Cable theft detecting system

Abstract

To provide a cable theft detecting system that realizes a function to detect a theft of a cable earlier and output an alarm at a low cost.SOLUTION: A cable theft detecting system 1 comprises: a cable 10 (10a, 10b) that transfers direct-current power; a crime prevention line 20 that is placed parallel to the cable 10 (10a, 10b); and an alarm device 30 connected to one end and the other end of the crime prevention line 20, which steadily supplies current from one end of the crime prevention line 20 to the other end, and which outputs an alarm signal to a remote report device 40 if no current is output from the other end of the crime prevention line 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cable theft detection system. [Background technology]

[0002] With the price of copper rising and its availability becoming increasingly difficult, there have been many cases of thefts in which power transmission cables have been cut and stolen. In particular, solar power generation sites are often located in large vacant lots with few neighbors, as they do not generate electricity at night, reducing the risk of electric shock during thefts. This has led to frequent thefts of thick trunk cables that collect DC power generated by solar panels and transmit it to power distribution panels and PCSs. In response to this issue, Patent Document 1 discloses a power conditioner that measures the capacitance between the DC input terminal connected to the solar panel and the ground terminal via the cable, detects a break in the cable based on the measured capacitance value, and notifies the user of the abnormality. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-169263 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 does not notify of an abnormality until the cable is cut, which could allow the thief to escape, and if a power conditioner is already installed, it would need to be replaced with the above-mentioned power conditioner, which could increase the labor and cost involved. Therefore, the problem that the present invention aims to solve is to provide a cable theft detection system that can detect cable theft more quickly and output an alarm at low cost. [Means for solving the problem]

[0005] The present invention has been made to solve at least some of the above-mentioned problems, and can be realized in the following aspects or application examples.

[0006] [Application example 1] The cable theft detection system of this application example is characterized by comprising a cable that transmits DC power, a security line arranged parallel to the cable, and an alarm device that is connected to one end and the other end of the security line, flows a steady current from one end to the other end of the security line, and outputs an alarm signal to a remote reporting device if the current is not output from the other end of the security line. In the cable theft detection system according to this application example, a security wire is installed parallel to the cable transmitting DC power, so if the cable is cut, there is a high possibility that the security wire will also be cut at the same time. In environments with high noise levels, methods that monitor the voltage between any two points on the security wire are prone to erroneously determining that the security wire is not cut due to noise voltage, even if it is cut. However, the cable theft detection system according to this application example is less susceptible to noise because it monitors the current flowing through the security wire. Furthermore, with the cable theft detection system according to this application example, if the security wire is cut before the cable is cut, the alarm device can detect the cable theft more quickly and output an alarm. Furthermore, since the security wire and alarm device can be added to existing equipment, there is no need to replace the existing equipment, and a cable theft detection system can be realized at low cost.

[0007] [Application example 2] In the cable theft detection system according to the above application example, the cable and the security wire may be housed in an internal space of a flexible pipe, and the security wire may be wound around the cable. According to the cable theft detection system of this application example, the security wire is housed together with the cable in the same internal space of the flexible pipe, which increases the probability that the security wire will also be cut when the cable is cut. Furthermore, because the security wire is wrapped around the cable, it is more likely that the security wire will be cut before the cable, which allows the alarm device to detect cable theft more quickly and issue an alarm.

[0008] [Application example 3] In the cable theft detection system according to the above application example, at least a portion of the security line may be a shielded twisted pair cable, and the twisted pair cable may have a first core wire and a second core wire that form a twisted pair, and a shielding material that is arranged to cover the first core wire and the second core wire, and one end of the first core wire and one end of the second core wire may be connected, and the shielding material may be grounded. In the cable theft detection system according to this application example, the shielding material is grounded, thereby reducing the first core wire-to-ground noise and the second core wire-to-ground noise. Furthermore, the first core wire and the second core wire form a twisted pair, thereby reducing the difference between the first core wire-to-ground noise and the second core wire-to-ground noise, thereby reducing the first core wire-to-second core wire noise. In this way, the cable theft detection system according to this application example can be expected to have a noise suppression effect, thereby reducing the risk of the alarm device malfunctioning due to noise.

