JPH11307801A - Sunlight tracking apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an external force acting on a light receiving surface or a mechanism for supporting the light receiving surface from becoming excessive due to weather conditions by inputting weather information that produces the external force acting on the light receiving surface and by driving the light receiving surface in such directions as to reduce the external force acting on the light receiving surface based on the inputted weather information. SOLUTION: A drive section 14 drives a light receiving surface 12 so as to track the direction of radiation with sunlight around a gravitational axis and left and right axes orthogonal to the gravity axis. An anemometer 24 provided in the vicinity of the surface 12 outputs a signal according to a wind direction, and outputs an electromotive force according to a wind velocity. Further, a snow coverage meter 26 provided in the vicinity of the surface 12 measures a time interval between the transmission of an emitted ultrasonic wave and its reception, and outputs a signal according to a snow coverage based on the measurement. Outputs from a solar direction sensor 12c, a proximity switch 22, and the meters 24 and 26 are sent to a control unit 18, and the unit 18, e.g. generates a sunlight tracking direction based on these input values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar tracking device, and more specifically, to a solar power generation device (solar cell).
Direction of arrival (arrival direction) of sunlight from solar panels and solar heat collectors
The present invention relates to a solar tracking device that improves the energy conversion efficiency by tracking the external force (mechanical load) acting on the light receiving surface due to wind and snow.

[0002]

2. Description of the Related Art Examples of the above-described sunlight tracking apparatus include the techniques described in JP-A-9-148610, JP-A-9-129910, and JP-A-9-140052. In these prior arts, the light receiving surface is driven in a three-dimensional space so that incident sunlight is maximized, and control is performed so that the conversion efficiency of the solar power generation device (solar cell) is maximized.

[0003]

However, such a solar tracking device is installed outdoors and has a relatively large light receiving surface area, so that the light receiving surface or the light receiving surface is supported by weather conditions such as wind and snow. The external force (mechanical load) acting on the mechanism sometimes became excessive.

SUMMARY OF THE INVENTION Accordingly, the present invention is to solve the above-mentioned inconvenience, and to prevent an external force (dynamic load) acting on a light receiving surface or a mechanism supporting the light receiving surface from being excessive due to weather conditions such as wind and snow. It is an object of the present invention to provide a solar tracking device as described above.

[0005]

According to a first aspect of the present invention, there is provided a solar tracking device including a driving unit for driving a light receiving surface of sunlight according to an incident direction. Weather information input means for inputting weather information that generates an external force acting on the light receiving surface; and the driving means includes a light receiving surface in a direction in which the external force acting on the light receiving surface is reduced based on the input weather information. Is configured to be driven. As a result, it is possible to prevent the external force (dynamic load) acting on the light receiving surface or the mechanism supporting the light receiving surface due to weather conditions such as wind and snow from becoming excessive.

According to a second aspect of the present invention, the weather information input means is a detecting means for outputting a signal corresponding to one of a wind speed acting on the light receiving surface and snow. This makes it possible to accurately detect an external force (mechanical load) acting on the light receiving surface or a mechanism supporting the light receiving surface, in addition to the above-described effects.

According to a third aspect of the present invention, the weather information input means is configured to be a calendar clock. This makes it possible to easily detect an external force (mechanical load) acting on the light-receiving surface or a mechanism supporting the light-receiving surface in addition to the above-described operation and effect, thereby simplifying the configuration.

According to a fourth aspect of the present invention, the weather information input means is configured as a switch operated by an operator. Thereby, in addition to the above-described effects, the configuration can be further simplified.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a solar tracking apparatus 10 according to the present invention.
It is the schematic which shows the whole.

As shown in the figure, the sunlight tracking apparatus 10 includes a light receiving surface 12, a driving unit 14, a support mechanism 16 for connecting the light receiving surface 12 and the driving unit 14, and a control unit 18 (driving means) comprising a microcomputer. ).

