CN103197690B - A kind of solar electrical energy generation sensor of following spot - Google Patents

Abstract

The invention provides a light tracking sensor for solar power generation, which belongs to the technical field of light tracking sensors. The invention includes a sensor shell, a convex lens of the sensor, a photoresistor and a circuit board, the photoresistor is fixed on the circuit board, the convex lens of the sensor is arranged on the upper shell of the sensor shell, and the lower end of the sensor shell is fixedly connected with the circuit board. The light tracking sensor for solar power generation of the present invention has the following advantages: in the process of sensor design and control, the sun trajectory is discretized according to the "pyramid-like" suede structure on the surface of the monocrystalline silicon photovoltaic panel, and the derivation of It really quantifies the number of times of movement of chasing light generation. The motor does not need to follow the light in real time, nor does it need to blindly follow the light intermittently.

Description

A light tracking sensor for solar power generation

technical field

The invention relates to a light tracking sensor for solar power generation, belonging to the technical field of sensors.

Background technique

Photovoltaic power generation has a series of advantages such as stable performance, long equipment life, high reliability, and low maintenance. However, due to the characteristics of low solar energy density and large randomness, photovoltaic power generation systems generally require large investment and high cost.

At present, the traditional solar power generation system mainly adopts fixed installation or simply uses software algorithm to realize light tracking. Fixed-installation products cannot adjust the attitude of the solar system according to changes in the sun's position, resulting in low solar energy collection and utilization, and high long-term investment costs. However, software tracking power generation equipment that only uses geographical location and time information, because many problems in the algorithm are difficult to be considered, often cause excessive movement of solar panels or malfunction.

However, most of the few products that use sensor light tracking devices install light tracking devices on solar panels, that is, each solar panel needs to install a light tracking device, so the number of light tracking devices is large, which increases the cost. At the same time, most of the existing light-following devices adopt the continuous light-following method (that is, the sensor controls the solar panel to align with the sun in real time, which is actually unnecessary), which consumes a lot of energy and is easy to cause malfunction, which also increases the corresponding cost. cost.

In addition, most researchers design the light-tracking device as a two-axis tracking device. Although one of the motors plays a role in positioning the sun, it can be completely omitted by improving the installation method of the light-tracking system. Therefore, this two-axis tracking The cost of the method is large, and the cost performance is also low.

Contents of the invention

The purpose of the present invention is to solve the existing problems in the prior art, that is, most of the products that use sensors to track the light install the light-tracking device on the solar panel, that is, each solar panel needs to install a light-tracking device, so the light-tracking device The quantity of equipment is many, increased cost. At the same time, most of the existing light-tracking devices adopt the continuous light-tracking method, which consumes a lot of energy and is prone to misoperation, which also increases the cost accordingly. Furthermore, a tracking light sensor for solar power generation is provided.

The purpose of the present invention is achieved through the following technical solutions:

A light tracking sensor for solar power generation, comprising a sensor housing, a convex lens of the sensor, a photoresistor and a circuit board, the photoresistor is fixed on the circuit board, the convex lens of the sensor is arranged on the upper shell of the sensor housing, and the lower end of the sensor housing Fixedly connected with the circuit board; five rows of photoresistors are arranged on the circuit board, the first row of photoresistors, the second row of photoresistors, the third row of photoresistors, the fourth row of photoresistors from one side of the circuit board to the other row of photoresistors and the fifth row of photoresistors; the focal length of the convex lens of the sensor=13.2mm, a straight line perpendicular to the circuit board is provided between the convex lens of the sensor and the third row of photoresistors, and the distance between the first row of photoresistors and the straight line angle between The angle between the second row of photoresistors and the line The angle between the fourth row of photoresistors and the line The angle between the fifth row of photoresistors and the line The distance between the fifth row of photoresistors and the straight line d1=49.26mm, the distance between the fourth row of photoresistors and the straight line d2=13.2mm, the distance between the second row of photoresistors and the straight line d3=3.5mm, the first The distance d4 between the row of photoresistors and the straight line is 13.2mm.

The light-following sensor for solar power generation of the present invention has the following advantages: the track of the sun is discretized in the process of sensor design and control, and the movement times of light-following power generation are truly quantified. The motor does not need to follow the light in real time, nor does it need to blindly follow the light intermittently. At the same time, by simplifying the light tracking model, the use of one motor is reduced on the basis that at least two motors are usually required to cooperate with the control, reducing energy consumption, reducing costs, and reducing system malfunctions, thereby achieving the purpose of high efficiency and stability. And it has better compatibility with the current photovoltaic power generation device.

