DC cable monitoring system for solar power generation facilities

Abstract

This invention provides a DC cable monitoring system for solar power generation facilities that can determine whether an abnormality in a monitored DC cable is due to theft or a malfunction such as a failure. [Solution] The system includes a resistance value measuring means 20 that can measure the resistance of the DC cable 6 connecting the aggregation unit 4, which aggregates the DC power generated by the solar cell unit 3, and the power conditioner 5, and the equipment connected to the DC cable 6; an abnormal resistance value setting means 30 that sets an upper limit L1 and a lower limit L2 of the normal resistance value NR of the DC cable 6 as a reference; and an abnormal state determination means 50 that, when monitoring the cable, determines that a break has occurred in the DC cable 6 if the resistance of the DC cable 6 and the equipment connected to the DC cable 6 is greater than or equal to the upper limit L1, and determines that a malfunction other than a break has occurred in the DC cable 6 and / or the equipment connected to the DC cable 6 if the resistance is less than the lower limit L2.

Description

TECHNICAL FIELD

[0001] The present invention relates to a direct current cable monitoring system for photovoltaic power generation facilities. More specifically, the present invention relates to a direct current cable monitoring system for photovoltaic power generation facilities that can determine whether an abnormality in a monitored direct current cable is caused by theft (disconnection) or by a malfunction or other defect.

BACKGROUND ART

[0002] Conventionally, a technique as disclosed in, for example, Patent Document 1 is known.

[0003] <Patent Document 1> Japanese Unexamined Patent Application Publication No. 2016-131470 Patent Document 1 describes that an object thereof is to "provide an abnormality detection system for photovoltaic power generation facilities that can reliably detect abnormalities such as theft even at night at low cost with a simple system configuration", "In an abnormality detection system for photovoltaic power generation facilities, comprising lower-level units that aggregate direct current power generated by solar cell units, and an upper-level unit that aggregates the direct current power collected by the lower-level units, a plurality of the lower-level units are connected in parallel to the upper-level unit, each wiring cable connecting each of the lower-level units and the upper-level unit is provided with a measuring instrument for measuring impedance, and upstream of each of these measuring units, a determination unit is provided that detects the abnormality based on the measurement result when the solar cell units are not generating power, wherein the measuring instrument measures, as the impedance, a combined impedance aggregated in each of all the lower-level units connected in parallel to the upper-level unit" an abnormality detection system for photovoltaic power generation facilities is described (see the abstract section of the same document).

[0004] Further, in paragraph 0030 of the same document, "(ST3) The determination unit 12 has pre-stored therein, as initial setting values, the resistance values (R1 to R3) of the electric circuits aggregated in each lower-level unit. The determination unit 12 compares ... (omitted) ... and if Z1 = 1 / (1 / R1 + 1 / R2 + 1 / R3), it makes a normal determination (determining that it is in a "normal state" without theft, malfunction, etc.), and at this point, it terminates the abnormality detection routine. It is stated that, and paragraph 0031 says, (ST4) If Z1 is anything other than 1 / (1 / R1 + 1 / R2 + 1 / R3), an abnormality is detected and a warning is displayed. It is stated as follows.

[0005] In other words, according to the technology described in Patent Document 1, it is possible to determine whether the electrical circuit (wiring cable) to be judged is in a "normal state" free from theft, malfunction, etc., or in an abnormal state.

[0006] However, the technology described in Patent Document 1 cannot determine whether the abnormal condition is due to theft or a malfunction.

[0007] [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2016-131470 [Overview of the project] [Problems that the invention aims to solve]

[0009] The problem that this invention aims to solve is to provide a DC cable monitoring system for solar power generation equipment that can determine whether an abnormality in the monitored DC cable is due to theft or a malfunction such as a failure. [Means for solving the problem]

[0010] To solve the above problems, the DC cable monitoring system for solar power generation equipment of the present invention is Solar cell unit and This solar cell unit generates DC power which is then aggregated into an aggregation unit, This power conditioner converts the DC power from this aggregation unit into AC power, In a solar power generation system comprising a DC cable connecting the aforementioned aggregation unit and a power conditioner, DC cable connecting the aforementioned aggregation unit and power conditioner and the equipment connected to this DC cable A resistance measuring means capable of measuring the resistance value, The DC cable measured by this resistance measuring means and the equipment connected to this DC cable The normal resistance value is used as the reference, upper limit The value and, Normal resistance value An abnormal resistance value setting means for setting a lower limit, During cable monitoring, the DC cable measured by the resistance measurement means and the equipment connected to this DC cable The resistance value of the above upper limit When the value is greater than or equal to the above, it is determined that a break has occurred in the DC cable, and Below When it is below the limit, the DC cable and / or equipment connected to this DC cable An abnormal state determination means that determines that a malfunction other than disconnection has occurred, A power conditioner location information storage means that stores the installation location of the power conditioner as power conditioner location information including at least latitude and longitude, A drone equipped with a camera capable of flying to the installation location of a power conditioner based on power conditioner location information stored in a power conditioner location information storage means, and capable of capturing images of the area around the installation location of the power conditioner, including the DC cable connected to the power conditioner, and a video transmission means capable of transmitting the images captured by the camera, It is characterized by having the following features.

[0011] Given the above configuration, the following effects and benefits can be obtained from this DC cable monitoring system in the solar power generation facility.

