WO2012172978A1

WO2012172978A1 - Solar tracking device and solar power generating device

Info

Publication number: WO2012172978A1
Application number: PCT/JP2012/063898
Authority: WO
Inventors: 基大田中
Original assignee: ナブテスコ株式会社
Priority date: 2011-06-15
Filing date: 2012-05-30
Publication date: 2012-12-20
Also published as: JP2013004684A

Abstract

The solar tracking device is equipped with a detector unit and a drive device. The detector unit includes a first plate having a through-hole, and a second plate disposed at a location in opposition to the first plate. The second plate is furnished with at least two photoreceptors. The drive device adjusts the angle of the detector unit. The at least two photoreceptors are disposed to the inside of a circle of a radius (R₂₎ calculated by Formula 1 below, centered on the intersection point of the second plate and the centerline of the through-hole. Formula 1: R₂= R₁ + L × tan(A/2), where R₁ is the radius of the through-hole, L is the distance between the first plate and the second plate, and A is the apparent diameter of the sun.

Description

Solar tracking device and solar power generation device

This application claims priority based on Japanese Patent Application No. 2011-133517 filed on June 15, 2011. The entire contents of that application are incorporated herein by reference. The present application relates to a solar tracking device and a solar power generation device including the solar tracking device.

装置 Devices that use solar energy are known. An example of such a device is a solar power generation device. In the solar power generation device, there is a type that tracks the sun according to the movement of the sun in order to increase the power generation efficiency. For example, in the case of a solar power generation apparatus having a panel (solar panel) with a solar cell attached to the surface, it is preferable to adjust the panel angle so that the surface of the panel is orthogonal to the sun by rotating the panel. . In the case of a solar power generation device (also referred to as a solar thermal power generation device) that concentrates sunlight on a condenser using a reflector, the sunlight is accurately collected in one place by rotating the reflector. It is preferable to adjust the angle of the reflecting mirror. In any photovoltaic power generation apparatus, it is necessary to accurately identify the position of the sun and adjust the angle of the panel (or reflecting mirror).

JP-A-2006-245519 discloses a solar power generation apparatus having a solar panel. In the following description, Japanese Patent Laid-Open No. 2006-245519 is referred to as Patent Document 1. The solar power generation device of Patent Literature 1 includes an angle sensor (solar tracking device) for detecting the angle of the solar panel with respect to the sun. The angle sensor of patent document 1 is comprised by the 2nd plate arrange | positioned in the position which opposes the 1st plate and 1st plate. Each of the first plate and the second plate is provided with one through hole. The through hole of the first plate and the through hole of the second plate are located on a substantially straight line. The angle sensor of Patent Document 1 is attached to the solar panel so that the first plate is parallel to the solar panel. In the technique of Patent Document 1, when the sunlight that has passed through the through hole of the first plate passes through the through hole of the second plate, it is determined that the solar panel is orthogonal to the sun. The technology of Patent Document 1 makes the solar panel orthogonal to the sun by adjusting the angle of the angle sensor so that sunlight passes through both the through hole of the first plate and the through hole of the second plate.

Sunlight that has passed through the through hole of the first plate travels toward the second plate while spreading. The area of sunlight that hits the surface of the second plate is larger than the area of the through hole of the first plate, depending on the sun's viewing diameter and the distance between the first plate and the second plate. Therefore, in the case of the solar tracking device of Patent Document 1, even if the first plate is not orthogonal to the sun, sunlight that has passed through the through hole of the first plate may pass through the through hole of the second plate. That is, in the technique of Patent Document 1, even if the solar panel is determined to be orthogonal to the sun, the solar panel may not actually be orthogonal to the sun. In the technique of Patent Document 1, the accuracy of specifying the position of the sun is not high. The present specification provides a technique for accurately identifying the position of the sun.

The solar tracking device disclosed in this specification includes a detection unit and a driving device. The detection unit includes a first plate and a second plate. The first plate has a through hole. The second plate is disposed at a position facing the first plate and has at least two light receiving portions. The drive device adjusts the angle of the detection unit. In this solar tracking device, at least two light receiving portions are arranged inside a circle having a radius R ₂ calculated by the following equation 1 with the intersection of the center line of the through hole and the second plate as the center. In the following formula, R _{1 is} the radius of the through hole, L is the distance between the first plate and the second plate, and A is the visual diameter of the sun.
R ₂ = R ₁ + L × tan (A / 2) (Formula 1)