Description of drawings

Fig. 1 is a schematic cross-sectional structure diagram of a light tracking sensor for solar power generation;

Fig. 2 is a top view structure schematic diagram of a light tracking sensor for solar power generation;

Fig. 3 is the calculation schematic diagram of photoresistor distance;

Fig. 4 is the structural representation of solar power generation device;

Fig. 5 is a circuit diagram of a light tracking sensor for solar power generation;

Fig. 6 is a schematic diagram that all light rays can be absorbed twice on the solar cell panel when direct sunlight;

Fig. 7 is a schematic diagram that all light rays can be absorbed twice when sunlight hits the solar panel at an incident angle of 20 degrees;

Figure 8 is a schematic diagram showing that part of the light can only be absorbed once when sunlight hits the solar panel at an incident angle greater than 20 degrees;

Fig. 9 is a schematic diagram of discretizing the track of the sun into five regions (discrete sky);

Fig. 10 is a schematic diagram of an area where the included angle between sunlight and sea level is between 15 degrees and 45 degrees;

Figure 11 is a schematic diagram of the unified management of regional planning in the early morning and evening hours to regions 1 and 5;

Fig. 12 is a schematic diagram of an area where the included angle between sunlight and sea level is between 45 degrees and 75 degrees;

Fig. 13 is a schematic diagram of an area where the included angle between sunlight and sea level is between 75 degrees and 105 degrees;

Fig. 14 is a model diagram of a theoretical follow-up light generating device. It consists of two motors (day motor and season motor), respectively tracking the sun's east-rising and west-setting motion and the sun's north-south movement with the seasons.

Fig. 15 is a schematic diagram showing that the maximum incident angle in the north-south direction is 23.5 degrees when the solar panel is placed horizontally on the equator;

FIG. 16 is a schematic diagram of solar panels placed on the Tropic of Cancer at an angle of 23.5 degrees to sea level.

Figure 17 is a schematic diagram showing that the solar energy in the northern hemisphere in summer is more than that in winter, so that aa' is properly rotated to the right, and α is reduced, so that θ1 can be reduced and θ2 can be increased, so that the summer solar energy in the northern hemisphere can be better utilized.

Figure 18 is outside the Tropic of Cancer in the northern hemisphere, and then aa' is rotated to the right to make α decrease, so that θ1 can be reduced again, and θ2 can be increased again, so that the summer solar energy can be better utilized at the expense of low-density energy in winter .

Figure 19 is a simplified model diagram of a single motor.

Fig. 20 is a control flowchart of the solar power generation device.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation is provided, but the protection scope of the present invention is not limited to the following embodiments.

As shown in Fig. 1 and Fig. 2, a kind of tracking light sensor for solar power generation involved in this embodiment includes a sensor housing 1, a convex lens 2 of the sensor, a photoresistor 3 and a circuit board 4, and the photoresistor 3 is fixed on the circuit board. On the board 4 , the convex lens 2 of the sensor is arranged on the upper shell of the sensor housing 1 , and the lower end of the sensor housing 1 is fixedly connected with the circuit board 4 .

As shown in Figure 3, the circuit board 4 is provided with five rows of photoresistors 3, and from one side of the circuit board 4 to the other side are the first row of photoresistors A, the second row of photoresistors B, and the third row of photoresistors. Photoresistor C, photoresistor D in the fourth row and photoresistor E in the fifth row.

As shown in Figure 3, the focal length f=13.2mm of the convex lens 2 of the sensor, a straight line F perpendicular to the circuit board 4 is arranged between the convex lens 2 of the sensor and the third row of photoresistors C, and the first row of photoresistors A Angle with line F The angle between the second row of photoresistors B and the straight line F The angle between the fourth row of photoresistor D and the straight line F The angle between the fifth row of photoresistor E and the straight line F The distance between the fifth row of photoresistors E and the straight line F is d1=49.26mm, the distance between the fourth row of photoresistors D and the straight line F is d2=13.2mm, and the distance between the second row of photoresistors B and the straight line F is d3 =3.5mm, the distance d4 between the first row of photoresistors A and the straight line F=13.2mm.