[0012] By the resistance value measuring means, the DC cable connecting the aggregation unit and the power conditioner and the equipment connected to this DC cable can have its resistance value measured. By the abnormal resistance value setting means, with reference to the normal resistance value of the DC cable measured by the resistance value measuring means, the normal upper limit value, Under normal circumstances and the lower limit value are set. During cable monitoring, the abnormal state determination means performs determination as follows. (a) When the resistance value of the DC cable measured by the resistance value measuring means and the equipment connected to this DC cable is equal to or greater than the upper limit value, it is determined that disconnection has occurred in the DC cable. (b) When the resistance value of the DC cable measured by the resistance value measuring means and the equipment connected to this DC cable is less than the lower Below limit value, it is determined that a defect other than disconnection has occurred in the DC cable. and / or equipment connected to this DC cable

[0013] Therefore, according to the DC cable monitoring system for a photovoltaic power generation facility, it is possible to determine whether an abnormality in the monitored DC cable is caused by theft (disconnection) or by a defect such as a failure (for example, a ground fault of the connection cable, or an accident caused by submergence or the like). Furthermore, this DC cable monitoring system for a photovoltaic power generation facility comprises: power conditioner position information storage means for storing the installation position of the power conditioner as power conditioner position information including at least latitude and longitude; a drone that is capable of flying to the installation position of the power conditioner as a destination based on the power conditioner position information stored in the power conditioner position information storage means, and is equipped with a camera capable of capturing video around the installation position of the power conditioner including the DC cable connected to the power conditioner, and video transmission means capable of transmitting the video captured by the camera; ​Because it is equipped with this feature, by flying a drone to the installation location of the power conditioner to which the DC cable experiencing the abnormality is connected, and having the drone capture video of the area around the installation location of the power conditioner, including the DC cable, it is possible to visualize and determine in real time whether the abnormality in the DC cable is due to theft (cutting) or a malfunction such as failure (for example, a ground fault in the connecting cable, or a malfunction due to an accident such as submersion). Since the way to deal with a DC cable malfunction differs depending on whether it is due to theft or a failure, this invention allows for appropriate action to be taken.

[0014] Furthermore, in order to solve the above problems, the DC cable monitoring system for solar power generation equipment of the present invention is Solar cell unit and Multiple aggregation units collect the DC power generated by this solar cell unit, A power conditioner that aggregates DC power from these multiple aggregation units, Each of the aforementioned multiple aggregation units and power conditioners Connect them in parallel In a solar power generation facility equipped with multiple DC cables, Multiple DC cables connecting each aggregation unit to the power conditioner. and the sum of the individual resistance values ​​of the devices connected to this DC cable A resistance measuring means capable of measuring the total resistance value, The DC cable measured by this resistance measuring means and the equipment connected to this DC cable Based on the overall normal resistance value, the normal resistance value upper limit The value and, Below the normal resistance value An abnormal resistance value setting means for setting a limit value, During cable monitoring, the DC cable measured by the resistance measurement means and the equipment connected to this DC cable The total resistance value is The upper limit is When the above is true, it is determined that a break has occurred in the DC cable, and Below When it is below the limit, the DC cable and / or equipment connected to this DC cable An abnormal state determination means that determines that a malfunction other than disconnection has occurred, A power conditioner location information storage means that stores the installation location of each of the aforementioned plurality of power conditioners as power conditioner location information including at least latitude and longitude, A drone equipped with a camera capable of flying to the installation location of a power conditioner based on power conditioner location information stored in a power conditioner location information storage means, and capable of capturing images of the area around the installation location of the power conditioner, including the DC cable connected to the power conditioner, and a video transmission means capable of transmitting the images captured by the camera, It is characterized by having the following features.

[0015] Given the above configuration, the following effects and benefits can be obtained from this DC cable monitoring system in the solar power generation facility.

[0016] The DC cable connecting the aggregation unit and the power conditioner is measured by a resistance measurement means. and the sum of the individual resistance values ​​of the devices connected to this DC cable The total resistance can be measured. The DC cable measured by the resistance value measuring means by the abnormal resistance value setting means and the equipment connected to this DC cable The overall normal resistance value is used as the reference, upper limit The value and, Below the normal resistance value A limit value is set. During cable monitoring, the abnormal condition determination means determines the following: (a) DC cable measured by the resistance measuring means and the equipment connected to this DC cable The total resistance value is as described above. upper limit When the value is greater than or equal to a certain value, it is determined that a break has occurred in the DC cable. (b) DC cable measured by the resistance measuring means and the equipment connected to this DC cable The total resistance value is Below When it is below the limit, the DC cable and / or equipment connected to this DC cable It is determined that a problem other than disconnection has occurred.

[0017] Therefore, this DC cable monitoring system for solar power generation facilities can determine whether an abnormality in the monitored DC cable is due to theft (cutting) or a malfunction such as a fault (for example, a ground fault in the connecting cable, or a malfunction due to an accident such as submersion). Furthermore, the DC cable monitoring system in this solar power generation facility is A power conditioner location information storage means that stores the installation location of each of the aforementioned plurality of power conditioners as power conditioner location information including at least latitude and longitude, A drone equipped with a camera capable of flying to the installation location of a power conditioner based on power conditioner location information stored in a power conditioner location information storage means, and capable of capturing images of the area around the installation location of the power conditioner, including the DC cable connected to the power conditioner, and a video transmission means capable of transmitting the images captured by the camera, Because it is equipped with this feature, by flying a drone to the installation location of the power conditioner to which the DC cable experiencing the abnormality is connected, and having the drone capture video of the area around the installation location of the power conditioner, including the DC cable, it is possible to visualize and determine in real time whether the abnormality in the DC cable is due to theft (cutting) or a malfunction such as failure (for example, a ground fault in the connecting cable, or a malfunction due to an accident such as submersion). Since the way to deal with a DC cable malfunction differs depending on whether it is due to theft or a failure, this invention allows for appropriate action to be taken.

