CN220380493U - A spherical photoelectric sensor for sun position detection - Google Patents

Abstract

The utility model discloses a spherical-like photoelectric sensor for sun position detection, which includes a spherical-like shell and several photosensitive elements. The outer part of the spherical-like shell is composed of several successively adjacent surfaces. The center of each surface A photosensitive element is embedded in each position, and a top photosensitive element is installed on the top plane of the spherical shell. A photosensitive element group is installed on the periphery of the top photosensitive element close to the top plane of the spherical shell. The photosensitive element, the top photosensitive element and The photosensitive element groups all use silicon photovoltaic cells, photoresistors, photodiodes or phototransistors with exactly the same area and electrical characteristics; the utility model combines the transmission system and computer control technology to achieve accurate calculation and tracking of the sun's position, and has a simple tracking algorithm , wide tracking range, high tracking accuracy and other advantages, it can be widely used in the field of photoelectric tracking.

Description

A quasi-spherical photoelectric sensor for sun position detection

Technical field

The utility model relates to the field of sun tracking, and in particular to a quasi-spherical photoelectric sensor used for sun position detection.

Background technique

Photoelectric tracking adjusts the position of photovoltaic modules based on the light intensity detection signal of the photoelectric sensor. The structural design of the photoelectric sensor will directly affect the tracking accuracy, tracking algorithm and tracking stability of the solar tracking system. Existing photoelectric tracking solutions mainly use the following sensors:

Four-quadrant photoelectric sensor: It uses four photocells arranged in a rectangular shape. Each photocell can independently output a voltage value when exposed to light. Through an external simple optical system, the light source is projected onto the array. The angle of the light source can be obtained by comparing the voltage of each photocell. However, the tracking angle range is small and the target is easily lost, causing failure of the control system and even malfunction of the execution structure;

Partition-type photoelectric sensor: Utilizing the blocking effect of the partition, when the angle between the incident light and the partition is different, the photosensitive elements on both sides receive different light intensities to determine the position of the sun. However, it is easily affected by external light sources and other scattered light, causing the motor to rotate frequently, resulting in poor system operation stability and low tracking accuracy;

Photovoltaic potential sensor: According to the difference in light intensity received by the two photoresistors on the slope, the concentrator can be oriented to the position with the maximum sunlight intensity. However, its accuracy is low and it is not suitable for dish-type solar photovoltaic power generation devices.

Therefore, in view of the above problems, the present invention proposes a quasi-spherical photoelectric sensor for sun position detection to solve the above problems.

Utility model content

The utility model solves the above technical problems through the following technical solutions. A spherical-like photoelectric sensor for sun position detection includes a spherical-like shell and several photosensitive elements. The outer part of the spherical-like shell is composed of several adjacent ones in sequence. It is composed of surfaces, and a photosensitive element is embedded in the center of each surface, and a top photosensitive element is installed on the top plane of the spherical shell, and a photosensitive element group is installed on the periphery of the top photosensitive element on the top plane of the spherical shell.

Preferably, the photosensitive element, the top photosensitive element and the photosensitive element group are all made of silicon photovoltaic cells, photoresistors, photodiodes or phototransistors with exactly the same area and electrical characteristics.

Preferably, the spherical-like shell is a spherical-like polyhedron.

A tracking method of a spherical photoelectric sensor for sun position detection. This method is based on two modules: coarse tracking and fine tracking. The coarse tracking module is installed in the upper left, lower left, upper right, lower right, and center of the solar panel. The above-mentioned quasi-spherical photoelectric sensors a, d, b, c, e are used to ensure that the light rays are directed vertically to the main axis of the solar panel during precise tracking. The specific tracking method steps are as follows:

S1: Set the photocurrent threshold output by the sensor to K when it is cloudy, at night, or when the sensor is not facing the direction of incident sunlight at all. The photocurrents I a and I b output by the five sensors a, _b , _c , d, and e are , I _c , I _d , and I _e are all less than the threshold K, it means that it is cloudy, night, or the sensor is not facing the direction of incident sunlight at all. At this time, the orientation is set according to the PLC, and the azimuth direction stepper motor and The altitude angle stepper motor adjusts the sensor to the position of the sun in the sky in the current astronomical calendar. If it is night, it will face the east and wait for the sunrise;

S2: When the photocurrent output by one or more of the five sensors a, b, c, d, and e is greater than the output photocurrent of the remaining sensors, it means that the sunlight deviates from the main axis of the solar panel, that is, a large current is output. The part is exposed to direct sunlight, and the PLC sends instructions to drive the stepper motors in the azimuth direction and the stepper motor in the altitude direction, and starts the coarse tracking mode;

