Security devices and security systems

Abstract

Identify the location of the cut in the severed cable. [Solution] The first security device 2A comprises a cable 22 having first to fourth wires 231 to 234 and a pipe member 24 housing them, a power supply unit 211 that supplies current to each of the first to fourth wires 231 to 234, first to fourth current detection units 213a to 213d that detect the current supplied by the power supply unit 211, and a cut determination unit 214b that determines whether the cable 22 has been cut based on the detection results from the first to fourth current detection units 213a to 213d. Each of the first to fourth wires 231 to 234 has a forward path 231a to 234a and a return path 231b to 234b that extend within the pipe member 24 to a predetermined turning point and then turn back, and the lengths of the first to fourth wires 231 to 234 in the extending direction are different from each other. The cut detection unit 214b further identifies the cut location of the cut cable 22 based on the detection results from the first to fourth current detection units 213a to 213d.

Description

Technical Field

[0001] The present invention relates to a security device and a security system.

Background Art

[0002] Conventionally, as this type of device, a device configured to detect intrusion into a site has been known (see, for example, Patent Document 1). In the device described in Patent Document 1, a cable is laid along a guardrail provided so as to surround a protected area, and a cable cutting act is detected based on the presence or absence of a current flowing through the cable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, simply detecting that a cable has been cut, as in the device described in Patent Document 1, it is particularly difficult to find the cutting location of a cable surrounding a vast site.

Means for Solving the Problems

[0005] A security device according to one aspect of the present invention includes a cable having a plurality of wires and a pipe member that houses the plurality of wires, a power supply unit that supplies current to each of the plurality of wires, a current detection unit that detects the current supplied by the power supply unit, and a cutting determination unit that determines whether the cable has been cut based on the detection result by the current detection unit. Each of the plurality of wires has an outgoing path and a return path that extend to a predetermined folding position and fold back within the pipe member, the lengths of the plurality of wires in the extending direction are different from each other, and the cutting determination unit further specifies the cutting location of the cut cable based on the detection result by the current detection unit.

[0006] Another aspect of the present invention is a security system comprising the security device, which further includes an alarm output unit that outputs an alarm to a pre-registered communication terminal based on the determination result of the cutting determination unit, and a communication terminal, wherein the cable is arranged to surround a solar power plant equipped with multiple solar panels. [Effects of the Invention]

[0007] According to the present invention, the location of the cut in a severed cable can be identified. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing an example of a solar power plant equipped with a security system that includes a security device according to an embodiment of the present invention. [Figure 2] A diagram showing the first security device attached to the first fence. [Figure 3] A diagram illustrating the arrangement of multiple wires within a cable. [Figure 4] A cross-sectional view of the cable according to this embodiment. [Figure 5] A block diagram showing the main components of the controller. [Figure 6] A circuit diagram showing how to pass current through wires 1 through 4. [Figure 7] A block diagram showing the main components of a communication terminal. [Figure 8] A flowchart showing an example of the cable disconnection detection process performed by the controller's calculation unit. [Modes for carrying out the invention]

[0009] One embodiment of the present invention will be described below with reference to the drawings. In recent years, from the perspective of promoting the use of renewable energy, the number of solar power plants that generate electricity using solar energy has been increasing. Solar power plants that generate electricity by installing a large number of solar panels require a large area of ​​land and are often built in places that are not easily visible to the public. In such solar power plants, PV cables used to connect the solar panels to each other are sometimes stolen. Therefore, in order to prevent the theft of relatively heavy PV cables, security measures are taken to surround solar power plants with fences to make them difficult to remove, but the fences can still be cut and the cables removed.

[0010] To address this, security measures can be taken by installing security devices that detect when the fence has been cut. However, as mentioned above, solar power plants are built on vast sites, making it difficult to locate the cuts simply by detecting when the fence has been cut. Therefore, a security system equipped with security devices that can also identify the cuts in the fence surrounding the solar power plant was configured as follows.