[0018] In this DC cable monitoring system for solar power generation facilities, further, When the abnormal condition determination means determines that a break has occurred in the DC cable, it issues a break occurrence alarm indicating that the DC cable has been cut. and / or equipment connected to this DC cable When it is determined that a malfunction other than a disconnection has occurred in the DC cable, and / or equipment connected to this DC cable An alarm issuing means that issues a malfunction alarm indicating that a malfunction has occurred, When the abnormal condition determination means determines that a break has occurred in the DC cable, or when it determines that a malfunction other than a break has occurred in the DC cable, the flight instruction means instructs the drone to fly to the location where the power conditioner is installed and where the break in the DC cable or the malfunction other than a break was determined to occur is located. It can be configured to include the following features. With this configuration, the alarm issuing mechanism can trigger an alarm indicating that an abnormality has occurred in the monitored DC cable, and whether the abnormality is due to theft (cutting) or a malfunction such as a fault (for example, a ground fault in the connecting cable, or a malfunction due to an accident such as submersion). At the same time, the flight instruction means can instruct the drone to fly to the installation location of the power conditioner where it has been determined that a DC cable has been cut or that a malfunction other than a cut has occurred. By capturing video of the area around the installation location of the power conditioner, including the DC cable, it becomes possible to visualize and determine in real time whether the abnormality in the DC cable is due to theft (cutting) or a malfunction such as a failure (for example, a ground fault in the connecting cable, or a malfunction due to an accident such as submersion).

[0019] In this DC cable monitoring system for solar power generation facilities, At a minimum, the resistance value measuring means, the abnormal state determination means, and the alarm signaling means are incorporated into the power conditioner. Furthermore, the system includes a management device installed at a distance from the power conditioner, which wirelessly receives disconnection alarms or malfunction alarms from the alarm transmission means and video footage from the drone. This management device can be configured to transmit the above-mentioned alarms and video to a designated recipient. This configuration allows for immediate and appropriate action to be taken when a problem occurs with a cable. [Brief explanation of the drawing]

[0020] [Figure 1] A system configuration diagram showing an embodiment of the DC cable monitoring system in a solar power generation facility according to the present invention. [Figure 2] A block diagram showing an example of the main components of the system. [Figure 3] A schematic diagram showing an example of a drone and drone storage facility. [Modes for carrying out the invention]

[0021] Hereinafter, embodiments of the DC cable monitoring system for a solar power generation facility according to the present invention will be described with reference to the drawings. In each figure, the same parts or corresponding parts are denoted by the same reference numerals.

[0022] As shown in Figure 1, the DC cable monitoring system 1 in this embodiment of the solar power generation facility is Solar cell unit 3, Multiple aggregation units 4 collect the DC power generated by this solar cell unit 3, A power conditioner 5 aggregates the DC power from these multiple aggregation units 4, Multiple aggregation units 4 and power conditioners 5 are each Connect them in parallel This method is applicable to a solar power generation system 2 equipped with multiple DC cables 6. Furthermore, as will be described later, it is also applicable even if there is only one DC cable 6.

[0023] As shown in Figure 2, the DC cable monitoring system 1 in this embodiment of the solar power generation facility is Multiple DC cables connecting each aggregation unit 4 and power conditioner 5. and the sum of the individual resistance values ​​of the equipment connected to this DC cable 6 (mainly the aggregation unit 4 and the power conditioner 5) A resistance measurement means 20 capable of measuring the total resistance value of 6T, The DC cable measured by this resistance measuring means 20 and the equipment connected to this DC cable 6 The normal resistance value NRT for the entire 6T is used as the reference, upper limit Value L1T, Normal resistance valueAn abnormal resistance value setting means 30 for setting a lower limit value L2T, During cable monitoring, the DC cable 6 measured by the resistance measurement means 20 and the equipment connected to this DC cable 6 The total resistance value of 6T is as described above. upper limit Value L1 T or more When the above is true, it is determined that a break has occurred in one or more of the DC cables 6, and the previous Below When the limit value is less than L2T, DC cable 6 (one or more of them) and / or equipment connected to this DC cable 6 An abnormal state determination means 50 that determines that a malfunction other than disconnection has occurred, A power conditioner location information storage means (storage means) 42 stores the installation positions P(1~n) of each of the plurality of power conditioners 5 as power conditioner location information PI, which includes at least latitude and longitude. A drone (an autonomous flying object that receives commands) 300 is equipped with a camera 301 (Figure 3) capable of capturing images of the area around the installation location of the power conditioner 5, including the DC cable 6 connected to the power conditioner 5, and a video transmission means 302 (Figure 3) capable of transmitting the images captured by the camera 301, which can fly to the installation location P(1~n) of the power conditioner 5 based on the power conditioner location information PI stored in the power conditioner location information storage means 42, and a video transmission means 302 (Figure 3) capable of transmitting the images captured by the camera 301. It is equipped with.

