Control method and system for linear actuator of photovoltaic tracking bracket

Abstract

This invention relates to a control method and system for a linear actuator of a photovoltaic tracking bracket, relating to the field of solar thermal technology. The method includes: acquiring the solar azimuth angle and solar irradiance; determining the reflection angle of a reflector based on the solar azimuth angle and the location of the heat-absorbing tower; controlling the actuator to adjust the reflector to the reflection angle to receive sunlight and acquire photovoltaic power; matching a reference power output based on the solar irradiance and the reflector area; defining the presence of a foreign object on the reflector surface based on the photovoltaic power output being less than the reference power output, controlling the actuator to tilt the reflector at a tilt angle and then resetting it, acquiring photovoltaic power output again; defining the foreign object as an attached foreign object only when the photovoltaic power output is less than the reference power output, locating the attached foreign object, and controlling the actuator to handle the attached foreign object. This application has the effect of cleaning the reflector to maximize the solar energy collection efficiency.

Description

Technical Field

[0001] This invention relates to the field of photothermal technology, and in particular to a control method and system for a linear actuator of a photovoltaic tracking bracket. Background Art

[0002] Linear actuators for photovoltaic tracking brackets are commonly used in solar thermal power generation. They are equipped with reflectors, and by driving the rotation or movement of the reflectors, the reflectors are kept at the optimal angle of incidence with the sun, thereby maximizing the efficiency of solar energy collection.

[0003] In concentrated solar power (CSP) generation, sunlight is focused and reflected by a reflector to a heat-absorbing tower, which then converts solar energy into heat for storage. To maximize solar energy collection efficiency, the reflector must maintain the optimal angle of incidence with the sun and its surface must be kept clean. However, reflectors and photovoltaic tracking brackets are typically installed in open outdoor areas, where reflectors are susceptible to dust and other contaminants. Furthermore, manual cleaning of the reflector's installation location is inconvenient, thus reducing its ability to reflect sunlight. Summary of the Invention

[0004] In order to clean the reflector and maximize the solar energy collection efficiency, the present invention provides a control method and system for a linear actuator of a photovoltaic tracking bracket.

[0005] In a first aspect, the present invention provides a control method for a linear actuator of a photovoltaic tracking bracket, employing the following technical solution:

[0006] A control method for a linear actuator of a photovoltaic tracking bracket includes:

[0007] S100: Collects solar azimuth and solar irradiance;

[0008] S101: Determine the reflection angle of the reflector based on the solar azimuth and the preset location of the heat absorption tower;

[0009] S102: Control the preset actuator to adjust the reflector to the reflection angle to receive light and collect photovoltaic power generation;

[0010] S103: Power generation benchmark based on matching solar irradiance and preset reflector area;

[0011] S104: Based on the fact that the photovoltaic power generation is less than the reference power generation, it is defined that there is a foreign object on the surface of the reflector. The actuator is controlled to tilt the reflector at a preset tilt angle and then reset it to obtain the photovoltaic power generation again.

[0012] S105: If and only if the photovoltaic power generation is less than the reference power generation, the foreign object is defined as an attached foreign object, the attached foreign object is located, and the actuator is controlled to handle the attached foreign object.

[0013] By employing the above technical solution, the system detects the power generation of the solar thermal power generation system. When a decrease in power generation is detected, it indicates the presence of foreign objects on the reflector surface. The system then analyzes the type of foreign object. By tilting the reflector to allow the foreign object to slide off, if the object does not slide off, it is considered an attached object. For attached foreign objects, the system locates and processes them. This method effectively removes foreign objects from the reflector surface, ensuring a clean reflector surface and maximizing solar energy collection efficiency.