The light receiving surface 12 is a flat member having a length of 3.0 m, a width of 4.0 m and a thickness of 0.5 m. FIG. 2 is an explanatory cross-sectional view, and as shown in FIG.
A plurality of 2a, more specifically, 168, are continuously laid.

The solar cell 12a is covered with a condenser lens 12b, and the condensed sunlight irradiates the solar cell. For convenience of understanding, FIG. 2 shows the number of solar cells 12a in a simplified manner. Although only one light receiving surface 12 is shown in the illustrated example, two or more light receiving surfaces 12 may be provided.

On the light receiving surface 12, one sun direction sensor 12c is provided.
Pieces are arranged near the center. As shown in FIG. 3, the sun direction sensor 12c has two shielding plates 12C1 and 12C2 orthogonal to each other, and has four photodetectors (photodiodes) at four corners divided by the two shielding plates 12C1 and 12C2. Etc.) 12C3, 12C4, 12C5, 12C6 are arranged.

In the above configuration, the two shielding plates 12C
If the cross axis 12C7 of 1,1C2 is shifted with respect to the irradiation light, the four light detecting elements 12C3, 12C4, 12C
A part of 5, 12C6 is shaded, and the output is different from other detection elements. Therefore, the outputs of the four photodetectors are input to the control unit 18 and compared with each other, so that the light receiving surface 1
Thus, it can be determined whether or not the sunlight 2 is appropriately tracked so as to be perpendicular to the irradiation light.

Further, a plurality of proximity switches 22 are arranged on the periphery of the light receiving surface 12, and output an ON signal when the light receiving surface 12 comes into contact with foreign matter.

The driving unit 14 includes two pulse motors (not shown), and follows the direction of sunlight through the support mechanism 16 in response to a command from the control unit 18.
The light receiving surface 12 is driven around a gravity axis (vertical line) and a right and left axis (X or Y axis) orthogonal thereto. FIG. 4 schematically shows this.

Further, near the light receiving surface 12, an anemometer 24 is provided.
Is provided. The anemometer 24 is composed of a well-known windmill type anemometer (trade name: Aerobane), transmits the movement of the vertical tail of the airplane-like base through a synchronizing device, outputs a signal corresponding to the wind direction, and is attached to the front end. The propeller-shaped windmill is connected to a generator and outputs an electromotive force according to the wind speed.

A snow gauge 26 is provided near the light receiving surface 12. The snow gauge 26 is of a known long sound wave type, and the ultrasonic wave emitted from the transmitter toward the ground surface is received by the receiver, the time from transmission to reception is measured, and the snow amount ( (Depth of snow). Note that a pressure-sensitive sensor may be attached to the condenser lens 12b to detect the pressure, and the snow amount may be estimated from the detected pressure value.

A keyboard 30 is connected to the control unit 18 so that commands from an operator, for example, stop of driving of the light receiving surface 12,
Driving to the evacuation direction (position) of the wind, driving instruction to the evacuation direction (position) of the snow cover, and the like are input.

Sun direction sensor 12c, proximity switch 2
2. The outputs of the anemometer 24 and the snow gauge 26 are sent to the control unit 18. As shown in FIG. 1, the control unit 18 generates a tracking direction of sunlight based on the input value. The output of the solar cell 12a in the light receiving surface 12 is indicated by an electric load (for example, an air conditioner) not shown.
Sent to

FIG. 5 is a flowchart showing the operation of this apparatus.

Before entering the description of the figure, the subject of the present invention will be re-explained.

Operating efficiency of solar cell (energy conversion efficiency)
Is proportional to the energy of the incident light, but when the light receiving surface 12 has an inclination with respect to a vertical line (vertical line) as shown in FIG.
The efficiency is obtained as in the following Expression 1. cosθ = cosZcosΔ + sinZsinΔcos (A−Ψ). . Equation 1

In equation (1), Z is the elevation angle of the sun, A is the azimuth angle of the sun, Δ is the angle between the vertical line (vertical line) and the normal line of the light receiving surface 12, and θ is the normal line of the light receiving surface 12 and the sun direction. Is an angle between the reference of the sun azimuth (that is, A = 0) and the light receiving surface. In FIG. 6, the amount of light received by the light receiving surface is proportional to cos θ with respect to the angle θ between the light receiving surface and the sun azimuth.

