JPS59214782A - Undersea cable hanging anchor detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 desirable to be able to instantly locate the point where the damage occurred.

The higher the accuracy of the sensing system for undersea cables, such as suspended anchors, used for this purpose, the more quickly response measures can be taken in the event of injury, and the sooner a serious accident occurs. Can you deal with it?

Normally, power cables laid between islands are laid on the bottom of the ocean, but they are often damaged by external forces from anchors, fishing gear, etc.

For example, injuries caused by anchors include dragging anchors, where a ship lowers its anchor onto the seabed and then pulls the cable when it moves, suspended anchors, where the cable is suspended by the anchor, and anchors falling onto cables laid on the seabed. However, 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 for suspended anchors, etc. 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. The accident occurred after receiving a signal from a sensor built into the cable.
A sensing device is needed that can determine the location of the accident, the extent of the accident, etc.

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. To explain this a little, it is as follows.

Figure 1 is a cross-sectional view showing an example of a submarine electric cable.
FIGS. 2(A) and 2(B) are cross-sectional views of the sensing wires installed in the submarine electric cable shown in FIG. 1.

In the figure, 1 indicates an insulated power wire core, 2 indicates a steel wire armor, and 3 indicates a sensing wire.

As shown in FIG. 2 (a), the brown wire 3 has three high-density polyethylene insulation sets 6 arranged around a bare center conductor 5, and three elastic high-density polyethylene insulation sets 6. A bare outer conductor 7 is arranged radially symmetrically with respect to the center conductor 5 along the extra space in the extra space between the strings formed by the groups 6 gathered together, and a flexible outer cover 8 is applied on top of the bare outer conductor 7. In particular, as shown in Figure (B), the conductor deforms in response to external pressure in the direction of the arrow, and the outer conductor 7 and the center conductor 5 come close to each other and eventually come into contact, and the external pressure disappears. In this case, it is equipped with a function to restore the 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 the extra space between the wire cores is created by gathering them together.
By aligning the cables in the length direction, interposing them in the gaps, binding them with a circular cross section, and applying iron wire sheathing to the outer circumferential surface, a submarine cable with sensing wires is formed.

Submarine power cables incorporating sensing wires are already known, but if sensing wires made up of multiple conductors as explained above are placed symmetrically in the radial direction about the center of the cable, these cables can be easily installed. With signals from multiple sensing lines, more and more accurate accident information can 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 targets a sensing cable in which sensing wires composed of a plurality of conductors are arranged radially symmetrically about the center of the cable, and uses the sensing wire signal for sensing an injury as a reference. Controls circuit switching between multiple sensing lines in land pipes, detects (+) injury, and locates 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 to calculate the injury point and transmit information to the display device. (3)
The object of the present invention is to provide a sensing device that performs operations such as displaying an alarm, the point of injury occurrence, and the like.

As with the sensing wire shown in Figure 2, which has already been explained, we conducted experiments to determine the degree of injury when a cable incorporating a central guiding wire receives external pressure from an anchor or other force, and Table 1 shows the degree of injury based on the deformation of the sensing wire. It is possible to establish a screening principle for the degree of injury shown.

Table 1 The present invention not only measures the approximate distance to the point of injury for instantaneous, short-term, and time-independent cable injuries in the clothing 1, but also measures the precise distance if the accident continues. , warning, distance to the point where the injury occurred, etc.

FIG. 3 shows a block diagram of an embodiment of the invention. As shown in the figure, it goes without saying that the IO is a cape with a built-in sensing wire, but the sensing wire 11 built into the cable is preferably the sensing wire shown in FIG. 2, which has already been described. Reference numeral 13 denotes a measurement section F), I4 a control section, and 15 constitutes the basic configuration.

First, the principle of approximate distance measurement when an injury such as a suspended anchor occurs will be explained.

Figure 4 shows the measurement circuit.

In the figure, the sensing line 3 (see Figures 1 and 2) is the center conductor 5.
On the other hand, although only one outer conductor 7 is shown, which is arranged symmetrically with respect to the center, it goes without saying that a plurality of outer conductors 7 may be arranged.

An ammeter 1 is always connected between the center conductor 5 and the outer conductor 7 (multiple conductors).
A DC voltage is applied from the DC power supply 17 via 8i,
For example, if the center conductor 5 and outer conductor 7 come into contact due to an injury at point X in the figure, resulting in a short circuit, 400 conductors...
(1) (A1: Current value, β: Distance to the point where the injury occurred) From this, it is possible to roughly know the distance to the point where the injury occurred.

Further, the principle of precise distance measurement to the point where the injury occurs will be explained using the measurement circuit shown in FIG. 5.

As shown in the figure, among the three sensing wires 3 arranged on the cable, a DC power supply I is connected between the terminals of the center conductor 5 of two sensing wires.
7, and if a short circuit occurs between the center conductor 5 and the outer conductor 7 due to an injury occurring at point The potential difference between X and E2 is β - 100 can.

An example of the measuring section 13 (FIG. 3) of the present invention, which combines two circuits having the functions described above, is the circuit shown in FIG. 6.

In the figure, b indicates the center conductor terminal of the sensing line, and a indicates the outer conductor.

Center conductor in each sensing line 1)1. b2. l) 3 are connected at the other end, each outer conductor a is all left open at the other end, and on the power supply side each outer conductor a in the same sensing line is connected.

