CN103277922A - Sunlight tracking sensor - Google Patents

Abstract

The present invention provides a solar tracking sensor, which at least includes: a light signal detector, fixed on the photovoltaic module and facing the same direction as the photovoltaic module, including: a multi-quadrant photosensitive element, with signal output terminals corresponding to each quadrant, and a light-shielding The structure is to separate the multi-quadrant photosensitive elements according to each quadrant; the controller is connected to the optical signal detector and the motor device, and is used to receive the electrical signal output by each group of output terminals of the optical signal detector After processing, the motor device is controlled by the relationship between the current values on each photosensitive element to realize the tracking of the sunlight by the photovoltaic module. The invention has low cost, simple structure, high tracking precision, is more sensitive to light rays with small incident angles, has a large precise tracking range, and can be widely used in the field of sunlight tracking.

Description

A solar tracking sensor

technical field

The invention belongs to the field of solar energy application equipment, in particular to a solar light tracking sensor.

Background technique

In the context of various energy crises, solar energy is attracting more and more attention, and solar trackers are an important part of photovoltaic equipment, and their tracking accuracy directly affects the efficiency of the entire photovoltaic system. At present, the method of tracking the sun mostly adopts the form of solar tracking and photoelectric sensor tracking. As the core component of photoelectric tracking, the photoelectric sensor has the characteristics of non-contact, fast response, low cost, light weight, reliable performance, and no electromagnetic interference. Advantages, so photoelectric tracking sensors are widely used.

However, the general photoelectric sensor often ignores the tracking range factor when ensuring high precision, resulting in the sensor often failing to search for the sun due to the small tracking range. Like the traditional light tube type, as shown in Figure 1, it consists of four-quadrant photocells and a light tube. The light tube has good shielding performance, little influence from external interference light, and high tracking accuracy. However, its tracking range is small and it cannot complete large-scale tracking. As shown in Figure 2, the traditional partition type is to directly connect the output terminals on both sides to the positive and negative input terminals of a comparator, and judge the sun position by the sign of the output value of the comparator. Although this type of tracker has a large tracking range, the design is simple The cost is low, but the tracking accuracy is very low, it is susceptible to stray light interference, and the system stability is poor.

Although some improved technologies have improved the tracking range and tracking accuracy of the sensor, they are still unsatisfactory due to reasons such as complex design and high cost. For example, Chinese patent application 00219971.8 discloses a solar tracking sensor, as shown in Figure 3, which consists of four-quadrant cells and intersecting light baffles. This design is simple in structure, but it is easily affected by stray light in terms of accuracy. Not enough, and the tracking system is not stable enough. Chinese patent application 200510120837.0 discloses a solar tracking sensor, as shown in Figure 4, which consists of four photosensitive elements, a light-reducing plate, and a box with a middle partition. Tracking, other directions need to be installed separately, the installation is not easy enough, and the circuit design is not flexible enough.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a solar tracking sensor with low cost, simple structure, high tracking accuracy, more sensitive to light rays with small incident angles, and a large precision tracking range.

In order to achieve the above purpose and other related purposes, the present invention provides a solar tracking sensor, which at least includes:

The optical signal detector is fixed on the photovoltaic module and has the same orientation as the photovoltaic module, which includes: a multi-quadrant photosensitive element with signal output terminals corresponding to each quadrant; a light-shielding structure that separates the multi-quadrant photosensitive element according to each quadrant ;

The controller is connected to the optical signal detector and the motor device, and is used for processing after receiving the electrical signals output by each group of output terminals of the optical signal detector, and the relationship between the current values on each photosensitive element The motor device is controlled to realize tracking of sunlight by the photovoltaic module.

As a preferred solution of the solar tracking sensor of the present invention, the controller can calculate the incident angle of the sun according to the signals of the photosensitive elements in each quadrant, so as to realize the adjustment of the east-west direction and north-south direction of the motor device.

As a preferred solution of the solar tracking sensor of the present invention, the controller is also connected to the photovoltaic module, and is used to control the motor device to track the sunlight after the solar tracking sensor realizes tracking of sunlight. The photovoltaic module performs a micro-motion search within a preset angle, and determines the direction of vertical incidence of sunlight by comparing the magnitude of the electrical signals output by the photovoltaic module at different angles.