Equation 1 takes the maximum value 1 at θ = 0, so that θ =
0, in other words, the control unit 18 drives the light receiving surface 12 via the support mechanism 16 and the driving unit 14 so that the normal of the light receiving surface 12 matches the direction of the sun.

Meanwhile, at the same time as the light receiving surface 12 receives light, the light receiving surface 12 and the support mechanism 16 are subjected to a mechanical load by wind as shown in FIG. As shown in FIG. 8, the light receiving surface 12 and the support mechanism 16 are also subjected to a mechanical load due to snow. 7 and 8 are side views of the light receiving surface 12. FIG.

In FIG. 7, a force (external force) N1 acting on the light receiving surface 12 is represented by the following equation 2 when a force caused by wind is F1. N1 = F1 cos θ1. . . Equation 2

Similarly, in FIG. 8, the force (external force) N2 acting on the light receiving surface 12 is expressed by the following equation 3 when the force caused by snow is F2. N2 = F2sin θ2. . . Equation 3

In equation (2), when the wind direction is horizontal, θ1
In Equation 3, N1 = 0 is derived at π / 2 (= 90 degrees), and in Equation 3, N2 = 0 is derived at θ2 = 0. That is, the mechanical load on the light receiving surface 12 can be canceled by providing the retreat angle θ. However, the evacuation angle is opposite for wind and snow, and the best evacuation angle for crosswind is the maximum mechanical load for snow, and the best evacuation angle for snow is the maximum mechanical load for wind. Become.

The operation of this apparatus will be described with reference to the flow chart of FIG. This operation is performed by the control unit 18, and the operation of the flow chart of FIG. 5 is also shown functionally in FIG. The program shown in FIG. 5 is started, for example, every 30 seconds.

First, in S10, the anemometer 24
It is determined whether or not the wind is blowing horizontally toward the light receiving surface 12 from the output of (1) and the wind speed exceeds a threshold value appropriately set. If the result is affirmative, the process proceeds to S12 to perform the evacuation control.

Specifically, it is assumed that the direction of the wind is horizontal, and θ1 is set to π / 2 = 90 so that N1 becomes 0 in Equation 2.
Specifically, the light receiving surface 12 is driven so as to be horizontal with respect to the road surface.

On the other hand, if the result in S10 is negative, the program proceeds to S14, in which it is determined whether or not there is an input from the operator via the keyboard 30. Here, if an instruction to horizontally drive the light receiving surface 12 has been input, the process proceeds to S12, and the same processing is performed.

When the result in S14 is NO, the program proceeds to S16,
It is determined from the output of the snow gauge 26 whether or not the amount of snow (snow depth) exceeds an appropriately set threshold value.
Proceed to 18 to perform evacuation control.

More specifically, the driving is performed so that θ2 = 0 so that N2 becomes 0 in Equation 3, and more specifically, the light receiving surface 12 is driven perpendicular to the road surface.

On the other hand, when the result in S16 is NO, the program proceeds to S20, in which it is determined whether or not there is an input from the operator via the keyboard 30. Here, when an instruction to vertically drive the light receiving surface 12 is input, the process proceeds to S18 and the same processing is performed.

When the result in S20 is NO, the program proceeds to S22,
It is determined whether or not the output of the proximity switch 22 is ON, that is, whether or not the light receiving surface 12 is in contact with a foreign substance. If the result is affirmative, the subsequent processing is skipped so as not to damage the light receiving surface 12.

When the result in S22 is NO, the program proceeds to S24, in which tracking control of sunlight is performed. That is, the light receiving surface 12 is drive-controlled so that θ in Expression 1 becomes 0.