[0024] This system 1 further, When the abnormal condition determination means 50 determines that a break has occurred in the DC cable 6, it sends a break occurrence alarm CA indicating that the DC cable 6 has been cut, and the DC cable 6 and / or equipment connected to this DC cable 6 When it is determined that a malfunction other than a break has occurred in the DC cable 6 and / or equipment connected to this DC cable 6 An alarm transmission means 60 that transmits a malfunction alarm FA indicating that a malfunction has occurred, When the abnormal condition determination means 50 determines that a break has occurred in the DC cable 6, or when it determines that a malfunction other than a break has occurred in the DC cable 6, the flight instruction means 80 instructs the drone 300 to fly to the installation position P(1~n) of the power conditioner 5 where it was determined that a break had occurred in the DC cable 6 or that a malfunction other than a break had occurred. It is equipped with.

[0025] In this system 1, The resistance measurement means 20, the abnormal state determination means 50, and the alarm signaling means 60 are configured as a unit 110 and incorporated into the power conditioner 5 (see Figure 1).

[0026] This system 1 further includes a management device 100 installed at a distance from the power conditioner 5, which wirelessly receives disconnection alarm CA or malfunction alarm FA from the alarm transmission means 60 and video (video signal) V from the drone 300. This management device 100 transmits the above-mentioned alarm and video to a predetermined notification destination 200.

[0027] Given the above configuration, the following effects and benefits can be obtained from this DC cable monitoring system in the solar power generation facility.

[0028] The resistance measurement means 20 measures the DC cable 6 connecting the aggregation unit 4 and the power conditioner 5. and the sum of the individual resistance values ​​of the devices connected to this DC cable 6 The total resistance value of 6 turns can be measured.

[0029] The DC cable 6 measured by the resistance measurement means 20 is determined by the abnormal resistance value setting means 30. and the sum of the individual resistance values ​​of the devices connected to this DC cable 6 The normal resistance value NRT for the entire 6T is used as the reference. upper limit Value L1T, Normal resistance value The lower limit L2T is set.

[0030] During cable monitoring, the abnormal condition determination means 50 makes the following determination:

[0031] (a) DC cable 6 measured by resistance measuring means 20 and the sum of the individual resistance values ​​of the devices connected to this DC cable 6 The total resistance value RT of 6T is as described above. upper limit When the value is L1T or greater, it is determined that a break has occurred in one or more of the DC cables 6.

[0032] (b) DC cable 6 measured by resistance measuring means 20 and the sum of the individual resistance values ​​of the devices connected to this DC cable 6 The total resistance value RT for 6T is Below When the limit value is less than L2T, DC cable 6 (one or more of them) and / or equipment connected to this DC cable 6 It is determined that a problem other than disconnection has occurred.

[0033] Therefore, according to the DC cable monitoring system in this solar power generation facility, it is possible to determine whether the abnormality in the monitored DC cable 6 is due to theft (cutting), a malfunction or other defect (for example, a ground fault in the connecting cable, or Malfunctions caused by accidents such as water damage to the connection point between cable 6 and the equipment, or water damage to part or all of the equipment. It is possible to determine whether it is due to ). Furthermore, the DC cable monitoring system in this solar power generation facility is A power conditioner location information storage means 42 stores the respective installation locations P(1~n) of multiple power conditioners 5 as power conditioner location information PI, which includes at least latitude and longitude. A drone 300 is equipped with a camera 301 capable of flying to the installation location P(1~n) of a power conditioner based on the power conditioner location information PI stored in the power conditioner location information storage means 42, and capable of capturing video V of the area around the installation location of the power conditioner 5 (including the area around the aggregation unit 4), including the DC cable 6 connected to the power conditioner 5, and a video transmission means 302 capable of transmitting the video V captured by the camera 301. Since it is equipped with this, by flying the drone 300 to the installation location P(1~n) of the power conditioner 5 to which the abnormal DC cable 6 is connected as the destination, and taking images of the area around the installation location of the power conditioner 5 including the DC cable 6, it is possible to determine whether the abnormality in the DC cable 6 is due to theft (cutting), a malfunction or other defect (for example, a ground fault in the connecting cable, or Submersion of the connection point between cable 6 and the equipment, or part or all of the equipment It is possible to visualize and determine in real time whether the problem is due to an accident such as submersion in water.

[0034] Since the response to an abnormality in DC cable 6 due to theft differs from the response to a malfunction such as a failure, this system allows for appropriate action to be taken.

[0035] This DC cable monitoring system in the solar power generation facility is further equipped with the alarm transmission means 60, so the alarm transmission means 60 will alert the DC cable 6 that is being monitored. and / or equipment connected to this DC cable 6 It can issue an alarm when an abnormality occurs, and whether that abnormality is due to theft (cutting) or a malfunction such as a breakdown. In other words, it can issue a cut-out alarm CA or a malfunction alarm FA. At the same time, the flight instruction means 80 instructs the drone 300 to fly to the installation location P(1~n) of the power conditioner 5 where it has been determined that a cut has occurred in the DC cable 6, or that a malfunction other than a cut has occurred. By capturing video of the area around the installation location of the power conditioner 5, including the DC cable 6, it becomes possible to visualize and determine in real time whether the abnormality in the DC cable is due to theft (cutting) or a malfunction such as a failure.