[0009] [Application example 4] In the cable theft detection system according to the above application example, the twisted pair cable may further have a third core wire arranged parallel to the first core wire and the second core wire, and the third core wire may be grounded. In the cable theft detection system according to this application example, the shielding material and the third core wire are grounded, thereby reducing the first core wire-to-ground noise and the second core wire-to-ground noise. Furthermore, the first core wire and the second core wire form a twisted pair, thereby reducing the difference between the first core wire-to-ground noise and the second core wire-to-ground noise, thereby reducing the noise between the first core wire and the second core wire and reducing the risk of the alarm device malfunctioning due to noise.

[0010] [Application example 5] In the cable theft detection system according to the above application example, the cable may be housed in the internal space of a flexible tube in which a steel wire is spirally embedded, the security cable may have a first core wire and a second core wire, a portion of the first core wire may be housed in the internal space of the flexible tube, one end of the second core wire may be connected to one end of the steel wire, and one end of the first core wire may be connected to the other end of the steel wire. According to the cable theft detection system of this application example, the steel wire built into the flexible pipe, which forms part of the security line, is cut before the cable is cut, allowing the alarm device to detect cable theft more quickly and output an alarm.

[0011] [Application Example 6] In the cable theft detection system according to the above application example, the cable may be housed in the internal space of a flexible pipe, and part of the security line may be a pseudo cable that imitates the cable, and the pseudo cable may be housed in the internal space of a flexible pipe different from the flexible pipe. According to the cable theft detection system of this application example, if a thief cuts a dummy cable by mistake, thinking it is a real cable that transmits DC power, an alarm is sounded before the real cable is stolen. The alarm device can detect the theft of the dummy cable and output an alarm. Furthermore, even if the dummy cable is cut, it does not affect the transmission of DC power through the real cable, reducing the cost and labor required for restoration work.

[0012] [Application Example 7] In the cable theft detection system according to the above application example, the cable may be fixed by a filler that fills a part of the interior of the flexible pipe. According to the cable theft detection system of this application example, even if a thief cuts the cable, he or she cannot easily pull it out or quickly take it away, which is expected to have the effect of discouraging cable theft.

[0013] [Application Example 8] In the cable theft detection system according to the above application example, the security line may have a plurality of detachable connection parts. According to the cable theft detection system of this application example, the security line can be broken not only when the cable is cut, but also when the connection comes loose due to the tension when the cable is pulled out, allowing the alarm device to detect cable theft more quickly and output an alarm.

[0014] [Application Example 9] The cable theft detection system according to the above application example includes a lighting device and a siren device, and the alarm device may operate the lighting device and the siren device when the current is not output from the other end of the security line. According to the cable theft detection system of this application example, when the security cable is cut, the lighting device and siren device are activated, which is expected to intimidate thieves and deter them from committing theft.

[0015] [Application Example 10] In the cable theft detection system according to the above application example, the cable may be a trunk cable that transmits DC power generated by solar panels installed at a solar power generation site. According to the cable theft detection system of this application example, the main cable that transmits the DC power generated by the solar panels is large in diameter and expensive, making it vulnerable to theft. However, the alarm device can detect the theft of the main cable more quickly and issue an alarm. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating an example of the configuration of a cable theft detection system according to a first embodiment. [Figure 2] 1 is a diagram illustrating a configuration of an alarm device and an example of connections with peripheral devices. [Figure 3] 3A to 3C are diagrams illustrating examples of mounting cables, security lines, and the like in the first embodiment. [Figure 4] (A) is an explanatory diagram of noise when the security line is a simple cable, (B) is an explanatory diagram of noise when the security line is a shielded twisted pair cable, and (C) is an explanatory diagram of noise when the security line is a shielded twisted pair cable with an open core. [Figure 5] FIG. 1 is a perspective view of a flexible pipe with steel wires. [Figure 6] 10A and 10B are diagrams illustrating examples of mounting cables, security lines, and the like in the second embodiment. [Figure 7] FIG. 10 is a diagram illustrating an example of the configuration of a cable theft detection system according to a third embodiment. [Figure 8] FIG. 10 is a diagram illustrating an example of the configuration of a cable theft detection system according to a fourth embodiment. [Figure 9] FIG. 10 is a diagram illustrating another example of the configuration of the cable theft detection system according to the fourth embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of the configuration of a cable theft detection system according to a fifth embodiment. [Figure 11] 1A and 1B are diagrams illustrating examples of laying cables and pseudo cables. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The drawings used in this description are for the convenience of explanation. Note that the embodiments described below do not unduly limit the content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0018] The following description will be given taking as an example a cable theft detection system that detects theft of cables laid at a solar power generation site.

