JP7855537B2 - Solar power generation system inspection device and inspection method - Google Patents

Description

Embodiments of the present invention relate to a solar power generation system inspection device and inspection method.

The operation and maintenance of solar power generation systems are increasingly demanding automation and unmanned operation through automated inspection devices, due to the increasing severity of natural disasters in recent years and concerns about a future shortage of electrical safety personnel.

In particular, large-scale solar power plants with an output exceeding 1 MW, known as mega-solar, require efficient inspection of solar panels installed on vast sites with diverse environmental conditions. Furthermore, solar panels may be installed in underwater locations such as reservoirs, mountainous areas, overgrown areas, and heavy snowfall regions, demanding inspection techniques robust to these various environments.

While inspection devices and methods for solar power generation panels using drones and other mobile aerial vehicles (UAVs) have been proposed (for example, Patent Documents 1 and 2), these conventional methods are limited to inspecting the integrity of the upper surface of the solar power generation panel, i.e., the surface exposed to sunlight. Inspection methods for the lower part of the solar power generation panel have not been shown.

Detecting abnormalities such as deterioration or burnt-out back panels, deterioration or burnt-out junction boxes, rust on mounting frames, loose fixing bolts, broken cables, disconnected ground wires, and insect nests on the underside of solar power generation systems is crucial in the maintenance and inspection of solar power generation systems. Neglecting these issues can lead to reduced power generation, a shortened overall system lifespan, and damage from natural disasters. Furthermore, with the potential for increased adoption of bifacial solar panels, the need for inspection of the underside of solar power generation panels is expected to increase even further. While inspection devices and methods for the underside of solar power generation panels have been proposed (e.g., Patent Documents 3 and 4), these methods utilize ground-based inspection systems and are limited to inspections of solar power generation panels in favorable installation environments.

Furthermore, attempting to photograph the underside of solar panels using a UAV would require the UAV to fly at a low altitude of approximately 1 meter or less. This raises safety concerns, including issues with the UAV's flight stability and the possibility of contact with the solar panels.

Patent No. 5197642 Patent No. 6970317 Patent No. 7118234 Japanese Patent Publication No. 2022-177417

Maintenance and inspection of solar power generation panels involves many on-site visual inspection items, heavily relying on the senses and observational skills of the inspection workers. Large-scale systems, such as mega solar power plants, present a particular challenge in that maintenance and inspection require a large number of personnel and considerable time.

Furthermore, in the case of solar power generation systems installed in locations that are difficult for inspection personnel to access, such as mountainous areas, overgrown areas, and heavy snowfall areas, it is difficult to guarantee the overall integrity of the system. Moreover, situations where inspection personnel cannot be secured due to infectious disease outbreaks or other factors may arise, so technological development toward labor-saving and unmanned operation is progressing.

To address these challenges, methods have been proposed for efficiently detecting anomalies in a short time using aerial photography with UAVs when inspecting mega solar power plants as a whole. However, most of these methods fail to address anomalies detected from the ground side where the solar panels are installed, which are crucial inspection items, and to analyze the locations of the anomalies based on the detection results.

Furthermore, observing solar power generation panels from the ground presents challenges due to the installation environment. Attempting observation using a UAV would require low-altitude flight, posing safety concerns as mentioned earlier.

To solve these problems, a device and method are needed to fly a UAV at a stable altitude and acquire information from the mounting surface side of the solar power generation panels. This will allow for stable inspection of components other than the solar power generation panels themselves, such as the mounting frame, junction boxes, and cables, as well as the back side of the solar power generation panels, enabling the detection of abnormalities that affect the overall health of the system.

As described above, by targeting abnormalities in areas that could not be confirmed by conventional aerial photography using UAVs, it is desirable to expand the inspection items and scope, and further improve inspection efficiency and achieve labor-saving or unmanned inspections by combining them with automated equipment. Furthermore, in the inspection of the underside of solar power generation panels using ground-based vehicles, it is desirable to resolve issues such as unstable photography and the inability to mount certain functions depending on the condition of the road surface.

This invention addresses the aforementioned conventional circumstances and aims to provide a solar power generation system inspection device and inspection method that enable stable inspection of the underside of solar power generation panels.