As a preferred solution of the solar tracking sensor of the present invention, the multi-quadrant photosensitive element is one of an amorphous silicon solar cell, a crystalline silicon solar cell, and a photodetector.

As a preferred solution of the solar tracking sensor of the present invention, the multi-quadrant photosensitive element is divided into three quadrants, four quadrants or five quadrants at least by the light-shielding structure.

As a preferred solution of the solar tracking sensor of the present invention, the light-shielding structure is made of opaque materials, or is composed of different medium interfaces.

Further, the light-shielding structure is also provided with a filter structure for filtering sunlight irradiated to the multi-quadrant photosensitive element.

Further, the filter structure is made of optical materials, which can filter the passing sunlight into light in a certain wavelength range.

As a preferred solution of the solar tracking sensor of the present invention, the light filtering structure is in the form of a convex lens that gathers light.

As mentioned above, the present invention provides a solar tracking sensor, which at least includes: a light signal detector, fixed on the photovoltaic module and facing the same direction as the photovoltaic module, including: a multi-quadrant photosensitive element, with signal output corresponding to each quadrant terminals, and a light-shielding structure, which separate the multi-quadrant photosensitive elements according to each quadrant; the controller, connected to the optical signal detector and the motor device, is used to receive the output of each group of the optical signal detector. The output electrical signals are then processed, and the motor device is controlled by the relationship between the current values on each photosensitive element to realize the tracking of the sunlight by the photovoltaic module. The present invention has the following beneficial effects:

1) The new solar tracking sensor is low in cost, exquisite in design, simple in structure, has a large detection range, and the accurate tracking range is close to ±90°.

2) The mirror shading structure can increase the response of the photosensitive element, which makes it more sensitive to light with small incident angles and improves the tracking accuracy.

3) The application of a hemispherical filter glass cover can play a protective role, and can also reduce the influence of scattered light in different bands of sunlight. For a certain wavelength of light, the tracking and detection accuracy of the photosensitive element can be improved.

4) The light tracker can be optimized by comparing the controller with the maximum output value of the photovoltaic module, and the position of the vertical irradiation point of the sun can be quickly found through the real-time algorithm.

Description of drawings

1 to 4 respectively show the structure diagrams of four different solar tracking sensors in the prior art.

Fig. 5 is a schematic structural diagram of the light signal detector of the solar light tracking sensor of the present invention.

FIG. 6 is a schematic top view of the multi-quadrant photosensitive element of the solar tracking sensor of the present invention.

FIG. 7 is a schematic diagram showing an application structure of the solar tracking sensor of the present invention.

FIG. 8 is a schematic diagram of the workflow of the solar tracking sensor of the present invention.

Component designation description

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figure 5 to Figure 8. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

As shown in Figures 5 to 8, this embodiment provides a sunlight tracking sensor for realizing the tracking of sunlight by the photovoltaic module 40, at least including:

The optical signal detector 10 is fixed on the photovoltaic module 40 and faces the same direction as the photovoltaic module 40, and includes: a multi-quadrant photosensitive element with signal output terminals respectively corresponding to each quadrant; Quadrant photosensitive elements are separated;

The controller 20 is connected to the optical signal detector 10 and the motor device 30, and is used for processing after receiving the electrical signals output by each group of output terminals of the optical signal detector 10, and the current value on each photosensitive element The relationship among them controls the motor device to realize tracking of sunlight by the photovoltaic module. Specifically, the controller 20 first detects the signal output by the multi-quadrant photosensitive element, the signal passes through the signal amplification and signal operation processing circuit, and then the analog signal is converted into a digital signal by the analog-to-digital conversion circuit and then transmitted to the motor device 30, After the motor device 30 processes the collected signals, it controls the motor driver to complete the control work of the two stepping motors.

In this embodiment, the multi-quadrant photosensitive elements are three-quadrant photosensitive elements 101 - 103 , as shown in FIGS. 5 and 6 . Of course, in other embodiments, the multi-quadrant photosensitive element may also be four-quadrant, five-quadrant, etc., and is not limited to the several types listed here.