[0036] Furthermore, in this solar power generation facility, the DC cable monitoring system incorporates at least a resistance value measuring means 20, an abnormal condition determination means 50, and an alarm transmission means 60 into the power conditioner 5. In addition, a management device 100 is installed at a location separated from the power conditioner 5. This management device 100 wirelessly receives disconnection alarms CA or malfunction alarms FA from the alarm transmission means 60 and video V from the drone 300, and transmits these alarms and video to a predetermined notification destination 200. This makes it possible to immediately take appropriate action according to the problem with the cable 6 in question.

[0037] Further details are provided below. The solar cell unit 3 can be composed of a group of known solar panels. Each aggregation unit 4 can be composed of a known and suitable aggregation unit, for example, a known junction box.

[0038] Each solar cell unit 3 and the aggregation unit 4 are connected by a known DC cable 3c and known connection structures The connections are made via this DC cable 3c. The DC power generated by the solar cell unit 3 is collected by each aggregation unit 4 through this DC cable 3c. This DC cable 3c is thinner than the DC cable 6.

[0039] The power conditioner 5 can be composed of any known and suitable power conditioner. In this embodiment, it is composed of a central type power conditioner.

[0040] Each aggregation unit 4 and power conditioner 5 are connected by a known DC cable 6. and known connection structures The DC power from each aggregation unit 4 is connected and aggregated to the power conditioner 5 via this DC cable 6. This DC cable 6 is thicker than the aforementioned DC cable 3c.

[0041] Both DC cable 3c and DC cable 6 have a current of approximately 0V after sunset, but DC cable 6 is thicker than DC cable 3c, making it more susceptible to theft. Furthermore, even if DC cable 3c is cut (stolen), The resistance is measured by the resistance measuring means 20. Because the resistance value changes, this system can also detect if a DC cable 3c has been stolen.

[0042] The power from the power conditioner 5 is supplied to the designated equipment via the AC cable 5c and the interconnection equipment 7. However, since the AC cable 5c has an AC voltage of approximately 380-600V applied to it except during power outages, it is unlikely to be a target for theft.

[0043] In Figure 2, 6(1), 6(2), ... 6(n) are the DC cables 6 mentioned earlier. Relays 21(1~n) are connected to each of these DC cables 6, and resistance measuring instruments 24 are connected via relays 21(1~n). Note that 6f is a terminal of cable 6, and 6b is a connection terminal block.

[0044] 22 is a PCS input voltage measuring means for measuring the input voltage to the power conditioner 5, and by being connected to the appropriate place on the power conditioner 5, it measures the input voltage to the power conditioner 5.

[0045] 23 is a relay operation control means that controls the operation of the relays 21(1~n) above. It receives the measurement result from the PCS input voltage measurement means 22, and when the measured voltage nV becomes approximately 0 (i.e., when power generation by the solar cell unit 3 becomes approximately 0 due to sunset), it sequentially operates the relays 21(1~n) to sequentially connect each DC system cable 6(1~n) to the resistance value measuring instrument 24, and each DC system cable 6(1~n) and the equipment connected to this DC cable 6 A relay activation signal is sent to each relay 21 (1 to n) to cause the resistance value R(1 to n) to be measured by the resistance meter 24.

[0046] As a result of the operation of the relay 21 (1 to n) above, the DC cables 6 (1 to n) whose resistance values ​​were sequentially measured by the resistance measuring instrument 24 and the equipment connected to this DC cable 6 The resistance values ​​R(1~n) are sequentially sent from the resistance meter 24 to the control unit 81, and the control unit 81 accumulates these resistance values ​​R(1~n) and uses the accumulated value to connect multiple DC cables 6 and the equipment connected to this DC cable 6 The total resistance value RT is determined.

[0047] Prior to cable monitoring, the abnormal resistance value setting means 30 sets the resistance value of multiple DC cables 6 measured by the resistance value measuring means 20. and the equipment connected to this DC cable 6 The normal resistance value NRT of the total resistance value RT is used as the reference value of the normal resistance value upper limit Value L1T, Normal resistance value Set the lower limit L2T. upper limit Value L1T and down The limit value L2T is stored in the storage unit 41 via, for example, the transmitting and receiving means 71, 72 and the control unit 81, which will be described later.

[0048] Specifically, for example, multiple DC cables 6 measured by the resistance measurement means 20 and the equipment connected to this DC cable 6 If the normal resistance value NRT of the total resistance value RT is 6MΩ, then using this 6MΩ as a reference, the upper limit value L1T of the normal resistance value is, for example... 6.3 MΩ ,under For example, the limit value L2T 0.5M Set to Ω. As mentioned above, these values ​​are stored in the memory unit 41. For example, if the normal combined resistance value RT is 6MΩ as described above, the percentages of the upper limit L1T and lower limit L2T relative to the normal combined resistance value RT will vary depending on the equipment configuration, cable size, and number of connected circuits, making it difficult to uniformly limit them. However, if the number of circuits is small, the resistance value will increase by 15% to 30% when one cable is cut, and if the number of circuits is large, the resistance value will increase by about 3% to 5% when one cable is cut. Therefore, the upper limit L1T can be set to, for example, 6.3MΩ, which is about 5% higher than the normal value. On the other hand, if an accident other than cable breakage occurs (short circuit, ground fault, or submersion), the combined resistance value RT becomes immeasurable (significantly reduced from the normal value and very close to 0Ω), so the lower limit L2T can be set to, for example, 0.5MΩ. In actual field operations, it is desirable to disconnect one of the connected circuits when installing the alarm system, check how much the resistance value increases, and then set the alarm range, i.e., the upper limit L1T and lower limit L2T.

