System and method for measuring internal voltage of insulated connecting unit for extra-high voltage lines or high voltage lines, and insulating plug for insulated connecting unit

Abstract

[Problem] To provide a means for more easily ascertaining the internal voltage of an insulated connecting unit used in extra-high voltage lines or high voltage lines. [Solution] This system for measuring the internal voltage of an insulated connecting unit 10 that is used in an extra-high voltage line or a high-voltage line and that comprises at least an insulator 11, a shielding electrode 12, an internal electrode 13, an opening 14, and an insulating plug 15 comprises at least: a part 20 to be measured, comprising one or more dielectrics connected in series with the insulating plug 15; a voltmeter 30 capable of measuring a voltage value across any one of the one or more dielectrics; and a calculating unit 40 for calculating, as the internal voltage of the insulated connecting unit 10, a value obtained by multiplying the voltage value of the dielectric to be measured by a coefficient assigned to each configuration of the part 20 to be measured, at least.

Description

System and method for measuring internal voltage of insulated joint for extra-high voltage line or high voltage line, and insulating plug for insulated joint

[0001] The present invention relates to a system and method for measuring the internal voltage of an insulated connection for an extra-high voltage line or a high voltage line, and to an insulating plug for an insulated connection.

[0002] To measure the internal voltage of an insulated connection used on an extra-high voltage line or high voltage line, it is necessary to bring a measurement system such as a voltage divider or high voltage probe to the site and perform the measurement with the line stopped. In addition, it is necessary to use a VCT (voltage transformer) to transform the voltage to a level that can be measured by a watt-hour meter, which results in problems such as the equipment being large in size.

[0003] Other examples of a method for measuring the internal voltage of an insulated connection part used to connect a power cable or the like include a method in which a voltage detector terminal is provided on an insulating plug attached to an opening that communicates with the inside of the connection part (Patent Document 1).

[0004] Japanese Patent Application Publication No. 08-163762

[0005] One of the objects of the present invention is to provide a means for easily determining the internal voltage of an insulated connection used in an extra-high voltage line or a high voltage line, using a method different from the conventional methods described above.

[0006] The present invention, which has been made to solve the above problems, is a system for measuring the internal voltage of an insulated connection used in an extra-high voltage line or a high voltage line and having at least an insulator, a shield electrode, an internal electrode, an opening, and an insulating plug, comprising at least a measurement target consisting of one or more dielectrics connected in series with the insulating plug, a voltmeter capable of measuring the voltage value of any one of the one or more dielectrics, and a calculation unit that calculates the internal voltage of the insulated connection by multiplying the voltage value of the dielectric being measured by at least a coefficient assigned to each configuration of the measurement target.The present invention also provides a method for measuring the internal voltage of an insulated connection used in an extra-high voltage line or a high voltage line and having at least an insulator, a shield electrode, an internal electrode, an opening, and an insulating plug, comprising: a measurement target consisting of one or more dielectrics connected in series with the insulating plug by a predetermined coefficient; The present invention also provides an insulating plug that can be inserted into an opening provided in an insulating connection part used in an extra-high voltage line or a high voltage line, and is characterized in that it has one or more dielectrics that are connected in series with the insulating plug and are configured to be able to measure voltage values.

[0007] According to the present invention, the internal voltage of an insulated connection used in an extra-high voltage line or a high voltage line can be more easily determined.

[0008] 1 is a functional schematic diagram of an internal voltage measurement system for an insulating connection according to Example 1. FIG. 2 is a partial enlarged view of the periphery of an insulating plug showing an example of mounting a measured part.

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

[0010] <1> Basic Configuration (Fig. 1) Fig. 1 shows a schematic diagram of an example of an internal voltage measurement system for an insulated connection according to the present invention (hereinafter also referred to simply as "measurement system A"). Measurement system A according to this embodiment is a system used to measure the internal voltage of an insulated connection 10, and is configured to include at least a measured part 20, a voltmeter 30, and a calculation part 40. Each part will be described in detail below.