As an example, the controller 20 can calculate the incident angle of the sun according to the signals of the photosensitive elements in each quadrant, so as to realize the adjustment of the east-west direction and the north-south direction of the motor device 30 . Further, the controller 20 is also connected to the photovoltaic assembly 40, and is used to control the motor device 30 to adjust the photovoltaic assembly 40 at a preset angle after the sunlight tracking sensor realizes tracking of sunlight. A micro-motion search is carried out within, and the direction of the vertical incidence of sunlight is determined by comparing the magnitudes of the electrical signals output by the photovoltaic modules 40 at different angles. Since sunlight tracking sensors are generally used in high-power concentrating tracking systems, and the output value of the concentrated photovoltaic module 40 is extremely sensitive to the incident angle of sunlight, a small angle of sunlight deviating from the vertical irradiation will affect the output of the photovoltaic module 40. Therefore, at the same time, the controller 20 is used to judge the position of the maximum output value of the photovoltaic module 40, and the photovoltaic module 40 is searched in all directions to find out the position of the maximum output value of the photovoltaic module 40, so that the sunlight and the photovoltaic module 40 parallel to the vertical axis. In order to facilitate man-machine dialogue, an LCD display module can be added to display the sun position signal accordingly to improve the convenience of use.

As an example, the multi-quadrant photosensitive element is one of an amorphous silicon solar cell, a crystalline silicon solar cell, and a photodetector. Since the amorphous silicon solar cell is more sensitive to weak light signals than other photosensitive elements, in this embodiment, the multi-quadrant photosensitive element is an amorphous silicon solar cell.

As an example, the light-shielding structure 104 is made of opaque material, or is composed of interfaces of different media, such as an air-glass interface.

In this embodiment, taking the multi-quadrant photosensitive element as an example of a three-quadrant photosensitive element, the light-shielding structure 104 is a T-shaped partition, and the T-shaped partition is a mirror reflective partition, and the three-quadrant photosensitive element The components are separated by the T-shaped partitions. Of course, the position of the combined structure of the three-phenomenon photosensitive elements can be adjusted according to requirements, and the shape of the light-shielding structure 104 can be selected according to the combined structural position of the three-phenomenon photosensitive elements. , are not limited to the T-type listed here. In this embodiment, the area of each side of the T-shaped separator is equal to the area of the amorphous silicon solar cells in each quadrant, so as to calculate the angle between the solar tracking sensor and the sunlight more accurately. Further, the material of the specular reflective partition includes metal film (plate), polished substrate, glass, reflective paint, and other composite materials. In this embodiment, the T-shaped specular reflective partition completely separates the three quadrants, and the performance and size of the three-quadrant photosensitive elements are completely consistent, which is convenient for comparison of signal tracking. Response to light.

As an example, the shading structure 104 is also provided with a filter structure 105 for filtering the sunlight irradiated to the multi-quadrant photosensitive element; and a base 106 matched with the filter structure 105, the base 106 There are wiring holes corresponding to each group of signal output terminals of the multi-quadrant photosensitive element, and its specific structure is shown in FIG. 5 .

As an example, the filter structure 105 is made of optical materials, which can filter the passing sunlight into light in a certain wavelength range. The shape of the filter structure 105 is hemispherical, ellipsoid, triangular prism or five The shape of the prism may be an integrated light-shielding structure covering the light-shielding structure 104 , or may be a plurality of light-shielding structures covering each quadrant respectively.

In this embodiment, the light filtering structure 105 is a structure in the form of a convex lens that gathers light. The filter structure 105 can reduce the impact of scattered light of different wavelengths in sunlight on the detector, and the shielding of stray light can improve the tracking accuracy of the photosensitive element to the sun position. While filtering the stray light, the filter structure 105 can It can also protect the photosensitive element and improve the reliability of the device.

It should be noted that the filter structure 105 and the base 106, especially the filter structure 105 can effectively improve the function of the solar tracker of the present invention, but they are not necessary components of the present invention. Therefore, in another In an embodiment, the filter structure 105 and the base 106 can be omitted.

