Anti-theft device
The anti-theft device for solar power systems applies voltage to the DC cable outside the power conditioner, addressing installation challenges and preventing theft with minimal modifications, ensuring versatility across systems.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- OBAYASHI CORP
- Filing Date
- 2025-06-27
- Publication Date
- 2026-06-11
AI Technical Summary
Existing solar power generation systems face high installation costs and complexity when retrofitting anti-theft devices due to the need for extensive modifications to incorporate components like DC-side MCs, reactors, and switches, making it difficult to prevent cable theft effectively.
An anti-theft device that applies a voltage to the DC side cable outside the power conditioner, using a changeover switch, rectifier circuit, and control device to deter theft by simulating power generation during non-operational hours, and optionally includes a current detection unit and alarm mechanism to alert potential thieves.
The device prevents cable theft by applying voltage or generating an alarm, deterring thieves without requiring major modifications to the power conditioner, thus being versatile for both new and existing systems.
Smart Images
Figure JP2025023266_11062026_PF_FP_ABST
Abstract
Description
Anti-theft device
[0001] This disclosure relates to an anti-theft device, and more particularly to a technology suitable for preventing theft of cables in solar power generation systems.
[0002] In a solar power generation system, solar energy is converted into direct current (DC) power by solar cell modules, and this DC power is sent through cables to a power conditioner where it is converted into alternating current (AC) power before being transmitted to the power grid and sold.
[0003] In so-called ground-mounted solar power generation systems, the recent surge in copper resource prices has led to a surge in theft of cables, including copper wires. Such thefts often occur at night when the solar power generation system is not operating, by cutting the cables on the DC circuit side, where the risk of electric shock is low. Measures to prevent theft include installing disconnection sensors on fences surrounding the solar power generation system or monitoring with infrared cameras. However, because the sites where solar power generation systems are installed are vast, installing disconnection sensors is costly, and infrared cameras cannot adequately monitor the entire site.
[0004] For example, Patent Document 1 discloses a device comprising a voltage application means for applying a DC voltage to a DC-side circuit including a cable at night, a current measuring instrument for measuring the current flowing through the DC-side circuit, and a disconnection detection processing unit for detecting a disconnection in the cable based on the measurement results of the current measuring instrument, wherein the disconnection detection processing unit detects a disconnection in the cable, thereby detecting theft of the cable.
[0005] Japanese Patent Publication No. 2017-169264
[0006] The voltage application means described in Patent Document 1 includes a DC voltage conversion circuit that converts the power supply on the power grid side into DC, a DC voltage application switch that is turned on when applying the DC voltage to the DC side circuit, a DC side MC that is disconnected only when the DC voltage application switch is turned on, a reactor connected between the P side wiring and the N side wiring, a switch connected in series with the reactor, etc., and these are incorporated inside the power conditioner.
[0007] Therefore, when retrofitting the device described in Patent Document 1 to an existing solar power generation system, extensive modifications are required to incorporate various components such as DC-side MCs, reactors, and switches into the power conditioner, resulting in problems such as high installation costs and long working hours. In other words, there is a need for a versatile anti-theft device that can be easily installed in existing solar power generation systems.
[0008] The technology disclosed herein was developed in view of the above circumstances and aims to provide a versatile anti-theft device that can be easily installed on existing power generation systems (solar power generation systems).
[0009] The anti-theft device of this disclosure is a power generation device (60) that generates electricity using renewable energy. ＿１ ~60 ＿ｎ ) and the power generation device (60 ＿１ ~60 ＿ｎ ) is connected to the power generator (60 ＿１ ~60 ＿ｎ An anti-theft device for preventing the theft of the DC side cable (C1) of a power generation system (50) comprising a power conditioner (70) that converts DC power generated by a power generator (60) into AC power and transmits the converted AC power to a power grid (100) through AC side cables (C2, C3), wherein the device is directly connected to the DC side cable (C1) located outside the power conditioner (70), and the power generation device (60) ＿１ ~60 ＿ｎ The system is characterized by providing voltage application means (10A, 10B, 10C) for applying a predetermined voltage to the DC side cable (C1) when the power generator is not generating power.