In the solar tracking device described above, “disposed at a position where the first plate and the second plate face each other” includes a surface on which the through hole of the first plate is formed and a light receiving portion of the second plate. It means that the surface is parallel. Therefore, when the first plate is orthogonal to the sun, the second plate is also orthogonal to the sun. In addition, the “center line of the through hole” means a straight line that passes through the center of the through hole and is orthogonal to the first plate. The “distance between the first plate and the second plate” refers to the surface of the first plate on the second plate side (hereinafter sometimes referred to as the back surface of the first plate) and the first plate of the second plate. It means the distance from the plate side surface (hereinafter sometimes referred to as the surface of the second plate). A circle of radius R ₂ which is calculated by the formula 1, when the first plate is perpendicular to the sun, equivalent to bounds of the sunlight passing through the through-hole of the first plate strikes the surface of the second plate To do.

In the solar tracking device described above, the sunlight that has passed through the through hole of the first plate travels while spreading and reaches the second plate. On the surface of the second plate, two or more light receiving portions are provided inside the circle having the radius R ₂ calculated by the above formula 1. Therefore, when the 1st plate is orthogonal to the sun, sunlight strikes all the light-receiving parts. If the first plate deviates from an angle perpendicular to the sun, the light will not hit any of the light receiving portions. In the above-described solar tracking device, when any of the light receiving units is not exposed to sunlight, it is determined that the first plate is not orthogonal to the sun. When the first plate is not orthogonal to the sun, the angle of the detection unit is adjusted using a driving device. If sunlight hits all the light receiving parts, it is determined that the first plate (detection unit) is orthogonal to the sun. The solar tracking device described above can compensate for the spread of sunlight that has passed through the first plate and can accurately identify the position of the sun.

The external appearance of a solar power generation device is shown. It is a figure which shows the structure of a sunlight detection unit typically. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a figure explaining arrangement | positioning of a light-receiving part. The state which the sunlight detection unit is orthogonal to the sun is shown. The state which the sunlight detection unit is not orthogonal to the sun is shown. The state which the sunlight detection unit has shifted | deviated from the angle orthogonal to the sun is shown (1). The state which the sunlight detection unit has shifted | deviated from the angle orthogonal to the sun is shown (2). A method for detecting sunlight that has reached the light receiving section will be described (1). A method for detecting sunlight that has reached the light receiving part is shown (2). It is a figure for demonstrating the method to correct | amend the angle of a panel. It is a control block diagram of a solar power generation device. It is a figure which shows other embodiment of arrangement | positioning of a light-receiving part. It is a figure which shows other embodiment of arrangement | positioning of a light-receiving part.

Hereinafter, some of the technical features of the embodiments disclosed in this specification will be described. The items described below have technical usefulness independently.

(Characteristic 1) All the light receiving parts may be arranged at equal intervals on the circumference of a circle centering on the intersection of the center line of the through hole of the first plate and the second plate. It should be noted that the position where the light receiving unit is disposed is sufficient if it is inside the circle of radius R ₂ calculated from Equation 1. However, by arranging the light receiving portions at equal intervals on the circumference of the circle centered on the intersection point, the first plate is orthogonal to the sun no matter which direction the first plate is displaced from the position orthogonal to the sun. It can be judged that it is not. That is, the detection accuracy of the detection unit does not depend on the direction of deviation from the sun.

(Feature 2) all of the light receiving portion, the intersection of the first plate central line and the second plate through hole of the center, have been arranged on the circumference of a circle with a radius R ₂ which is calculated from Equation 1 Also good. When the light receiving unit is arranged at such a position, the first plate is slightly shifted from the position orthogonal to the sun, and sunlight does not hit any of the light receiving units. Such a sun tracking device can track the sun more accurately.

(Feature 3) The sun tracking device may further include a controller for controlling the driving device.

(Characteristic 4) The controller that controls the drive device, when the light amount difference between the light receiving units exceeds a predetermined range, commands to adjust the angle of the detection unit until the light amount difference between the light receiving units is within the predetermined range. The value may be output to the driving device. A slight deviation in the angle of the detection unit with respect to the sun can be corrected by setting the difference in the amount of light between the light receiving portions within a predetermined range (for example, zero).

(Feature 5) The light receiving unit may be arranged at a symmetrical (line symmetric or point symmetric) position about the intersection of the center line of the first through hole and the second plate.

(Feature 6) The detection unit may include two second plates (an upper second plate and a lower second plate). In this case, the upper second plate and the lower second plate are arranged at positions facing each other with a slight distance. A second through hole is formed in the upper second plate, and an optical sensor is disposed on the lower second plate. When the two second plates are viewed in plan, the second through hole may overlap with the optical sensor.