[0011] <2> Insulated Connection (FIG. 1) The insulated connection 10 is a component for connecting power cables, power equipment, and the like. In the present invention, the shape, structure, material, and the like of the insulated connection 10 are not particularly limited, and any form can be selected from known shapes and structures. The insulated connection 10 according to the present invention naturally includes a T-shaped terminal connection for connecting a power cable to power equipment, an intermediate connection for connecting power cables, an I-shaped bushing, a T-shaped rubber connector, a Y-shaped branch connection, and the like. Note that the insulated connection 10 according to this embodiment is a T-shaped terminal connection.

[0012] <2.1> Member configuration (Fig. 1) The insulated connection part 10 according to the present invention has at least an insulator 11 constituting the main body of the insulated connection part 10, a shielding electrode 12 provided on the outer surface of the insulator 11, an internal electrode 13 disposed inside the insulator 11, an opening 14 connecting the inside and outside of the insulator 11, and an insulating plug 15 that can be inserted into the opening 14. Each member and each part will be described in detail below.

[0013] <2.2> Insulator (FIG. 1) The insulator 11 constitutes the main body of the insulating connection 10 and is a member for insulating the internal electrode 13 (described later) from the outside. In the present invention, the shape, structure, etc. of the insulator 11 are not particularly limited. The insulator 11 can be made of a hard plastic resin material with high mechanical strength (for example, epoxy resin or fiber reinforced plastics (FRP)).

[0014] <2.3> Shielding electrode (Fig. 1) The shielding electrode 12 is a member for preventing leakage of current from the internal electrode 13 provided in the insulator 11 to the outside. The shielding electrode 12 can be formed by a conductive member provided on the outer surface of the insulator 11 or by a conductive paint applied to the outer peripheral surface of the insulator 11.

[0015] <2.4> Internal Electrode (FIG. 1) The internal electrode 13 is a component disposed inside the insulator 11 to conduct electricity between the power cable, power equipment, etc. connected to the insulated connection part 10. The internal electrode 13 can be made of a conductive material suitable for conducting electricity, such as copper, aluminum, a copper alloy, or an aluminum alloy, or semiconductive rubber. In FIG. 1, the internal electrodes 13 include an internal electrode 13A electrically connected to the equipment located on the left side of the page, and an internal electrode 13B electrically connected to the power cable connected from below the page. The internal electrodes 13A and 13B are electrically connected via a connecting conductor B disposed in a hollow portion provided inside the insulator 11.

[0016] <2.5> Opening (FIG. 1) The opening 14 is a portion formed to allow communication between the inside and outside of the insulator 11. In the present invention, the position, shape, etc. of the opening 14 are not particularly limited. In this embodiment, the opening 14 is provided on the right side of the insulator 11 as viewed from the page. This opening 14 is normally used with an insulating plug 15 attached, and during a voltage resistance test, it is used as a charging part to which a charging cable (not shown) can be connected.

[0017] <2.6> Insulating Plug (Figure 1) The insulating plug 15 is a component for closing the opening 14. In the present invention, the shape, structure, material, etc., of the insulating plug 15 are not particularly limited, and any known shape, structure, material, etc. may be selected. The insulating plug 15 according to this embodiment has a shape and structure that allows it to be inserted into and fitted into the opening 14, which functions as a voltage-carrying part in a T-shaped terminal connection (also referred to as a "T-shaped terminal connection"). The insulating plug 15 includes a main body 151 made of an insulating material, a high-voltage conductor 152 provided at the front end of the main body 151, and a shielding conductor 153 provided at the rear end of the main body 151. After the insulating plug 15 is fitted into the opening 14, the high-voltage conductor 152 is electrically connected to the internal electrode 13. In the T-shaped terminal connection shown in the embodiment, the main body 151 of the insulating plug 15 is made of rubber such as ethylene propylene rubber or silicone rubber. However, in the case of a T-shaped rubber connector, the portion corresponding to the insulator 11 (the insulating portion on the side where the insulating plug is inserted) is made of rubber, so the main body 151 of the insulating plug 15 in this case is made of, for example, epoxy resin. In the embodiment, the high-voltage conductor 152 is provided with a spring (symbol omitted) at the rear end of the shielding conductor 153 for pressing the main body 151 of the insulating plug 153 against the inner surface of the insulator 11 of the opening 14 while applying surface pressure. Although multiple springs are provided in the embodiment shown in Figure 2, a single spring may be sufficient as long as the surface pressure between the insulator 11 and the main body 151 is applied, or a configuration without a spring may be used if the compliance of the insulator 11 is sufficient.