[0010] In the anti-theft device of the present disclosure, the voltage application means (10A, 10B) includes a changeover switch (12) attached to the AC side cable (C2) located outside the power conditioner (70), a connection cable (11) having one end connected to the changeover switch (12) and the other end connected to the DC side cable (C1) located outside the power conditioner (70), a rectifier circuit (13) provided in the connection cable (11) for converting AC power into DC power, and a control device (20) for controlling the changeover switch (12). The changeover switch (12) is configured to be switchable between a power generation mode in which the power conditioner (70) and the power grid (100) are electrically connected and a non-power generation mode in which the connection cable (11) and the power grid (100) are electrically connected. The control device (20) is configured to convert AC power transmitted from the power grid (100) into DC power by the rectifier circuit (13) and supply it to the DC side cable (C1) by setting the changeover switch (12) to the non-power generation mode when the power generation device (60 ＿１ ~60 ＿ｎ ) is not generating power, i.e., in the non-power generation state.
[0011] In the anti-theft device of another aspect of the present disclosure, the voltage application means (10C) includes a rechargeable battery (30) and a connection cable (31) having one end connected to the battery (30) and the other end connected to the DC side cable (C1) located outside the power conditioner (70). During power generation when the power generation device (60 ＿１ ~60 ＿ｎ ), the DC power generated by the power generation device (60 ＿１ ~60 ＿ｎ ) is stored in the battery (30) through the connection cable (31), and at the same time, the power generation device (60 ＿１ ~60 ＿ｎWhen not generating electricity, it is desirable to be configured to apply the DC voltage stored in the battery (30) to the DC side cable (C1) through the connection cable (31).
[0012] The anti-theft device according to another aspect of the present disclosure includes current detection means (15) provided in the connection cable (11, 31) for detecting the current value of the DC current flowing through the connection cable (11, 31), and the power generation device (60 ＿１ ~60 ＿ｎ ), and alarm means (25) for giving an alarm when the current value detected by the current detection means (15) drops below a predetermined value when not generating electricity. It is desirable to further include.
[0013] In the anti-theft device of the present disclosure, the power generation device (60 ＿１ ~60 ＿ｎ ) may be a solar cell module that generates electricity using solar energy.
[0014] In the above description, for the purpose of assisting the understanding of the present disclosure, the reference numerals used in the embodiments are attached to the constituent elements corresponding to the embodiments in parentheses, but each constituent element is not limited to the embodiments defined by the reference numerals.
[0015] According to the technology of the present disclosure, it is possible to provide an anti-theft device having versatility that can be easily attached to an existing power generation system (solar power generation system).
[0016] This is a schematic overall configuration diagram showing the anti-theft device according to the first embodiment and the solar power generation system to which the anti-theft device is applied. This is a flowchart explaining the processing routine of anti-theft control by the control device according to the first embodiment. This is a schematic overall configuration diagram showing the anti-theft device according to the second embodiment and the solar power generation system to which the anti-theft device is applied. This is a flowchart explaining the processing routine of anti-theft control by the control device according to the second embodiment. This is a schematic overall configuration diagram showing the anti-theft device according to the third embodiment and the solar power generation system to which the anti-theft device is applied. This is a schematic overall configuration diagram showing the anti-theft device according to a modified example and the solar power generation system to which the anti-theft device is applied.
[0017] The anti-theft device according to this embodiment will be described below with reference to the attached drawings.
[0018] [First Embodiment] Figure 1 is a schematic overall diagram showing the anti-theft device 10A according to the first embodiment and the solar power generation system 50 to which the anti-theft device 10A is applied.
[0019] As shown in Figure 1, the photovoltaic power generation system 50 is connected to the power grid 100 and has at least one or more solar cell modules 60 ＿１ ~60 ＿ｎ The system also includes a power conditioner 70 and a transformer 80. The solar power generation system 50 may also be a so-called transformerless inverter, where the transformer 80 and the power conditioner 70 are integrated into a single unit.
[0020] Solar cell module 60 ＿１ ~60 ＿ｎ It is composed of multiple cells connected in series or parallel, and converts solar energy into DC power. Each solar cell module 60 ＿１ ~60 ＿ｎ It is connected to the power conditioner 70 via the DC cable C1. The DC cable C1 is connected to the solar cell module 60 ＿１ ~60 ＿ｎFrom the side, the first switch S1 and the DC voltage detection unit 62 are provided. At least part or all of the DC side cable C1 is exposed to the outside.