[0011] <Solar power plant> Figure 1 shows an example of a solar power plant 100 equipped with a security system 1 that includes a security device 2 according to an embodiment of the present invention. As shown in Figure 1, the solar power plant 100 is located on a vast site with a perimeter of several hundred meters to several kilometers, and has tens to hundreds of solar panels (solar modules) 101 installed. Each solar panel 101 is made by connecting the required number of solar cells, which are the basic units of solar cells, in series and packaging them with reinforced glass, sealing material, aluminum frame, etc. Each of the multiple solar panels 101 is connected to collect power by a PV cable 102. The PV cable 102 is also used for transmitting power from the solar power plant 100 to a predetermined power grid.

[0012] A fence 110 is erected around the solar power plant 100. In this embodiment, the solar power plant 100 is located on a roughly rectangular site, and the fence 110 consists of first to fourth fences 110A to 110D arranged to surround it on all four sides. The length of each of the first to fourth fences 110A to 110D ranges from several tens to several hundreds of meters.

[0013] Each of the first to fourth fences 110A to 110D comprises a grid-like mesh fence 111 extending in the circumferential direction, a plurality of barbed wires 112 extending in the circumferential direction above the mesh fence 111, and a plurality of support posts 113 that support the mesh fence 111 and the plurality of barbed wires 112. The plurality of support posts 113 are provided at predetermined intervals in the circumferential direction, and each of the circumferentially extending mesh fence 111 and the plurality of barbed wires 112 is fixed to each support post 113.

[0014] Each of the first to fourth fences 110A to 110D is approximately 2.5 to 3 meters high, so that, for example, an average adult male cannot reach the top even if he stretches his arms, and even if he were to climb over the mesh fence 111, it would be difficult to get over due to the barbed wire 112 located at the top. Note that each of the first to fourth fences 110A to 110D may use diamond-shaped wire mesh nut fences or expandable metal fences instead of the grid-like mesh fence 111, and may also be configured without barbed wire 112. Furthermore, the height is not limited to the above and may be higher or lower.

[0015] <Security System> The security system 1 comprises a first security device 2A attached to the first fence 110A, a second security device 2B attached to the second fence 110B, a third security device 2C attached to the third fence 110C, a fourth security device 2D attached to the fourth fence 110D, and a pre-registered communication terminal 3.

[0016] Each of the first to fourth security devices 2A to 2D has a controller 21 and a cable 22, and the cable 22 is attached to each of the first to fourth fences 110A to 110D so as to surround the solar power plant 100. In the present embodiment, each of the first to fourth security devices 2A to 2D is attached to each of the first to fourth fences 110A to 110D in two vertically arranged side by side.

[0017] Each of the two first to fourth security devices 2A to 2D is attached to each of the first to fourth fences 110A to 110D so as to be located at a height of about 20 cm and about 40 cm from the ground. By attaching each of the two first to fourth security devices 2A to 2D at the above height, when the mesh fence 111 of the first to fourth fences 110A to 110D is cut to take out the PV cable 102 from the solar power plant 100, the cable 22 of each of the two first to fourth security devices 2A to 2D is easily cut together with the mesh fence 111 of the first to fourth fences 110A to 110D.

[0018] For example, when cutting the PV cable 102 from the solar panel 101 and taking the PV cable 102 out of the solar power plant 100, it is often dragged out by its weight. Therefore, the mesh fence 111 is often cut at a location close to the ground. Similarly, when entering the solar power plant 100, when the fence 110 is configured to be difficult to climb over by barbed wire 112 or the like, or when securing an escape route in advance, etc., the location close to the ground is often cut. Accordingly, it is preferable that each of the two first to fourth security devices 2A to 2D is provided at equal intervals within a range of 10 to 50 cm from the ground. When only one of the first to fourth security devices 2A to 2D is provided, it is preferably provided within a range of about 10 to 100 cm from the ground.

[0019] In this embodiment, the two first to fourth security devices 2A to 2D are provided at intervals of 20 cm from the ground. However, the number of each of the first to fourth security devices 2A to 2D is not limited to two, and the interval between each of the two first to fourth security devices 2A to 2D is not limited to about 20 cm. In any case, each of the first to fourth security devices 2A to 2D is preferably provided at a low position where the cable 22 is likely to be cut together with the mesh fence 111 when the mesh fence 111 is cut.