[0018] <3> Measured Part (FIG. 1) The measured part 20 is a part whose voltage value is measured by the voltmeter 30. The measured part 20 can be composed of at least one dielectric connected in series with the insulating plug 15 to form a series circuit. In the present invention, the measured part 20, which is composed of at least one dielectric, is configured so that its capacitance is greater than that of the insulating plug 15. Furthermore, in the present invention, the type of dielectrics constituting the measured part 20 is not particularly limited, and ceramic materials, plastic materials, glass, and the like can be used. For example, even if a material with a low dielectric constant (such as a semiconductor) is used as the dielectric, it is sufficient that the measured part 20 is configured by connecting multiple dielectrics in series, so that the capacitance of the measured part 20 is greater than that of the insulating plug 15. The internal voltage of the insulating connection part 10 (the voltage applied to the internal electrode 13) generates divided voltages in the insulating plug 15 and the dielectrics connected in series to the insulating plug 15.

[0019] <3.1> Series Connection Method with Insulating Plug In the present invention, the method for connecting the dielectric constituting the measured portion 20 and the insulating plug 15 in series is not particularly limited, and may include a method of abutting the dielectric against the insulating plug 15 or a method of separately wiring the insulating plug 15 and the dielectric in series. For example, in FIG. 2 , the dielectric constituting the measured portion 20 is disposed between the shielding conductor 153 located at the rear end of the insulating plug 15 and the back cover C (made of metal in this embodiment) that presses the insulating plug 15 toward the front end, thereby abutting the dielectric against the insulating plug 15. For example, in the embodiment of FIG. 2 , the dielectric is abutted against the shielding conductor 153, but this is not a limitation. Furthermore, although the shape of the measured portion 20 is depicted as cylindrical in the embodiment of FIG. 2 , the shape is not limited. 2, in the case where a spring is provided at the rear end of the insulating plug 15 (specifically, the rear end of the shielding-side conductor 153), a hole through which the spring passes may be provided in the dielectric of the measured part 20 so that the spring does not interfere with the dielectric. Also, the outer shape does not have to be circular.

[0020] <3.2> Regarding the measurement value of the dielectric to be measured, it is preferable to design the number and type of dielectrics used in the measurement part 20 so that the voltage value measured in the dielectric to be measured in the measurement part 20 is below a safe voltage, i.e., 50 V or less, more preferably 25 V or less. For example, the greater the number of dielectrics connected in series, the lower the voltage value of the dielectric. Also, the higher the dielectric constant of the dielectric, the lower the voltage value generated in the dielectric. In the present invention, the number and type of dielectrics can be appropriately designed with reference to the above-mentioned effects and the expected value of the internal voltage of the insulated connection part 10.

[0021] <3.3> Method of Attaching the Measured Part The measured part 20 can be configured in various ways, such as being pre-integrated with the insulating plug 15 or being detachable. For example, if the measured part 20 is pre-integrated with the insulating plug 15, it is possible to add the function of measuring the internal voltage of the insulated connection part 10 to an existing insulated connection part 10 simply by replacing the previous insulating plug 15 with the insulating plug 15 of the present invention. Furthermore, if the measured part 20 is configured to be detachable from the insulating plug 15, it is possible to add the function of measuring the internal voltage of the insulated connection part 10 while still using the insulating plug 15 used in the existing insulated connection part 10.

[0022] <4> Voltmeter (Fig. 1) The voltmeter 30 is a device for measuring the voltage value of the dielectric being the measurement target in the measured portion 20. In the present invention, there are no particular limitations on the type or number of voltmeters 30, or the method for measuring the voltage across the dielectric. As shown in Fig. 1, the voltmeter 30 is connected in parallel with the measured portion 20, which is connected in series with the insulating plug 15.

[0023] <5> Calculation Unit (FIG. 1) The calculation unit 40 is a device that performs the function of determining the internal voltage of the insulated connection part 10 based on at least the voltage value measured by the voltmeter 30. The calculation unit 40 can be an information processing device that acquires the voltage value measured by the voltmeter 30 by any method (automatically or manually). The information processing device can be an application installed on a general-purpose information processing terminal such as a PC, tablet, or smartphone, or a dedicated built-in device in which a calculation program is built into a microcomputer or the like.