As shown in Figure 4, the present embodiment is a solar power generation device using the above-mentioned solar power generation light tracking sensor, including a solar panel 11, a stepper motor 12, a pillar 13, a central control system 14, a base 15, an energy storage system 16, Convex lens 17, light-shielding tube 18 and light tracking sensor 19 of power generating device, described light-shielding tube 18 is fixed on one side on the base 15, and the convex lens 17 of power-generating device is fixed on the upper end of light-shielding tube 18, and the bottom in the light-shielding tube 18 is provided with Tracking light sensor 19, on the other side of base 15, support 13 is fixed, and the upper end of support 13 is fixed with stepper motor 12 and solar panel 11, and central control system 14 and energy storage system 16 are all fixed on base 15.

The tracking light sensor for solar power generation (referred to as the sensor) is a sun orientation detection device that relies on photosensitive diodes and optical devices. When a convex lens with a suitable focal length is used to focus sunlight (approximately parallel light) in the shading tube. According to the imaging principle of geometric optics, parallel light will form an effective spot at the focal plane (the bottom of the shading tube). At this time, the photosensitive sensor is properly arranged on the focal plane, and the AD sampling is performed on the sensor through the single-chip microcomputer in time-sharing, and then the sampling values are compared and sorted, and the position information of the effective light spot at this time can be obtained.

In order to improve the photoelectric conversion efficiency of monocrystalline silicon photovoltaic panels, its surface is often made into a "pyramid-like" textured structure. Using the light-trapping effect of the "pyramid-like" textured structure can reduce the reflectance of sunlight and enhance The absorption rate of sunlight, thereby improving the photogenerated current density and the conversion efficiency of photovoltaic cells.

When sunlight directly hits the ideal textured monocrystalline silicon photovoltaic panel (at this time, the incident angle of sunlight is 0 degrees), all the light can be absorbed twice (see Figure 6); increases, the sunlight keeps moving until the incident angle of the sunlight increases to 20 degrees, at this time all the light can be absorbed twice (see Figure 7); when the incident angle is greater than 20 degrees, part of the sunlight will not be absorbed After being absorbed twice, it is reflected off the surface of the single crystal silicon after being absorbed only once (see Figure 8). Therefore, for an ideal textured monocrystalline silicon photovoltaic cell panel, when the incident angle is less than or equal to 20 degrees, the light absorption rate of monocrystalline silicon has little difference. Here, we might as well call this phenomenon the "maximum tolerated incident angle of textured monocrystalline silicon photovoltaic cells", or "maximum tolerated angle" for short.

Considering that the actual suede structure may not be ideal, and the "pyramid-like" structure on its surface may have some defects, considering economic factors, the actual maximum tolerance angle is usually taken as 15 degrees.

According to the fact that the maximum tolerance angle is 15 degrees, the sky can be discretized into five regions (see Figure 9). On a fixed sea level, the sun rises from the east of the sea level and sets from the west, moving counterclockwise in Figure 8. During the two 15-degree periods when the sun is just rising and setting, that is, morning and dusk under normal circumstances, the light intensity at this time is extremely weak, and there is no need to follow the light, so these two areas are ignored.

Then, as the sun continues to move, when the angle between the sun and the sea level is between 15 degrees and 45 degrees (see Figure 10), the area is symmetrical with the thick solid line 1 in the figure, then at this time , as long as the plane of the solar panel is perpendicular to the solid line 1, the incident angle of sunlight in area 1 is always smaller than the actual maximum tolerated angle by 15 degrees. As mentioned earlier,

The early morning sunlight can be assigned to area 1 for unified management, that is, when the angle between the sunlight and the sea level is between 0 degrees and 45 degrees,

The solar panel is always perpendicular to ray 1. Similarly, the situation in area 5 can be obtained (see Figure 11).

Similarly, as the sun continues to move, we can easily get the relevant situation of areas 2, 3 and 4 (see Figure 12 and Figure 13).

In order to express this process more clearly, this process is now listed as an illustration (see Table 1)

Table 1. The process of discretizing the sky

To sum up, solar panels only need to complete five actions in a timely manner in a day to achieve the purpose of chasing light and generating electricity with high efficiency and low consumption. In other words, as long as the sensor can perceive these five areas and make corresponding actions, the task of tracking light can be completed. This is also one of the principles of the previous photoresistor distribution.

This can not only greatly improve the power generation efficiency of the solar panel, but also reduce the loss of the motor and reduce the malfunction of the motor, thereby reducing the cost of solar power generation.

The control strategy of the light-following sensor needs to be considered based on the earth model first.