[0020] The communication terminal 3 is configured to be able to communicate with each of the first to fourth security devices 2A to 2D via a communication network. The communication network includes not only public wireless communication networks represented by the Internet network, mobile phone networks, etc., but also closed communication networks provided for each predetermined management area, such as wireless LAN, Wi-Fi (registered trademark), etc.

[0021] In FIG. 1, a portable terminal is shown as the communication terminal 3. However, a personal computer may be registered as the communication terminal, or a plurality of devices including the portable terminal and the personal computer may be registered as the communication terminal.

[0022] <The first to fourth security devices> Since each of the first to fourth security devices 2A to 2D has the same configuration, here, the configuration of the first security device 2A will be described, and for the configurations of the second to fourth security devices 2B to 2D, the description of the first security device 2A will be incorporated and the description will be omitted.

[0023] Figure 2 shows the first security device 2A attached to the first fence 110A. As shown in Figure 2, the first security device 2A includes a controller 21 attached to a support post 113 located at one end of the first fence 110A, and a cable 22 attached to the mesh fence 111 so as to extend from the controller 21 toward a support post 113 located at the other end of the first fence 110A. When the cable 22 is cut together with the mesh fence 111, the controller 21 performs a cable cut detection process to identify the location of the cut in the cable 22. The specific configuration of the controller 21 will be described later.

[0024] Figure 3 illustrates the arrangement of multiple wires 23 placed within a cable 22. As shown in Figure 3, the cable 22 comprises n wires 23 and a tubular member 24 that houses the n wires 23, and is divided into first to nth areas 251 to 25n depending on the arrangement of the n wires 23.

[0025] Specifically, the n wires 23 consist of a first wire 231, a second wire 232, a third wire 233, ..., and an nth wire 23n. The first wire 231 extends from the controller 21 (one end of the first fence 110A) to the first position 261, the second wire 232 extends from the controller 21 to the second position 262, the third wire 233 extends from the controller 21 to the third position 263, ..., and the nth wire 23n extends from the controller 21 to the other end of the first fence 110A (the nth position 26n). Then, the section from the controller 21 to the first position 261 constitutes the first area 251, the section from the first position 261 to the second position 262 constitutes the second area 252, the section from the second position 262 to the third position 263 constitutes the third area 253, ..., and the section from the (n-1) position to the other end of the cable 22 constitutes the nth area 25n.

[0026] In the first area 251, all wires 1 through n (231 through 23n) are wired; in the second area 252, wires 2 through n (232 through 23n) are wired; in the third area 253, wires 3 through n (232 through 23n) are wired; and in the nth area 25n, only wire n (23n) is wired. This allows the area containing the break in the cable 22 to be identified based on the number of broken wires 23. For example, if n wires are found to be broken, it can be determined that the cable 22 was cut in the first area 251; and if (n-1) wires are found to be broken, it can be determined that the cable 22 was cut in the second area 252.

[0027] The following describes an example in which a cable 22 having wires 1 to 4 (231 to 234) is partitioned into 1st to 4th areas (251 to 245) by these wires.

[0028] Figure 4 is a cross-sectional view of the cable 22 according to this embodiment. As shown in Figure 4, the cable 22 comprises wires 1 to 4 231 to 234 and a pipe member 24 that houses wires 1 to 4 231 to 234.

[0029] Each of the wires 1 to 4, 231 to 234, has a forward path and a return path that extend to a predetermined turning point and then turn back. Specifically, wire 1, 231, is configured in a bent shape with a forward path 231a extending from the controller 21 to the first position 261, and a return path 231b that turns back at the first position 261 and extends to the controller 21. Wire 2, 232, is configured in a bent shape with a forward path 232a extending from the controller 21 to the second position 262, and a return path 232b that turns back at the second position 262 and extends to the controller 21. Wire 3, 233, is configured in a bent shape with a forward path 233a extending from the controller 21 to the third position 263, and a return path 233b that turns back at the third position 263 and extends to the controller 21. The fourth wire 234 is configured in a folded shape, having a forward path 234a extending from the controller 21 to the fourth position 264, and a return path 234b that turns back at the fourth position 264 and extends back to the controller 21.