[0019] 1. First embodiment FIG. 1 is a diagram illustrating an example of the configuration of a cable theft detection system 1 according to a first embodiment. As shown in FIG. 1, the cable theft detection system 1 is constructed at a photovoltaic (PV) site 100. In FIG. 1, DC power generated by each of a plurality of solar panels 2 installed at the solar power generation site 100 is collected at a junction box 3 via a string cable 6, and the collected DC power at the junction box 3 is transmitted to a power collection panel 4 via cables 10 (10a, 10b). The cables 10 (10a, 10b) are trunk cables installed at the solar power generation site 100 and transmit the DC power generated by each of the solar panels 2. Specifically, the cable 10a is a trunk cable that transmits P-phase power, and the cable 10b is a trunk cable that transmits N-phase power. At a solar power generation site 100 where a large number of solar panels 2 are installed, the solar panels 2 are divided into multiple groups, and the DC power generated by each of the multiple solar panels 2 belonging to each group is collected in a corresponding junction box 3. The DC power collected in each junction box 3 is transmitted by cables 10 (10a, 10b) and collected in a collector board 4. The DC power collected in the collector board 4 is converted into AC power (three-phase 400V AC) by a PCS (Power Conditioning System) 5 and sent to, for example, an electric power company via an AC power cable 7.

[0020] The cables 10 (10a, 10b) are thick cables of about 38 sq. to 100 sq. in order to transmit high voltages of about 400 V to 1500 V. Therefore, the cables 10 are expensive and have a high risk of being cut and stolen. To reduce the risk of theft of the cables 10, the cable theft detection system 1 is equipped with a security line 20 and an alarm device 30. The security line 20 is arranged in parallel with the cables 10 (10a, 10b). That is, the security line 20 is arranged in the vicinity of the cables 10 (10a, 10b) so as to run parallel to the cables 10. The security line 20 is a low-voltage power cable of about 2 sq. in diameter, which is considerably thinner than the cables 10. Therefore, when a thief cuts the cables 10, there is a high possibility that the security line 20 will also be cut.

[0021] The alarm device 30 is connected to one end and the other end of the security line 20 and steadily passes a current i (loop current) of several mA from one end of the security line 20 to the other. If the security line 20 is cut, the loop current flowing through the security line 20 is interrupted. Therefore, the alarm device 30 monitors the current i x output from the other end of the security line 20. If the current i x is not output from the other end of the security line 20, it determines that the security line 20 has been cut and outputs an alarm signal (non-voltage contact signal) to the remote notification device 40. Upon receiving the alarm signal, the remote notification device 40 notifies a security company or the like located outside the solar power generation site 100. The cable theft detection system 1 may further include a lighting device 50 and a siren device 60. In this case, the alarm device 30 activates the lighting device 50 and the siren device 60 if the current i x is not output from the other end of the security line 20. That is, the alarm device 30 causes the lighting device 50 to emit light and the siren device 60 to emit a warning sound in order to intimidate thieves. The power collection board 4, PCS 5, alarm device 30, and remote notification device 40 are stored in a locked shelter, making it difficult for thieves to steal them or disable monitoring.

[0022] FIG. 2 is a diagram showing the configuration of an alarm device 30 and an example of its connection to peripheral devices. As shown in FIG. 2, the alarm device 30 includes multiple repeaters 31 and an alarm indicator 32. Each repeater 31 steadily supplies a current (loop current) to one end of a corresponding security line 20 and monitors the loop current output from the other end of the security line 20. If no loop current is output from the other end of the security line 20, the repeater 31 determines that the security line 20 has been disconnected and notifies the alarm indicator 32. The alarm indicator 32 operates by receiving a 100V AC power supply voltage and, upon receiving a notification from the repeater 31, lights up a corresponding LED and outputs an alarm signal (non-voltage contact signal) to the remote notification device 40. Furthermore, the alarm indicator 32 instructs the intimidation control unit 80 to illuminate the lighting device 50 and to generate an alarm sound from the siren device 60. Since the security line 20 is laid outdoors along with the cable 10 and is therefore at risk of being struck by lightning, an SPD (Surge Protective Device) 70 is attached to the security line 20 to protect the repeater 31 from lightning surges. An SPD 70 is also attached to the AC 100V power line to protect the alarm display 32 from lightning surges. For the same purpose, SPDs 70 are also attached to the signal line between the alarm display 32 and the remote notification device 40, the signal line between the intimidation control unit 80 and the lighting device 50, and the signal line between the intimidation control unit 80 and the siren device 60.

