituting the insulated connection part B. With the above configuration, the dielectric 10 is in a state where voltages divided by the internal voltage of the insulated connection part B (the voltage applied to the internal electrode in the insulated connection part B) are generated, and a voltage is generated by the piezoelectric effect when vibration occurs.

[0013] <3.1>Types of Dielectrics In this embodiment, the dielectric 10 can be appropriately selected from materials exhibiting a dielectric effect, and ceramic materials, plastic materials, glass, or the like can be used. It should be noted that the overall capacitance of the dielectric 10 is preferably configured to be larger than the capacitance of the insulating portion B2 connected in series therewith. In this case, even when a material with a low dielectric constant is used as the dielectric 10, by connecting a plurality of dielectrics 10 in series, it is only required that the overall capacitance of the dielectric 10, which is the voltage value measurement object, is larger than the capacitance of the insulating portion B2.

[0014] <3.2>Design Method of Dielectric In the present invention, it is preferable to design the voltage value measured by the dielectric 10 serving as the voltage value measurement object to be equal to or lower than a safe voltage, that is, 50 V or lower, more preferably 25 V or lower. For example, the larger the number of dielectrics 10 connected in series, the lower the voltage value across the dielectric 10. In addition, the higher the dielectric constant of the dielectric material used as the dielectric 10, the lower the voltage value generated across the dielectric 10. In the present invention, the number and type of each material constituting the dielectric 10 may be appropriately designed with reference to the above-described operation and the predetermined value of the internal voltage of the insulating connection portion B.

[0015] <3.3>Installation Method of Dielectric The dielectric 10 can employ various configurations, such as a configuration pre-integrated with the insulating portion B2 which is a component of the insulating connection portion B, or a configuration detachably attachable to and detachable from the insulating portion B2.

[0016] <4>Notification Unit (Fig. 1) The notification unit 20 is means for notifying whether there is a live line in the insulating connection portion B. The notification unit 20 is configured to notify the presence or absence of a live line using a voltage induced in at least one dielectric 10. In the present invention, the notification unit 20 may be integrally incorporated in any of the constituent elements of the insulating connection portion B, or may be detachably incorporated therein. A configuration example of the notification unit 20 will be described below.

[0017] <4.1>Emitting type The light-emitting type is a method that uses a light-emitting element such as an LED as the notification unit 20. In this method, the circuit should be designed so that the voltage induced by the dielectric 10 is less than or equal to the rated voltage of the light-emitting element constituting the notification unit 20.

[0018] <4.2> Signal-emitting type The signal-emitting method is a method that uses a signal transmitter as the notification unit 20. In this method, the circuit should be designed so that when a voltage above a certain level is induced in the dielectric 10, a wired or wireless signal is emitted from the signal transmitter. In this invention, the signal specifications are not particularly limited. Furthermore, the present invention does not particularly limit the type of signal receiver, and may include a receiving device fixed in the vicinity of the work site or a receiving terminal worn or held by a worker. Also, the signal transmission timing may be at regular intervals or continuous.

[0019] <4.3> Switch type The switch-type method uses a switching circuit consisting of a MOSFET or the like as the notification unit 20. In this method, when a voltage above a certain level is induced in the dielectric 10, the circuit design should be such that it lights up a light-emitting element such as an LED connected to a separate power supply, outputs various sounds such as an electronic horn, motor siren, or voice, or transmits a signal to provide some kind of notification. In this case, because a separate power supply is provided, the light-emitting element such as an LED can be lit more stably compared to the method that lights up the LED or other light-emitting element using only a voltage sensor. Furthermore, in a configuration where the light-emitting element is kept constantly lit by power supplied from a separate power source when the power line is live, it will be necessary to replace the battery for the separate power source as described above. Therefore, to conserve power, a separate switch may be provided so that power is supplied from the separate power source only during inspection work. In addition, this method may be designed to include a circuit that illuminates a light-emitting element as a safety indicator when a voltage above a certain level is not induced in the dielectric 10.

[0020] <5> summary According to the live-line notification system A of this embodiment, the presence or absence of a live wire in the insulated connection part B can be confirmed visually or by other means using the voltage induced in the dielectric 10. [Examples]

[0021] <1> Basic configuration (Figure 2) As shown in Figure 2, the live-line notification system A according to the present invention can also be configured to further include a voltmeter 30 and a calculation unit 40, in addition to the live-line notification system according to Embodiment 1. The details of each component are described below.

