High-altitude photovoltaic array maintenance system and method

Abstract

The application discloses a high-altitude photovoltaic array maintenance system and method, and relates to unmanned remote monitoring and maintenance of a photovoltaic power generation array established in a high-altitude mountainous area. The photovoltaic power generation array comprises photovoltaic panel assemblies, a current combiner box and an inverter connected in sequence, and the inverter is connected to a power grid. The system comprises a first detection point, a second detection point and a third detection point arranged on a line from each minimum-area series-connected photovoltaic panel assembly to the current combiner box, and used for acquiring current and voltage values output by each minimum-area series-connected photovoltaic panel assembly. The system further comprises a data terminal with a data processing module and a transceiver module. The application is simple and stable, and can realize long-period unmanned remote monitoring for problems that are difficult for people to reach in high-altitude areas.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photovoltaic power generation, and particularly relates to a photovoltaic array maintenance system and method in high-altitude areas. BACKGROUND

[0002] Photovoltaic power generation is a technology for directly converting solar energy into electric energy by using the photovoltaic effect of semiconductors. The core equipment includes photovoltaic panels, combiner boxes, inverters, transformers and the like. The photovoltaic panels generate direct current through the photoelectric effect, the direct current is collected by the combiner boxes, and then converted into alternating current by the inverters, and then the alternating current is boosted by the transformers and connected to the power grid. In recent years, photovoltaic power generation technology has developed towards high efficiency and intelligence, and new high-efficiency cell pieces (such as HJT and TOPCon) and intelligent inverters (integrating MPPT and communication functions) have been widely used. At the same time, the scale of photovoltaic power stations has also developed from scattered to centralized and base, and the demand for remote monitoring and automatic management is increasingly urgent.

[0003] In photovoltaic power generation projects in high-altitude and other special areas, due to complex terrain and harsh climate, personnel cannot reach the site for manual maintenance, and can only rely on remote management systems to realize equipment operation and maintenance. However, the existing detection and maintenance methods have obvious shortcomings: traditional monitoring is mostly based on the overall data of the inverter end, which is difficult to locate local faults and has low sensitivity to problems such as shading and damage of photovoltaic panels; the wireless transmission network has insufficient coverage in complex terrain, high data delay and easy interruption; there is a lack of accurate fault identification algorithms, which cannot timely detect early abnormalities, resulting in accumulation of equipment faults, and seriously affecting the power generation efficiency and reliability of the power station. SUMMARY

[0004] In order to solve the problems existing in the prior art, the application provides a photovoltaic array maintenance system and method in high-altitude areas, which detects and maintains the photovoltaic array that is difficult to manually patrol in high-altitude areas through the automatic detection system and the cloud management method.

[0005] The technical scheme adopted by the application is as follows:

[0006] In a first aspect, the application provides a photovoltaic array maintenance system in high-altitude areas, which is used for unmanned remote monitoring and maintenance of a photovoltaic power generation array established in a high-altitude mountainous area. The photovoltaic power generation array includes photovoltaic panel assemblies, combiner boxes and inverters connected in sequence, and the inverters are connected to the power grid; and the system comprises:

[0007] A first detection point is arranged on a line through which each inverter in the photovoltaic power generation array is connected to the power grid, and is used to acquire current and voltage values output by the inverter;

[0008] A second detection point is arranged on a line through which each combiner box is connected to the inverter, and is used to acquire current and voltage values output by the combiner box;

[0009] a third detection point arranged on each line from the minimum-area series-connected photovoltaic panel assembly to the combiner box, for obtaining the current and voltage values of the output of each minimum-area series-connected photovoltaic panel assembly; and

[0010] a data terminal having a data processing module and a transceiver module, the transceiver module being configured to obtain the data of the first detection point, the second detection point and the third detection point and interact with a remote management server, and the data processing module being configured to analyze the fault risk according to the periodically obtained second detection point data, and obtain the third detection point data of the combiner box corresponding to the second detection point determined as faulty for fault positioning.

[0011] In combination with the first aspect, the first embodiment of the first aspect further includes a light sensor arranged at each minimum-area series-connected photovoltaic panel assembly.

[0012] In combination with the first aspect, the second embodiment of the first aspect has the data terminal arranged in the combiner box, and the data terminal is connected to the first detection point, the second detection point and the third detection point through a wire harness.