[0023] FIG. 3 is a diagram showing an example of the implementation of the cable 10 and the security wire 20. As shown in FIG. 3, the cable 10 (10a, 10b) and the security wire 20 are housed in the internal space of a flexible pipe 90. By housing the cable 10 (10a, 10b) and the security wire 20 in the same internal space of the flexible pipe 90, the probability that the security wire 20 will also be cut when the cable 10 is cut increases. Furthermore, as shown in FIG. 3, the security wire 20 is preferably wrapped around the cable 10 (10a, 10b). By wrapping the security wire 20 around the cable 10 (10a, 10b), the probability that the security wire 20 will also be cut when the cable 10 is cut further increases. The security wire 20 has a first core wire 21 and a second core wire 22, and one end of the first core wire 21 is connected to one end of the second core wire 22. The other end of the first core wire 21 and the other end of the second core wire 22 are connected to the alarm device 30. The alarm device 30 supplies current to the other end of the first core wire 21 (corresponding to one end of the security line 20) and monitors the current output from the other end of the second core wire 22 (corresponding to the other end of the security line 20). When a current is output from the other end of the second core wire 22, the alarm device 30 lights up an LED indicating that the security line 20 is normal, and when no current is output from the other end of the second core wire 22, the alarm device 30 lights up an LED indicating that the security line 20 is disconnected. Alternatively, as shown in FIG. 2, the alarm device 30 may not light up the LED when a current is output from the other end of the second core wire 22, and may light up the LED when no current is output from the other end of the second core wire 22. The alarm device 30 may also light up a lighting device 50 (a patrol lamp in FIG. 3) and generate a warning sound from a siren device 60 (a speaker in FIG. 3). The alarm device 30 may also supply a current to the other end of the second core wire 22 and monitor the current output from the other end of the first core wire 21.

[0024] The PCS 5 generates harmonic noise because it converts DC power to AC power through high-frequency switching. For this reason, it is considered to use a shielded cable as at least a part of the security line 20. As shown in FIG. 4(A), the shielded cable includes a first core wire 21, a second core wire 22, and a shielding material 25 provided to surround the first core wire 21 and the second core wire 22. One end of the first core wire 21 and one end of the second core wire 22 are connected to each other to allow a loop current to flow. However, if the noise generated by the PCS is very large, the noise between the first core wire 21 and the ground and the noise between the second core wire 22 and the ground will increase, resulting in increased line-to-line noise between the first core wire 21 and the second core wire 22, which may cause the alarm device 30 to malfunction. In order to reduce inter-wire noise between the first core wire 21 and the second core wire 22, it is preferable that at least a portion of the security line 20 be a shielded twisted pair cable. As shown in Fig. 1, the shielded twisted pair cable has a first core wire 21 and a second core wire 22 that form a twisted pair, and a shielding material 25 that is provided to cover the first core wire 21 and the second core wire 22. One end of the first core wire 21 is connected to one end of the second core wire 22 to allow a loop current to flow. The shielding material 25 is also grounded. Grounding the shielding material 25 reduces noise between the first core wire 21 and the ground and between the second core wire 22 and the ground. Furthermore, because the first core wire 21 and the second core wire 22 form a twisted wire, the difference between the noise between the first core wire 21 and the ground and the noise between the second core wire 22 and the ground is reduced, resulting in reduced noise between the first core wire 21 and the second core wire 22. This reduces the risk of the alarm device 30 malfunctioning.