[0014] Optionally, a temperature sensor array is provided on the back of the reflector; methods for locating foreign objects on the reflector surface include:

[0015] S200: Collects temperature values ​​at various points on the surface of the reflector and generates a surface temperature distribution map;

[0016] S201: Determine the reflection temperature region enclosed by a preset reference reflection temperature from the surface temperature distribution map;

[0017] S202: Identify and determine abnormal temperature areas outside the reflected temperature areas from the surface temperature distribution map;

[0018] S203: Remove the transition region bounded by the preset transition temperature range from the abnormal temperature region to obtain the correction region;

[0019] S204: Determine the location of the correction area on the surface of the mirror based on the surface temperature distribution map, and output the location of the area.

[0020] Optionally, the attached foreign matter includes dust and large pieces of adhesive material. Methods for distinguishing between these two different types of attached foreign matter include:

[0021] S300: Determine the extreme temperatures in the correction zone from the surface temperature distribution map;

[0022] S301: Determine whether the extreme temperature is greater than the reference reflection temperature;

[0023] S3011: When the extreme temperature is greater than the reference reflection temperature, the correction area is defined as the high temperature correction area. The foreign matter attached in the high temperature correction area is dust. The dust on the surface of the reflector is removed by the preset dust removal method.

[0024] S3012: When the extreme temperature is not greater than the reference reflection temperature, the correction area is defined as the low temperature correction area. The foreign matter attached in the low temperature correction area is a large piece of adhesive. The adhesive on the surface of the reflector is removed by the preset adhesive removal method.

[0025] Optionally, the actuator is equipped with a water collection box, and the edge of the reflector has a water groove; dust removal methods include:

[0026] S400: Identify and determine the location of all high-temperature correction areas on the surface of the mirror by analyzing the surface temperature distribution map.

[0027] S401: Connect all high-temperature areas using a preset path planning method to form a flushing path, with the end of the flushing path closest to the water tank as the starting point;

[0028] S402: Connect the starting point of the flushing path to the preset water tank to form a water guiding path;

[0029] S403: The water guiding state position of guiding water in the water tank into the water guiding path based on water guiding path matching;

[0030] S404: Dynamic attitude change information of the reflector as the water flows along the flushing path based on the flushing path matching;

[0031] S405: The controller adjusts the reflector from the reflection angle to the preset water-taking position so that the water tank of the reflector is rotated and extended into the water collection box to take water;

[0032] S406: After the reflector completes water intake, the controller adjusts the reflector from the water intake state to the water guiding state, and uses attitude dynamic change information to control the reflector to adjust its attitude so as to drive the water flow along the flushing path to flush away the dust in the flushing path.

[0033] Optional, also includes:

[0034] S500: Calculate the difference between the extreme temperature and the reference reflection temperature at each high-temperature region location, and define it as the high-temperature difference;

[0035] S501: Determine the dust thickness at the location of the high-temperature area based on the temperature difference;

[0036] S502: Matching water flow velocity when water passes through a high-temperature area based on dust thickness;

[0037] S503: The tilt angle of the reflector is matched based on the water flow velocity;

[0038] S504: When the water flows through each high-temperature zone, the actuator adjusts the elevation angle of the reflector according to the tilt angle to control the speed of the water flow when passing through the high-temperature zone.

[0039] Optionally, water stains on the surface of the reflector need to be dried. Methods for drying water stains include:

[0040] S600: Controls the reflector to rotate horizontally around the actuator as the rotation center at a preset circumferential rotation speed, and obtains the rotational wind force of the reflector in each circumferential direction;

[0041] S601: Based on the reference wind force matched with the circumferential rotation speed and the reflector area;

[0042] S602: Determine whether the rotating wind force is consistent with the reference wind force;

[0043] S6021: When the rotating wind force is consistent with the reference wind force, continue to rotate the reflector horizontally at a circular rotation speed;

[0044] S6022: When the rotating wind force is inconsistent with the reference wind force, the rotating wind force is analyzed to determine the maximum pressure, and the wind direction is determined based on the maximum pressure;

[0045] S60221: Calculate the difference between the maximum pressure and the reference wind force, which is defined as the wind force difference;

[0046] S60222: If and only if the wind force difference is greater than the reference wind force, the control actuator will adjust the reflector to face the wind direction and rotate at a preset rotation speed.