[0013] In combination with the second embodiment of the first aspect, the third embodiment of the first aspect further includes a power supply module, the power supply module including a storage battery and a power supply assembly arranged under the ground of the bottom of the combiner box, and an electricity access part arranged in the combiner box and connected to any group of series-connected lines;

[0014] The power supply assembly includes an input end including an anti-reverse connection module, a voltage reduction module and a charge management module connected in sequence to the electricity access part, and a voltage stabilizing module of an output end, the voltage stabilizing module being connected to the data terminal for power supply, and the first detection point, the second detection point and the third detection point being controlled by the data terminal for power supply.

[0015] In combination with the third embodiment of the first aspect, the fourth embodiment of the first aspect has the power supply assembly further including a communication line for transmitting power supply information to the data terminal, and the power supply assembly obtains the current information of the inverter connected to the power grid through the first detection point;

[0016] When the string voltage of all combiner boxes obtained by the inverter is less than a set grid-connected threshold value and the current data of the third detection point on the circuit connected to the electricity access part meet a set charging threshold value, the data terminal controls the electromagnetic valve of the electricity access part to be turned on and the input end of the power supply assembly to be connected to the current for charging the storage battery;

[0017] When the storage battery has a power higher than a set threshold value or the inverter is connected to the power grid, the data terminal closes the circuit of the electricity access part to stop charging.

[0018] In conjunction with the third or fourth implementation of the first aspect, the present invention provides a fifth implementation of the first aspect, which further includes a drone station. A square coverage area is defined by using the maximum inspection distance of the drones in the drone station as the diagonal. The drone station is set up with the center point within 2m of the combiner box. The entire photovoltaic power generation array is covered in such a way that the overlapping area of ​​the coverage areas of adjacent drone stations does not exceed 10% of the coverage area. The drone station is powered and controlled by a data terminal.

[0019] In conjunction with the fifth embodiment of the first aspect, the present invention provides a sixth embodiment of the first aspect, wherein the data terminal is equipped with an industrial mesh network module, and a remote communication base station connected to a remote management server is provided at any combiner box or inverter, and all data terminals in the combiner box form a jumper communication network connected to the remote communication base station through the industrial mesh network module.

[0020] Secondly, the present invention also provides a maintenance method, which uses the high-altitude photovoltaic array maintenance system described above to perform detection, maintenance and management of the photovoltaic power generation array. The specific maintenance method is as follows:

[0021] The monitoring cycle is set by a remote management server. When the monitoring cycle is reached, all status data acquired by all data terminals according to the detection plan within the monitoring cycle is collected and fed back through a remote communication base station. The data terminals calculate the risk value based on the status data of each data terminal within the monitoring cycle. When the risk value exceeds the set threshold, the corresponding data terminal is located. Then, the data of the managed secondary and tertiary detection points is obtained in real time through the located data terminal. The defect type and the location of the corresponding minimum area series-connected photovoltaic panel module are determined according to the current defect calculation method. Based on the determined defect type, the nearest drone station of the photovoltaic panel module is activated for remote control inspection. Finally, the defect location is located and dealt with.

[0022] In conjunction with the second aspect, the present invention provides a first embodiment of the second aspect, wherein the current defect calculation method is specifically as follows:

[0023] First, environmental factors are normalized, relying on the light intensity from the light sensors located at corresponding positions. And the measured current obtained by the current sensor is and temperature By obtaining the average illumination of the same date and time in history and average temperature According to the following formula:

[0024] in For the standard equivalent current after correcting the illumination and temperature effects, the current of the photovoltaic panel decreases by 0.4% / ℃ as the temperature rises, and the compensation coefficient is reversely corrected in the formula;

[0025] Then, data filtering processing is performed, 5-minute sliding average is adopted to eliminate local cloud instantaneous shadow interference, and outliers are removed;

[0026] Abnormal current identification is performed, first, the normalized current mean and standard deviation of a plurality of combiner boxes 2 of the photovoltaic power generation array are judged.

[0027] If the current of a certain combiner box , and the duration exceeds 15 minutes to exclude the influence of short-term cloud shading, it is marked as preliminary abnormality, wherein k 1=1.5, corresponding to 93% confidence level;

[0028] Longitudinal historical comparison is further performed, the normalized current mean and standard deviation of the combiner box in the same time period in the past 7 days are extracted, if and , it is confirmed as abnormality;

[0029] The current value determined as abnormality, if the abnormality of the combiner box current is within 1 hour above, and the same period illumination sensor data shows a sudden drop to a recovery process, it is determined as temporary shading; if the current is continuously abnormal for more than 4 hours, and the current of the adjacent combiner box is normal, if the current of several strings is synchronously decreased, it is determined as fixed shading, if the current of a certain string is significantly lower than that of other strings, and the voltage is lower than the normal value, it is determined as photovoltaic panel damage.