[0022] <2> Dielectric (Figure 2) In the live-line notification system A according to this embodiment, in addition to dielectric materials such as ceramic materials, plastic materials, and glass as shown in Example 1, a material equivalent to both a dielectric material and a piezoelectric material (a dielectric material having a piezoelectric effect) can also be used as the dielectric 10. Examples of dielectric materials that exhibit the piezoelectric effect include quartz, barium titanate (BaTiO3), lead titanate (PbTiO3), lead zirconate (PbZrO3), lead titanate-lead zirconate (PZT), and bismuth titanate (Bi4Ti3O3). 12 ), polyvinylidene fluoride (PVDF), topaz (Al2SiO4(F,OH)2), tourmaline, zinc oxide (ZnO), aluminum nitride (AlN), lithium niobate (LiNbO3), potassium niobate (KNbO3), Rochelle salt (KNaC4H4O6·4H2O), zirconium phosphate (ZrPO4), lithium tantalate (LiTaO3), bismuth sulfate (Bi2(SO4)3), indium oxide (In2O3), etc. can be used. When a dielectric material having a piezoelectric effect is used for the dielectric 10, a voltage is generated by dividing the voltages of the internal voltage of the insulating connection part B (voltage applied to the internal electrodes in the insulating connection part B), while a voltage is also generated by the piezoelectric effect when vibration occurs.

[0023] <3> Voltmeter (Figure 2) The voltmeter 30 is a device for measuring the voltage value of any of the dielectrics 10. In this invention, there are no particular limitations on the type or number of voltmeters 30, or the method for measuring the voltage to the dielectric. As shown in Figure 2, the voltmeter 30 is connected in parallel with the dielectric 10, which is connected in series with the insulating part B2.

[0024] <4> Calculation unit (Figure 2) The calculation unit 40 is a device for performing the process of calculating voltage values ​​and / or vibration values ​​from the voltage waveform of at least one dielectric 10 that is measured by the voltmeter 30.

[0025] <4.1>When calculating the voltage value In this invention, various methods can be employed for the process of calculating the voltage value from the voltage waveform induced in the dielectric 10. For example, the calculation unit 40 may further have a function to calculate the internal voltage of the insulating connection part B as a value obtained by multiplying the effective value of the voltage waveform of at least one dielectric 10 by a predetermined coefficient. This coefficient is configured to be assigned to each value of the voltage applied to the internal electrodes and to each component of the dielectric 10 (such as the number and type of dielectric 10). For example, Table 1 below shows an example of a table of coefficient assignments for each planned voltage applied to the internal electrodes when a perovskite-type oxide is used as the dielectric 10 to be measured for voltage value.

[0026] [Table 1] TIFF2026142851000002.tif40151

[0027] This allocation table can be prepared by creating a test specimen of the live-line notification system A according to the present invention, performing a voltage division test on this specimen, and obtaining a coefficient by dividing the voltage value of the dielectric being measured by the voltage value actually applied, and appropriately adding it to a database.

[0028] <4.2>When calculating vibration values When calculating vibration values ​​in the calculation unit 40, the vibration waveform is separated from the voltage waveform (hereinafter also referred to as "measured waveform 31") of at least one dielectric 10 that is the object of measurement by the voltmeter 30, and the process of calculating vibration values ​​from the vibration waveform is executed. In the present invention, various methods can be employed to separate the oscillation waveform from the voltage waveform measured by the voltmeter 30. Examples include the Fast Fourier Transform (FFT), Short Time Fourier Transform (STFT), wavelet transform, and calibration. The calculation unit 40 can use an information processing device C that acquires the voltage waveform measured by the voltmeter 30 by any method (automatically or manually). As the information processing device C, applications installed on general-purpose information processing terminals such as PCs, tablets, and smartphones, or dedicated embedded devices with calculation programs incorporated into microcomputers, etc., can be used.

[0029] <4.2.1> Separation image of each waveform (Figure 3) Figure 3 shows an image illustrating the separation of the vibration waveform from the voltage waveform measured by the voltmeter 30. The measurement waveform 31 measured by the voltmeter 30 is separated by the calculation unit 40 into a vibration waveform 311 and the separated voltage waveform 312, and the vibration waveform 311 is used in the vibration value calculation process. The separated voltage waveform 312 may also be subject to the voltage value calculation process shown in <4.1> above.

[0030] <4.2.2> Calculation process of vibration values ​​(Figure 2) In the present invention, various methods can be employed for the process of calculating vibration values ​​from vibration waveforms 311. Examples include simply measuring the peak value of the amplitude, calculating the effective value (RMS value), performing frequency analysis such as fast Fourier transform (FFT), and performing time-domain analysis.