[0030] The lengths from the controller 21 to the first to fourth positions 261 to 264 are different from each other, and the first to fourth positions 261 to 264 are arranged such that the circumferential lengths of the first area 251, second area 252, third area 253, and fourth area 254 are the same. As a result, the second wire 232 is twice the length of the first wire 231, the third wire 233 is three times the length of the first wire 231, and the fourth wire 234 is four times the length of the first wire 231.

[0031] The pipe member 24 is configured to accommodate wires 1 to 4 231 to 234, and in this embodiment, a resin corrugated tube is used for the pipe member 24. Wires 1 to 4 231 to 234 housed inside the corrugated tube are bundled together. Since resin corrugated tubes are easy to bend and have strong resistance to impact and compression, using a resin corrugated tube improves the workability when attaching the cable 22 to the first fence 110A.

[0032] In this embodiment, an example using a corrugated tube for the pipe member 24 has been described, but the pipe member is not limited to this. It may also be a tubular structure made of synthetic resin such as polyethylene resin (PE) or polyvinyl chloride (PV) capable of housing the bundled wires 1 to 4 231 to 234 arranged in the above configuration, or the bundled wires 1 to 4 231 to 234 may be wrapped with tape such as polyvinyl chloride to cover them. Furthermore, the bundled wires 1 to 4 231 to 234 arranged in the above configuration may be integrated with synthetic resin. For example, a heat-shrinkable tube made of polyolefin resin may be used.

[0033] Figure 5 is a block diagram showing the main components of the controller 21. As shown in Figure 5, the controller 21 is composed of a computer having a power supply unit 211 that supplies current to each of the first to fourth wires 231 to 234, first to fourth grounding units 212a to 212d that ground each of the first to fourth wires 231 to 234, first to fourth current detection units 213a to 213d that detect the current flowing through each of the first to fourth wires 231 to 234, an arithmetic unit 214 such as a CPU, a storage unit 215 such as RAM, ROM, or hard disk, a communication unit 216, and other peripheral circuits not shown such as an I / O interface.

[0034] Figure 6 is a circuit diagram showing how current flows through wires 1 to 4, 231 to 234. As shown in Figure 6, the power supply unit 211 applies a voltage to one end of each of the first to fourth wires 231 to 234, which are arranged in parallel (the end on the forward path 231a to 234a side). The first to fourth grounding units 212a to 212d each ground the other end of each of the first to fourth wires 231 to 234 (the end on the return path 231b to 234a side). The first to fourth current detection units 213a to 213d each detect the current flowing through each of the first to fourth wires 231 to 234 based on the potential difference between the power supply unit 211 and the first to fourth grounding units 212a to 212d.

[0035] The calculation unit 214 has, functionally, an information receiving unit 214a, a disconnection determination unit 214b, and an alarm output unit 214c. The information receiving unit 214a receives detection results (e.g., current value or presence or absence of current) detected by each of the first to fourth current detection units 213a to 213d. The disconnection determination unit 214b determines whether the cable 22 has been disconnected based on the detection results detected by each of the first to fourth current detection units 213a to 213d, and if it determines that the cable has been disconnected, it identifies the location of the disconnection of the cable 22.

[0036] Specifically, the break detection unit 214b identifies the number of broken wires 23 among the first to fourth wires 231 to 234 based on the detection results detected by each of the first to fourth current detection units 213a to 213d, and identifies the break location based on the identified number. For example, if four wires 23 are broken, it determines that the cable 22 in the first area 251, where the four wires 23 are wired, has been cut, and identifies the first area 251 as the break location. If three wires 23 are broken, it determines that the cable 22 in the second area 252, where the three wires 23 are wired, has been cut, and identifies the second area 252 as the break location. If two wires 23 are broken, it determines that the cable 22 in the third area 253, where the two wires 23 are wired, has been cut, and identifies the third area 253 as the break location. Furthermore, if only one wire 23 is broken, it is determined that the cable 22 in the fourth area 254 to which the single wire 23 is routed has been cut, and the fourth area 254 is identified as the location of the break.