[0030] In combination with the first embodiment of the second aspect, the application provides a second embodiment of the second aspect, when the photovoltaic panel is damaged or shaded, according to the position of the smallest area string connected photovoltaic panel assembly determined, the unmanned aerial vehicle station is started to perform inspection;

[0031] After the unmanned aerial vehicle reaches the corresponding position, the thermal imaging device carried is used to scan the panel surface of the photovoltaic panel assembly and locate the temperature abnormal area, if the temperature is obviously higher than that of the surrounding area, it is determined as a shaded hot spot area, if the temperature is obviously lower than that of the surrounding area, it is determined as a damaged area, then the smallest unit photovoltaic panel is determined according to the hot spot area or the damaged area, and the photovoltaic panel is cleaned or disconnected.

[0032] The application has the following beneficial effects:

[0033] (1) The present application is directed to a photovoltaic power generation array in high altitude areas, a remote monitoring and maintenance system and method are proposed, on the basis of controlling the cost, through the setting of three detection points, and the corresponding data terminal obtains data for calculation, so that in limited conditions, the current data analysis can be carried out for the fault problems which are not easy to confirm remotely in the photovoltaic power generation array, and the smallest series photovoltaic component can be located, so that accurate remote disposal is facilitated, and reliable remote detection and maintenance effect is realized in the plateau area which is difficult for personnel to reach and has variable climate conditions and multiple risk sources;

[0034] (2) The present application can accurately identify photovoltaic panel shielding, damage and other abnormalities through a three-level monitoring system and current-voltage normalization algorithm, combined with environmental factor correction and string-to-string / historical data comparison, overcome the defects of traditional overall data monitoring, and locate the fault from the inverter level to the string level, greatly improve the sensitivity and accuracy of abnormal detection;

[0035] (3) In the power supply design, the present application uses photovoltaic string connection line power supply combined with battery energy storage, realizes the self-power supply of monitoring equipment through isolation type DC-DC conversion and intelligent charging control, avoids the influence on the main power generation system, and adapts to the continuous operation and maintenance demand of unattended scenes such as high altitude;

[0036] (4) The detection and disposal at the end of the present application adopts the setting mode of unmanned aerial vehicle station, uses the functions of existing unmanned aerial vehicles, can confirm the specific fault type and position after obtaining the approximate fault type and the positioning position of the smallest series photovoltaic component, thereby providing more accurate information guidance for disposal, and also can perform some simple disposal through unmanned aerial vehicles, replace manual processing, and reduce cost;

[0037] (5) The present application adopts industrial-grade wireless Mesh network, private LTE and other communication schemes, constructs multi-hop ad hoc network or dedicated wireless link, can realize large-area coverage and stable data transmission of photovoltaic power station, solves the coverage blind area problem of traditional single-point communication in complex terrain, and ensures the real-time connection of the data terminal of the combiner box and the center base station. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a schematic diagram of the detection system of the photovoltaic power generation array corresponding to the maintenance system in the embodiment of the present application.

[0039] Figure 1 In the figure: 1-photovoltaic panel component, 2-combiner box, 3-inverter, 4-power grid. DETAILED DESCRIPTION

[0040] The present application will be further explained in combination with the drawings and specific embodiments.

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0043] It should be noted that similar reference numerals and letters in the following drawings represent similar items, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0044] In the description of the present application, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, if the terms "first", "second" and the like appear in the description of the present application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0045] In addition, if the terms "horizontal", "vertical" and the like appear in the description of the present application, they do not mean that the component must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0046] In the description of the present application, it should also be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. Embodiments

[0047] The application provides a maintenance system for a photovoltaic array in a high-altitude area. The system can automatically realize state monitoring, determine fault types and fault positioning according to data, and provide guide information for remote disposal under the premise that personnel cannot reach the photovoltaic array.