S3: First adjust the azimuth angle roughly, and compare the sum of photocurrents output by sensors a and d (I _a +I _d ) with the sum of photocurrents output by sensors b and c (I _b +I _c ). When I _a When +I _d >I _b +I _c , it means that the position of the sun is on the left side of the main axis of the solar panel. The PLC drives the azimuth stepper motor to rotate clockwise until I _a +I _d =I _b +I _c , and the sun When the position is on the right side of the main axis of the solar panel, vice versa, the coarse tracking adjustment of the coarse tracking module is completed;

S4: After the coarse tracking is completed, the main axis of the solar panel has been basically aligned with the sun, that is, the sensor e has been basically aligned with the sun at this time. At this time, the fine tracking mode is started, and the PLC controls the sensor e to perform fine tracking operations;

S5: Collect the current signals I ₁ , I _{2 , I 3 , I 4 ... I n output by each silicon photovoltaic cell 1, 2} , ₃ , ₄ ... _n in the sensor e, and convert them into voltage signals V ₁ , V ₂ , V ₃ , V ₄ ……V _n ;

S6: By comparing the voltages output by all silicon photovoltaic cells, determine the silicon photovoltaic cell with the largest output voltage, which corresponds to the position of the sun at this time. Use Matlab to determine the coordinates (Ψ, θ) of the light spot falling on the largest silicon photovoltaic cell to further drive the orientation. The angular direction stepper motor rotates to Ψ in the horizontal direction, and the height angular direction stepper motor rotates to θ;

S7: Set the photocurrent threshold range of the vertically incident solar panel to L ₁ -L ₂ . When the photocurrent output by the top photosensitive element on the topmost plane is the largest, and the photocurrent output by the surrounding photosensitive element groups is equal or in the set If the photocurrent threshold range of a certain vertical incident sunlight of the solar panel is L ₁ -L ₂ , then the sunlight is considered to be vertically incident on the solar panel, and the tracking operation is completed.

Compared with the existing technology, the utility model has the following advantages:

1. The spherical structure of the photoelectric sensor in this utility model can capture sunlight within 360° of the sensor's altitude angle and azimuth angle, overcoming the shortcomings of the traditional photoelectric sensor's small viewing angle range and ensuring that the sensor can track and position the sun in all directions;

2. Adopt a coarse-fine two-level tracking mode to effectively reduce errors caused by the impact of the external environment during the tracking process;

3. The sensor can use photoresistor or photocell as the photosensitive component, which has low cost and high application value and use prospects;

4. The sensor only needs to compare the output voltages of different planar silicon photovoltaic cells to determine the maximum illumination surface, and then calculate and output the altitude angle and azimuth angle of the sun based on the spherical coordinate system through MATLAB. The algorithm is simple and the control strategy is simple.

Description of the drawings

Figure 1 is a schematic structural diagram of a spherical photoelectric sensor used for sun position detection according to the present invention;

Figure 2 is a top view of the spherical shell of a spherical-type photoelectric sensor used for sun position detection according to the present invention;

Figure 3 is a schematic coordinate diagram of the maximum illumination surface of the spherical shell of the spherical-like photoelectric sensor used for sun position detection of the utility model based on the spherical coordinate system;

Figure 4 is a schematic coordinate diagram of the maximum illumination surface under Matlab of a spherical-type photoelectric sensor used for sun position detection according to the present invention;

Figure 5 is a schematic diagram of sensor installation in the coarse tracking mode of the spherical-type photoelectric sensor used for sun position detection according to the present invention.

Detailed ways

The following is a detailed description of the embodiments of the present utility model. This embodiment is implemented based on the technical solution of the present utility model and provides detailed implementation modes and specific operation processes. However, the protection scope of the present utility model is not limited to the following. the described embodiments.

As shown in Figures 1-5, this embodiment provides a technical solution: a spherical-like photoelectric sensor for sun position detection, including a spherical-like housing 1 and several photosensitive elements 2. The outside of the spherical-like housing 1 is composed of several It consists of two consecutively adjacent surfaces, and a photosensitive element 2 is embedded in the center of each surface. The top photosensitive element 3 is installed on the top plane of the spherical shell 1. The top photosensitive element 3 is installed on the top plane of the spherical shell 1. A photosensitive element group 4 is installed on the periphery of element 3.

The photosensitive element 2, the top photosensitive element 3 and the photosensitive element group 4 are all made of silicon photovoltaic cells, photosensitive resistors, photosensitive diodes or photosensitive transistors with exactly the same area and electrical characteristics.

The photosensitive element 2 is evenly embedded in the center position of each surface of the outer wall of the spherical shell 1. It can not only be used as a power source, but also can be used as a photoelectric sensor to detect the incident light of the sun at 360° without blind spots.