[0021] The power conditioner 70 is a device also called a power conditioner or PCS (Power Conditioning System). The power conditioner 70 has an inverter 71 and a PCS control device 75. The inverter 71 controls the solar cell module 60 ＿１ ~60 ＿ｎ It converts the DC power generated by the generator into AC power.
[0022] The transformer 80 is connected to the power conditioner 70 via the first AC cable C2. The transformer 80 is also connected to the power grid 100 via the second AC cable C3. The transformer 80 transforms (steps up) the AC power supplied from the power conditioner 70 to a predetermined voltage suitable for transmission to the power grid 100. The first AC cable C2 is provided with a second switch S2, and the second AC cable C3 is provided with a third switch S3. The second switch S2 and the third switch S3 are basically kept in an ON state at all times. As mentioned above, if the solar power generation system 50 is a transformerless inverter, the transformer 80 can be omitted.
[0023] The PCS control device 75 is a so-called microcomputer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and interfaces. The PCS control device 75 uses the DC voltage value detected by the DC voltage detection unit 62 (solar cell module 60 ＿１ ~60 ＿ｎ The PCS control device 75 controls the on / off state of the first switch S1 according to the voltage value of the DC power input from the solar cell module 60. ＿１ ~60 ＿ｎ The first switch S1 is turned on during the daytime when the solar cell module 60 is generating power (for example, when the DC voltage value detected by the DC voltage detection unit 62 is equal to or greater than a predetermined value). The PCS control device 75 also controls the solar cell module 60 ＿１~60 ＿ｎ The first switch S1 is turned off during nighttime hours when no power is being generated (for example, when the DC voltage detected by the DC voltage detection unit 62 is approximately zero).
[0024] In the solar power generation system 50, the solar cell module 60 ＿１ ~60 ＿ｎ During nighttime hours when no power is being generated, no voltage is applied to the DC circuit, including the DC cable C1. Therefore, cable theft often occurs by cutting the DC cable C1, which poses no risk of electric shock at night.
[0025] The anti-theft device 10A according to this embodiment is a solar cell module 60 ＿１ ~60 ＿ｎ The purpose is to prevent the theft of the DC cable C1 by applying a DC voltage to the DC circuit, including the DC cable C1, during nighttime hours when the power generator is not operating, and by alerting anyone attempting to cut the DC cable C1. Specifically, the anti-theft device 10A comprises a voltage application cable 11, a changeover switch 12, a rectifier circuit 13 including a semiconductor rectifier, a DC connection terminal 14, and a control device 20.
[0026] The changeover switch 12 is provided at one end of the voltage application cable 11. The changeover switch 12 is a so-called two-way changeover switch and includes a changeover terminal 12A, a first connection terminal 12B, and a second connection terminal 12C. The changeover switch 12 is attached to the first AC side cable C2 outside the power conditioner 70 by simple wiring work. The changeover switch 12 can be selectively switched in response to a command from the control device 20 between a "power generation mode" in which the changeover terminal 12A is connected to the first connection terminal 12B and the power conditioner 70 and the transformer 80 are electrically connected, and a "non-power generation mode" in which the changeover terminal 12A is connected to the second connection terminal 12C and the transformer 80 and the voltage application cable 11 are electrically connected.
[0027] The rectifier circuit 13 is provided between one end and the other end of the voltage application cable 11. The rectifier circuit 13 converts the AC power supplied from the power system 100 into DC power when the changeover switch 12 is set to "non-power generation mode". The DC connection terminal 14 is provided at the other end of the voltage application cable 11. The DC side connection terminal 14 can be attached to any position on the DC side cable C1 by simple wiring work.
[0028] The control device 20 is a so-called microcomputer equipped with a CPU, ROM, RAM, and interface device. When predetermined anti-theft activation conditions are met, the control device 20 switches the changeover switch 12 from "power generation mode" to "non-power generation mode". The anti-theft activation conditions are met, for example, when either of the following activation conditions (1) or (2) is satisfied. Activation condition (1): When the current time is nighttime (sunset time). Activation condition (2): When the illuminance around the solar power generation system 50 decreases to a predetermined threshold illuminance.