[0048] It should be noted that the photovoltaic array in the present application is different from the existing plain areas with good light conditions, such as the Gobi area. The risks mainly come from the reduction of power generation efficiency caused by the surface accumulation of sand and dust, and the influence of high temperature on power generation efficiency. The sunshine condition in the high-altitude area is good, but it mainly concentrates in winter. In summer, various weather changes often occur, especially the rainfall is obviously higher than that in the Gobi desert area, and the cloud layer changes greatly, often appearing sunny one moment and cloudy the next moment. In addition, sudden strong winds often occur, which are often the normal wind on the windward side of the slope. The wind speed of such sudden strong winds is high, and it is easy to blow the gravel or other objects to hit the photovoltaic array. In practical application, the fault defects of the photovoltaic array in the high-altitude area mainly include the change of light conditions and the local damage caused by gravel impact.

[0049] The photovoltaic panel assembly 1, the current collection box 2 and the inverter 3 connected in sequence in the embodiment are connected to the power grid 4 by the inverter 3. The whole architecture is a traditional photovoltaic array architecture, which is not limited to its scale and corresponding number, but must meet the grid connection requirements. The scale degree has a lower limit, that is, at least one inverter 3 exists, and the photovoltaic array area corresponding to the inverter 3 is more than 2000 square meters.

[0050] Specifically, the maintenance system in the embodiment is a remote management system, which includes a local system and a remote management server. The local system can be arranged together when the photovoltaic array is built, or it can be built in the existing photovoltaic array which has been arranged and put into operation. Referring to Figure 1 The local system includes a first detection point arranged on the line where each inverter 3 in the photovoltaic array is connected to the power grid 4, which is used to obtain the current and voltage values output by the inverter 3. A second detection point is arranged on the line where each current collection box 2 is connected to the inverter 3, which is used to obtain the current and voltage values output by the current collection box 2. A third detection point is arranged on the line from each minimum-area series-connected photovoltaic panel assembly 1 to the current collection box 2, which is used to obtain the current and voltage values output by each minimum-area series-connected photovoltaic panel assembly 1.

[0051] Also included are several data terminals, which have data processing modules and transceiver modules, through which the data of the primary detection points, secondary detection points and tertiary detection points are obtained and data is interacted with the remote management server, the data processing module analyzes the risk of failure according to the periodically obtained secondary detection point data, and the tertiary detection point data of the junction box 2 corresponding to the secondary detection point determined to be faulty is obtained to locate the fault.

[0052] Due to the characteristics of the photovoltaic power generation array, when a fault occurs, the current will change, but the current of the bus cannot directly reflect the current change of the single photovoltaic panel assembly 1, and the smallest one that can track the data change is the smallest series of photovoltaic panel assemblies 1 connected to the junction box 2, that is, a plurality of photovoltaic panel assemblies 1 connected in series. At the same time, in order to reduce interference information, such as the change of the most important interference source, light intensity, the embodiment also sets a plurality of light sensors in the photovoltaic power generation array for the light parameters required to be obtained, and the light sensors are connected to the data terminal and powered by the data terminal. Among them, the light sensors are arranged in a uniform manner, and are also arranged based on the smallest series of photovoltaic panel assemblies 1 as anchor points, mainly used to reflect the characteristics of the constantly changing light area caused by the sparse cloud layer on the plateau, and to eliminate interference information for the data terminal.

[0053] Further, the embodiment also includes a UAV station, which defines a square coverage area according to the maximum patrol distance of the UAV in the UAV station as the diagonal, and sets the UAV station with the center point within 22m of the junction box, and covers the entire photovoltaic power generation array in a way that the overlapping area of adjacent UAV stations does not exceed 10% of the coverage area, and the UAV station is powered and controlled by the data terminal.

[0054] The UAV station has at least one set of automatic patrol UAV, and the normal cruising range of the UAV is 5km, and a single UAV can cover a large area of photovoltaic power generation array, and generally three UAV stations can achieve large-scale coverage with the smallest overlapping area.

[0055] The embodiment also provides a detection and maintenance method, which implements remote automatic detection and maintenance work through the above maintenance system. First, a self-checking period of the local system and a monitoring period of the remote management server are set. The local system automatically detects according to the self-checking period and temporarily stores the detection data. Then, the remote management server sets the monitoring period, collects all state data obtained by all data terminals in the monitoring period according to the detection plan through the link remote communication base station when the monitoring period is reached, and feeds back the state data. The data terminal calculates the risk value according to the state data of each data terminal in the monitoring period, locates the corresponding data terminal when the risk value exceeds the set threshold, then obtains the data of the managed secondary detection point and tertiary detection point in real time through the located data terminal, and determines the defect type and the location of the minimum area series photovoltaic panel assembly 1 according to the current defect calculation method. According to the judged defect type, the nearest unmanned aerial vehicle station of the photovoltaic panel assembly 1 is started to remotely control the inspection, and finally the defect position is located and disposed.