[0049] During cable monitoring (at sunset), the relay 21 (1-n) is activated, and the DC cables 6 (1-n) whose resistance values ​​are sequentially measured by the resistance meter 24 are... and the equipment connected to this DC cable 6 The resistance values ​​R(1~n) are accumulated in the control unit 81, and the accumulated value is then used for multiple DC cables 6 and the equipment connected to this DC cable 6 The total resistance value RT is determined and sent to the abnormal state determination means 50.

[0050] The abnormal state determination means 50 is DC cable 6 and the equipment connected to this DC cable 6 The total resistance value RT is set by the abnormal resistance value setting means 30. upper limit Value L1 T or more When the above is true, it is determined that a break has occurred in one or more DC cables 6. ,under When the limit value L2T is less than the DC cable 6 and / or equipment connected to this DC cable 6 It is determined that a problem other than disconnection has occurred.

[0051] For example, the abnormal state determination means 50 is DC cable 6 and the equipment connected to this DC cable 6 The total resistance value RT is 6.4 If the value is MΩ, it is determined that DC cable 6 is disconnected, and if the value is 0Ω, DC cable 6 and / or equipment connected to this DC cable 6 It is determined that a problem other than disconnection has occurred. This determination signal is sent to the alarm transmission means 60 (61) and then sent to the management device 100 of this system 1 via the transmission / reception means 71.

[0052] The alarm transmitting means 60 receives a determination signal from the abnormal state determination means 50, and when the abnormal state determination means 50 determines that the DC cable 6 has been cut, it transmits a cable cut occurrence alarm CA indicating that the cable has been cut, and the DC cable 6 and / or equipment connected to this DC cable 6 When it is determined that a malfunction other than disconnection has occurred in cable 6 and / or equipment connected to this DC cable 6 A malfunction alert (FA) is issued indicating that a malfunction has occurred.

[0053] In this embodiment, the resistance value measuring means 20, abnormal state determination means 50, alarm transmission means 61(60), and transmitting / receiving means 71 described above are configured as a unit 110 and incorporated into the power conditioner 5 (see Figure 1). The management device 100 includes a unit identification information assigning means 10, and the unique unit identification information UI assigned to each unit 110 by this unit identification information assigning means 10 is stored in the storage unit 41 for each unit 110 via the transmitting / receiving means 71, 72 and the control unit 81 for each unit 110.

[0054] In this embodiment, the power conditioner location information PI, which includes at least latitude and longitude, is formed as part of the unique unit identification information UI for each unit 110. Therefore, the storage means 42 of the management device 100 constitutes a power conditioner location information storage means that stores the respective installation locations P(1~n) of the power conditioners 5 as power conditioner location information PI, which includes at least latitude and longitude. The power conditioner location information PI can also include altitude information that the drone 300 should reach.

[0055] The signal from the alarm transmission means 61 is sent via the transmission / reception means 71 to the transmission / reception means 72 of the management device 100 of this system 1, along with the unit identification information UI (i.e., the identification information of the unit to which the disconnected or malfunctioning cable 6 is connected). Both of these transmission / reception means 71 and 72 can be composed of known transmission / reception means that can operate in a wireless communication environment (including wireless LAN and Wi-Fi environments).

[0056] Unit 110 is provided with a control means (e.g., an MCU) 81 that controls each of the means 22, 23, 24, 50, 61, and 71 within Unit 110.

[0057] The management device 100 can be composed of a known personal computer equipped with control means (e.g., a CPU) for controlling each of the means of the device 100, and input means such as a keyboard and mouse (not shown), a display (not shown), etc.

[0058] When the management device 100 receives unit identification information UI(1~n) including the power conditioner location information PI and a malfunction alarm FA (or disconnection alarm CA) from the unit 110, it transmits these alarms to a predetermined notification destination (e.g., a fault response department, a theft response department, etc.) 200, and also instructs the drone 300 via the transmission / reception means 72 using the flight instruction means 80 to fly to the installation location P(1~n) of the power conditioner 5 that issued the malfunction alarm FA (or disconnection alarm CA).

[0059] The basic configuration of the Drone 300 can be made up of known GPS-equipped drones. In addition to the basic configuration described above, the drone 300 of this embodiment includes a location information storage unit 303 that stores at least power conditioner location information PI (installation location P(1~n)) and hangar location information, which will be described later, provided by the management device 100; a transmission / reception means 304 that enables the transmission and reception of various information, including video signals, between the management device 100 and the hangar 400, which will be described later; and a control means 305 that controls these parts (including the parts described later). When the drone receives a flight instruction from the flight instruction means 80 with the installation location P(1~n) of the power conditioner 5 as its destination, it reads the destination information corresponding to the flight instruction (for example, the installation location P(1) of the power conditioner 5(1)) from the location information storage unit 303 and flies toward that installation location.