[0029] The operating condition (1) can be determined based on the timer function and calendar function of the control device 20. The operating condition (2) can be determined based on the detection signal of the anti-theft device 10A or the illuminance sensor (not shown) of the photovoltaic power generation system 50. The threshold illuminance is determined by the solar cell module 60 ＿１ ~60 ＿ｎ The setting should be based on the illuminance level at which the device stops operating.
[0030] When either of the above operating conditions (1) or (2) is met, the control device 20 switches the changeover switch 12 from "power generation mode" to "non-power generation mode". That is, AC power transmitted from the power system 100 side via each AC side cable C2, C3 is supplied to the voltage application cable 11, converted to DC power by the rectifier circuit 13, and then supplied to the DC side cable C1. As a result, the solar cell module 60 ＿１ ~60 ＿ｎ Even during nighttime hours when power generation is stopped, voltage can be continuously applied to the DC circuit, including the DC cable C1, making it possible to prevent theft by cutting the DC cable C1.
[0031] When a predetermined anti-theft termination condition is met, the control device 20 switches the changeover switch 12 from "non-power generation mode" to "power generation mode". The anti-theft termination condition is met, for example, when either of the following termination conditions (1) or (2) is satisfied. Termination condition (1): When the current time is daytime (sunrise time). Termination condition (2): When the illuminance around the solar power generation system 50 rises to or above a predetermined threshold illuminance.
[0032] The termination condition (1) can be determined based on the timer function and calendar function of the control device 20. The termination condition (2) can be determined based on the detection signal of the illuminance sensor (not shown) of the anti-theft device 10 or the solar power generation system 50.
[0033] Next, with reference to Figure 2, the routine for the theft prevention control process by the control device 20 according to the first embodiment will be described. This routine applies, for example, to the solar cell module 60 ＿１ ~60 ＿ｎ It starts while power is being generated.
[0034] In step S100, the CPU of the control device 20 determines whether the anti-theft activation conditions are met. If the anti-theft activation conditions are met (Yes), that is, if either of the above-mentioned activation conditions (1) or (2) is met, the CPU of the control device 20 proceeds to the process in step S110. On the other hand, if the anti-theft activation conditions are not met (No), the CPU of the control device 20 repeats the determination process in step S100.
[0035] In step S110, the CPU of the control device 20 switches the changeover switch 12 from "power generation mode" to "non-power generation mode". As a result, AC power from the power system 100 is supplied to the rectifier circuit 13 via the voltage application cable 11, and the DC power converted by the rectifier circuit 13 is applied to the DC side circuit including the DC side cable C1.
[0036] Next, in step S120, the CPU of the control device 20 determines whether the anti-theft termination condition is met. If the anti-theft termination condition is met (Yes), that is, if either of the termination conditions (1) or (2) described above is met, the CPU of the control device 20 proceeds to the process in step S130. On the other hand, if the anti-theft termination condition is not met (No), the CPU of the control device 20 continues the process in step S110.
[0037] In step S130, the CPU of the control device 20 switches the changeover switch 12 from "non-power generation mode" to "power generation mode," and then returns this routine.
[0038] According to the anti-theft device 10A of the first embodiment described in detail above, the solar cell module 60 ＿１ ~60 ＿ｎ When it is nighttime and no power is being generated, the changeover switch 12 is switched from the "power generation mode," which connects the power conditioner 70 and the transformer 80, to the "non-power generation mode," which connects the transformer 80 and the voltage application cable 11. In other words, the solar cell module 60 ＿１ ~60 ＿ｎ During nighttime hours when no power is being generated, AC power from the power grid 100 is supplied to the voltage application cable 11. The rectifier circuit 13 converts the AC power to DC power, which is then continuously applied to the DC side circuit, including the DC side cable C1. This configuration makes it possible to deter anyone attempting to cut the DC side cable C1 at night by applying an electrical shock or generating sparks, thereby preventing theft.