[0056] Further, for the local system, the setting mode and the power supply mode of the data terminal are limited, and a maintenance system based on photovoltaic power generation array power supply is set.

[0057] Among them, the data terminal is set as an independent module in the combiner box 2, and the data terminal is connected with the primary detection point, the secondary detection point and the tertiary detection point through the wire harness.

[0058] The local system also includes a power supply module for supplying power to the data terminal, and the power supply module includes a storage battery and a power supply assembly arranged under the ground of the bottom of the combiner box 2, and a power connection part arranged in the combiner box 2 and connected with any group of series connection lines; the power supply assembly includes an input end, the input end includes an anti-reverse connection module, a voltage reduction module and a charge management module connected with the power connection part in sequence, and further includes a voltage stabilizing module of an output end, the data terminal is supplied with power through the voltage stabilizing module, and the primary detection point, the secondary detection point and the tertiary detection point are controlled to supply power by the data terminal.

[0059] Among them, the anti-reverse connection module is a series Schottky diode or uses a MOSFET anti-reverse circuit to avoid reverse discharge of the storage battery to the group string. Then a DC-DC converter with wide input voltage is selected, for example, input 100-1000V DC, output 48V / 24V DC, which is suitable for group string voltage fluctuation.

[0060] In order to cope with the influence of extreme weather, the storage battery is arranged underground and a certain waterproof project is arranged, which can play a heat preservation and waterproof effect. The storage battery in the embodiment selects lithium iron phosphate battery or valve regulated lead acid battery, which has stable performance and low cost. According to the calculation of three level load consumption, the current and voltage sensors corresponding to the detection points of the three levels, the average power consumption is 2w, and the number of photovoltaic panel components 1 can be powered by 12v / 30ah lithium iron phosphate battery.

[0061] The power supply assembly further includes a communication line for transmitting power supply information to the data terminal, and the power supply assembly obtains current information of the inverter 3 connected to the power grid 4 through the first detection point; the data terminal judges that when the string voltage of all the combiner boxes 2 obtained by the inverter 3 is less than the set grid-connected threshold and the current data of the three detection points on the circuit connected to the power supply part meet the set charging threshold, the data terminal controls the electromagnetic valve of the power supply part to be turned on and connects the current to the storage battery through the input end of the power supply assembly to charge the storage battery; the data terminal judges that when the battery power is higher than the set threshold or the inverter 3 is connected to the grid, the circuit of the power supply part is closed to stop charging.

[0062] The charging start condition is to avoid affecting the grid-connected power generation, but since the capacity of the storage battery itself is small, before the daily photovoltaic power generation array starts, that is, in the morning or at sunset, the light condition is insufficient to reach the grid-connected condition, at this time, the direct current side switch of the inverter 3 is usually in the on state, allowing the current of the photovoltaic string to flow in, but since the alternating current side is not connected to the grid, the inverter 3 will not convert the direct current into alternating current and output to the power grid 4. In this case, there is current in the string circuit, but the current is not consumed by the grid connection, so the current in the string circuit can be used as the power source for the storage battery.

[0063] Further, for such a sparse and uniform maintenance system, if the communication mode of all data adopts a wired mode, the arrangement cost is high, and it cannot be repaired after failure. In the embodiment, a communication arrangement mode is provided, the data terminal is provided with an industrial mesh network module, and a remote communication base station connected to a remote management server is arranged at any combiner box 2 or inverter 3, and all data terminals in the combiner box 2 form a hop communication network connected to the remote communication base station through the industrial mesh network module. Through the Mesh node self-organizing network, data can be relayed to the center base station through multiple nodes, without the need for each terminal to directly communicate with the base station, which is suitable for large-area and dispersed layout of photovoltaic power stations. And using time division multiple access or frequency division multiple access mechanism, reduce the conflict, cooperate with the special protocol, the delay can be controlled within 50ms, meet the real-time control demand of unmanned aerial vehicle. The remote communication base station is deployed at the commanding heights of the power station, and the combiner box 2 data terminal is used as a Mesh node to form a star+Mesh hybrid topology, reduce the hop count to reduce the delay.

[0064] Further, the embodiment is directed to a maintenance method, and provides a current defect calculation method.