[0025] To further reduce the inter-wire noise between the first core wire 21 and the second core wire 22, at least a portion of the security cable 20 is preferably a shielded twisted pair cable having a twisted pair and an open core wire. As shown in FIG. 4(C), this shielded twisted pair cable includes the first core wire 21 and the second core wire 22 that constitute the twisted pair, a third core wire 23 that is an open core wire arranged parallel to the first core wire 21 and the second core wire 22, and a shielding material 25 that covers the first core wire 21 and the second core wire 22. One end of the first core wire 21 is connected to one end of the second core wire 22 to allow a loop current to flow. The shielding material 25 and the third core wire 23 are also grounded. Grounding the shielding material 25 and the third core wire 23 further reduces the noise between the first core wire 21 and the ground and between the second core wire 22 and the ground. Furthermore, because the first core wire 21 and the second core wire 22 form a twisted wire, the difference between the noise between the first core wire 21 and the ground and the noise between the second core wire 22 and the ground is reduced, resulting in a further reduction in the noise between the first core wire 21 and the second core wire 22. This further reduces the risk of the alarm device 30 malfunctioning. If the solar power generation site 100 is equipped with a surveillance camera whose monitoring direction can be changed, the alarm device 30 may change the direction of the surveillance camera to the direction of the corresponding cable 10 when it determines that a security line 20 has been cut. The alarm device 30 may also store map information in which the position information of each cable 10 is mapped on the solar power generation site 100, and when it determines that a security line 20 has been cut, display an image showing the position of the corresponding cable 10 on the map information.

[0026] As described above, in the cable theft detection system 1 according to the first embodiment, the security wire 20 is arranged in parallel with the cable 10 (10a, 10b) that transmits DC power, so there is a high possibility that the security wire 20 will be cut when the cable 10 is cut. Therefore, the alarm device 30 monitors the current flowing through the security wire 20, and if no current is flowing, it can detect the theft of the cable 10 and output an alarm. In particular, since the security wire 20 is housed together with the cable 10 in the same internal space of the flexible pipe 90, there is a higher probability that the security wire 20 will also be cut when the cable 10 is cut. Furthermore, because the security wire 20 is wrapped around the cable 10, there is a high possibility that the security wire 20 will be cut before the cable 10, so the alarm device 30 can detect the theft of the cable 10 earlier and output an alarm. Furthermore, in a high-noise environment such as the solar power generation site 100, a method of monitoring the voltage between any two points on the security cable 20 can easily erroneously determine that the security cable 20 is not disconnected due to noise voltage, even when the security cable 20 is actually disconnected. However, the cable theft detection system 1 according to the first embodiment monitors the current flowing through the security cable 20, making it less susceptible to noise. Furthermore, since the security cable 20 and alarm device 30 can be added to existing equipment such as the PCS 5, there is no need to replace the existing equipment, and the cable theft detection system 1 can be realized at low cost. Furthermore, the cable theft detection system 1 according to the first embodiment can activate the lighting device 50 and siren device 60 when the security cable 20 is disconnected, thereby deterring potential thieves and discouraging them from committing theft.

[0027] 2. Second embodiment Below, for the second embodiment of the cable theft detection system 1, the same symbols will be used for configurations that are similar to those in the first embodiment, and explanations that are similar to those in the first embodiment will be omitted or simplified, with the focus being mainly on the differences from the first embodiment. A cable theft detection system 1 according to the second embodiment uses a flexible pipe 110 with steel wires. FIG. 5 is a perspective view of the flexible pipe 110 with steel wires. FIG. 6 is a diagram showing an example of the implementation of a cable 10, a security wire 20, and the like. As shown in FIG. 5, a steel wire 111 is embedded in the flexible pipe 110 in a spiral shape. As shown in FIG. 6, the cable 10 (10a, 10b) is housed in the internal space of the flexible pipe 110. The security wire 20 has a first core wire 21 and a second core wire 22, and a portion of the first core wire 21 is housed in the internal space of the flexible pipe 110. One end of the second core wire 22 is connected to one end of the steel wire 111, and one end of the first core wire 21 is connected to the other end of the steel wire 111. The other end of the first core wire 21 and the other end of the second core wire 22 are connected to an alarm device 30.