When the earth is used as the reference system, the motion of the sun can be decomposed into two parts: one part is the sun's rising and setting during the day, and the other part is the sun's north-south motion with the seasons. Starting from theoretical analysis, if a solar panel that follows light to generate electricity is to follow light well, it must track these two movements. Therefore, the theoretical chasing light generation model board consists of at least two motors, one for radial rotation and one for axial rotation (see Figure 14). One of the motors is responsible for tracking the east-rising and west-setting movement of the sun during the day, here we call it the "day motor", and the other motor is responsible for tracking the north-south movement of the sun with the seasons throughout the year, here we call it the "seasonal motor" .

When a solar panel is placed horizontally on the equator (see Figure 15), according to relevant astronomical knowledge, the north-south movement of the sun in a year can only reach the Tropic of Cancer as far as it can go. Then in a year, the maximum incident angle in the north-south direction is only 23.5 degrees. Therefore, in a year, the incident angle of the north-south direction of the solar panels in this region is less than the theoretical maximum tolerance angle of 20 degrees most of the time, and the range of the actual theoretical maximum tolerance angle of 15 degrees almost contains the solar energy in a year. The vast majority of the time when the resource is most abundant. From the above analysis, it can be concluded that solar panels placed horizontally on the equator hardly need "seasonal motors" to better complete the task of chasing light and generating electricity throughout the year.

When a solar panel on the Tropic of Cancer is placed at an angle of 23.5 degrees to the sea level (see Figure 16), the same conclusion as that at the equator can still be obtained—there is no need for a "seasonal motor". In the same way, we can get the situation of the Tropic of Capricornus.

Based on the position of the equator and the position of the Tropic of Cancer, it can be concluded that the light-following power generation device within the range of the Tropic of Cancer can complete the task of light-following power generation without the need for a "seasonal motor" through reasonable installation.

When the solar panel is outside the Tropic of Cancer, because the region is rich in solar energy resources in summer, but less in winter. Therefore, the angle between the solar panel and the sea level can be properly adjusted to make better use of solar energy resources in summer. At this time, considering economic factors, it is still a wise choice to omit the "seasonal motor" (see Figure 17 and Figure 17). 18).

Based on the above analysis, when we reasonably arrange the angle between the solar panels and the sea level, we can find that the contribution rate of Nichiden Motors in the chasing solar power generation device is extremely low, and Nichiden Motors increases energy consumption and loss, which is unreasonable. Therefore, we can choose a compromise solution, as shown in Figure 19, using only one solar panel to control the solar panel to follow the light. The improved device is superior to the traditional type in terms of energy consumption, cost and steering gear control, and the improved device has a simpler structure than the traditional one.

The above are only preferred specific implementations of the present invention. These specific implementations are all based on different implementations under the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field Within the technical scope disclosed in the present invention, any changes or substitutions that can be easily conceived by a skilled person shall fall within the protection scope of the present invention.

Claims (1)

1. a solar electrical energy generation sensor of following spot, comprise sensor outer housing (1), the convex lens (2) of sensor, photoresistance (3) and circuit board (4), described photoresistance (3) is fixed on circuit board (4), the convex lens (2) of sensor are arranged in the upper body of sensor outer housing (1), and the lower end of sensor outer housing (1) is fixedly connected with circuit board (4); It is characterized in that, described circuit board (4) is provided with five row's photoresistance (3), is followed successively by first row photoresistance (A), second row photoresistance (B), the 3rd row's photoresistance (C), the 4th row's photoresistance (D) and the 5th row's photoresistance (E) from the side of circuit board (4) to opposite side; Focal distance f=the 13.2mm of the convex lens (2) of described sensor, the convex lens (2) and the 3rd of sensor are arranged and to be provided with one article of straight line (F) vertical with circuit board (4) between photoresistance (C), angle φ 1=45 ° between first row photoresistance (A) and straight line (F), angle φ 2=15 ° between second row photoresistance (B) and straight line (F), angle φ 3=45 ° between 4th row's photoresistance (D) and straight line (F), the angle φ 4=75 ° between the 5th row's photoresistance (E) and straight line (F); Distance d1=49.26mm between 5th row's photoresistance (E) and straight line (F), distance d2=13.2mm between 4th row's photoresistance (D) and straight line (F), distance d3=3.5mm between second row photoresistance (B) and straight line (F), the distance d4=13.2mm between first row photoresistance (A) and straight line (F).