Power cable measurement system
The power cable measurement system with an optical fiber inside the conductor provides direct and real-time conductor temperature measurement, overcoming limitations of existing methods by eliminating estimation and enabling accurate cable condition assessment.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SWCC CORP KAWASAKI CITY
- Filing Date
- 2024-12-25
- Publication Date
- 2026-07-07
AI Technical Summary
Existing methods for measuring conductor temperature in power cables using optical fibers either measure only the outer periphery or rely on estimated values, lack real-time capability, and do not address the extraction of optical fibers at the cable end.
A power cable measurement system with an optical fiber housed inside the conductor, equipped with a connector and measuring device to directly measure conductor temperature, allowing for real-time and accurate assessment without estimation models.
Enables direct and accurate measurement of power cable conditions, facilitating real-time monitoring and eliminating the need for complex estimation models.
Smart Images
Figure 2026112854000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a measurement system for measuring the state of a power cable, and more particularly to a measurement system for measuring the state of a power cable using an optical fiber.
Background Art
[0002] As one of the parameters for measuring the state of a power cable, there is the temperature of a conductor provided inside the power cable (hereinafter also referred to as "conductor temperature"). As a method for measuring this conductor temperature, a method of using an optical fiber provided in the power cable as a temperature sensor has been devised. For example, Patent Document 1 discloses a power cable in which an optical fiber-containing pipe is wound around the outer periphery of a cable core formed by providing an insulating layer on the outer periphery of a conductor, thereby reducing the risk of buckling of the optical fiber and realizing temperature measurement on the entire circumference of the power cable. Further, Patent Document 2 discloses an estimation method in which an optical fiber is provided between a power cable and a pipeline, and the conductor temperature of the power cable is estimated from the internal temperature of the pipeline measured by the optical fiber.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, the techniques described in the above patent documents have at least one of the problems described below. (1) In Patent Document 1, it only measures the temperature on the outer periphery of the cable core with an optical fiber, and does not directly measure the temperature of the conductor. (2) The conductor temperature of the power cable obtained in Patent Document 2 is merely an estimated value based on the internal temperature of the conduit, and therefore does not correspond to the actual measured value of the conductor temperature. Furthermore, the complexity of the estimation model may hinder real-time temperature measurement. Moreover, different estimation models need to be prepared depending on the size, structure, constituent materials, and surrounding environment of the cable, which increases the complexity. (3) Neither Patent Document 1 nor 2 discloses any method for extracting optical fibers at the end of a power cable.
[0005] Therefore, the present invention aims to provide a means for measuring the condition of power cables with greater accuracy using a method different from the conventional methods described above. [Means for solving the problem]
[0006] The present invention, made to solve the above problems, is a power cable measurement system comprising at least a power cable, a connector, and a measuring device, wherein the power cable houses an optical fiber inside, the connector is capable of extracting a measurement signal from the optical fiber when connected to the power cable, and the measuring device is capable of measuring the measurement signal from the optical fiber extracted by the connector. Furthermore, the present invention is characterized in that a housing portion is provided in a conductor located inside the power cable, and the optical fiber is housed in the housing portion. Furthermore, the present invention is characterized in that the connecting body is a terminal connecting part. Furthermore, the present invention is characterized in that the connecting body is an intermediate connecting part. Furthermore, the present invention is characterized in that the connector is provided with a connector for connecting the end of the optical fiber housed in the power cable. Furthermore, the present invention is a power cable having a conductor inside, characterized in that a housing section is provided inside the conductor, and an optical fiber is housed in the housing section. Furthermore, the present invention is a power cable having a conductor inside, characterized in that a housing section capable of accommodating various sensors is provided inside the conductor. [Effects of the Invention]
[0007] According to the present invention, the condition of power cables can be measured with greater accuracy. [Brief explanation of the drawing]
[0008] [Figure 1] A schematic cross-sectional view of the power cable according to the present invention. [Figure 2] A schematic diagram of the power cable measurement system according to the present invention. [Figure 3] A schematic cross-sectional view showing the connection between the connector (insulated connection part) and the power cable. [Modes for carrying out the invention]
[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Examples]
[0010] <1> Overall structure (Figure 1) Figure 1 is a schematic cross-sectional view of the power cable according to the present invention. The power cable A according to the present invention (hereinafter sometimes simply referred to as "cable A") is characterized in that a housing portion 20 is provided in a conductor 10 located inside cable A. The details of each part are explained below.
[0011] <2> Conductor (Figure 1) The conductor 10 is a component that allows electric current to flow inside the power cable A. In this invention, the material, external shape, size, etc., of the conductor 10 are not particularly limited. Furthermore, there are no particular limitations on the components of cable A other than the conductor 10. In this invention, a housing portion 20 is provided inside the conductor 10, which extends in the longitudinal direction of the cable A.