[0028] The alarm device 30 includes a repeater 31 and an alarm indicator 32. The repeater 31 supplies current to the other end of the first core wire 21 (corresponding to one end of the security line 20) and monitors the current output from the other end of the second core wire 22 (corresponding to the other end of the security line 20). The repeater 31 may supply current to the other end of the second core wire 22 and monitor the current output from the other end of the first core wire 21. Since the cable 10 (10a, 10b) is housed in the internal space of the flexible tube 110, there is a higher probability that the steel wire 111 spirally embedded in the flexible tube 110 will also be cut when the cable 10 is cut. When the steel wire 111 is cut, current is no longer output from the other end of the second core wire 22, and the alarm indicator 32 lights up an LED indicating that the security line 20 is cut. Furthermore, when no current is output from the other end of the second core wire 22, the alarm indicator 32 causes the lighting device 50 to emit light and the siren device 60 to emit a warning sound. Note that the alarm device 30 may supply current to the other end of the second core wire 22 and monitor the current output from the other end of the first core wire 21.

[0029] As described above, according to the cable theft detection system 1 of the second embodiment, the steel wire 111 built into the flexible pipe 110 that forms part of the security line 20 is cut before the cable 10 is cut, so that the alarm device 30 can detect the theft of the cable 10 more quickly and output an alarm. In addition, the cable theft detection system 1 of the second embodiment has the same effects as the cable theft detection system 1 of the first embodiment.

[0030] 3. Third embodiment Below, for the cable theft detection system 1 of the third embodiment, the same symbols are used for configurations that are similar to those of the first or second embodiment, and explanations that are similar to those of the first or second embodiment are omitted or simplified, and the explanation will mainly focus on the differences from the first and second embodiments. FIG. 7 is a diagram illustrating an example of the configuration of a cable theft detection system 1 according to a third embodiment. As shown in FIG. 7, the security line 20 has multiple detachable connectors 120 and is arranged parallel to the cables 10 (10a, 10b). That is, the security line 20 is arranged near the cables 10 (10a, 10b) and runs parallel to them. The connectors 120 are, for example, bullet terminals, and the multiple connectors 120 are arranged at regular intervals. Therefore, the security line 20 can be broken not only when a thief cuts the cable 10, but also when the connectors 120 come loose due to tension when the cable 10 is pulled out. The alarm device 30 is connected to one end and the other end of the security line 20, steadily passes a current i (loop current) of several mA from one end of the security line 20 to the other, and monitors the current ix output from the other end of the security line 20. If the current ix is ​​not output from the other end of the security line 20, the alarm device 30 determines that the security line 20 has been broken, and outputs an alarm signal (non-voltage contact signal) to the remote notification device 40. Furthermore, if the current ix is ​​not output from the other end of the security line 20, the alarm device 30 causes the lighting device 50 to emit light and the siren device 60 to emit an alarm sound.

[0031] As described above, according to the cable theft detection system 1 of the third embodiment, the security line 20 breaks not only when the cable 10 is cut, but also when the connection part 120 comes loose due to the tension when the cable 10 is pulled out, so the alarm device 30 can detect the theft of the cable 10 more quickly and output an alarm. In addition, the cable theft detection system 1 of the third embodiment has the same effects as the cable theft detection system 1 of the first or second embodiment.

[0032] 4. Fourth embodiment Below, for the fourth embodiment of the cable theft detection system 1, the same symbols are used for configurations that are similar to any of the first to third embodiments, and explanations that are similar to any of the first to third embodiments are omitted or simplified, and the following mainly describes the differences from any of the first to third embodiments. FIG. 8 is a diagram showing an example of the configuration of a cable theft detection system 1 according to a fourth embodiment. As shown in FIG. 8, the cables 10 (10a, 10b) and the security wire 20 (core wires 21, 22) are housed in the interior space of a flexible pipe 90, and the security wire 20 (core wires 21, 22) is, for example, wound around the cables 10 (10a, 10b). At least the cables 10 (10a, 10b) are fixed in place by a filler 200 that fills a portion of the interior of the flexible pipe 90, and the security wire 20 (core wires 21, 22) may also be fixed by the filler 200. It is preferable that the interior of the flexible pipe 90 be filled with the filler 200 at regular intervals.