[0047] Optionally, methods for removing adhesive residues include:

[0048] S700: Identify and determine the location of the low-temperature correction area on the surface of the mirror from the surface temperature distribution map;

[0049] S701: Connect the low-temperature area to the water tank to form an immersion path;

[0050] S702: Heat the water in the water collection box and control the actuator to adjust the reflector from the reflection angle to the water intake position so that the water tank of the reflector is rotated and extended into the water collection box to obtain hot water;

[0051] S703: After the reflector completes water intake, the actuator is controlled to adjust the reflector from the water intake state position to the water guiding state position so as to guide the hot water into the wetting path to wet the adhering material and reduce the adhesion force.

[0052] S704: Using a concentrated heating method, adjacent mirrors are used to concentrate heat on the adhesive in the low-temperature region to dry the adhesive;

[0053] S705: Controls the actuator to vibrate the reflector with a preset vibration force to shake off the adhering material.

[0054] Optionally, the concentrated heating method includes:

[0055] S800: Identify the location and contour of low-temperature regions from the surface temperature distribution map;

[0056] S801: The low-temperature region outline is rasterized based on the preset spot area, and the area of ​​each grid is no larger than the spot area.

[0057] S802: Determine the relative height of each grid cell based on the water guiding status position, and number each grid cell from low to high relative height to obtain the focusing number;

[0058] S803: Concentrating heating path is formed based on the concentrator number;

[0059] S804: Determine the focusing angle of adjacent reflectors based on the focusing heating path and solar azimuth angle;

[0060] S805: Controls adjacent actuators to adjust the angle of the reflector at a focusing angle to dry the adhesive along the focusing heating path.

[0061] Secondly, this application provides a control system for a linear actuator of a photovoltaic tracking bracket, which adopts the following technical solution:

[0062] A control system for a linear actuator of a photovoltaic tracking bracket includes:

[0063] The data acquisition module is used to acquire solar azimuth angle, solar irradiance, photovoltaic power generation, temperature values ​​at various points on the surface of the reflector, and wind force during the rotation of the reflector in various circumferential directions.

[0064] A memory used to store the program for the control method of the linear actuator of the photovoltaic tracking bracket;

[0065] The processor and the program in the memory can be loaded and executed by the processor to implement the control method of the linear actuator of the photovoltaic tracking bracket.

[0066] In summary, this application includes at least one of the following beneficial technical effects:

[0067] The system monitors the power output of the concentrated solar power (CSP) system. If a decrease in power output is detected, it indicates the presence of foreign matter on the reflector surface. The system then analyzes the type of foreign matter. By tilting the reflector to allow the foreign matter to slide off, if it doesn't slide off, the foreign matter is considered attached. For attached foreign matter, the system locates and processes it. This method effectively removes foreign matter from the reflector surface, ensuring a clean reflector surface and maximizing solar energy collection efficiency.

[0068] The system uses a temperature sensor to obtain the surface temperature of the reflector. When the temperature is higher than the reference reflection temperature, the foreign object is dust. The system locates the position of all dust and controls the water tank of the reflector to draw water from the water collection box and wash all the dust along the flushing path, thereby removing the dust from the surface of the reflector. During the process of cleaning the dust with water, the water can cool the reflector at the dust location to eliminate the deformation of the reflector surface caused by the temperature rise, so that the reflector can accurately reflect sunlight to the heat absorption tower to maximize the solar energy collection efficiency.