The solar power generation system inspection device of the embodiment is a solar power generation system inspection device for photographing the underside of a solar power generation panel opposite to the side of the solar power generation panel that is irradiated with sunlight, and comprises: a flight movement mechanism that flies above the passage between the solar power generation panels; a photographing device for photographing the underside of the panel; a field of view adjustment mechanism for adjusting the orientation of the photographing device; a connecting part that extends downward from the flight movement mechanism and connects the flight movement mechanism and the field of view adjustment mechanism to position the photographing device at a height at which the underside of the panel can be photographed; a position acquisition mechanism for acquiring the position of the flight movement mechanism or the photographing device; and a height control mechanism for maintaining the photographing device at a constant height above the ground , wherein the connecting part is of variable length, and the height control mechanism comprises a height measuring mechanism disposed at the same level as the photographing device and a length changing mechanism that changes the length of the connecting part based on the height above measured by the height measuring mechanism.

The embodiment of the solar power generation system inspection method is a solar power generation system inspection method for photographing the underside of a solar power generation panel opposite to the side of the solar power generation panel that is irradiated with sunlight, and is characterized in that it uses a solar power generation system inspection device comprising: a flying movement mechanism that flies over the passage between the solar power generation panels; a photographing device for photographing the underside of the panel; a field of view adjustment mechanism for adjusting the orientation of the photographing device; a connecting part that extends downward from the flying movement mechanism and connects the flying movement mechanism and the field of view adjustment mechanism to position the photographing device at a height at which the underside of the panel can be photographed; a position acquisition mechanism for acquiring the position of the flying movement mechanism or the photographing device ; and a height control mechanism for maintaining the photographing device at a constant height from the ground, wherein the connecting part is of variable length, and the height control mechanism comprises a height measuring mechanism disposed at the same level as the photographing device, and a length changing mechanism that changes the length of the connecting part based on the height above measured by the height measuring mechanism.

According to embodiments of the present invention, a solar power generation system inspection device and inspection method are provided that enable stable inspection of the underside of solar power generation panels.

A schematic diagram showing the basic configuration of a solar power generation system inspection device according to the first embodiment. A schematic diagram showing a modified configuration of a solar power generation system inspection device according to the first embodiment. A schematic diagram showing the configuration of another modified example of the solar power generation system inspection device according to the first embodiment. A schematic diagram showing the configuration of another modified example of the solar power generation system inspection device according to the first embodiment. A schematic diagram showing the configuration of a solar power generation system inspection device according to the second embodiment. A diagram illustrating an example of data communication content in the second embodiment.

The following describes the solar power generation system inspection device and inspection method according to the embodiment, with reference to the drawings.

(First Embodiment)
Figures 1 and 2 schematically show the general configuration of a solar power generation system inspection device and inspection method according to the first embodiment. As mentioned above, the present invention aims to reduce manpower and automate the maintenance and inspection of solar power generation systems. The basic configuration is shown in Figure 1, and the configuration in which the flight position and flight height are controlled by a device near the imaging device is shown in Figure 2.

For example, in a large-scale solar power generation system called a mega solar, numerous solar panels are installed. In the example shown in Figures 1 and 2, the solar panel to be inspected, 1, and the adjacent solar panel 2 are arranged separated by a passageway 3. In this embodiment, to enable observation and inspection from the side opposite to the surface of solar panel 1 that is directly exposed to sunlight, i.e., from below solar panel 1, the basic configuration consists of an inspection device 10 that flies above the passageway 3 between solar panels 1 and 2.

The inspection device 10 comprises a flight movement mechanism 11 that flies above the passageway 3, a photography device 12 that photographs the underside of the solar power generation panel 1, a field-of-view adjustment mechanism 13 for directing the photography direction of the photography device 12 to a desired direction, and a connection part 14 that connects the flight movement mechanism 11 and the field-of-view adjustment mechanism 13. The inspection device 10 also includes a position acquisition device 15 for acquiring photography position information and a height control mechanism 16 for controlling the photography height. The example shown in Figure 1 illustrates the use of the position acquisition device 15 and height control mechanism 16 as they are integrated into the flight movement mechanism 11.