[0033] FIG. 9 is a diagram showing another example of the configuration of a cable theft detection system 1 according to a fourth embodiment. The cable theft detection system 1 shown in FIG. 9 is basically configured similarly to the cable theft detection system 1 according to the second embodiment shown in FIG. 6, and the cables 10 (10a, 10b) and a portion of the first core wire 21 of the security line 20 are housed in the internal space of a flexible pipe 110 in which a steel wire 111 is embedded in a spiral shape. As in FIG. 8, at least the cables 10 (10a, 10b) are fixed in place by a filler 200 that fills a portion of the interior of the flexible pipe 110, and the first core wire 21 may also be fixed by the filler 200. Preferably, the interior of the flexible pipe 110 is filled with the filler 200 at regular intervals.

[0034] For example, various hardening resins are used as the filler 200. For example, a syringe may be used to inject urethane foam into the flexible tube 90 or 110 at regular intervals, and the urethane foam may harden over time to fix the cables 10 (10a, 10b). 6, the first core wire 21 and the second core wire 22 of the security cable 20 are connected to an alarm device 30, and when the first core wire 21 or the steel wire 111 is cut, the alarm indicator 32 lights up an LED indicating that the security cable 20 has been cut. The alarm indicator 32 also causes the lighting device 50 to emit light and the siren device 60 to emit a warning sound.

[0035] According to the cable theft detection system 1 of the fourth embodiment described above, the cable 10 is fixed in place by the filler 200 that fills the interior of the flexible pipe 90 or flexible pipe 110 at regular intervals, so even if a thief cuts the cable 10, they cannot easily pull it out and cannot quickly make off with it. Furthermore, if the security wire 20 is cut along with the cable 10, the alarm device 30 is activated, which is expected to have the effect of deterring the thief from stealing the cable 10. In addition, the cable theft detection system 1 of the fourth embodiment has the same effects as the cable theft detection systems 1 of any of the first to third embodiments.

[0036] 5. Fifth embodiment Below, for the cable theft detection system 1 of the fifth embodiment, the same symbols are used for configurations that are similar to any of the first to fourth embodiments, and explanations that are similar to any of the first to fourth embodiments are omitted or simplified, and the following mainly describes the differences from any of the first to fourth embodiments. FIG. 10 is a diagram illustrating an example of the configuration of a cable theft detection system 1 according to a fifth embodiment. As shown in FIG. 10, cables 10 (10a, 10b) are housed in the internal space of a flexible pipe 90. Dummy cables 11 (11a, 11b) are cables that do not transmit DC power generated by a solar panel 2 and are housed in the internal space of a flexible pipe 91. For example, the flexible pipe 91 is the same type of flexible pipe as the flexible pipe 90, and there is no difference between the two in appearance. The dummy cables 11a, 11b are inexpensive cables with finished outer diameters similar to those of the cables 10a, 10b, respectively. In other words, the dummy cables 11 (11a, 11b) are cables that imitate the cables 10 (10a, 10b), and there is almost no difference between the two in appearance.

[0037] The security line 20 is composed of a first core wire 21, a second core wire 22, and dummy cables 11a and 11b. One end of the first core wire 21 is connected to one end of the dummy cable 11a, one end of the second core wire 22 is connected to one end of the dummy cable 11b, and the other end of the dummy cable 11a is connected to the other end of the dummy cable 11b. The other end of the first core wire 21 and the other end of the second core wire 22 are connected to the alarm device 30. The flexible pipe 91 housing the dummy cable 11 (11a, 11b) is laid in a location where theft of the cable 10 (10a, 10b) is likely to occur. To make the flexible pipe 91 more conspicuous than the flexible pipe 90, for example, as shown in FIG. 11 , multiple flexible pipes 91 may be arranged to cover the flexible pipe 90. Depending on the location and manner in which the dummy cable 11 (11a, 11b) is laid, a thief is more likely to mistake the dummy cable 11 (11a, 11b) for the cable 10 (10a, 10b) and cut it. When the dummy cable 11 (11a, 11b) is cut, the alarm indicator 32 lights up an LED indicating that the security line 20 has been cut. The alarm indicator 32 also causes the lighting device 50 to emit light and the siren device 60 to emit a warning sound.