[0031] <5> summary According to the live wire notification system A of this embodiment, the dielectric 10 makes it possible to detect whether or not the terminal connection B is live, and furthermore, at least one of the following effects can be obtained. (1) The internal voltage can be determined while the insulated connection B remains live. (2) Unlike the case where detectors are attached to power cables or grounding wires for monitoring, it is possible to monitor the voltage at each insulated connection point B, so fault detection can be performed on a phase-by-phase basis rather than detecting all three phases at once. (3) The dielectric 10 to be measured is designed so that the voltage value is 50V or less, so that the measurement work can be performed while ensuring the safety of the workers. (4) Since the voltage fluctuation of the dielectric 10 being measured is linked to the fluctuation of the internal voltage of the insulating connection B, it can also be used for voltage monitoring purposes. (5) By using the inverse conversion of vibration measurement and selecting the dielectric material 10 so that vibration occurs when an abnormal voltage occurs, it can be used for voltage monitoring purposes by simply monitoring the presence or absence of vibration without calculating the voltage value. [Examples]

[0032] <1> Overall structure (Figure 4) In the live-line notification system A according to the present invention, an example of the configuration in which a termination connection is selected as the insulated connection B will be described with reference to Figure 4.

[0033] <2> Termination connection section (Figure 4) The insulating connection part B shown in Figure 4 comprises at least an insulator 100 constituting the insulating portion of the main material of the insulating connection part B, a shielding electrode 200 provided on the outer surface of the insulator 100, an internal electrode 300 arranged inside the insulator 100, and an insulating plug 400 that can be inserted into the open opening 110 of the insulator 100. In this embodiment, at least the internal electrode 300 corresponds to the energized section B1 in Figure 1, and the insulating plug 400 corresponds to the insulating section B2. More specifically, in the embodiment shown in Figure 4, the internal electrode 300A, the internal electrode 300B, the connecting conductor 500, the conductor of the power cable (not shown), and the high-voltage side conductor 420 at the tip of the insulating plug 400 correspond to the energized section B1 in Figure 1, and the main body 410 of the insulating plug 400 corresponds to the insulating section B2.

[0034] <2.1> Insulator (Figure 4) The insulator 100 constitutes the insulating portion of the main body material of the insulating connection part B and is a component for insulating the internal electrode 300, which will be described later, from the outside. In the present invention, the shape, structure, etc., of the insulator 100 are not particularly limited. The insulator 100 can be made of a rigid plastic resin material with high mechanical strength (for example, epoxy resin or fiber-reinforced plastics (FRP)).

[0035] <2.1.1> Open opening (Figure 4) The opening 110 is a portion formed to connect the inside and outside of the insulator 100. In this invention, the position, shape, etc., of the opening 110 are not particularly limited. In this embodiment (Figure 4), an opening 110 is provided on the right side of the paper of the insulator 100. Under normal circumstances (when the power cable (not shown) connected to the insulated connection part B is energized), an insulating plug 400 is fitted to the opening 110, and during the withstand pressure test, an energizing cable (not shown) is connected to it.

[0036] <2.2> Shielding electrode (Figure 4) The shielding electrode 200 constitutes the shielding layer of the main body material of the insulating connection part B and is a component that prevents leakage of current from the internal electrode 300 provided on the insulator 100 to the outside. The shielding electrode 200 can be composed of a conductive member provided on the outer surface of the insulator 100, or a conductive paint applied to the outer surface of the insulator.

[0037] <2.3> Internal electrodes (Figure 4) The internal electrode 300 constitutes the high-voltage electrode of the main body material of the insulating connection part B, and is placed inside the insulator 100 to conduct electricity between the power cable (not shown) and power equipment connected to the insulating connection part B. The internal electrode 300 can be made of a conductive material suitable for current conduction, such as copper, aluminum, a copper alloy, or an aluminum alloy, or semiconducting rubber. The internal electrodes 300 (300A and 300B in the embodiment shown in Figure 4) and the insulator 100, which constitute the main body material of the insulating connection part B, are integrally formed by mold molding. Figure 4 shows that the internal electrode 300 includes an internal electrode 300A that is electrically connected to the equipment located on the left side of the page, and an internal electrode 300B that is electrically connected to a power cable (not shown) connected from the bottom of the page. The internal electrode 300A and the internal electrode 300B are electrically connected via a connecting conductor 500 located in a cavity 110 provided inside the insulator 100. In the embodiment shown in Figure 4, the internal electrodes 300A and 300B are described as being electrically connected by a connecting conductor 500 as the high-voltage electrodes of the main body material of the insulating connection part B. However, internal electrodes made of a single component (for example, a structure like the internal conductor 11 in Japanese Patent No. 7494255) may also be used.