As shown in Figure 8, taking the multi-quadrant photosensitive element as an example of a three-quadrant photosensitive element, a specific implementation process is as follows: start the system, initialize the device and related parameters, first read the clock chip in the controller to obtain the system date And time, from 17:00 pm to 9:00 am the next day, the sun tracking sensor enters the waiting time, and the sun tracking sensor is in a balanced position; if the time is between 9:00 am and 17:00 pm, the sun tracking sensor system is normal Work; first, the control system is initialized to detect the output signal of the three-quadrant amorphous silicon battery. When the sunshine is less than the set value, the system does not work and enters the equilibrium position to wait. When the sunshine is greater than the set value, the light tracking sensor works normally and detects the signal of the three-quadrant amorphous silicon battery. Into the motor device 30, the motor device 30 controls the motor driver to complete the precise tracking work in two directions after processing the collected signal. At this time, the position of the maximum output value of the photovoltaic module 40 is detected, and the micro-motion search is performed on each direction of the photovoltaic module 40 to find the maximum output position of the photovoltaic module 40 to complete PV precision tracking. And enter the waiting time, waiting for the next tracking.

To sum up, the present invention provides a solar tracking sensor, which at least includes: a light signal detector fixed on the photovoltaic module and facing the same direction as the photovoltaic module, which includes: a multi-quadrant photosensitive element with signals corresponding to each quadrant The output terminal and the light-shielding structure are used to separate the multi-quadrant photosensitive elements according to each quadrant; the controller is connected to the optical signal detector and the motor device, and is used to receive each group of output terminals of the optical signal detector The outputted electrical signals are then processed, and the motor device is controlled by the relationship between the current values on each photosensitive element to realize tracking of sunlight by the photovoltaic module. The present invention has the following beneficial effects:

1) The new solar tracking sensor has low cost, exquisite design, simple structure, large detection range, and the precise tracking range can be close to ±90°.

2) The mirror shading structure can increase the response of the photosensitive element, which makes it more sensitive to light with small incident angles and improves the tracking accuracy.

3) The application of the hemispherical filter glass cover can not only play a protective role, but also reduce the influence of scattering and refraction of different wavelengths of sunlight in sunlight, and improve the tracking and detection accuracy of the photosensitive element for a certain wavelength band.

4) The light tracker can be optimized through the maximum output value of the controller and the photovoltaic module, and the position of the vertical irradiation point of the sun can be quickly found through the real-time algorithm.

Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (9)

1. A solar tracking sensor, characterized in that it at least comprises: The optical signal detector is fixed on the photovoltaic module and faces the same direction as the photovoltaic module, which includes: The multi-quadrant photosensitive element has signal output terminals respectively corresponding to each quadrant; a light-shielding structure, separating the multi-quadrant photosensitive elements according to each quadrant; The controller is connected to the optical signal detector and the motor device, and is used for processing after receiving the electrical signals output by each group of output terminals of the optical signal detector, and the relationship between the current values on each photosensitive element The motor device is controlled to realize tracking of sunlight by the photovoltaic module. 2 . The solar tracking sensor according to claim 1 , wherein the controller can calculate the incident angle of the sun according to the signals of the photosensitive elements in each quadrant, so as to realize the adjustment of the east-west direction and north-south direction of the motor device. 3. The solar tracking sensor according to claim 2, characterized in that: the controller is also connected to the photovoltaic module, and is used to control the solar tracking sensor after tracking the sunlight. The motor device performs a micro-motion search on the photovoltaic assembly within a preset angle, and determines the direction of vertical incidence of sunlight by comparing the magnitude of the electrical signals output by the photovoltaic assembly at different angles. 4. The sunlight tracking sensor according to claim 1, wherein the multi-quadrant photosensitive element is one of an amorphous silicon solar cell, a crystalline silicon solar cell, and a photodetector. 5 . The sunlight tracking sensor according to claim 4 , wherein the multi-quadrant photosensitive element is divided into three quadrants, four quadrants or five quadrants at least by the light-shielding structure. 6. The solar tracking sensor according to claim 5, characterized in that, the light-shielding structure is made of opaque material, or is composed of interfaces of different media. 7 . The solar tracking sensor according to claim 5 , wherein the light shielding structure is further provided with a filter structure for filtering the sunlight irradiated to the multi-quadrant photosensitive element. 7 . 8. The sunlight tracking sensor according to claim 7, characterized in that: the light filtering structure is made of optical material, which can filter the passing sunlight into light in a certain wavelength range. 9. The solar tracking sensor according to claim 7, characterized in that: the light filtering structure is a structure in the form of a convex lens that gathers light.

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