(Feature 7) The solar power generation apparatus may include a solar cell on the surface of the panel. The sunlight detection unit may be fixed to the panel so that the first plate is parallel to the surface of the panel.

(Feature 8) The driving device for driving the panel may be a driving device for driving the sunlight detection unit.

In the embodiment, a solar power generation device including a solar tracking device is disclosed. The solar power generation device has high power generation efficiency because the solar panel can accurately track the sun by the solar tracking device.

1 includes a support 8, a panel support shaft 3 that rotates with respect to the support 8, and a panel 2 that is fixed to the panel support shaft 3. A sunlight detection unit 10 is fixed to the panel 2. A driving device 5 is disposed between the support column 8 and the panel support shaft 3. The drive device 5 includes a first drive device 6 and a second drive device 4. The driving device 5 rotates the panel support shaft 3 in the arrow X direction and the arrow Y direction with respect to the support column 8. Therefore, the panel 2 can rotate with respect to the support column 8 in the arrow X direction and the arrow Y direction. The solar power generation device 100 can rotate around two axes. In the solar power generation device 100, the position of the sun is specified using the solar light detection unit 10, and the driving device 5 adjusts the angle of the panel 2.

When the driving device 5 rotates the panel 2, the sunlight detection unit 10 rotates together with the panel 2. Therefore, the drive device 5 that drives the panel 2 also functions as a drive device for the sunlight detection unit 10. In other words, it can be said that the solar tracking device 15 is configured by the sunlight detection unit 10 and the driving device 5. When the drive device 5 adjusts the sunlight detection unit 10 to an angle orthogonal to the sun, the panel 2 is orthogonal to the sun.

In the solar power generation device 100, the angle of the panel 2 is changed according to the movement of the sun. The panel 2 always rotates so as to be orthogonal to the sun according to a predetermined operation program. Since the orbit of the sun is known in advance, the operation pattern of the panel 2 is also stored in the program in advance. The sun tracking device 15 is used to correct the difference between the angle of the panel 2 determined in the program and the actual angle of the panel 2. For example, it is used when calibrating an initial program when the solar power generation apparatus 100 is assembled or correcting a change in the angle of the panel 2 over time. Alternatively, the sun tracking device 15 can correct the angle of the panel 2 in real time during operation of the panel 2 and can be used so that the panel 2 is always orthogonal to the sun.

The solar light detection unit 10 will be described. As shown in FIG. 2, the sunlight detection unit 10 includes a first plate 12 and a second plate 18. The first plate 12 and the second plate 18 are fixed to both ends of the hollow body 16. The first plate 12 is disposed at a position facing the second plate 18. In other words, the first plate 12 and the second plate 18 are arranged in parallel via the body 16. The first plate 12 and the second plate 18 are separated by the length L of the body 16. More precisely, the back surface of the first plate 12 and the surface of the second plate 18 are separated by a length L (see FIG. 3). One first through hole 14 is formed in the first plate 12. Four light receiving portions 20 are arranged on the second plate 18.

FIG. 4 is a plan view of the second plate 18. As shown in FIGS. 3 and 4, the light receiving portion 20 is a through hole formed in the second plate 18. In the following description, the through hole formed in the second plate 18 may be referred to as the second through hole 20. A point 22 shown in FIG. 4 is an intersection of the center line C14 of the first through hole 14 and the second plate 18. As shown in FIG. 3, the center line C <b> 14 is a straight line that passes through the center of the first through hole 14 and is orthogonal to the first plate 12. The first through-hole 14 is a pin hole of radius _{R 1.}

As shown in FIG. 4, the four second through holes 20 are formed at equal intervals on the circumference of a circle 24 having a radius r with the point 22 as the center. More precisely, the center of the second through hole 20 is located on the circumference of the circle 24. It can also be expressed that the four second through holes (light receiving portions) 20 are formed at point-symmetric positions separated by a distance r with the point 22 as the center. Each of the second through holes 20 is inscribed in a circle 26 having a radius R ₂ centered on the point 22. Precisely, the center of the second through hole 20 is located inside a circle 26 having a radius R ₂ centered on the point 22. Radius r is smaller than the radius _{R 2.} It will be described later radius _{R 2.}