[0039] Furthermore, according to the anti-theft device 10A of the first embodiment, it can be easily installed without making any major modifications to the power conditioner 70 by simply attaching a changeover switch 12 to the AC side cable C2 outside the power conditioner 70 and attaching a DC connection terminal 14 to any position on the DC side cable C1. In other words, the anti-theft device 10A is configured to be installed externally rather than being incorporated inside the power conditioner 70. This makes it possible to achieve versatility, allowing it to be easily installed not only in newly installed solar power generation systems but also in existing solar power generation systems.
[0040] [Second Embodiment] Figure 3 is a schematic overall configuration diagram showing the anti-theft device 10B according to the second embodiment and the photovoltaic power generation system 50 to which the anti-theft device 10B is applied. The photovoltaic power generation system 50 is the same as in the first embodiment, so a detailed explanation is omitted.
[0041] The anti-theft device 10B of the second embodiment includes, similar to the first embodiment, a voltage application cable 11, a changeover switch 12, a rectifier circuit 13, a DC side connection terminal 14, and a control device 20. In addition, the anti-theft device 10B of the second embodiment includes a current detection unit 15 and an alarm mechanism 25.
[0042] The current detection unit 15 is located between the rectifier circuit 13 and the DC-side connection terminal 14 of the voltage application cable 11. The current detection unit 15 detects the current value of the DC current flowing through the DC-side circuit, including the DC-side cable C1, when the changeover switch 12 is set to "non-power generation mode," that is, when power is applied from the power system 100. The current value detected by the current detection unit 15 is transmitted to the control device 20 in real time.
[0043] When the changeover switch 12 is set to "non-power generation mode," the control device 20 transmits an alarm command to the alarm mechanism 25 if the current value detected by the current detection unit 15 drops below a predetermined value. Upon receiving the alarm command from the control device 20, the alarm mechanism 25 activates an alarm to notify those nearby of the abnormality. The alarm mechanism 25 may be, for example, a speaker, buzzer, patrol light (registered trademark), or lighting fixture. Upon receiving the alarm command, the alarm mechanism 25 will emit a warning sound from the speaker or buzzer, or turn on a patrol light (registered trademark) or lighting fixture to warn anyone attempting to cut the DC cable C1. This makes it possible to prevent the theft of the DC cable C1.
[0044] Furthermore, if the changeover switch 12 is set to "non-power generation mode" and the current value detected by the current detection unit 15 drops below a predetermined value, the control device 20 may perform a notification process to notify terminal devices, etc., held by facility managers or security guards via a communication device (not shown) of the occurrence of an abnormality.
[0045] Next, with reference to Figure 4, the routine for the theft prevention control process by the control device 20 according to the second embodiment will be described. This routine applies, for example, to the solar cell module 60 ＿１ ~60 ＿ｎ It starts while power is being generated.
[0046] In step S200, the CPU of the control device 20 determines whether the anti-theft activation condition is met. If the anti-theft activation condition is met (Yes), the CPU of the control device 20 proceeds to the process in step S210. On the other hand, if the anti-theft activation condition is not met (No), the CPU of the control device 20 repeats the determination process in step S200.
[0047] In step S210, the CPU of the control device 20 switches the changeover switch 12 from "power generation mode" to "non-power generation mode". As a result, AC power from the power system 100 is supplied to the rectifier circuit 13 via the voltage application cable 11, and the DC power converted by the rectifier circuit 13 is applied to the DC side circuit including the DC side cable C1.
[0048] Next, in step S220, the CPU of the control device 20 determines whether the current value detected by the current detection unit 15 has decreased to or below a predetermined value. If the current value has not decreased to or below a predetermined value (No), the CPU of the control device 20 proceeds to the process in step S230. On the other hand, if the current value has decreased to or below a predetermined value (Yes), the CPU of the control device 20 proceeds to the process in step S250.
[0049] When the process proceeds from step S220 to step S230, the CPU of the control device 20 determines whether the anti-theft termination condition is met. If the anti-theft termination condition is met (Yes), the CPU of the control device 20 proceeds to step S240. On the other hand, if the anti-theft termination condition is not met (No), the CPU of the control device 20 continues the process of step S210.
[0050] In step S240, the CPU of the control device 20 switches the changeover switch 12 from "non-power generation mode" to "power generation mode," and then returns this routine.