[0038] According to the cable theft detection system 1 of the fifth embodiment described above, even if a thief mistakes the dummy cable 11 (11a, 11b) for the real cable 10 (10a, 10b) and cuts it, the alarm device 30 can detect the theft of the dummy cable 11 (11a, 11b) and output an alarm before the real cable 10 (10a, 10b) is stolen. Furthermore, since the dummy cable 11 (11a, 11b) is an inexpensive cable, even if the dummy cable 11 (11a, 11b) is cut and taken away, the damage is small. Furthermore, even if the dummy cable 11 (11a, 11b) is cut, the transmission of DC power through the real cable 10 (10a, 10b) is not affected, and the cost and labor required for restoration work are reduced.

[0039] 6. Variations In each of the above embodiments, the security wire 20 is arranged parallel to the cables 10 (10a, 10b), but it may also be arranged parallel to the string cable 6. That is, the security wire 20 may be arranged so as to run parallel to the string cable 6 in the vicinity of the string cable 6. Alternatively, the security wire 20 may be arranged parallel to the alternating current (AC) power cable 7 on the output side of the PCS 5. That is, the security wire 20 may be arranged so as to run parallel to the alternating current (AC) power cable 7 in the vicinity of the alternating current (AC) power cable 7.

[0040] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention includes substantially the same configurations as those described in the embodiments (for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects). The present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that have the same effects as the configurations described in the embodiments or that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments. [Explanation of symbols]

[0041] 1...cable theft detection system, 2...solar panel, 3...junction box, 4...power collection board, 5...PCS, 6...string cable, 7...alternating current (AC) power cable, 10, 10a, 10b...cable, 11, 11a, 11b...pseudo cable, 20...security line, 21...first core, 22...second core, 23...third core, 25...shielding material, 30...alarm device, 31...repeater, 32...alarm display, 40...remote notification device, 50...lighting device, 60...siren device, 70...SPD, 80...threat control unit, 90...flexible pipe, 91...flexible pipe, 100...solar power generation site, 110...flexible pipe, 111...steel wire, 120...connection part, 200...filler

Claims

1. a cable for transmitting DC power; a security wire arranged parallel to the cable; A cable theft detection system characterized by comprising an alarm device connected to one end and the other end of the security line, which constantly flows an electric current from one end to the other end of the security line, and which outputs an alarm signal to a remote reporting device if the electric current is not output from the other end of the security line.

2. 2. The cable theft detection system according to claim 1, The cable and the security line are housed in an internal space of the flexible pipe, A cable theft detection system characterized in that the security wire is wrapped around the cable.

3. 2. The cable theft detection system according to claim 1, At least a portion of the security line is a shielded twisted pair cable, the twisted pair cable includes a first core wire and a second core wire that constitute a twisted pair, and a shielding material that is provided to cover the first core wire and the second core wire, A cable theft detection system, characterized in that one end of the first core wire and one end of the second core wire are connected, and the shielding material is grounded.

4. 4. The cable theft detection system according to claim 3, the twisted pair cable further includes a third core wire arranged in parallel with the first core wire and the second core wire, A cable theft detection system, wherein the third core wire is grounded.

5. 2. The cable theft detection system according to claim 1, The cable is housed in an internal space of a flexible tube in which a steel wire is spirally embedded, the security cable has a first core wire and a second core wire, a portion of the first core wire is accommodated in the internal space of the flexible pipe; One end of the second core wire is connected to one end of the steel wire, A cable theft detection system, characterized in that one end of the first core wire and the other end of the steel wire are connected.

6. 2. The cable theft detection system according to claim 1, The cable is accommodated in an internal space of the flexible tube, a part of the security line is a pseudo cable that imitates the cable, A cable theft detection system, characterized in that the pseudo cable is housed in an internal space of a flexible pipe different from the flexible pipe.

7. The cable theft detection system according to claim 2 or 5, A cable theft detection system, characterized in that the cable is fixed by a filler that fills a part of the inside of the flexible pipe.

8. 7. The cable theft detection system according to claim 1, A cable theft detection system, wherein the security cable has a plurality of detachable connection parts.

9. 7. The cable theft detection system according to claim 1, A lighting device and a siren device are provided, When the current is not output from the other end of the security line, the alarm device and a cable theft detection system, characterized by activating the siren device.

10. 7. The cable theft detection system according to claim 1, A cable theft detection system characterized in that the cable is a main cable that transmits DC power generated by solar panels installed at a solar power generation site.

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