The flight-moving mechanism 11 is a mechanism capable of stably transporting the imaging device 12 regardless of the installation environment of the passageway 3. As long as stable flight movement is possible, the flight path is not limited; for example, flight on a free path by a drone or helicopter, or flight along rails, cables, or electronically controlled paths installed on the passageway 3 are conceivable. The movement control of the flight-moving mechanism 11 can be remotely controlled by a human or through automatic flight by learning a flight path; the method is not limited. Furthermore, the flight-moving mechanism 11 may be equipped with an inspection mechanism 22 (see Figure 4) for inspecting the upper surface of the solar power generation panel 1. The form of the camera used in the inspection mechanism 22 is not limited; in addition to the camera mounted on the flight-moving mechanism 11, a general-purpose camera, or a thermal camera for temperature measurement can be used.

The imaging device 12 is a device for photographing the underside of the solar power generation panel 1. The format of the data acquired by the imaging device 12, such as images and videos, is not restricted. Any device capable of photographing the underside of the solar power generation panel 1 is acceptable; in addition to general cameras, 360-degree cameras, smartphone cameras, stereo cameras, etc., are possible. Furthermore, an image acquisition mechanism 21 that simultaneously or individually acquires images with different wavelength ranges of light, such as a thermal camera or multispectral camera, may be used as the camera. Figure 3 shows a configuration diagram when using the image acquisition mechanism 21 as the camera.

The field-of-view adjustment mechanism 13 adjusts the orientation of the shooting device 12 (or image acquisition mechanism 21) in a certain direction to acquire images within a desired range. The field-of-view adjustment mechanism 13 can utilize mechanisms such as physical fixing of the shooting device 12 or electronically controlled drive and fixing, and can use stabilizers (gimbals), tripods (tripod heads), etc.

The connecting section 14 extends downward from the flight movement mechanism 11 and connects the flight movement mechanism 11 to the field of view adjustment mechanism 13. This allows the camera 12 to be positioned to photograph the underside of the solar power generation panel 1 while the flight movement mechanism 11 flies above the solar power generation panels 1 and 2 at a stable altitude. The connecting section 14 can be made of any material or structure as long as it can be transported by the flight movement mechanism 11. For example, it can be connected using a single rubber band, multiple rubber bands, a rigid body such as a plastic rod, or a variable-length connection attached to a winch or motor.

The position acquisition device 15 is a device that acquires positional information of the flight movement mechanism 11 or the imaging device 12, linking the captured position to the captured position in order to manage the imaging data of the imaging device 12 as inspection results. Examples of this position acquisition device 15 include GPS (Global Positioning System). Here, GPS is a system for measuring the current position on Earth using artificial satellites. Note that any GPS with a transmitter will suffice; this transmitter could be, for example, a transmitter built into the flight movement mechanism 11 or an external small transmitter. Figure 1 shows a configuration in which the transmitter is built into the flight movement mechanism 11.

Furthermore, as the position acquisition device 15, for example, SLAM (Simulated Localization and Mapping) can be used. Here, SLAM is a method for determining location information by creating an environmental map from imaging data of the surrounding environment and simultaneously integrating the environmental map with the imaging data. The type of camera used for SLAM is not limited; examples include stereo cameras and 360-degree cameras. Figure 2 shows a configuration in which a 360-degree camera is mounted as the position acquisition device 15.

The height control mechanism 16 is a mechanism for maintaining the altitude of the imaging device 12 at a desired height, ensuring that the underside of the solar power generation panel 1 is always photographed from that desired height. Examples of this height control mechanism 16 include flight height control based on altitude measurement built into the flight movement mechanism 11, as shown in Figure 1. Alternatively, as shown in Figure 2, a height control mechanism 16 can be used that maintains a constant height of the imaging device 12 by using a height measurement mechanism 16a positioned at the same level as the imaging device 12, and a length changing mechanism 16b that changes the length of the connecting section 14 based on the altitude measured by the height measurement mechanism 16a. Here, examples of methods for measuring altitude include laser or ultrasonic measurement. Examples of methods for controlling the length of the connecting section 14 by the length changing mechanism 16b include winches, telescopic structures, metal belts, jacks, etc.