[0051] When the process proceeds from step S220 to step S250, the CPU of the control device 20 sends an alarm command to the alarm mechanism 25. That is, the alarm mechanism 25 issues a warning. After the alarm mechanism 25 issues a warning, the CPU of the control device 20 returns to this routine.
[0052] According to the anti-theft device 10B of the second embodiment described in detail above, when a voltage is applied from the power system 100 to the DC side circuit including the DC side cable C1, and the current value detected by the current detection unit 15 drops below a predetermined value, the alarm mechanism 25 is configured to emit a warning sound from a speaker or buzzer, or to illuminate a patrol light (registered trademark) or lighting fixture. This provides an early warning to anyone attempting to cut the DC side cable C1, making them abandon the cutting attempt and thus preventing theft.
[0053] Furthermore, according to the anti-theft device 10B of the second embodiment, similar to the first embodiment, it can be easily installed without making any major modifications to the power conditioner 70 by simply attaching the changeover switch 12 to the AC side cable C2 outside the power conditioner 70 and attaching the DC connection terminal 14 to any position on the DC side cable C1. In other words, the anti-theft device 10B is configured to be installed externally rather than being incorporated inside the power conditioner 70. This makes it possible to achieve versatility, allowing it to be easily installed not only in newly installed solar power generation systems but also in existing solar power generation systems.
[0054] [Third Embodiment] Figure 5 is a schematic overall diagram showing the anti-theft device 10C according to the third embodiment and the photovoltaic power generation system 50 to which the anti-theft device 10C is applied. Since the photovoltaic power generation system 50 is the same as in the first and second embodiments, a detailed explanation is omitted.
[0055] The anti-theft device 10C of the third embodiment includes a battery 30, a charging / discharging cable 31, a relay 32, and a battery connection terminal 35.
[0056] The battery 30 is a rechargeable battery, and for example, a lithium-ion battery can be used. Alternatively, any rechargeable battery such as a lead-acid battery or nickel-metal hydride battery can also be used.
[0057] A battery connection terminal 35 is provided at one end of the charging / discharging cable 31. The battery connection terminal 35 can be attached to any position on the DC cable C1 by simple wiring work. The other end of the charging / discharging cable 31 is connected to the battery 30.
[0058] Relay 32 is provided on the charging / discharging cable 31. Relay 32 is always on, and the solar cell module 60 ＿１ ~60 ＿ｎ It is only turned off when performing maintenance on these components. Note that relay 32 is not a mandatory component and can be omitted.
[0059] According to the anti-theft device 10C of the third embodiment, the solar cell module 60 ＿１ ~60 ＿ｎ During the daytime when it generates electricity, the solar cell module 60 ＿１ ~60 ＿ｎ A portion of the electricity generated by the solar cell module 60 is stored in the battery 30 via the charge / discharge cable 31. ＿１ ~60 ＿ｎ At night, when the generator is not producing electricity, a voltage is applied from the battery 30 to the DC circuit, including the DC cable C1, via the charge / discharge cable 31.
[0060] In other words, during the daytime, the solar cell module 60 ＿１ ~60 ＿ｎ The system is configured to charge the battery 30 while simultaneously applying voltage from the battery 30 to the DC cable C1 at night. This provides an electrical shock or generates sparks to anyone attempting to cut the DC cable C1 at night, thereby deterring them from cutting the cable and preventing theft. Furthermore, since the system uses power stored in the battery 30, there is no need to supply power from the electrical system 100, effectively preventing increased electricity costs at night.
[0061] Furthermore, according to the third embodiment of the anti-theft device 10C, it can be easily installed without making any major modifications to the power conditioner 70, simply by attaching the battery connection terminal 35 to any position on the DC side cable C1. In other words, the anti-theft device 10C is configured to be installed externally rather than being incorporated inside the power conditioner 70. This makes it possible to achieve versatility, allowing it to be easily installed not only in newly installed solar power generation systems but also in existing solar power generation systems.
[0062] [Other] This disclosure is not limited to the embodiments described above, and can be modified and implemented as appropriate without departing from the spirit of this disclosure.