[0012] <3>Containment section (FIG. 1) The containment section 20 is a part for containing various sensors 30 for measuring the state of the power cable A. The containment section 20 is formed by providing a hollow portion inside the conductor 10. In the present invention, the cross-sectional shape of the containment section 20 is not particularly limited, and an appropriate preferable mode can be selected according to the size and structure of the various sensors 30 to be contained.
[0013] <4>Object to be contained (FIG. 1) In the present invention, the various sensors 30 to be contained in the containment section 20 correspond to various sensors for measuring the state of the power cable A, and include, for example, a temperature sensor, a strain sensor, a pressure sensor, a vibration sensor, etc. Moreover, members constituting these sensors include an optical fiber, etc.
[0014] <5>Summary According to the power cable A according to the present invention, at least one of the following-described effects can be obtained. (1) By containing various sensors 30 in the containment section 20 provided inside the conductor 10, the conductor 10 can be directly measured, and the state of the power cable A can be measured more accurately. (2) The process of calculating an estimated value based on the measured value becomes unnecessary, and more real-time state measurement becomes possible. (3) There is no need to prepare an estimation model for each type of power cable A and the surrounding environment, and complicated management is not required.
Example
[0015] Next, a measurement system using the power cable A described in Example 1 will be described.
[0016] <1>Overall configuration (FIG. 2) The power cable measurement system according to the present invention comprises at least a power cable A, a connector B, and a measuring device C.
[0017] <2> Power cable (Figure 2) For the power cable A used in this embodiment, please refer to Embodiment 1 described above, and a detailed explanation will be omitted. In the measurement system shown in Figure 2, optical fibers 31 are used as various sensors 30 housed in the housing section 20 of the conductor 10 of power cable A.
[0018] <3> Measuring device (Figure 2) The measuring device C is a device that directly or indirectly extracts signals from various sensors 30 housed inside the power cable A and measures a value from those signals. In the present invention, the measuring device C may use various devices depending on the type of parameter to be measured, with various sensors 30 housed inside the power cable A. In the system configuration shown in Figure 2, an introducer is used as the measuring device C.
[0019] <4> Connector (Figure 3) Connector B is the component to which power cable A is connected. In the present invention, the type of connector B is not particularly limited, but it includes insulating connectors B1 (such as terminal connectors and intermediate connectors) used in extra-high voltage lines or high voltage lines. In this embodiment, a terminal connector is used as the insulating connector B1. The configuration of the insulating connection part B1 according to this embodiment will be described below.
[0020] <4.1> Components of each part (Figure 3) The connector B (insulated connector B1) shown in Figure 3 comprises at least an insulator 40 that constitutes the main body of the insulating connector B1, a shielding electrode 50 provided on the outer surface of the insulator 40, an internal electrode 60 arranged inside the insulator 40, an open port 70 that connects the inside and outside of the insulator 40, and an insulating plug 80 that can be inserted into the open port 70. The following describes the details of each component and part.
[0021] <4.2> Insulator (Figure 3) The insulator 40 constitutes the main body of the insulating connection part B1 and is a component for insulating the internal electrode 60, which will be described later, from the outside. In the present invention, the shape, structure, etc. of the insulator 40 are not particularly limited. The insulator 40 can be made of a rigid plastic resin material with high mechanical strength (for example, epoxy resin or fiber-reinforced plastics (FRP)).
[0022] <4.3> Shielding electrode (Figure 3) The shielding electrode 50 is a component that prevents leakage of current from the internal electrode 60 provided on the insulator 40 to the outside. The shielding electrode 50 can be composed of a conductive member provided on the outer surface of the insulator 40, or a conductive paint applied to the outer surface of the insulator.
[0023] <4.4> Internal electrodes (Figure 3) The internal electrode 60 is a component placed inside the insulator 40 to conduct electricity between the power cable A connected to the insulated connection part B1 and power equipment, etc. The internal electrode 60 can be made of a conductive material suitable for current conduction, such as copper, aluminum, a copper alloy, or an aluminum alloy. In a T-shaped terminal connector (also called a "T-shaped terminal connector") as in the embodiment, the internal electrode 60 is made of a metallic conductive material suitable for current conduction, but in the case of a T-shaped rubber connector, the internal electrode 60 is made of semiconducting rubber. Figure 3 shows an internal electrode 60 which has an internal electrode 60A that is electrically connected to the equipment located on the left side of the paper, and an internal electrode 60B that is electrically connected to the power cable A connected from the bottom of the paper. The internal electrode 60A and the internal electrode 60B are electrically connected via a connecting conductor 90 which is placed in a cavity 41 inside the insulator 40.