[0065] Firstly, environmental factor normalization processing is performed, and the light intensity of the light sensor arranged at the corresponding position and the measured current obtained by the current sensor are , and the temperature , by obtaining the average light and the average temperature of the same date and time period in history, according to the following formula:

[0066] wherein is the standard equivalent current after correction of the influence of light and temperature, wherein the photovoltaic panel current decreases by 0.4% / ℃ as the temperature rises, and the compensation coefficient is taken in the formula to correct in the opposite direction;

[0067] Then, data filtering processing is performed, 5-minute sliding average is adopted to eliminate local cloud instantaneous shadow interference, and outliers are removed, and the specific formula is as follows:

[0068] wherein:

[0069] , is the standard deviation of the data of the day, if the above conditions are met, it is considered as noise, and is replaced.

[0070] Abnormal current recognition is performed, firstly, the normalized current mean and standard deviation of a plurality of combiner boxes 2 of the photovoltaic power generation array are used for judgment. The normalized current mean μ and the standard deviation of all combiner boxes 2 in the same area are calculated, and the specific formula is as follows:

[0071]

[0072] If the current of a combiner box 2 and the duration exceeds 15 minutes to exclude the influence of short-time cloud shadow, it is marked as preliminary abnormality, wherein k 1=1.5, corresponding to 93% confidence;

[0073] Then, longitudinal historical comparison is performed, the normalized current mean and standard deviation of the combiner box 2 in the same time period in the past 7 days are extracted, if and , it is confirmed as abnormality;

[0074] If the abnormality of the current value of the combiner box 2 is within 1 hour ​Above, and the same period light sensor data shows a sudden drop to the process of recovery, determined to be temporary obstruction; If the current continues to be abnormal more than 4 hours, and the adjacent junction box 2 current is normal, if several strings of current synchronous decline, determine to be fixed obstruction, if a string of current is significantly lower than other strings, and the voltage is lower than the normal value, determine to be photovoltaic panel damage.

[0075] Typical scenario description

[0076] Scenario 1: local cloud obstruction for five minutes

[0077] The phenomenon is that the current of the junction box 2 drops by 30%, and recovers after 10 minutes with the cloud moving away. The algorithm processing process is that the duration < 15 minutes, and the light sensor synchronously records the light intensity drop, which is determined to be temporary obstruction, and does not trigger the detection of the third level detection point.

[0078] Scenario 2: bird droppings fixed obstruction for 6 hours

[0079] The phenomenon is that the current is continuously lower than the average value by 20%, the light sensor data is stable, and the current of the adjacent junction box 2 is normal. The algorithm processing process is to trigger the detection of the third level detection point, find that the current of certain 3 strings under the junction box 2 is synchronously decreased (difference < 5%), and determine to be fixed obstruction, which is cleaned by the unmanned aerial vehicle or the set cleaning device.

[0080] Scenario 3: photovoltaic panel breakage for more than 12 hours

[0081] The phenomenon is that the current is continuously lower than the average value by 30%, the temperature is 25℃ and there is no overheating interference, and the adjacent junction box 2 is normal. The third level detection point shows that the current of a string is 15% lower than that of other strings, and the voltage is decreased by 8%, which is determined to be damaged. After positioning, the minimum photovoltaic panel unit of the photovoltaic panel assembly 1 is disconnected to avoid fire hazards.

[0082] Further, for the disposal mode, the unmanned aerial vehicle can be used in the embodiment to finally confirm the fault condition and the position. When the photovoltaic panel is damaged or obstructed, the unmanned aerial vehicle station is started to patrol according to the position of the minimum area string connected photovoltaic panel assembly 1. The unmanned aerial vehicle reaches the corresponding position, scans the panel surface of the photovoltaic panel assembly 1 through the carried thermal imaging device, and locates the temperature abnormal area. If the temperature is obviously higher than the surrounding area, it is determined to be a hot spot area that is obstructed, and if the temperature is obviously lower than the surrounding area, it is determined to be a damaged area. Then, the minimum unit photovoltaic panel is determined according to the hot spot area or the damaged area, and the photovoltaic panel is cleaned or disconnected.

[0083] In another embodiment, the photovoltaic panel assembly 1 at a specific location can be provided with a surface detection circuit, that is, a number of conductive lines are drawn on the panel surface of the photovoltaic panel assembly 1 by conductive transparent paint, the conductive lines are drawn from both sides of the panel surface, and are connected to the detection circuit on the back side of the corresponding photovoltaic panel assembly 1 through a wire harness. The detection circuit can determine whether the panel surface is damaged and cracked by determining the change of resistance by applying a test current when it is necessary to determine whether the panel surface is damaged.