FIG. 5 shows a state in which the sunlight detection unit 10 is orthogonal to the sun 30. In this case, the first plate 12 and the second plate 18 are orthogonal to the sun 30. As shown in FIG. 5, the sunlight 32 that has passed through the first through-hole 14 proceeds while spreading in the sunlight detection unit 10 (inside the body 16) by an amount corresponding to the visual diameter A of the sun, and the second plate 18 is reached. The “sun's visual diameter” is an angle of the apparent diameter of the sun and is generally between 32′32 ″ and 31′28 ″. The range of sunlight 32 that strikes the surface of the second plate 18 is the inside of a circle having a diameter of 2 × R ₂ . The radius R ₂ is the radius of the sunlight 32 that hits the surface of the second plate 18. The circle 26 is a range of sunlight 32 that hits the second plate 18 when the sunlight detection unit 10 is orthogonal to the sun 30. In the following description, the circle 26 may be referred to as a reference range 26. The radius R ₂ is obtained by geometric calculation and can be expressed by the following formula 1. In the following formula 1, R _{1 is} the radius of the first through hole 14, L is the distance between the first plate and the second plate, and A is the visual diameter of the sun. If 32 ′ is adopted as the viewing diameter A, it can correspond to almost all places on the earth.
R ₂ = R ₁ + L × tan (A / 2) (Formula 1)

As described above, the four second through holes 20 are formed inside the circle 26 having the radius R ₂ (see FIG. 4). More precisely, the four second through holes 20 are inscribed in the circle 26. Therefore, when the sunlight detection unit 10 is orthogonal to the sun 30, the sunlight 32 passes through all the second through holes 20 and reaches the back side of the second plate 18. Thereby, when the sunlight 32 has passed all the 2nd through-holes 20, it can be judged that the sunlight detection unit 10 is orthogonal to the sun 30. FIG. In FIG. 5, two second through

holes

20 a and 20 b among the four second through holes 20 appear. The sunlight 32 also passes through the other two second through holes 20.

As shown in FIG. 6, even when the sunlight detection unit 10 is not orthogonal to the sun 30, the sunlight 32 passes through any one of the four second through holes 20. There is. In FIG. 6, the sunlight 32 passes through the second through hole 20a and does not pass through the second through hole 20b. In the sunlight detection unit 10, when the sunlight 32 does not pass through any of the four second through holes 20, it is determined that the sunlight detection unit 10 is not orthogonal to the sun 30.

The features of the sunlight detection unit 10 will be described in detail. As described above, in the solar light detection unit 10, the four second through holes (light receiving portions) 20 are formed at equal intervals on the circumference of the circle 24 centered on the point 22 (see FIG. 4). reference). Therefore, it is possible to detect the “direction” in which the sunlight detection unit 10 is deviated from the position orthogonal to the sun.

For example, in FIG. 7, of the four second through holes 20 (20a to 20d), only the through holes 20d are not exposed to sunlight 32. In this case, for example, it can be detected that the sunlight 32 is shifted from the reference range 26 in the Y direction of FIG. That is, the sun tracking device 15 can detect that the sunlight detection unit 10 (panel 2) of FIG. 1 is shifted in the Y direction from a position orthogonal to the sun. Based on the measurement result of the solar tracking device 15, the solar power generation device 100 can make the solar light detection unit 10 (panel 2) orthogonal to the sun by the second drive device 4.

Moreover, as shown in FIG. 8, when the sunlight 32 does not hit only the through-hole 20a, the solar tracking device 15 is shifted in the X direction from the position where the sunlight detection unit 10 (panel 2) is orthogonal to the sun. Can be detected. Based on the measurement result of the solar tracking device 15, the solar power generation device 100 can make the solar light detection unit 10 (panel 2) orthogonal to the sun by the first drive device 6. When the panel 2 is deviated from an angle orthogonal to the sun, the sun tracking device 15 can detect the direction of deviation and correct the deviation.

FIG. 9 shows one implementation form of the sunlight detection unit. The solar light detection unit 10a shown in FIG. 9 includes two second plates 18 (an upper second plate 18a and a lower second plate 18b). The second through hole 20 is formed in the upper second plate 18a, and the optical sensor 40 is disposed in the lower second plate 18b. The optical sensor 40 is a sensor that measures a received light amount (light intensity), and is, for example, a phototransistor. The optical sensor 40 is disposed at a position corresponding to the second through hole 20. In other words, the second through hole 20 overlaps the optical sensor 40 when the second plate 18 is viewed in plan. Although two optical sensors 40 are shown in the drawing, there is an optical sensor corresponding to the second through hole that does not appear in the cross section of FIG. 9. That is, the same number of photosensors 40 as the number of second through holes 20 are arranged in the sunlight detection unit 10a.

FIG. 10 shows another embodiment of the solar light detection unit. In the sunlight detection unit 10b, the optical sensor 40 is the light receiving unit 20 itself. The position where the optical sensor 40 is disposed may be the same as the position of the second through hole 20 in the above-described embodiment (sunlight detection unit 10).