[0069] The system uses a temperature sensor to obtain the surface temperature of the reflector. When the temperature is lower than the reference reflection temperature, the foreign object is considered an adhesive. The system locates the adhesive, then heats the water in the collection box and directs the hot water to the location of the adhesive, thereby reducing the adhesion between the adhesive and the reflector. The system then controls adjacent reflectors to concentrate sunlight and heat the adhesive location for drying. Finally, vibration shakes the adhesive off the reflector surface. The process of wetting the adhesive with hot water eliminates the deformation of the reflector surface caused by cooling, allowing the reflector to accurately reflect sunlight to the heat absorption tower, thus maximizing the solar energy collection efficiency. Attached Figure Description

[0070] Figure 1 This is a schematic diagram of the control method for the linear actuator of the photovoltaic tracking bracket according to an embodiment of the present invention;

[0071] Figure 2 This is a flowchart of the control method for the linear actuator of the photovoltaic tracking bracket according to an embodiment of the present invention;

[0072] The parts referred to by the numbers in the above attached diagrams are as follows: 1. Reflector; 2. Actuator; 3. Water tank; 4. Water collection box. Detailed Implementation

[0073] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0074] Reference Figure 1 This application discloses a control method for a linear actuator of a photovoltaic tracking bracket. The system determines whether there are foreign objects attached to the reflector 1 and determines the location of the foreign objects by detecting the photovoltaic power generation. Then, the system draws water from the water collection box 4 installed on the actuator 2 through the water tank 3 on the reflector 1 and flushes the foreign objects on the reflector 1 to remove them.

[0075] Reference Figure 2 A control method for a linear actuator of a photovoltaic tracking bracket includes the following steps:

[0076] Step S100: Collect solar azimuth and solar intensity.

[0077] The solar azimuth angle refers to the position of the sun in the sky. Solar intensity refers to the intensity of sunlight received by reflector 1 when it is directly facing the sun; it is also the maximum intensity of ambient light.

[0078] Both the solar azimuth angle and solar intensity can be detected by a photosensitive sensor. The photosensitive sensor detects the light intensity around the sun and determines the direction with the strongest light intensity. This direction is the solar azimuth angle, and the light intensity at this direction is the solar intensity.

[0079] Step S101: Determine the reflection angle of reflector 1 based on the solar azimuth angle and the preset location of the heat absorption tower.

[0080] The absorption tower is used to absorb sunlight reflected by reflector 1, thereby generating heat energy. The location of the absorption tower is the position where it is installed.

[0081] The reflection angle refers to the angle at which the reflector 1 can reflect sunlight to the heat absorption tower.

[0082] Once the solar azimuth and the location of the absorption tower are determined, the reflection angle of mirror 1 can be determined according to the principle of light reflection, where the incident angle equals the reflection angle.

[0083] Step S102: Control the preset actuator 2 to adjust the reflector 1 to the reflection angle to receive the light and obtain the photovoltaic power generation.

[0084] Reflector 1 is mounted on top of actuator 2, which controls the rotation of reflector 1 to adjust its orientation. Once the reflection angle is determined, the system controls actuator 2 to adjust reflector 1 to the desired angle to reflect sunlight onto the heat absorption tower.

[0085] Photovoltaic power generation refers to the power of a heat-absorbing tower after receiving sunlight and converting it into heat energy to generate electricity. The heat-absorbing tower is equipped with a power measuring instrument, and the system can directly read the photovoltaic power generation from the power measuring instrument.

[0086] Step S103: Match the power generation benchmark based on the solar irradiance and the preset reflector area.

[0087] The area of ​​reflector 1 is a fixed dimension parameter of reflector 1, which is determined during installation and will not be described in detail here.

[0088] The reference power generation refers to the power generation of the heat absorption tower when it reflects sunlight of maximum intensity under the condition that the surface of reflector 1 is clean.

[0089] The reference power generation is obtained by inputting the solar irradiance and the area of ​​reflector 1 into a preset power table and then looking it up. The power table is obtained in advance by technicians through test measurements and contains a one-to-one correspondence between solar irradiance, reflector 1 area, and reference power generation, which will not be elaborated here.