[0024] <4.5> Open opening (Figure 3) The T-shaped terminal connector has a cable connection port for connecting power cable A on the lower side of Figure 3 and an energization port on the right side of Figure 3. The open port 70 is formed in the energized port and is a portion that connects the inside and outside of the insulator 40. In this invention, the position, shape, etc., of the opening 70 are not particularly limited. In this embodiment (Figure 3), an opening 70 is provided on the right side of the insulator 40. This opening 70 is normally used with an insulating plug 80 attached (when power cable A is energized), and during the withstand pressure test, it is used as an energized section to which an energized cable (not shown) can be connected.
[0025] <4.6> Insulating plug (Figure 3) The insulating plug 80 is a component for closing the open port 70. In the present invention, the shape, structure, material, etc. of the insulating plug 80 are not particularly limited, and any form can be selected from known shapes, structures, materials, etc. The insulating plug 80 according to this embodiment has a shape and structure that allows it to be inserted into and fitted into the open opening 70 which functions as the energized part of the T-shaped terminal connection, and has a main body 81 made of insulating material, a high-voltage side conductor 82 provided on the tip side of the main body 81, and a shielding side conductor 83 provided on the rear end side of the main body 81. After the insulating plug 80 is fitted into the open port 70, the high-voltage side conductor 82 has a structure that electrically connects to the internal electrode 60B. In the case of a T-shaped terminal connection as in the embodiment, the main body 81 of the insulating plug 80 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 40 (the insulating part on the side into which the insulating plug 80 is inserted) is made of rubber, so in this case the main body 81 of the insulating plug 80 is made of epoxy resin or the like. In this embodiment, the high-voltage side conductor 82 is provided with a spring (not shown in the reference numerals) at the rear end of the shielding side conductor 83 to press the main body 81 of the insulating plug 80 against the inner surface of the insulator of the opening 70 while applying surface pressure. In the configuration shown in Figure 3, multiple springs are provided, but one spring may suffice if surface pressure is applied between the insulator 40 and the main body 81, or a configuration without springs may be used if the conformability of the insulator 40 is sufficient.
[0026] <4.7> Power cable connection (Figure 3) Since power cable A is connected to the cable connection port of insulated connection part B1 using known connection methods such as stress cones, compression devices, and protective fittings, detailed explanations and illustrations are omitted.
[0027] <5> Extracting signals from optical fiber (Figure 3) The optical fiber 31 housed inside the power cable A is exposed within the cavity 41 through a through-hole (not shown) that penetrates the cavity 41 and through the opening of the internal electrode 60B into which the power cable A is inserted. The other optical fiber C1, which passes through the inside of the insulating plug 80, is connected to the insulating connection part B1 via a connector 42 inside the cavity 41. Then, by connecting the other optical fiber C1 to the measuring device C, the signal from the optical fiber 31 housed inside the power cable A can be extracted to the outside, and the measurement value can be calculated by the measuring device C.
[0028] <6> summary According to the power cable measurement system of the present invention, at least one of the following effects can be obtained. (1) By housing various sensors 30 in a housing section 20 provided inside the conductor 10 of the power cable A, the conductor 10 can be measured directly, and the state of the power cable A can be measured with greater accuracy. (2) The process of calculating estimated values based on measured values is eliminated, enabling more real-time status measurement. (3) It is no longer necessary to prepare estimation models for each type of power cable A and the surrounding environment, thus eliminating the need for cumbersome management. (4) Through the connector B to which the power cable A is connected, the signals from the various sensors 30 housed inside the power cable A can be taken out of the shielded space. [Explanation of Symbols]
[0029] A: Power cable 10: Conductor 20: Detention Unit 30: Various sensors 31: Fiber optic B: Connector B1: Insulated connection part 40: All traffic delays 50: Shielding electrode 60: Internal electrode 70: Open mouth 80: Insulating plug 81: Main body 82: High-voltage side conductor 83: Shielding side conductor 90: Connecting conductor C: Measuring device C1: Optical fiber C2: Connector
Claims
1. It comprises at least a power cable, a connector, and a measuring device. The aforementioned power cable houses an optical fiber inside. The connector is capable of extracting measurement signals from the optical fiber when connected to the power cable. The aforementioned measuring device is The measurement signal of the optical fiber extracted by the connector can be measured. Characterized by, A power cable measurement system.
2. A housing is provided in the conductor located inside the aforementioned power cable. The optical fiber is housed in the aforementioned housing section. The power cable measurement system according to claim 1.
3. The connector is characterized in that it is a terminal connector. The power cable measurement system according to claim 1.
4. The aforementioned connector is characterized by being an intermediate connector. The power cable measurement system according to claim 1.
5. The connector is characterized by being provided with a connector for connecting the end of the optical fiber housed in the power cable. The power cable measurement system according to claim 1.
6. A power cable having a conductor inside, A housing is provided inside the conductor, The housing section is characterized in that it houses an optical fiber. Power cable.
7. A power cable having a conductor inside, The conductor is characterized by having a housing section inside which various sensors can be housed. Power cable.