[0038] <2.4> Insulating plug (Figure 4) The insulating plug 400 is a component for closing the open port 110. In the present invention, the shape, structure, material, etc. of the insulating plug 400 are not particularly limited, and any form can be selected from known shapes, structures, materials, etc. The insulating plug 400 according to this embodiment has a shape and structure that allows it to be inserted into and fitted into the opening 110 of a T-shaped terminal connector (also called a "T-shaped terminal connector"), and has a main body 410 made of insulating material, a high-voltage side conductor 420 provided on the tip side of the main body 410, and a shielding side conductor 430 provided on the rear end side of the main body 410. After the insulating plug 400 is fitted into the open port 110, the high-voltage side conductor 420 has a structure that electrically connects to the internal electrode 300B. In the case of a T-shaped terminal connection as in the embodiment, the main body 410 of the insulating plug 400 is made of rubber such as ethylene-propylene rubber or silicone rubber. However, in the case of a rubber connector that has a T-shape, the part corresponding to the insulator 100 (the insulating part on the side into which the insulating plug 400 is inserted) is made of rubber, so in this case the main body 410 of the insulating plug 400 is made of epoxy resin or the like. In this embodiment, the high-voltage side conductor 420 is provided with a spring (not shown in the reference numerals) at the rear end of the shielding side conductor 430 for pressing the main body 410 of the insulating plug 400 against the inner surface of the insulator of the opening 110 while applying surface pressure. In the configuration shown in Figure 4, multiple springs are provided, but one spring may suffice if surface pressure is applied between the insulator 100 and the main body 410, or a configuration without springs may be used if the conformability of the insulator 100 is sufficient.

[0039] <3> Example of connection between dielectric and insulating plug In this embodiment, the method of connecting the insulating plug 400, which corresponds to the insulating part B2, and the dielectric 10 in series is not particularly limited. For example, a method of bringing the dielectric 10 into contact with the insulating plug 400, or a method of separately wiring the insulating plug 400 and the dielectric 10 in series can be employed. Furthermore, the dielectric 10 can be configured in various ways, such as being pre-integrated with the insulating plug 400 or being detachable from the insulating plug 400. For example, if the dielectric 10 is pre-integrated into the insulating plug 400, then by simply replacing the conventional insulating plug with an insulating plug 400 that has a structure that allows the dielectric 10 to be connected in series, it is possible to add a function to measure the internal voltage and vibration value of the insulating connection part B. Furthermore, by making the dielectric 10 detachable from the insulating plug 400, it is possible to reuse the insulating plug 400 used in the existing insulating connection part B while adding a function to measure internal voltage and vibration to the insulating connection part B. [Explanation of symbols]

[0040] A: Live Wire Notification System 10: Dielectrics 20:Notification section 30: Voltmeter 31: Measured waveform 311: Vibration waveform 312: Separation of voltage waveform 40: Arithmetic section B: Insulated connection B1: Power charging section B2: Insulation part 100: Insulator 110: Open mouth 200: Shielding electrode 300: Internal electrode 400: Insulating plug 410: Main body 420: High-voltage side conductor 430: Shielding side conductor 500: Connecting conductor

Claims

1. A live-line detection system for detecting the presence or absence of a live wire in a power transmission system having at least an insulated connection part, The aforementioned insulating connection portion comprises at least an insulator, a shielding electrode, an internal electrode, an open port, and an insulating plug. One or more dielectrics connected in series with the insulating plug, A notification unit capable of notifying whether a wire is live or not based on a voltage induced in at least one of the aforementioned dielectrics, Characterized by comprising at least the following: Live wire notification system.

2. The notification unit is characterized in that it is a light-emitting element. The live wire notification system according to claim 1.

3. The notification unit is characterized in that it is a signal transmitter. The live wire notification system according to claim 1.

4. The notification unit is characterized by being a switching circuit. The live wire notification system according to claim 1.

5. A voltmeter for acquiring the voltage waveform of the dielectric, A calculation unit that calculates the internal voltage value and / or vibration value of the insulating connection part from the voltage waveform of the dielectric, It is further characterized by having the following features: The live wire notification system according to claim 1.

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