The spherical shell 1 is a spherical polyhedron. The spherical shell 1 is a polyhedron that is approximately a sphere, and a photosensitive element 2 is installed at the center of each plane on its outer wall. Due to the angle between the planes, when sunlight shines on silicon photovoltaic cells on different planes, the voltages generated by the different planes are: Deviation, from which the altitude and azimuth angle of the sun relative to the sensor can be calculated.

A tracking method of a spherical photoelectric sensor for sun position detection. This method is based on two modules: coarse tracking and fine tracking. The coarse tracking module is installed in the upper left, lower left, upper right, lower right, and center of the solar panel. The above-mentioned quasi-spherical photoelectric sensors a, d, b, c, e are used to ensure that the light rays are directed vertically to the main axis of the solar panel during precise tracking. The specific tracking method steps are as follows:

S1: Set the photocurrent threshold output by the sensor to K when it is cloudy, at night, or when the sensor is not facing the direction of incident sunlight at all. The photocurrents I a and I b output by the five sensors a, _b , _c , d, and e are , I _c , I _d , and I _e are all less than the threshold K, it means that it is cloudy, night, or the sensor is not facing the direction of incident sunlight at all. At this time, the orientation is set according to the PLC, and the azimuth direction stepper motor and The altitude angle stepper motor adjusts the sensor to the position of the sun in the sky in the current astronomical calendar. If it is night, it will face the east and wait for the sunrise;

S2: When the photocurrent output by one or more of the five sensors a, b, c, d, and e is greater than the output photocurrent of the remaining sensors, it means that the sunlight deviates from the main axis of the solar panel, that is, a large current is output. The part is exposed to direct sunlight, and the PLC sends instructions to drive the stepper motors in the azimuth direction and the stepper motor in the altitude direction, and starts the coarse tracking mode;

S3: First adjust the azimuth angle roughly, and compare the sum of photocurrents output by sensors a and d (I _a +I _d ) with the sum of photocurrents output by sensors b and c (I _b +I _c ). When I _a When +I _d >I _b +I _c , it means that the position of the sun is on the left side of the main axis of the solar panel. The PLC drives the azimuth stepper motor to rotate clockwise until I _a +I _d =I _b +I _c , and the sun When the position is on the right side of the main axis of the solar panel, vice versa, the coarse tracking adjustment of the coarse tracking module is completed;

It should be noted that the precision tracking module establishes a spherical coordinate system through Matlab and can directly output the coordinates of the maximum illumination surface.

S4: After the coarse tracking is completed, the main axis of the solar panel has been basically aligned with the sun, that is, the sensor e has been basically aligned with the sun at this time. At this time, the fine tracking mode is started, and the PLC controls the sensor e to perform fine tracking operations;

S5: Collect the current signals I ₁ , I _{2 , I 3 , I 4 ... I n output by each silicon photovoltaic cell 1, 2} , ₃ , ₄ ... _n in the sensor e, and convert them into voltage signals V ₁ , V ₂ , V ₃ , V ₄ ……V _n ;

S6: By comparing the voltages output by all silicon photovoltaic cells, determine the silicon photovoltaic cell with the largest output voltage, which corresponds to the position of the sun at this time. Use Matlab to determine the coordinates (Ψ, θ) of the light spot falling on the largest silicon photovoltaic cell to further drive the orientation. The angular direction stepper motor rotates to Ψ in the horizontal direction, and the height angular direction stepper motor rotates to θ;

S7: Set the photocurrent threshold range of vertically incident sunlight to the solar panel L ₁ -L ₂ , when the photocurrent output by the top photosensitive element 3 on the topmost plane is the largest, and the photocurrent output by the surrounding photosensitive element group 4 is equal or Within the set photocurrent threshold range L ₁ -L ₂ of vertically incident sunlight on the solar panel, it is considered that sunlight is vertically incident on the solar panel, and the tracking operation is completed.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and cannot be construed as limitations of the present invention. Those of ordinary skill in the art are within the scope of the present invention. Changes, modifications, substitutions and variations may be made to the above-described embodiments.

Claims (3)

1. The utility model provides a spheroid type photoelectric sensor for sun position detects, its characterized in that includes spheroid shell (1) and a plurality of photosensitive element (2), spheroid shell (1) outside comprises a plurality of adjacent face in proper order, and the central point of every face puts and all inlays and establishes and installs a photosensitive element (2), and the top photosensitive element (3) are installed on the top plane of spheroid shell (1), lean on the top planar top photosensitive element (3) periphery of spheroid shell (1) to install photosensitive element group (4).

2. A spheroid photoelectric sensor for solar position detection according to claim 1, wherein: the photosensitive element (2), the top photosensitive element (3) and the photosensitive element group (4) are all made of silicon photocells, photoresistors, photodiodes or phototriodes with the same area size and electrical characteristics.

3. A spheroid photoelectric sensor for solar position detection according to claim 2, wherein: the spheroid shell (1) is a polyhedron of a spheroid.