[0090] Step S104: Based on the fact that the photovoltaic power generation is less than the reference power generation, it is defined that there is a foreign object on the surface of the reflector 1. The actuator 2 is controlled to tilt the reflector 1 at a preset tilt angle and then reset it, and the photovoltaic power generation is obtained again.

[0091] If, under sufficient sunlight, the photovoltaic power generation is not less than the reference power generation, it indicates that the surface of reflector 1 is relatively clean and no cleaning is required. However, if the photovoltaic power generation is less than the reference power generation, it indicates that there may be foreign objects on the surface of reflector 1, thus affecting the reflection of sunlight by reflector 1.

[0092] To determine whether a foreign object is attached to the surface of reflector 1, the system controls actuator 2 to tilt reflector 1 at a tilt angle, and then reset it. If the foreign object is not attached to the surface of reflector 1 during the tilting process, it will fall off. The tilt angle is a parameter preset by technicians; foreign objects on reflector 1 will fall off when it is tilted, which will not be elaborated further here. Whether the foreign object has fallen off is determined by re-testing the photovoltaic power generation.

[0093] Step S105: If and only if the photovoltaic power generation is less than the reference power generation, the foreign object is defined as an attached foreign object, the attached foreign object is located, and the actuator 2 is controlled to process the attached foreign object.

[0094] If the photovoltaic power generation is not less than the reference power generation at this time, it indicates that the foreign object has fallen off and is not an attached object. If the photovoltaic power generation is still less than the reference power generation at this time, it indicates that the foreign object has not fallen off and is attached to the surface of reflector 1. For this type of foreign object, the system first locates it and then processes it. The location and processing methods for attached foreign objects are not described in detail here, but will be introduced in detail in subsequent embodiments.

[0095] The method for locating foreign objects on the surface of mirror 1 includes the following steps:

[0096] Step S200: Collect the temperature values ​​at various points on the surface of mirror 1 and form a surface temperature distribution map.

[0097] A surface temperature distribution map refers to a temperature distribution image formed by the continuous temperature of all points on the surface of reflector 1. The temperature value of each point on the surface of reflector 1 is acquired by temperature sensors located on the back of reflector 1. Temperature sensors are arranged in a dot matrix array on the back of reflector 1, enabling the analysis of the temperature of each point on the surface of reflector 1.

[0098] Step S201: Determine the reflection temperature region enclosed by the preset reference reflection temperature from the surface temperature distribution map.

[0099] The reference reflection temperature refers to the temperature of the surface of mirror 1 when it reflects sunlight under clean conditions. It is determined in advance by technicians and will not be elaborated here.

[0100] The reflection temperature region refers to the area on the surface of mirror 1 where the temperature is the reference reflection temperature.

[0101] The reflection temperature region is obtained by analyzing all reference reflection temperature regions from the surface temperature distribution map.

[0102] Step S202: Identify and determine abnormal temperature areas outside the reflective temperature areas from the surface temperature distribution map.

[0103] When a foreign object is present on the surface of mirror 1, the surface temperature of mirror 1 at the location of the foreign object differs from the ambient temperature. The ambient temperature is the reference reflection temperature, while the temperature at the location of the foreign object may be higher or lower than the reference reflection temperature.

[0104] The abnormal temperature region is the area where the foreign object is located. The abnormal temperature region and the reflected temperature region merge to form the entire surface of mirror 1. Therefore, the abnormal temperature region is obtained by removing the reflected temperature region from the surface temperature distribution map.

[0105] Step S203: Remove the transition region enclosed by the preset transition temperature range from the abnormal temperature region to obtain the correction region.

[0106] Because temperature changes continuously, there are transition zones at the edges of abnormal temperature areas, where temperatures continuously change from high to low or vice versa. These transition zones are outside the coverage area of ​​foreign matter and need to be removed. The transition temperature range is determined by technicians based on the temperature range of the transition zone measured in experiments, offset to both sides from the reference reflection temperature; this will not be elaborated upon here. The correction zone is the area remaining after removing the transition zone from the abnormal temperature area; this area is within the coverage area of ​​the foreign matter.