[0037] The alarm output unit 214c outputs an alarm or the like to a pre-registered communication terminal 3 based on the determination result by the disconnection determination unit 214b. Specifically, when the disconnection determination unit 214b determines that the cable 22 has been cut, the alarm output unit 214c outputs information about the area identified by the disconnection determination unit 214b (information about the location of the cut) along with the alarm to the communication terminal 3. For example, the identified area name is output to the communication terminal 3 along with the alarm.

[0038] The memory unit 215 stores various programs and data executed by the calculation unit 214. For example, it stores the judgment program performed by the disconnection judgment unit 214b, and area information for the first to fourth security devices 2A to 2D, which are associated with the first to fourth fences 110A to 110D, respectively.

[0039] The communication unit 216 is configured to wirelessly communicate with pre-registered communication terminals 3 via a communication network. For example, the communication unit 216 is configured to wirelessly communicate with multiple devices, including communication terminals 3 held by personnel of a security company guarding the solar power plant 100, and personal computers owned by the security company.

[0040] <Communication terminal> Figure 7 is a block diagram showing the main components of the communication terminal 3. The communication terminal 3 is a mobile terminal carried by a security company employee responsible for guarding the solar power plant 100, and consists of a portable wireless terminal such as a smartphone.

[0041] As shown in Figure 7, the communication terminal 3 is composed of a computer having an arithmetic unit 31 such as a CPU, a storage unit 32 such as RAM, ROM, or hard disk, a communication unit 33, an input / output unit 34, and other peripheral circuits (not shown) such as an I / O interface.

[0042] The communication unit 33 is configured to wirelessly communicate with the controller 21 and other communication terminals 3 via a communication network. For example, in addition to the controller 21, it is configured to wirelessly communicate with multiple devices, including portable terminals and personal computers owned by the administrator managing the solar power plant 100. The input / output unit 34 is a general term for devices that input and output various commands and information, and is composed of monitors, touch panels, etc. Personnel holding a communication terminal 3 can also view video of a specified area via the input / output unit 34 through cameras or other devices separately installed at the solar power plant 100.

[0043] The calculation unit 31 has, functionally speaking, an information receiving unit 311 and an information display unit 312. The information receiving unit 311 receives various information transmitted from the controller 21 via the communication unit 33. For example, the information receiving unit 311 receives area information (information on the disconnection location) and alarms identified by the disconnection determination unit 214b transmitted from the controller 21. The information display unit 312 displays the various information received by the information receiving unit 311 on the input / output unit (monitor) 34. For example, the information display unit 312 displays the area information received by the information receiving unit 311 on the input / output unit (monitor) 34.

[0044] The memory unit 32 stores various programs and data executed by the arithmetic unit 31. For example, the memory unit 32 stores a display program that displays area information transmitted from the controller 21 on the input / output unit (monitor) 34.

[0045] Figure 8 is a flowchart showing an example of the cable break detection process performed by the calculation unit 214 of the controller 21. The process shown in this flowchart starts when the power supply unit 211 of the controller 21 is turned ON and current flows through each of the first to fourth wires 231 to 234.

[0046] First, in step S1, the information receiving unit 214a receives the detection results detected by the first to fourth current detection units 213a to 213d. Next, based on the received detection results, the disconnection determination unit 214b identifies the number of disconnected wires 23. In step S2, it is determined whether or not only one wire is disconnected. If the result in step S2 is positive, in step S3, the disconnection determination unit 214b identifies that the cable 22 in the fourth area 254 has been disconnected. If the result in step S2 is negative, the process proceeds to step S4.

[0047] In step S4, it is determined whether there are two broken wires or not. If the result in step S4 is positive, in step S5, the break detection unit 214b identifies that the cable 22 in the third area 253 has been cut. If the result in step S4 is negative, the process proceeds to step S6. In step S6, it is determined whether there are three broken wires or not. If the result in step S6 is positive, in step S7, the break detection unit 214b identifies that the cable 22 in the second area 252 has been cut. If the result in step S6 is negative, the process proceeds to step S8. In step S8, it is determined whether there are four broken wires or not. If the result in step S8 is positive, in step S9, the break detection unit 214b identifies that the cable 22 in the first area 251 has been cut. If the result in step S8 is negative, it is determined that there are no broken wires and the cable 22 has not been cut, and the process returns to step S1.