[0060] The drone 300 has a comparison and determination means 306 that compares the drone's current position with the installation position and determines that the destination has been reached when both positions are within a predetermined range (for example, within a range of 1m when converted to distance in both latitude and longitude). When the comparison and determination means 306 determines that the destination has been reached, the control means 305 activates the camera 301 based on the arrival signal. Camera 301 consists of cameras equipped with motion detection capabilities. Camera 301 captures video (video signal) V around the installation location of the power conditioner 5 and sends the video (video signal) V to the management device 100. The control device 100 sends this video to a designated notification destination 200. This allows for real-time visualization of the status of problematic cables and enables appropriate countermeasures to be taken accordingly. The video (video signal) V from camera 301 may be sent directly to a predetermined notification destination 200 without going through the management device 100.

[0061] This DC cable monitoring system 1 is equipped with a hangar (storage box) 400 for housing the drone 300. As shown in Figure 3, the hangar 400 comprises a hangar body 401, a door 402 that is openable and closable and located on the top of the hangar body 401, a door opening and closing drive mechanism 403 for opening and closing the door 402, and a charging device 405 for contactless charging of the drone 300's drive battery (not shown).

[0062] The door opening / closing drive mechanism 403 has a means of communication (not shown) with the drone 300. When it receives a signal from the drone 300 inside the hangar body 401 that it is ready to transmit, it opens the door 402 to allow the drone 300 to launch. When the drone 300 lands inside the hangar body 401 after flight, it receives a landing signal from the drone 300 and closes the door 402.

[0063] The hangar 400 is installed at a suitable location within the area to which this DC cable monitoring system 1 is applied. The opening and closing drive mechanism 403 for opening and closing the door 402 can be a known mechanism (for example, the mechanism disclosed as a roof opening and closing device 4 in Japanese Patent Publication No. 7200324). The charging device 405 can also be configured with a known and suitable charging device. The power supply for the equipment and charging device 405 inside the hangar 400 will be configured to include a backup power supply (UPS) to enable startup even in the event of a power outage. The drone 300 can store the location information (latitude and longitude) of the hangar 400 in the location information storage unit 303. A mobile router can also be used as a means of communication between the drone 300 and the hangar 400.

[0064] The sequence of operations for the Drone 300 described above is as follows: <In standby mode> During standby (when there is no abnormality in the DC cable), the drone 300 is located inside the hangar 400 and receives charging as needed from the charging device 405. <In case of an emergency> (1) When the aircraft receives a flight instruction from the flight instruction means 80 with the installation position P (any of 1 to n) of the power conditioner 5 as the destination, it enters a launch preparation phase. The aircraft reads destination information corresponding to the flight instruction (for example, the installation position P(1) of the power conditioner 5(1)) from the position information storage unit 303, and once the launch preparation is complete, it sends a signal ready to launch to the door opening / closing drive mechanism 403. (2) The door opening / closing drive mechanism 403, upon receiving the signal to transmit, opens the door 402. (3) Upon receiving the signal to open door 402, the drone 300 is launched and flies toward the destination mentioned above. (4) Upon arrival at the destination, camera 301 is activated and captures video V including the DC cable around the installation location of the power conditioner 5 to which the malfunctioning DC cable is connected, and sends the video (video signal) V to the management device 100. (5) When motion detection by the camera 301 ceases, or when a predetermined time has elapsed, the camera 301 stops taking pictures and returns to the storage compartment 400. The control device 100 may also be configured to directly issue a return command signal to the drone 300. (6) When the drone 300 lands in the storage compartment 400, the door opening / closing drive mechanism 403 receives a landing signal from the drone 300 and closes the door 402, returning to the standby state described above.

[0065] The cable monitoring operation described above is repeated, for example, until the voltage measured by the voltage measuring means 22 becomes a predetermined voltage of 0 or higher, due to sunrise.

[0066] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and can be appropriately modified and implemented within the scope of the gist of the present invention. For example, although the above embodiment described a case where there are multiple power conditioners 5, it is also applicable to the case where there is only one. Similarly, this method is also applicable when there is only one cable 6. In this case, in the above embodiment, The resistance measurement means 20 measures the single DC cable 6 connecting the aggregation unit (4) and the power conditioner (5). and the equipment connected to this DC cable The configuration is designed to measure the resistance value, The abnormal resistance value setting means 30 uses the normal resistance value NR of the DC cable 6 measured by the resistance value measuring means 20 as a reference, and sets the normal resistance value upper limit Value L1 and ,under The configuration is such that a limit value L2 is set, The abnormal condition determination means 50 determines the DC cable 6 measured by the resistance value measuring means 20 during cable monitoring. and the equipment connected to this DC cable The resistance value of the above Upper limit L1 or higher When this occurs, it is determined that a break has occurred in the DC cable 6, Below When the limit value L2 is less than the DC cable 6 and / or equipment connected to this DC cable 6 This can be applied by configuring the system to determine if a malfunction other than disconnection has occurred. [Explanation of Symbols]

[0067] 3: Solar cell unit 4: Aggregation Unit 5: Power Conditioner 5 6: DC cable 20: Resistance measurement means 30: Abnormal resistance value setting means 50: Abnormal State Determination Method 300: Drone