[0084] The principle is that the number of conductive lines drawn on the panel surface have a certain resistance, which are connected in parallel to the detection circuit, and the small current applied by the detection circuit can obtain the corresponding resistance after passing through a number of parallel conductive lines. Once the resistance changes, it indicates that at least one of the conductive lines is disconnected, resulting in a change in the resistance of the parallel circuit.

[0085] In order to avoid affecting the power generation of the photovoltaic panel itself, a cheap metal oxide is used as the paint material, for example, zinc oxide, and according to the requirements, a gap is set on the panel surface, each conductive line has the same gap and is arranged in parallel, and the surface of the conductive line is further covered with a layer of waterproof resin, that is, a layer of resin paint is coated on the surface of the conductive layer. This way is only for the photovoltaic panel assembly 1 which is prone to damage by stone impact at a specific location.

[0086] The present application is not limited to the above-mentioned optional embodiments, and anyone can derive other various forms of products under the inspiration of the present application. The above specific embodiments should not be understood as limiting the protection scope of the present application, and the protection scope of the present application should be defined by the claims, and the specification can be used to explain the claims.

Claims

1. A photovoltaic array maintenance system for high-altitude areas, designed for unmanned remote monitoring and maintenance of photovoltaic power generation arrays established in high-altitude mountainous areas, wherein the photovoltaic power generation array comprises photovoltaic panel components (1), a combiner box (2), and an inverter (3) connected in sequence, and the inverter (3) is connected to the power grid (4); characterized in that: include: The primary detection point is set on the line connecting each inverter (3) in the photovoltaic power generation array to the power grid (4) to obtain the current and voltage values ​​output by the inverter (3); Secondary detection points are set on the line connecting each combiner box (2) to the inverter (3) to obtain the current and voltage values ​​of the combined output of the combiner box (2); The three-level detection points are set on the line from each minimum area series-connected photovoltaic panel module (1) to the combiner box (2) to obtain the output current and voltage values ​​of each minimum area series-connected photovoltaic panel module (1). as well as The data terminal has a data processing module and a transceiver module. The transceiver module acquires data from the first-level detection point, the second-level detection point and the third-level detection point and interacts with the remote management server. The data processing module analyzes the fault risk based on the second-level detection point data acquired periodically, and acquires the third-level detection point data of the junction box (2) corresponding to the second-level detection point that is determined to be faulty for fault location. The data terminal is installed in the combiner box (2) and is connected to the first-level detection point, the second-level detection point, and the third-level detection point via a wiring harness. It also includes a power supply module, which comprises a battery and power supply components installed at the bottom of the combiner box (2), and a power connector installed in the combiner box to connect to any set of series lines. The power supply components include an input terminal, which includes a reverse connection protection module, a step-down module, and a charging management module connected sequentially to the power connector. It also includes a voltage regulator module at the output terminal, which connects to the data terminal for power supply and controls the power supply to the first-level, second-level, and third-level detection points. The power supply components also include a module for transmitting power supply information to the data terminal. The communication line and power supply components obtain the current information of the inverter connected to the grid through the first detection point. Before the photovoltaic power generation array is started in the early morning or at sunset, the light conditions are insufficient to meet the grid connection conditions. At this time, the DC side switch of the inverter (3) is usually in the on state. Then, the data terminal determines that when the string voltage of all combiner boxes obtained by the inverter is less than the set grid connection threshold and the current data of the three-level detection point on the circuit connected to the corresponding connection part meets the set charging threshold, the data terminal controls the solenoid valve of the connection part to be turned on and the current is connected to the input terminal of the power supply components to charge the battery. When the data terminal determines that the battery power is higher than the set threshold or the inverter is connected to the grid, the circuit of the connection part is turned off to stop charging. A surface detection circuit is provided for the photovoltaic panel assembly (1). The surface detection circuit is formed by drawing several conductive lines on the surface of the photovoltaic panel assembly (1) using a conductive transparent coating. The conductive lines are drawn from both sides of the panel surface and connected to the detection circuit on the back side of the corresponding photovoltaic panel assembly (1) through a wire harness. The detection circuit can determine whether the board surface is damaged or cracked by applying a test current and measuring the change in resistance when it is necessary to determine whether the board surface is damaged or cracked. Gap lines are marked on the board surface, with each conductive line having the same gap and being set in parallel. The surface of the conductive lines is also covered with a layer of waterproof resin.