Figure 4 shows an example configuration with additional equipment added to the basic setup described above. As shown in Figure 4, in addition to the inspection device 10, a sensor 23 may be used to detect abnormalities that cannot be confirmed by visual inspection. Inspection items that rely on the five senses of the inspection worker, other than visual inspection, include, for example, odors emitted due to burning or rust, localized overheating due to broken wires inside the solar power generation panel, abnormal noises inside the junction box, loose bolt fastenings, and instability of the mounting structure due to landslides. These can be measured using odor sensors, non-contact thermometers, audible microphones, laser vibrometers, laser rangefinders, ultrasonic sensors, etc., but other sensors 23 may also be used.

Furthermore, in addition to the inspection device 10, a data determination device 24 may be provided to determine the presence or absence of abnormalities based on the data captured by the imaging device 12. The data determination device 24 performs image processing or learning on the image or video data transmitted from the imaging device 12 to detect abnormalities occurring on the underside of the solar power generation panel 1. As mentioned above, various abnormalities can occur on the underside of the solar power generation panel 1, such as deterioration or burnout of the back panel, deterioration or burnout of the junction box, rust on the mounting frame or loosening of fixing bolts, cable breakage, disconnection of the ground wire, and insect nests. An image processing or learning method capable of detecting these is desirable. For example, classification of the presence or absence of abnormalities using unsupervised learning, or abnormality detection by training with captured data of the underside of a normal solar power generation panel, are possible.

According to the first embodiment configured as described above, the following effects (1) to (4) can be obtained.
(1) By using the inspection device 10, it is possible to photograph the underside of the solar power generation panel 1 with a stable field of view and shooting position in solar power plants with poor installation environments such as mountainous areas, weed-covered areas, and heavy snow areas. In other words, robust inspection of the underside of the panel is possible regardless of the installation environment or flight environment. This can replace the visual inspection of the underside of the solar power generation panel 1 that was conventionally performed by inspectors.
(2) By automating the flight control of the flight movement mechanism 11, it is possible to automate visual inspections. This will reduce not only inspection costs but also costs associated with traveling to solar power plants located in remote areas.
(3) The image acquisition mechanism 21, inspection mechanism 22, and various sensors 23 can detect abnormalities that cannot be detected by visual inspection. Examples of abnormalities that cannot be detected by visual inspection include localized overheating of the solar power generation panel 1, smells of burning or rust, abnormal noises inside the junction box, loosening of bolt fastenings, and instability of the mounting frame due to landslides. This makes it possible to replace inspection work other than visual inspection.
(4) The data determination device 24 makes it possible to determine whether or not an abnormality occurs on the lower side of the panel. By linking this with the position information obtained from the position acquisition device 15, it is possible to manage the presence or absence of abnormalities linked to the position. This simplifies the management of inspection results and reduces the costs required for maintenance.

(Second Embodiment)
In this second embodiment, we will describe an inspection device 30 that is equipped with a communication function to enable data transmission and reception, as described in the first embodiment. Figure 5 schematically shows the general configuration of the inspection device 30 equipped with a communication device 31. In this second embodiment, parts that are the same as in the first embodiment will be denoted by the same reference numerals as in the first embodiment, thereby simplifying or omitting their description.

The inspection device 30 differs from the inspection device 10 of the first embodiment in that it is configured to transmit data acquired by the inspection device 30 via the communication device 31 and receive it with the remote communication device 32. In the example shown in Figure 5, the remote communication device 32 is connected to the data determination device 24, which determines whether or not there is an abnormality on the underside of the solar power generation panel 1.

Figure 6 shows an example of data transmission and reception via communication. As shown in Figure 6, the communication device 31 of the inspection device 30 transmits image data from the imaging device 12 and image location data from the position acquisition device 15, and the data is received by the remote communication device 32. The received data can be viewed and analyzed remotely; for example, by installing a data determination device 24 at a remote location, it is possible to determine the presence or absence of abnormalities remotely. Based on the received data, new information can be transmitted from the remote communication device 32 and received by the communication device 31. For example, a new detailed inspection route can be set based on the received data, and image data obtained by the flight mobile mechanism 11 flying along that route can be communicated. Furthermore, the data received by the remote communication device 32 is stored in cloud storage 33, allowing the inspection result history to be displayed in subsequent inspections.