Since the present embodiment is configured as described above, it is possible to prevent the external force (dynamic load) acting on the light receiving surface or the mechanism supporting the light receiving surface from becoming excessive due to weather conditions such as wind and snow.

Further, since the weather condition is detected by using the anemometer 24 and the snow gauge 26, the external force can be detected with high accuracy, and the (dynamic load) can be more appropriately prevented from becoming excessive. it can.

FIG. 9 is a block diagram showing a second embodiment of the solar tracking apparatus according to the present invention, and FIG. 10 is a flowchart showing the operation thereof.

As shown in the figure, in the second embodiment, a calendar clock 32 is used in place of the weather sensor. That is, empirically, the occurrence of snow cover is concentrated from winter to early spring, and the occurrence of wind, especially strong winds (typhoon, etc.) is concentrated from spring to autumn, so that the light receiving surface 12 is driven horizontally or vertically accordingly. I made it.

Referring to the flow chart of FIG. 10, it is determined in S100 whether or not there is an input from the operator via the keyboard 30.
To read the calendar clock 32 and determine whether or not the current time is in the daylight hours (daytime).

When the result in S102 is affirmative, the process proceeds to S104, in which it is determined whether or not the output of the proximity switch 22 is ON. When the result is affirmative, the subsequent processing is skipped. As in the first embodiment, the light receiving surface 12 is driven so that θ in Expression 1 becomes 0, and tracking control of sunlight is performed.

On the other hand, when the result in S102 is negative, that is, when it is determined that the current time is at night (or when the result in S100 is affirmative), the process proceeds to S108, and the season viewed from the calendar clock is any of spring, summer, and autumn. Or winter.

If it is determined in S108 that it is in spring, summer, or autumn, the process proceeds to S110, where the direction of the wind is regarded as horizontal, and N1 becomes 0 in equation 2, as in the first embodiment. Thus, the light receiving surface 12 is driven horizontally with respect to the road surface.

If it is determined in step S108 that it is winter, the process proceeds to step S112, and as in the first embodiment, equation 3
To drive the light receiving surface 12 perpendicularly to the road surface so that N2 becomes zero.

Since the second embodiment is configured as described above, the same operation and effect as those of the first embodiment can be obtained. In addition, since the calendar clock 32 is used, the weather condition can be easily reduced. Detection can be performed, and the configuration can be simplified.

FIG. 11 is a block diagram showing a third embodiment of the solar tracking apparatus according to the present invention, and FIG. 12 is a flowchart showing the operation thereof.

As shown in the figure, in the third embodiment, a switch 34 operated by an operator is provided, and one of two positions, evacuation of wind and evacuation of snow, is selected.
The light receiving surface 12 is driven horizontally or vertically according to the input (selection).

Referring to the flowchart of FIG. 12, it is determined in S200 whether or not there is an input from the operator via the keyboard 30.
To read the calendar clock 32 and determine whether or not the current time is in the daylight hours (daytime).

When the result in S202 is affirmative, the process proceeds to S204, in which it is determined whether or not the output of the proximity switch 22 is ON. When the result is affirmative, the subsequent processing is skipped. Similarly to the above embodiment, the light receiving surface 12 is drive-controlled so that θ in Expression 1 becomes 0, and tracking control of sunlight is performed.

On the other hand, when the result in S202 is negative (or when the result in S200 is affirmative), the process proceeds to S208, where the input (selection) of the switch 34 is determined. The light receiving surface 12 is driven horizontally with respect to the road surface in the same manner as in the first embodiment, and when snow retreat is selected, the process proceeds to S212 and the light receiving surface 12 is moved relative to the road surface as in the previous embodiment. Drive vertically.

Since the third embodiment is configured as described above, the same operation and effect as those of the first embodiment can be obtained, and the configuration can be further simplified.