2. The photovoltaic array maintenance system for high-altitude areas according to claim 1, characterized in that: It also includes a light sensor located at each of the photovoltaic panel modules (1) connected in series at the minimum area.

3. The photovoltaic array maintenance system for high-altitude areas according to claim 1, characterized in that: It also includes drone stations. The coverage area is defined as a square based on the maximum inspection distance of the drones in the drone station as the diagonal. The drone stations are set up with the center point within 2m of the combiner box. The entire photovoltaic power generation array is covered in such a way that the overlapping area of ​​the coverage areas of adjacent drone stations does not exceed 10% of the coverage area. The drone stations are powered and controlled by the data terminal.

4. The photovoltaic array maintenance system for high-altitude areas according to claim 3, characterized in that: The data terminal is equipped with an industrial mesh network module, and a remote communication base station connected to a remote management server is installed at any combiner box or inverter. All data terminals in the combiner box form a jumper communication network connected to the remote communication base station through the industrial mesh network module.

5. A maintenance method, characterized in that: The photovoltaic array maintenance system for high-altitude areas described in claim 4 is used to perform inspection, maintenance, and management of the photovoltaic power generation array. The specific maintenance method is as follows: The monitoring cycle is set by the remote management server. When the monitoring cycle is reached, the system collects all status data obtained by all data terminals in the monitoring cycle according to the detection plan through the remote communication base station and feeds it back. The data terminal calculates the risk value based on the status data of each data terminal in the monitoring cycle. When the risk value exceeds the set threshold, the corresponding data terminal is located. Then, the data of the managed secondary detection point and tertiary detection point are obtained in real time through the located data terminal. The defect type and the location of the corresponding minimum area photovoltaic panel module (1) are determined according to the current defect calculation method. The nearest drone station of the photovoltaic panel module (1) is started for remote control inspection according to the determined defect type. Finally, the defect location is located and dealt with.

6. The maintenance method according to claim 5, characterized in that: The specific method for calculating current defects is as follows: First, environmental factors are normalized. The light intensity S from the light sensor located at the corresponding position and the measured current from the current sensor are then used as the basis for the calculation. I raw and temperature T By obtaining the average illumination of the same date and time in history and average temperature According to the following formula: ； in I norm To correct for the standard equivalent current affected by light and temperature, where the photovoltaic panel current decreases by 0.4% / ℃ with increasing temperature, a compensation coefficient is used in this formula for inverse correction. Then, data filtering is performed, using a 5-minute moving average to eliminate interference from local cloud momentary shadows and remove outliers; To identify abnormal currents, the normalized mean and standard deviation of the current of several combiner boxes in the same photovoltaic power generation array are used for judgment. The normalized mean μ and standard deviation σ of the current of all combiner boxes (2) in the same area are calculated. If the current of a certain combiner box is... I filter < μ - k 1× σ If the duration exceeds 15 minutes to rule out the impact of short-term cloud cover, it is marked as a preliminary anomaly. k 1 = 1.5, corresponding to a 93% confidence level; Then, a longitudinal comparison with the historical data of the same period was performed, and the normalized mean current of the combiner box for the same time period over the past 7 days was extracted. μ hist and standard deviation σ hist If the abnormal current value is determined, and the abnormal combiner box current recovers to normal within 1 hour... μ hist If the current value is above 0.95 and the concurrent light sensor data shows a sudden drop and recovery process, it is determined to be temporary shading; if the current remains abnormal for more than 4 hours and the current in the adjacent combiner box is normal, if the current of several strings drops synchronously, it is determined to be fixed shading; if the current of one string is significantly lower than that of the others and the voltage is lower than the normal value, it is determined to be photovoltaic panel damage.

7. A maintenance method according to claim 6, characterized in that: When it is determined that the photovoltaic panel is damaged or blocked, the drone station is activated to conduct inspection based on the location of the photovoltaic panel module (1) connected in series with the smallest area. After the drone reaches the corresponding position, it scans the surface of the photovoltaic panel (1) and locates the temperature abnormal area using the thermal imaging equipment it is equipped with. If the temperature is significantly higher than the surrounding area, it is determined to be a hot spot area that is blocked. If the temperature is significantly lower than the surrounding area, it is determined to be a damaged area. Then, the smallest unit of the photovoltaic panel is determined according to the hot spot area or the damaged area, and the photovoltaic panel is cleaned or disconnected.

Images