When the sunlight 32 is detected using the optical sensor 40, the angle of the panel 2 can be corrected in real time during the operation of the panel 2 using the detection signal. As shown in FIG. 11, when the sunlight 32 deviates from the reference range 26, the light amounts detected by the optical sensors 40a to 40d are different. The amount of light detected by the

optical sensors

40b and 40c is large, the amount of light detected by the optical sensor 40a is medium, and the amount of light detected by the optical sensor 40d is small (almost zero). The light amount data detected by the optical sensors 40a to 40d is input from the sunlight detection unit 10 to the controller 50 (see FIG. 12). The controller 50 determines that the sunlight detection unit 10 (panel 2) is slightly shifted in the X direction from the light amount data of the

optical sensors

40a and 40b. Moreover, the controller 50 determines that the sunlight detection unit 10 has shifted | deviated largely in the Y direction based on the light quantity data of the

optical sensors

40c and 40d. The controller 50 calculates an angle at which the difference between the light amounts of the optical sensors 40a to 40d becomes almost zero, and outputs a command value for adjusting the angle of the sunlight detection unit 10 to the driving device 5. By correcting the angle of the panel 2 during the operation of the panel 2, the panel 2 is always orthogonal to the sun, and the power generation efficiency can be increased.

The number of light receiving parts is not limited to four. For example, in the case of a solar power generation device in which the panel rotates around one axis, two light receiving sections 20 may be provided as shown in FIG. The two light receiving units 20 may be disposed within the reference range 26 centered on the point 22, or three light receiving units 20 may be provided as shown in FIG. 14. In both cases of FIGS. 13 and 14, the plurality of light receiving portions are arranged within the reference range 26 centered on the intersection point 22 and at equal intervals on the circumference centered on the intersection point 22. Note that the center of the light receiving unit may be located on the boundary of the reference range 26. That is, the radius r of the circle 24 in which the light receiving unit is disposed may be the same as the radius R ₂ of the reference range 26. By adopting such a configuration, the position of the sun can be specified with higher accuracy.

In the above embodiment, the solar tracking device in which the solar light detection unit is directly fixed to the panel has been described. Therefore, the drive device that rotates the panel is also the drive device that rotates the sunlight detection unit. The drive device that rotates the sunlight detection unit may be different from the drive device that rotates the panel. In this case, the freedom degree of the place which fixes a sunlight detection unit increases.

The above-described solar tracking device can also be used in a solar power generation device that concentrates sunlight on a collector using a reflecting mirror. In this solar power generation device, the reflecting mirror is not orthogonal to the sun. Therefore, the solar tracking device (sunlight detection unit) is not directly fixed to the reflecting mirror. A solar tracking device is installed separately from the reflector, and the position of the sun is specified by making the solar tracking device orthogonal to the sun. By accurately identifying the position of the sun, the reflector can be directed to the sun at an appropriate angle relative to the position.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

Claims

A detection unit including a first plate having a through-hole, and a second plate disposed at a position facing the first plate and having at least two light receiving portions;
A drive device for adjusting the angle of the detection unit;
Solar least two light receiving portions, centered on the intersection of the center line and the second plate of the through hole, characterized in that it is arranged inside the circle of radius R 2 which is calculated by the following formula 1 Tracking device.
R 2 = R 1 + L × tan (A / 2) (Formula 1)
Here, R 1 is the radius of the through hole, L is the distance between the first plate and the second plate, and A is the viewing diameter of the sun.
2. The solar tracking device according to claim 1, wherein all the light receiving units are arranged at equal intervals on a circle around the intersection.
All of the light receiving portion, the solar tracking device according to claim 1 or 2, characterized in that it is arranged on the circumference of a circle of radius R 2.
All of the light receiving portion, the solar tracking device according to claim 1 or 2, characterized in that it is inscribed in a circle of radius R 2.
The sun according to any one of claims 1 to 4, wherein each of the light receiving portions is disposed at a symmetric position with respect to an intersection between the center line of the through hole and the second plate. Tracking device.
The second plate includes an upper second plate and a lower second plate disposed at a position facing the upper second plate,
A second through hole is provided in the upper second plate;
The solar tracking device according to any one of claims 1 to 5, wherein an optical sensor is provided on the lower second plate.
The solar tracking device according to any one of claims 1 to 6, further comprising a controller that controls the driving device so that a difference in light quantity between the light receiving units is within a predetermined range.
A solar power generation device comprising the solar tracking device according to any one of claims 1 to 7.