According to the second embodiment configured as described above, in addition to achieving the same effects (1) to (4) as described above for the first embodiment, the following effects (5) and (6) can be obtained.
(5) By transmitting and receiving data via the communication device 31, there is an advantage in that the number of devices mounted on the inspection device 30 can be reduced. As a result, the payload capacity required for the flight mobile mechanism 11 is reduced, and the flight mobile mechanism 11 can be made smaller.
(6) By combining data transmission via the communication device 31 with the flight movement mechanism 11 that automatically sets a flight path and flies, it becomes possible to automatically perform visual inspections at solar power plants even without inspectors present, and to view and manage the inspection results. This reduces the costs required for visual inspections of solar power plants.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as described in the claims.

1...Solar power generation panel (item to be inspected), 2...Solar power generation panel, 3...Passageway, 10...Inspection device, 11...Flight movement mechanism, 12...Photography device, 13...Field of view adjustment mechanism, 14...Connection part, 15...Position acquisition device, 16...Height control mechanism, 16a...Height measurement mechanism, 16b...Length change mechanism, 21...Image acquisition mechanism, 22...Inspection mechanism, 23...Sensor, 24...Data judgment device, 30...Inspection device, 31...Communication device, 32...Remote communication device, 33...Cloud storage.

Claims (7)

A solar power generation system inspection device for photographing the underside of a solar power generation panel, on the side opposite to the side that is irradiated by sunlight,
A flying mobile mechanism that flies above the passage between the aforementioned solar power generation panels,
A camera for photographing the lower side of the aforementioned panel,
A field of view adjustment mechanism for adjusting the orientation of the aforementioned imaging device,
A connecting portion extending downward from the aforementioned flight movement mechanism, connecting the aforementioned flight movement mechanism and the aforementioned field of view adjustment mechanism, and positioning the shooting device at a height that allows it to photograph the lower side of the panel,
A position acquisition mechanism for acquiring the position of the flight movement mechanism or the imaging device,
A height control mechanism for maintaining the aforementioned imaging device at a constant height above the ground,
It is equipped with ,
The aforementioned connecting part is of variable length,
The height control mechanism is,
A height measuring mechanism is installed at the same level as the aforementioned imaging device,
A length changing mechanism that changes the length of the connecting part based on the height above measured by the height measuring mechanism,
A solar power generation system inspection device characterized by having the following features. A solar power generation system inspection device according to claim 1 ,
A solar power generation system inspection device characterized by having an image acquisition mechanism that simultaneously or individually acquires images with different wavelength ranges of light. A solar power generation system inspection device according to claim 1 ,
A solar power generation system inspection device characterized in that the flying mobile mechanism is equipped with an inspection mechanism for simultaneously inspecting the upper surface of the solar power generation panel. A solar power generation system inspection device according to claim 1 ,
A solar power generation system inspection device characterized by being equipped with one or more sensors from among odor sensors, non-contact thermometers, laser rangefinders, laser vibrometers, audible microphones, and ultrasonic sensors. A solar power generation system inspection device according to claim 1 ,
A solar power generation system inspection device characterized by comprising a data determination device that stores data acquired by the aforementioned imaging device and determines whether the inspection location is normal or abnormal. A solar power generation system inspection device according to claim 1 ,
A solar power generation system inspection device characterized by being equipped with a communication device that connects to a network and transmits acquired data. A method for inspecting a solar power generation system, for photographing the underside of a solar power generation panel opposite to the side that is irradiated by sunlight,
A flying mobile mechanism that flies above the passage between the aforementioned solar power generation panels,
A camera for photographing the lower side of the aforementioned panel,
A field of view adjustment mechanism for adjusting the orientation of the aforementioned imaging device,
A connecting portion extending downward from the aforementioned flight movement mechanism, connecting the aforementioned flight movement mechanism and the aforementioned field of view adjustment mechanism, and positioning the shooting device at a height that allows it to photograph the lower side of the panel,
A position acquisition mechanism for acquiring the position of the flight movement mechanism or the imaging device,
A height control mechanism for maintaining the aforementioned imaging device at a constant height above the ground,
It is equipped with ,
The aforementioned connecting part is of variable length,
The height control mechanism is,
A height measuring mechanism is installed at the same level as the aforementioned imaging device,
A length changing mechanism that changes the length of the connecting part based on the height above measured by the height measuring mechanism,
A method for inspecting a solar power generation system, characterized by using a solar power generation system inspection device having the following features.