[0048] If, in steps S3, S5, S7, or S9, it is determined that a cable 22 in any of the first to fourth areas has been severed, then in step S10, the alarm output unit 214c outputs the severed area information along with the alarm information to the communication terminal 3 via the communication unit 216, and the process ends.

[0049] The operation of the security system 1 according to this embodiment can be summarized as follows. First, when the power supply units 211 of the first to fourth security devices 2A to 2D are turned ON, current flows through the first to fourth wires 231 to 234 of the first to fourth security devices 2A to 2D, respectively. Subsequently, when a cable 22 of any of the first to fourth security devices 2A to 2D is cut, the area where the cable 22 was cut is identified based on the detection results from the first to fourth current detection units 213a to 213d of the first to fourth security devices 2A to 2D, respectively. After that, the information of the cut area is transmitted to a pre-registered communication terminal 3 along with an alarm.

[0050] This embodiment can provide the following effects and advantages. (1) The first security device 2A according to this embodiment includes a cable 22 having first to fourth wires 231 to 234 and a tubular member 24 that houses the first to fourth wires 231 to 234, a power supply unit 211 that supplies current to each of the first to fourth wires 231 to 234, first to fourth current detection units 213a to 213d that detect the current supplied by the power supply unit 211, and a cut determination unit 214b that determines whether or not the cable 22 has been cut based on the detection results from the first to fourth current detection units 213a to 213d. Each of the first to fourth wires 231 to 234 has forward paths 231a to 234a and return paths 231b to 234b that extend within the tubular member 24 to each of the first to fourth positions 261 to 264 and then fold back, and the lengths of the first to fourth wires 231 to 234 in the extending direction are different from each other. The cut detection unit 214b further identifies the cut location of the cut cable 22 based on the detection results from the first to fourth current detection units 213a to 213d.

[0051] This configuration allows for the identification of not only the cable 22 being cut, but also the location of the cut. Therefore, it is possible to install suitable security equipment even for facilities built on large plots of land.

[0052] (2) In the first security device 2A described in (1), the cut determination unit 214b determines the number of broken wires 23 among the first to fourth wires 231 to 234 based on the detection results from the first to fourth current detection units 213a to 213d, and identifies the cut location based on the determined number. With this configuration, the cut location of the cable 22 is identified based on the number of wires 23 housed in the cable 22, so the cut location of the cable 22 can be identified with a simple configuration.

[0053] (3) In the first security device 2A described in (1) or (2), the multiple wires 23 are n wires 23, and the cut determination unit 214b identifies one of the n areas obtained by dividing the cable 22 according to the length of each of the n wires 23 as the cut location. With this configuration, the cable 22 is divided into multiple areas based on the number of wires 23, so the cut location of the cable 22 can be identified as an area. In addition, on a large site, the distance between the divided areas can be shortened by increasing the number of wires 23, making it easier to identify the cut location of the cable 22.

[0054] (4) The first security device 2A described in any one of (1) to (3) further comprises an alarm output unit 214c that outputs an alarm to a pre-registered communication terminal 3 based on the determination result of the cut determination unit 214b, and the alarm output unit 214c outputs information of the cut location identified by the cut determination unit 214b to the communication terminal 3 along with the alarm. With this configuration, when the cable 22 is cut, information can be immediately sent to the communication terminal 3. At this time, information of the cut location is also sent, making it easy to identify the cut location, and for example, one can go directly to the cut location.

[0055] (5) The security system 1 comprises the first security device 2A described in (4) and a communication terminal 3, and the cable 22 is arranged to surround the solar power plant 100 on which multiple solar panels 101 are installed. With this configuration, a suitable security device can be installed for the solar power plant 100, and an efficient security system can be constructed even for solar power plants 100 located on a large site that is not easily visible to the public.

[0056] The above embodiment can be modified into various forms. Modifications will be described below.

[0057] In the above embodiment, a security system 1 was described using first to fourth security devices 2A to 2D to surround the solar power plant 100, but the number of security devices 2 surrounding the solar power plant 100 is not limited to this. The security system may be configured such that, for example, the length of the cable 22 is long enough to surround the solar power plant 100, with one security device 2 surrounding the solar power plant 100, or it may be configured with two or more security devices 2 surrounding the solar power plant 100. By changing the number of security devices 2 used based on the site area (size) of the solar power plant 100, an efficient security system 1 can be constructed.

