JPH0231829B2 - KAITEIKEEBURUNOKENBYOTOKANCHISOCHI - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a device for sensing suspended anchors, etc. of laid submarine cables. [Background technology] When a laid submarine cable is damaged by a ship's anchor, etc., it is necessary to detect this quickly and reliably, and at the same time, it is extremely important to be able to instantly locate the point where the damage occurred. desirable. The higher the accuracy of the submarine cable anchor detection system used for this purpose, the better.
In the event of an injury, it is possible to take prompt action and take action before a serious accident occurs. Usually, the power cables laid between islands are
Although it is installed on the bottom several tens of meters below the ocean floor, it is not an anchor. Cables are often injured by external forces such as fishing gear. For example, injuries caused by anchors include dragging anchors, where the cable is caught when the ship moves with the anchor on the seabed, hanging anchors, where the cable is suspended by the anchor, and accidents where the anchor falls onto a cable laid on the seabed. In these cases, including those caused by fishing gear, cables are more or less subject to damage such as compressive deformation, bending, and destruction. Therefore, as mentioned above, a sensing system such as a suspended anchor is required, but as can be understood from the above explanation, first of all, it is necessary for the submarine cable itself to be equipped with some kind of sensor. There is a need for a sensing device that can receive signals from a sensor built into the cable and determine the occurrence of an accident, the location of the accident, and the extent of the accident. For this reason, the present applicant and others previously proposed a submarine power cable with sensing wires as shown in FIGS. 1 and 2 as an example. A brief explanation of this is as follows. FIG. 1 is a sectional view showing an example of a submarine power cable, and FIGS. 2A and 2B are sectional views of sensing wires incorporated into the submarine power cable of FIG. In the figure, 1 indicates an insulated power wire core, 2 indicates a steel wire armor, and 3 indicates a sensing wire. The sensing wire 3 is made by arranging three high-density polyethylene insulated strings 6 around a bare center conductor 5, and three elastic high-density polyethylene insulating strings 6 as shown in FIG. A bare outer conductor 7 is arranged radially symmetrically with respect to the center conductor 5 along the remaining space between the strings, and a flexible outer sheath 8 is applied thereon. (b) As shown in the figure,
The outer conductor 7 deforms due to external pressure in the direction of the arrow.
and the center conductor 5 are close to each other and eventually come into contact with each other, and when the external pressure is removed, it has a function of restoring to a non-contact state within a certain range of external force. The three sensing wires 3 having such a configuration are twisted around the three insulated power wire cores 1, and aligned in the length direction of the cable in the free space between the wire cores created by gathering them, leaving no intervention in the gap. A submarine cable with sensing wires is formed by binding the wires with a circular cross section and applying iron wire sheathing to the outer circumferential surface. Submarine power cables incorporating sensing wires are already known, but if sensing wires made up of multiple conductors as explained above are arranged radially symmetrically from the center of the cable, these multiple The signal from the sensing line allows more and more accurate accident information to be obtained from any direction, even if there is contact with an anchor or the like. [Disclosure of the Invention] As explained above, the present invention is directed to a cable with a sensing wire in which sensing wires made of a plurality of conductors are arranged symmetrically in the radial direction from the center of the cable.
Based on the sensing line signal that detects an injury, circuit switching between multiple sensing lines is controlled on land, etc.
(1) Detect injuries and locate the point of injury. (2) Based on the circuit switching control of the measuring section and the results obtained by the measuring section, the minicomputer performs processing for calculating the point of injury occurrence and transmitting the information to the display device. (3) Alarm;
It is an object of the present invention to provide a sensing device that performs operations such as displaying the point of injury occurrence, etc. As shown in the sensing wire in FIG.
An experiment was conducted to determine the degree of injury when a cable incorporating a sensing wire in which a plurality of outer conductors 7 are centrally arranged centrally symmetrically is subjected to an external pressure such as an anchor, and the degree of injury is shown in Table 1 based on the deformation state of the sensing wire. It is possible to establish a principle for selecting the degree of injury.

[action, effect]

Here again, if we look at the cables with sensing wires and the operations in the embodiments illustrated in FIGS. This can be done automatically. According to the present invention, even in the case of minor injuries shown in Table 1, it is possible to record the number of occurrences of minor injuries that occur frequently, and even the date and time in some cases. Furthermore, since it is possible to sufficiently distinguish between moderate and severe injuries, it is possible to take measures such as cutting off the cable line if necessary, and since the point of injury can be accurately measured, repair work can be carried out quickly. . The present invention can be widely applied to submarine cables, such as submarine OF cables, CV cables, and submarine communication cables.

[Brief explanation of drawings]

FIG. 1 shows a cross-sectional view of an example of a submarine cable with sensing wires. FIGS. 2A and 2B are explanatory diagrams of the cross-sectional structure of the sensing wire and its deformation during compression. FIG. 3 shows the basic structure of the sensing device of the present invention in a block diagram. FIGS. 4 and 5 are explanatory diagrams of injury point detection according to the present invention. FIG. 6 shows an example of the measuring circuit of the present invention. 1... Insulated power wire core, 2... Armored iron wire, 3,1
1... Sensing line, 4... Intervening, 5... Center conductor, 6
...Insulating string, 7...Outer conductor, 8...Outer sheath, 9...
...display device, 13...measuring section, 14...control section,
15...modulator/demodulator, 16...power supply, 17...DC power supply.

Claims (1)

[Claims] 1. A circuit that applies a voltage between the conductor terminals of the sensing wires of a cable provided with a plurality of sensing wires each consisting of a plurality of conductors, and determines the approximate point of injury occurrence from a short circuit current caused by contact of the conductors to which the voltage is applied; A circuit is provided for applying a voltage between the conductor terminals of a plurality of sensing wires and determining a more precise point of injury occurrence from the partial voltage generated by contact with the conductor of the sensing wire to which no voltage is applied and the applied voltage. A sensing device for a suspended anchor, etc. of a submarine cable, characterized in that it is configured to switch.