CN209945373U - An online monitoring device for water inflow of power cables - Google Patents

Abstract

The utility model discloses an on-line monitoring device for water inflow of a power cable. The monitoring device is composed of a sensing optical fiber and a water-absorbing swelling material. The inner layer is a sensing optical fiber, which serves as a sensor and serves as a monitoring signal transmission line at the same time; the outer layer is a water-absorbing swelling material. After absorbing moisture, the inner layer will be expanded and squeezed, so that the inner layer sensing fiber will be deformed, and the propagation characteristics of the signal in the fiber will be changed. By analyzing the signal drawn from the sensing fiber, the real-time monitoring of the water inflow to the cable can be realized. The overall material of the monitoring device is soft and has good plasticity. It is suitable for various power cables with related needs. It is installed in the internal structure of the cable by spiral winding or in a straight line along the axis of the cable, so that the monitoring device fits the inner structure of the cable. Close, to ensure the sensitivity of monitoring.

Description

An online monitoring device for water inflow of power cables

technical field

The utility model relates to the technical field of on-line monitoring of cable lines, in particular to an on-line monitoring device for water inflow of power cables.

Background technique

Power cable is an important equipment for transmitting and distributing electric energy in power system, and its safe operation is of great significance to ensure the reliability of power supply. With the wide application of cables in urban power transmission and distribution networks, the number of faults has also been increasing year by year in recent years. The quality of the manufacturer's products and the craftsmanship of the on-site construction and installation personnel are the main reasons for the failure of the cable. The water ingress caused by the two is an important factor affecting the safe and reliable operation of the cable. Water entering the cable will accelerate the thermal aging of the insulation, and at the same time, the metal shield and even the conductor inside the cable will be corroded, which will greatly shorten the service life of the cable and cause a series of accidents. At present, there is no special monitoring device for real-time monitoring of cable water inflow, and it is often found that the problem of internal water inflow is serious after the cable line fails. Therefore, the development of an online monitoring device for power cable water inflow is of great significance for timely detection of cable insulation defects and hidden faults in operation, and to ensure the safe and reliable operation of the power grid.

Utility model content

The purpose of this utility model is to solve the above-mentioned defects in the prior art, and to provide an on-line monitoring device for water inflow of a power cable. The device can monitor the water inflow inside the running cable in real time, and is suitable for all kinds of power cables. It solves the problem that real-time monitoring of the water inflow of the running cable is impossible at this stage. The device can effectively improve the intelligent operation and maintenance of the cable line. Level.

The purpose of the present utility model can be achieved by adopting the following technical solutions:

An on-line monitoring device for water inflow of a power cable, the monitoring device is composed of a sensing optical fiber 1 and a water-absorbing swelling material 2, wherein the inner layer of the monitoring device is a sensing optical fiber 1, which serves as a sensor and serves as a monitoring signal transmission line at the same time; Expansion material 2, after absorbing water, generates expansion and extrusion force on the inner sensing fiber 1, changes the propagation characteristics of the signal in the sensing fiber 1, and analyzes the signal drawn out of the sensing fiber 1 to realize the water inflow to the cable. real-time monitoring.

Further, the sensing optical fiber 1 is an optical fiber with an optical fiber sensing unit or an optical fiber cable-like structure with a sheath.

Further, the water-absorbing swelling material 2 is a soft water-absorbing swelling material including hydrophilic rubber.

Further, the water-absorbing swellable material 2 can be processed into a cylindrical shape or other shapes as required to tightly wrap the inner layer of optical fibers.

Further, the water swellable material 2 wraps the inner sensing optical fiber in a full-section or segmented manner as required, and the segment length is adjusted as required.

Further, the overall material of the monitoring device is soft and has good plasticity, and is suitable for power cables including submarine cables, land cables, and single-core and three-core cables, and the installation position inside the cable is not limited, and can be installed according to actual needs. In the cable filling layer, cable core conductor layer and other parts, it forms a closed integrated structure with the cable to ensure the close contact between the monitoring device and the cable.

Further, according to process requirements, the monitoring device can be placed in a helical winding or placed in a straight line along the axial direction inside the cable.

Compared with the prior art, the utility model has the following advantages and effects:

1) The utility model utilizes the performance characteristics of the water-absorbing swelling material, combined with the sensing optical fiber, to form an on-line monitoring device for water inflow of a power cable. After the water-absorbing swelling material absorbs water, it generates an expansion and extrusion force, which deforms the inner optical fiber and changes the propagation characteristics of the optical signal in the optical fiber. By monitoring the optical signal drawn out of the optical fiber, the function of real-time monitoring of the water inflow inside the operating cable can be realized, and the cable is improved. Efficiency of operation and maintenance.

2) The overall material of the power cable water inlet online monitoring device disclosed by the present utility model is soft and has good plasticity. The close contact avoids the interference of environmental factors, and at the same time effectively protects the monitoring device and improves the reliability of the monitoring device.