R8 is connected between one terminal of the power supply 17 and the center conductor l)1.
゜ Connect the contacts and connect the other terminal of the power supply 17 and aII+ ”
121813, two contacts R are connected between the ammeter A+ and the ammeter A+.

Further, the other terminal of the power source 17 and the center conductor 1)I are connected through a contact RI+R3. As shown in the figure, connections are made between the power supply 17 and the sensing wires through contacts in the other sensing wires, and an ammeter is connected between each contact R and RQ.
8 is also each center conductor, b2. A voltmeter 19 is connected between each center conductor and the outer conductor, and one end of each power source 17 is connected to have the same potential.

In the figure, relay contact R8l ROI, RQ21 RQ
3 is closed and the other contacts are open, for example, b1 to al
If bl and aI+ are short-circuited at l, the approximate distance can be measured by AI, but for example, the measured current value measured at A is input to the minicomputer installed in the control unit 14,
Although a detailed explanation will be omitted, the minicomputer calculates the approximate distance measurement value, maintains the same value, and calculates the duration from the beginning of the accident, so that even after 10 seconds, for example, the approximate distance measurement value is still maintained. When the accident occurs, the display unit 15 displays the fact that an injury has occurred and the approximate distance at which the injury occurred.

The aforementioned 10 seconds is one example, but if the distance measurement value disappears during this time, it is an instantaneous contact injury of the anchor, etc. to the cable in Table 1, and the external pressure applied by the anchor, etc. is released. Think of it as something.

Injuries occurring within this 10 second period can also be recorded each time in the control unit minicomputer.

The above explanation is based on the case of contact or short circuit between the center conductor 5 and one outer conductor 7 within one detection line.
Contact between the other outer conductor 7 and the center conductor 5 in the same detection line,
It is well understood from the drawings that the same effect occurs in the event of a short circuit or when contact damage occurs between the center conductor 5 and the plurality of outer conductors 7 of the plurality of detection wires.

If, for example, one minute has elapsed after the initial approximate distance measurement value was displayed due to the occurrence of an injury, the minicomputer in the control unit 14 determines the elapsed time and displays this on the display 9. and issue warnings, etc.
If necessary, disconnect the cable line in question.

In this case, the minicomputer sends a relay switching signal to the measuring section 13, operates the relay, and switches the contacts.

At this time, the aforementioned contacts R6, Rol, RO2, and R03 are once opened, and then, first, contacts R81 and R1 are closed by a command from the minicomputer, and a DC voltage is generated between the center conductor S and b2. As already explained in FIG. 5, if bl and aI+ are in contact or short-circuited, the minicomputer in the control unit 14 calculates the distance to the point of injury based on the voltage difference EI+E2, and obtains a precise result. The signal is transmitted and displayed on the display device via the modem unit 15i via the line W.

On the other hand, if a2I and b2 contact or short-circuit, contacts R82 and R2 are fully closed, and from this, E, J, E2L,
(, and if a3. and b3 contact or short-circuit, E, II, and E2II can be obtained in the same way, and a more precise distance to the point of injury can be obtained.

However, if the contact state continues, the minicomputer sends switching signals for ROI and R1 and Ro2 and R2 to the control unit 14 and measuring unit I3, and the measuring unit 13 detects the short circuit position each time. The distance to the accident point is determined precisely based on this result. in this case,
The distance to the point of injury should be the same, so it can be expected to be more accurate, and if this kind of contact continues for any length of time, it will be judged as a major injury by using a minicomputer.

In the above explanation, it was explained that the conversion of the measured voltage and current obtained by the measuring section into distance is performed by the control section minicomputer. It can also be converted.

[action, effect]

Here again, if we look at the sensing and binding cables illustrated in FIGS. 1 and 2 and the operation of the embodiment described above, the selection shown in Table 1 can be carried out in the embodiment described above, and if all minicomputers are used, This can be done completely 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, it is possible to adequately distinguish between moderate and severe injuries.
In some cases, measures such as cutting off the cable line can be taken, and the point of injury can be accurately measured.
Repair work can be done quickly.

The present invention relates to submarine cables, such as submarine OF cables, 4C
It can be widely applied to V cables, submarine communication cables, etc.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of an example of a submarine cable with sensing wires. FIGS. 2A and 2B are explanatory views of the cross-sectional structure of the sensing wire and its deformation during compression. FIG. 3 shows the basic configuration 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. ■... Insulated power wire core, 2... Armored iron wire, 3, 11... Sensing wire, 4... Interposition, 5... Center conductor, 6... Insulator, 7... Outer conductor, 8...・・Outer cover, 9・Display device, 1
3...Measurement section, 14.Control section, 15.Modulator/demodulator, 1
6...Power supply, 17...DC power supply. Sho 1 Figure Yoshi 2 Figure A 3 Note 4 Figure-48'

Claims (1)

[Claims] (1) A circuit that applies a voltage between the conductor terminals of the sensing wires of a cable equipped with multiple sensing wires made of multiple conductors, and determines the approximate point of injury from the short-circuit current caused by contact of the conductors to which the voltage is applied. and a circuit that applies a voltage between the conductor terminals of the plurality of sensing wires and determines a precise injury occurrence point from the voltage generated by contact with the conductor of the sensing wire to which no voltage is applied and the applied voltage, A device for sensing a suspended anchor, etc. of a submarine cable, characterized in that it is configured to switch between the two circuits.