[0024] <5.1> Calculation Contents (FIG. 1) The calculation unit 40 has a function of multiplying the voltage value measured by the voltmeter 30 by a predetermined coefficient to calculate the internal voltage of the insulated connection unit 10. This coefficient is configured to be assigned to each value of the voltage applied to the internal electrode 13 and each configuration of the measured unit 20 (number, type, etc. of dielectrics). For example, the following Table 1 shows an example of an allocation table of coefficients for each expected value of the voltage applied to the internal electrode 13 when a single dielectric made of perovskite oxide or the like is used as the measured unit 20.

[0025] [Table 1]

[0026] This allocation table can be prepared by creating a test specimen for this system, conducting a voltage division test on this test specimen, and calculating coefficients by dividing the voltage value of the dielectric being measured from the value of the actually applied voltage, and then appropriately creating a database.

[0027] <5.2> Addition of a Monitoring Function In the present invention, the calculation unit 40 may be provided with a monitoring function for detecting abnormalities in the internal voltage of the insulated connection part 10. For example, the calculation unit 40 may be provided with a function for storing an expected normal value of the internal voltage in advance, comparing the calculated internal voltage with the expected normal value, and notifying the user of an alarm if the calculated internal voltage is lower than the expected normal value. Note that in the present invention, in addition to monitoring the internal voltage of the insulated connection part calculated by the calculation unit 40, the voltage value of the dielectric being measured may also be monitored. In this case, the calculation unit 40 may separately store an expected normal value for the dielectric voltage value and compare it with the expected normal value.

[0028] <6> Summary As explained above, the internal voltage measurement system for an insulated connection according to the present invention can achieve at least one of the following effects. (1) The internal voltage of an insulated connection can be monitored while the line is live. (2) Unlike monitoring by attaching a detector to a power cable or a grounding wire, voltage monitoring is possible for each insulated connection, making it possible to detect faults on a phase-by-phase basis rather than detecting all three phases at once. (3) Because the voltage value of the dielectric being measured is designed to be 50 V or less, measurement work can be performed while ensuring the safety of workers. (4) Because fluctuations in the voltage value of the dielectric being measured by the measurement unit are linked to fluctuations in the internal voltage of the insulated connection, it can also be used for voltage monitoring.

[0029] A: Measurement system 10: Insulated connection part 11: Insulator 12: Shielding electrode 13: Internal electrode 14: Opening 15: Insulating plug 151: Main body 152: High voltage side conductor 153: Shielding side conductor 20: Part to be measured 30: Voltmeter 40: Calculation part B: Connecting conductor C: Back cover

Claims

1. A system for measuring the internal voltage of an insulated connection used in an extra-high voltage line or a high voltage line and having at least an insulator, a shielding electrode, an internal electrode, an opening, and an insulating plug, characterized by comprising at least: a part to be measured consisting of one or more dielectrics connected in series with the insulating plug; a voltmeter capable of measuring the voltage value of any one of the one or more dielectrics; and a calculation unit that calculates the internal voltage of the insulated connection by multiplying the voltage value of the dielectric being measured by at least a coefficient assigned to each configuration of the part to be measured.

2. The internal voltage measurement system for an insulated connection according to claim 1, characterized in that the part to be measured is configured so that the voltage value in the dielectric being measured is 50 V or less.

3. The internal voltage measurement system for an insulated connection according to claim 1, characterized in that the calculation unit assigns the coefficient according to the type of dielectric, the number of dielectrics, and the expected value of the voltage applied to the insulated connection.

4. The internal voltage measurement system for an insulated connection as set forth in claim 1, wherein the capacitance of the measured part is greater than the capacitance of the insulating plug.

5. A method for measuring the internal voltage of an insulated connection used in an extra-high voltage line or a high voltage line and having at least an insulator, a shielding electrode, an internal electrode, an opening, and an insulating plug, characterized in that the internal voltage of the insulated connection is calculated by multiplying the voltage value of a dielectric connected in series to the insulating plug by a predetermined coefficient.

6. An insulating plug for an insulated connection that can be inserted into an opening provided in an insulated connection used in an extra-high voltage line or a high voltage line, characterized in that it is provided with one or more dielectrics that are connected in series with the insulating plug and are configured to be able to measure voltage values.

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