[0063] For example, the anti-theft device 10C of the third embodiment can be configured by adding the current detection unit 15, alarm mechanism 25, and control device 20 of the anti-theft device 10B of the second embodiment. Specifically, the current detection unit 15 can be installed on the charging / discharging cable 31, and the control device 20 can be configured to send an alarm command to the alarm mechanism 25 when the DC side cable C1 is cut. In this case as well, an early warning can be given to anyone attempting to cut the DC side cable C1, making it possible to deter them from cutting the cable and thus prevent theft.
[0064] Furthermore, while the anti-theft device 10A of the first embodiment and the anti-theft device 10B of the second embodiment were described as using a changeover switch 12, as shown in Figure 6, it is also possible to configure the anti-theft device 10D to have an on / off switch 12S instead of a changeover switch 12. Specifically, one end of the voltage application cable 11 is directly connected to the first AC side cable C2, and the on / off switch 12S is provided on the voltage application cable 11. In this case, when the control device 20 transitions from "power generation mode" to "non-power generation mode", it should sequentially control the first switch S1 to off (open) and the on / off switch 12S to on (close), and when transitioning from "non-power generation mode" to "power generation mode", it should sequentially control the on / off switch 12S to off (open) and the first switch S1 to on (close).
[0065] Furthermore, in the above embodiment, the solar cell module 60 ＿１ ~60 ＿ｎ Although a photovoltaic power generation system 50 equipped with the above has been described as an example, the technology disclosed herein can be broadly applied to other power generation systems that generate electricity using renewable energy, such as wind power generation systems and hydroelectric power generation systems.
[0066] 10A, 10B, 10C, 10D...Anti-theft device, 11...Voltage application cable, 12...Changeover switch, 12A...Changeover terminal, 12B...First connection terminal, 12C...Second connection terminal, 12S...On / off switch, 13...Rectifier circuit, 14...DC side connection terminal, 15...Current detection unit, 20...Control device, 25...Alarm mechanism, 30...Battery, 31...Charging / discharging cable, 32...Relay, 35...Battery connection terminal, 50...Solar power generation system, 60 ＿１ ~60 ＿ｎ ...solar module, 70...power conditioner, 71...inverter, 75...PCS control device, 80...transformer, C1...DC side cable, C2...first AC side cable, C3...second AC side cable, S1...first switch, S2...second switch, S3...third switch, 100...power system
Claims
1. An anti-theft device for preventing the theft of a DC-side cable in a power generation system comprising a power generation device that generates electricity using renewable energy, and a power conditioner connected to the power generation device via a DC-side cable, which converts the DC power generated by the power generation device into AC power and transmits the converted AC power to the power grid via an AC-side cable, characterized in that the anti-theft device is directly connected to the DC-side cable located outside the power conditioner and comprises a voltage application means for applying a predetermined voltage to the DC-side cable when the power generation device is not generating electricity.
2. The anti-theft device according to claim 1, wherein the voltage application means comprises: a changeover switch attached to the AC side cable located outside the power conditioner; a connecting cable having one end connected to the changeover switch and the other end connected to the DC side cable located outside the power conditioner; a rectifier circuit provided on the connecting cable for converting AC power to DC power; and a control device for controlling the changeover switch, wherein the changeover switch is configured to be switchable between a power generation mode for electrically connecting the power conditioner and the power system and a non-power generation mode for electrically connecting the connecting cable and the power system, and the control device is configured to convert AC power transmitted from the power system into DC power by the rectifier circuit and supply it to the DC side cable when the power generation device is not generating power by setting the changeover switch to the non-power generation mode.
3. The anti-theft device according to claim 1, wherein the voltage applying means comprises a rechargeable battery and a connecting cable having one end connected to the battery and the other end connected to the DC side cable located outside the power conditioner, and is configured to store DC power generated by the power generator in the battery via the connecting cable when the power generator is generating power, and to apply the DC voltage stored in the battery to the DC side cable via the connecting cable when the power generator is not generating power.
4. An anti-theft device according to claim 2 or 3, further comprising: a current detection means provided on the connecting cable for detecting the current value of the DC current flowing through the connecting cable; and an alarm means that, when the power generation device is not generating power, sounds an alarm if the current value detected by the current detection means drops below a predetermined value.
5. The theft prevention device according to claim 1, wherein the power generation device is a solar cell module that generates electricity using solar energy.