As described above, in the first to third embodiments, in the solar light tracking device provided with the driving means (control unit 18) for driving the light receiving surface of sunlight according to the incident direction, the light receiving surface is In addition to providing weather information input means (anemometer 24, snow gauge 26, calendar clock 32, switch 34) for inputting weather information that produces an external force acting thereon, the driving means (control unit 18) provides the input weather information. , The light receiving surface is driven in a direction in which the external force acting on the light receiving surface decreases (S10 to S24).

Further, the weather information input means is constituted as a detection means (anemometer 24, snow gauge 26) for outputting a signal corresponding to either the wind speed acting on the light receiving surface or snow.

Further, the weather information input means is constituted as a calendar clock (calendar clock 32).

Further, the weather information input means is constituted by a switch 34 operated by an operator.

Although the present invention has been described by taking a case where a solar cell is used as a power generation mechanism as an example, since the energy of sunlight includes heat energy, it is appropriate to provide a power generation mechanism using a heat engine.

[0061]

According to the present invention, it is possible to prevent the external force (dynamic load) acting on the light receiving surface or the mechanism supporting the light receiving surface from becoming excessive due to weather conditions such as wind and snow.

According to the second aspect, in addition to the above-described functions and effects, an external force (mechanical load) acting on the light receiving surface or a mechanism supporting the light receiving surface can be detected with high accuracy.

According to the third aspect, in addition to the above-described functions and effects, an external force (mechanical load) acting on the light receiving surface or a mechanism supporting the light receiving surface can be easily detected, thereby simplifying the configuration. be able to.

According to the fourth aspect, in addition to the above-described functions and effects, the configuration can be further simplified.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the entire configuration of a solar tracking device according to the present invention.

FIG. 2 is an explanatory sectional view of a light receiving surface of the device in FIG. 1;

FIG. 3 is an explanatory perspective view of a sun azimuth sensor arranged on a light receiving surface of the device in FIG. 1;

FIG. 4 is an explanatory diagram showing driving of a light receiving surface of the device in FIG. 1;

FIG. 5 is a flowchart showing the operation of the apparatus in FIG. 1;

FIG. 6 is an explanatory diagram showing calculation of a sunlight tracking direction of the apparatus in FIG. 1;

FIG. 7 is an explanatory diagram showing a force (dynamic load) received by a light on a light receiving surface of the apparatus in FIG. 1;

FIG. 8 is an explanatory diagram showing a force (dynamic load) received by snow on a light receiving surface of the apparatus in FIG. 1;

FIG. 9 is a schematic diagram showing an overall configuration of a solar tracking device according to a second embodiment of the present invention.

FIG. 10 is a flowchart showing the operation of the apparatus in FIG. 9;

FIG. 11 is a schematic diagram showing an overall configuration of a solar tracking device according to a third embodiment of the present invention.

FIG. 12 is a flowchart showing the operation of the apparatus in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Solar tracker 12 Light receiving surface 12a Solar cell 12c Sun direction sensor 14 Drive unit 16 Support mechanism 18 Control unit (drive unit) 22 Proximity switch 24 Anemometer (weather information input unit, detection unit) 26 Snow meter (weather information) Input means, detection means) 30 keyboard 32 calendar clock (weather information input means) 34 switch (weather information input means)

Claims (4)

[Claims] 1. A sunlight tracking device comprising a driving means for driving a light receiving surface of sunlight according to an incident direction, comprising: a. Weather information input means for inputting weather information that generates an external force acting on the light receiving surface, and the driving means, the driving means, in a direction in which the external force acting on the light receiving surface is reduced based on the input weather information A solar tracking device characterized by driving a light receiving surface. 2. The sunlight tracking device according to claim 1, wherein said weather information input means is a detection means for outputting a signal corresponding to one of a wind speed and snow acting on said light receiving surface. . 3. The solar tracking apparatus according to claim 1, wherein said weather information input means is a calendar clock. 4. The solar tracking apparatus according to claim 1, wherein the weather information input means is a switch operated by an operator.