Description of drawings

1 is a three-dimensional structural diagram of a power cable water inlet online monitoring device disclosed in an embodiment of the present invention;

2 is a three-dimensional diagram of the water-absorbing and swelling material of the outer layer of the power cable water inflow online monitoring device disclosed in the embodiment of the present utility model using a segmented wrapping method;

3 is a cross-sectional view of the installation of the power cable water inflow online monitoring device disclosed in the embodiment of the present invention on the filling layer of a single-core cable;

4 is a three-dimensional diagram of the spiral winding of the power cable water inflow online monitoring device disclosed in the embodiment of the present invention in a single-core cable;

FIG. 5 is a three-dimensional diagram of the on-line monitoring device for water inflow of a power cable disclosed in the embodiment of the present invention placed in a straight line in a single-core cable.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. The embodiments described above are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Example

As shown in FIG. 1 , this embodiment discloses an on-line monitoring device for water inflow of a power cable. The monitoring device is composed of a sensing optical fiber 1 and a water-swelling material 2 , wherein the inner layer of the monitoring device is a sensing optical fiber 1 , which is used as a sensor. At the same time, it is used as a monitoring signal transmission line; the outer layer is a water-absorbing swelling material 2, and the two-layer structure is closely attached to form a water inflow monitoring device. When water enters the inside of the cable, the water-absorbing swelling material 2 absorbs water and generates an expansion and squeezing force on the inner sensing fiber 1, which changes the propagation characteristics of the signal in the sensing fiber 1. By analyzing the signal drawn from the sensing fiber 1, that is Real-time monitoring of cable water ingress can be realized.

The sensing optical fiber 1 is an optical fiber with an optical fiber sensing unit or an optical cable-like structure with a sheath. The outer layer of the monitoring device is a soft water-swellable material 2 including hydrophilic rubber, and the outer layer of the water-swellable material 2 It can be processed into a cylindrical shape or other shapes as required, and tightly wrap the sensing fiber 1 in the inner layer.

As shown in FIG. 2 , the outer layer of water-swellable material 2 in the monitoring device can wrap the inner layer sensing fiber 1 in a full-section or segmented manner as required, and the segment length is not limited.

The monitoring device is suitable for power cables including submarine cables, land cables, and single-core and three-core cables, and the installation position inside the cable is not limited. It can be installed in the cable filling layer, cable core conductor and other parts according to actual needs. . As shown in Figure 3, the monitoring device for monitoring water ingress of a cable is used as an example to apply to the filling layer of a single-core cable. The monitoring device includes a sensing fiber 1 and a water-swelling material 2. The cable is the cable core conductor from the inside to the outside. 3. Insulating layer inner shield 4, insulating layer 5, insulating layer outer shield 6, filling layer 7, aluminum sheath layer 8 and outer sheath layer 9.

As shown in FIG. 4 and FIG. 5 , according to process requirements, the on-line monitoring device for water ingress of a power cable disclosed in this embodiment can be placed inside the cable by spiral winding or placed in a straight line along the cable axis.

The above-mentioned embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited by the above-mentioned embodiments, and any other changes, modifications, and substitutions made without departing from the spirit and principle of the present utility model , combination and simplification, all should be equivalent replacement methods, which are all included in the protection scope of the present invention.

Claims (7)

1. A power cable water inlet online monitoring device, characterized in that the monitoring device comprises a sensing optical fiber and a water-swellable material, wherein the sensing optical fiber is located in the inner layer of the monitoring device, as a sensor, and simultaneously as a monitoring device. Signal transmission line; the water-absorbing swellable material is located on the outer layer of the monitoring device, tightly wraps the inner-layer sensing optical fiber, and after absorbing water, generates expansion and squeezing force on the inner-layer sensing optical fiber, changing the propagation characteristics of the signal in the sensing optical fiber, By analyzing the signal drawn from the sensing fiber, the real-time monitoring of the water inflow to the cable can be realized. 2 . The online monitoring device for water inflow of a power cable according to claim 1 , wherein the sensing optical fiber is an optical fiber with an optical fiber sensing unit or an optical fiber cable-like structure with a sheath. 3 . 3 . The on-line monitoring device for water inflow of a power cable according to claim 1 , wherein the water-absorbing swellable material is a soft water-absorbing swellable material including hydrophilic rubber. 4 . 4 . The on-line monitoring device for water inflow of a power cable according to claim 1 , wherein the water-absorbing swelling material is cylindrical. 5 . 5. A power cable water inflow online monitoring device according to claim 1, wherein the water-swelling material wraps the inner layer sensing optical fiber in a full-section or segmented manner, wherein the segment length is as required Adjustment. 6 . The online monitoring device for water inflow of a power cable according to claim 1 , wherein the sensor is suitable for power cables including submarine cables, land cables, and single-core and three-core cables. 7 . 7 . The online monitoring device for water inflow of a power cable according to claim 1 , wherein the sensor is arranged inside the cable, and is placed in a spiral winding or a straight line along the axis of the cable. 8 .

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