Claims

1. Solar cell unit (3), This solar cell unit (3) generates DC power which is then aggregated by an aggregation unit (4), A power conditioner (5) converts the DC power from this aggregation unit (4) to AC power, In a solar power generation system (2) comprising a DC cable (6) connecting the aggregation unit (4) and a power conditioner (5), A DC cable (6) connecting the aggregation unit (4) and the power conditioner (5), and a resistance measuring means (20) capable of measuring the resistance of the equipment connected to the DC cable (6), An abnormal resistance value setting means (30) sets an upper limit (L1) and a lower limit (L2) of the normal resistance value, based on the normal resistance value (NR) of the DC cable (6) and the equipment connected to the DC cable (6) measured by this resistance value measuring means (20). An abnormal condition determination means (50) determines that a break has occurred in the DC cable (6) when the resistance value of the DC cable (6) and the equipment connected to the DC cable (6), as measured by the resistance value measuring means (20), is equal to or greater than the upper limit value (L1), and determines that a malfunction other than a break has occurred in the DC cable (6) and / or the equipment connected to the DC cable (6), when the resistance value of the DC cable (6) and the equipment connected to the DC cable (6), as measured by the resistance value measuring means (20) during cable monitoring, A power conditioner location information storage means (42) stores the installation location (P(1 to n)) of the power conditioner (5) as power conditioner location information (PI) including at least latitude and longitude, A drone (300) is equipped with a camera (301) capable of capturing images of the area around the installation location of the power conditioner (5), including the DC cable (6) connected to the power conditioner (5), and a video transmission means (302) capable of transmitting the images captured by the camera (301), which is capable of flying to the installation location (P(1 to n)) of the power conditioner (5) based on the power conditioner location information (PI) stored in the power conditioner location information storage means (42), and the drone (300) is equipped with a camera (301) capable of capturing images of the area around the installation location of the power conditioner (5), including the DC cable (6) connected to the power conditioner (5), and a video transmission means (302) capable of transmitting the images captured by the camera (301). A DC cable monitoring system for solar power generation facilities, characterized by having the following features.

2. Solar cell unit (3), Multiple aggregation units (4) collect the DC power generated by this solar cell unit (3), A power conditioner (5) aggregates the DC power from these multiple aggregation units (4), In a solar power generation system (2) comprising a plurality of DC cables (6) connecting the plurality of aggregation units (4) and power conditioners (5) in parallel, A resistance measurement means (20) capable of measuring the total resistance value obtained by summing the individual resistance values ​​of multiple DC cables (6) connecting each aggregation unit (4) and the power conditioner (5), and the equipment connected to these DC cables (6), An abnormal resistance value setting means (30) sets an upper limit (L1T) and a lower limit (L2T) of the normal resistance value, based on the normal resistance value (NRT) of the DC cable (6) and the equipment connected to the DC cable (6) as measured by this resistance value measuring means (20). An abnormal condition determination means (50) determines that, when monitoring the cable, if the total resistance of the DC cable (6) and the equipment connected to the DC cable (6), as measured by the resistance value measuring means (20), is equal to or greater than the upper limit value (L1T), a break has occurred in the DC cable (6), and if it is less than the lower limit value (L2T), a malfunction other than a break has occurred in the DC cable (6) and / or the equipment connected to the DC cable (6), A power conditioner location information storage means (42) stores the installation locations (P(1 to n)) of each of the plurality of power conditioners (5) as power conditioner location information (PI) including at least latitude and longitude, A drone (300) is equipped with a camera (301) capable of capturing images of the area around the installation location of the power conditioner (5), including the DC cable (6) connected to the power conditioner (5), and a video transmission means (302) capable of transmitting the images captured by the camera (301), which is capable of flying to the installation location (P(1 to n)) of the power conditioner (5) based on the power conditioner location information (PI) stored in the power conditioner location information storage means (42), and the drone (300) is equipped with a camera (301) capable of capturing images of the area around the installation location of the power conditioner (5), including the DC cable (6) connected to the power conditioner (5), and a video transmission means (302) capable of transmitting the images captured by the camera (301). A DC cable monitoring system for solar power generation facilities, characterized by having the following features.

3. In claim 1 or 2, further, When the abnormal condition determination means (50) determines that a break has occurred in the DC cable (6), the alarm issuing means (60) issues a break occurrence alarm (CA) indicating that the DC cable (6) has been broken, and when it determines that a malfunction other than a break has occurred in the DC cable (6) and / or the equipment connected to the DC cable (6), the alarm issuing means (60) issues a malfunction occurrence alarm (FA) indicating that a malfunction has occurred in the DC cable (6) and / or the equipment connected to the DC cable (6). When the abnormal condition determination means (50) determines that a break has occurred in the DC cable (6), or when it determines that a malfunction other than a break has occurred in the DC cable (6), the flight instruction means (80) instructs the drone (300) to fly to the installation location (P(1 to n)) of the power conditioner (5) where it was determined that a break had occurred in the DC cable (6) or that a malfunction other than a break had occurred. A DC cable monitoring system for solar power generation facilities, characterized by having the following features.

4. In claim 3, At least the resistance value measuring means (20), the abnormal state determination means (50), and the alarm signaling means (60) are incorporated into the power conditioner (5). Furthermore, the system includes a management device (100) installed at a distance from the power conditioner (5) that wirelessly receives disconnection alarms (CA) or malfunction alarms (FA) from the alarm transmission means (60) and video from the drone (300). This management device (100) is a DC cable monitoring system for a solar power generation facility, characterized by transmitting the above-mentioned alarms and video to a predetermined notification destination (200).

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