[0058] In the above embodiment, the solar power plant 100 is surrounded by the first to fourth security devices 2A to 2D. However, the solar power plant 100 may be surrounded by the cables 22 of the first to fourth security devices 2A to 2D, and the detection results of the current detection unit may be acquired by wireless communication. In other words, a part of the controller 21 may be located away from the cables 22. By making a part of the controller 21 a separate unit, centralized management of multiple security devices 2 becomes easier, and cost reduction can be expected.

[0059] In this embodiment, the first security device 2A divides one cable 22 into four areas (first to fourth areas 251 to 254) using four wires (first to fourth wires 231 to 234), and identifies the cut area from among the four areas (first to fourth areas 251 to 254). However, the number of wires 23 and the number of areas are not limited to this, and a configuration in which n wires are used to divide one cable 22 into n areas to identify the cut area may also be used.

[0060] In this embodiment, the number of broken wires 23 among the first to fourth wires 231 to 234 was determined, and the cutting location was identified based on the determined number. However, it is also possible to determine the combination of broken wires 23 among the first to fourth wires 231 to 234, and identify the cutting location based on the determined combination. For example, the combination of the first wire 231 and the second wire 232, the combination of the first to third wires 231 to 233, and the combination of the first to fourth wires 231 to 234 may be determined, and the cutting location may be identified based on these combinations.

[0061] In this embodiment, an example of applying the security system 1, which includes a security device 2, to a solar power plant 100 has been described. However, the security system 1 can be applied to facilities other than solar power plants 100. For example, it can be suitably used in facilities (including farmland, etc.) located on large plots of land that are not easily visible to the public.

[0062] The above description is merely an example, and the present invention is not limited by the embodiments and modifications described above, as long as the features of the present invention are not impaired. It is also possible to arbitrarily combine one or more of the above embodiments and modifications, and to combine modifications with each other. [Explanation of Symbols]

[0063] 1 Security system, 2 Security device, 2A First security device, 3 Communication terminal, 21 Controller, 22 Cable, 23 Wire, 24 Pipe component, 100 Solar power plant, 101 Solar panel, 211 Power supply unit, 213a~213d First to fourth current detection unit, 214b Cutting detection unit, 231~234 First to fourth wire, 231a~234a Outbound path, 231b~234b Return path

Claims

1. A cable having multiple wires and a tubular member that houses the multiple wires, A power supply unit that supplies current to each of the aforementioned multiple wires, A current detection unit for detecting the current supplied by the power supply unit, The system includes a disconnection determination unit that determines whether or not the cable has been cut based on the detection result from the current detection unit, Each of the plurality of wires has a forward path and a return path that extend within the pipe member to a predetermined turning point and then turn back. The lengths of the aforementioned plurality of wires in the extending direction are different from each other. The security device is characterized in that the cut determination unit further identifies the cut location of the cut cable based on the detection result by the current detection unit.

2. In the security device described in claim 1, The security device is characterized in that the break detection unit determines the number of broken wires among the plurality of wires based on the detection result by the current detection unit, and identifies the break location based on the determined number.

3. In the security device described in claim 1, The security device is characterized in that the break detection unit determines the combination of broken wires among the plurality of wires based on the detection result by the current detection unit, and identifies the break location based on the determined combination.

4. In the security device according to any one of claims 1 to 3, The aforementioned plurality of wires are n wires, The security device is characterized in that the cut determination unit identifies one of the n areas obtained by dividing the cable according to the length of each of the n wires up to the bend position as the cut location.

5. In the security device according to any one of claims 1 to 3, The system further includes an alarm output unit that outputs an alarm to a pre-registered communication terminal based on the determination result from the disconnection determination unit. The alarm output unit is characterized by outputting information of the cut location identified by the cut determination unit to the communication terminal along with the alarm.

6. The security device described in claim 5, The communication terminal and, A security system characterized in that the aforementioned cables are arranged to surround a solar power plant equipped with multiple solar panels.

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