[0107] Once the abnormal temperature region is determined, the transitional region within the abnormal temperature range is removed based on the temperature distribution within the abnormal temperature region, and the remaining region is the correction region.

[0108] Step S204: Determine the location of the correction area on the surface of mirror 1 based on the surface temperature distribution map, and output the location of the area.

[0109] The area location refers to the actual position of the correction area on the surface of mirror 1, that is, the actual position of the foreign object on the surface of mirror 1. After determining the correction area based on the temperature distribution, the location of the correction area is then analyzed from the surface temperature distribution map.

[0110] Adhering foreign matter includes dust and large pieces of adhesive material. The method for distinguishing between the two different types of adhered foreign matter includes the following steps:

[0111] Step S300: Determine the extreme temperatures in the correction zone from the surface temperature distribution map.

[0112] The extreme temperature refers to the temperature value in the corrected area that deviates most from the reference reflection temperature. Once the corrected area is determined, its temperature is analyzed from the surface temperature distribution map to obtain the extreme temperature. Due to the different physical properties of dust and adhering substances on mirror 1, the extreme temperature may be higher or lower than the reference reflection temperature.

[0113] Step S301: Determine whether the extreme temperature is greater than the reference reflection temperature.

[0114] By determining the relationship between the extreme temperature and the reference reflection temperature, it can be determined whether the foreign matter attached to the reflector 1 is dust or adhesive.

[0115] Dust particles are small and inherently absorb light, with an absorption rate typically higher than that of the surface of mirror 1. When light passes through the dust layer, some of its energy is absorbed and converted into heat. This heat is then conducted to the surface of mirror 1, causing its temperature to rise.

[0116] If the adhesive is large, sunlight cannot easily pass through it. In this case, the adhesive blocks the sunlight, making the area below the adhesive dark and the temperature lower.

[0117] Step S3011: When the extreme temperature is greater than the reference reflection temperature, the correction area is defined as the high temperature correction area. The foreign matter attached in the high temperature correction area is dust. The dust on the surface of the reflector 1 is removed by the preset dust removal method.

[0118] If the extreme temperature is greater than the reference reflection temperature, it indicates that the foreign matter attached to the correction area is dust. In this case, the correction area is marked as a high-temperature correction area for subsequent system processing. For dust in the high-temperature correction area, the system will use a dust removal method to remove dust from the surface of the reflector 1. The dust removal method will not be described in detail here, but will be introduced in detail in subsequent embodiments.

[0119] Step S3012: When the extreme temperature is not greater than the reference reflection temperature, the correction area is defined as the low temperature correction area. The foreign matter attached in the low temperature correction area is a large piece of adhesive. The adhesive on the surface of the reflector 1 is removed by the preset adhesive removal method.

[0120] If the extreme temperature is not greater than the reference reflection temperature, it indicates that the foreign matter attached to the correction area is a large piece of adhesive. This large piece of adhesive blocks sunlight, thus lowering the temperature. The system will mark this correction area as a low-temperature correction area for subsequent processing. For adhesives within the low-temperature correction area, the system uses an adhesive removal method to remove them. This method will not be detailed here but will be described in detail in subsequent embodiments.

[0121] Dust removal methods include the following steps:

[0122] In this embodiment, the actuator 2 is equipped with a water collection box 4, which can collect and store rainwater during rainy days. The edge of the reflector 1 has a water trough 3. When it is necessary to clean the dust on the surface of the reflector 1, the system draws water from the water collection box 4 through the water trough 3 on the edge of the reflector 1 and uses it to rinse the dust.

[0123] Step S400: Identify and determine the location of all high-temperature correction areas on the surface of mirror 1 from the surface temperature distribution map.

[0124] The high-temperature area refers to the actual location on mirror 1 that is covered with dust. The temperature of the dust-covered area is higher than that of the area that is not covered by dust.

[0125] Once all high-temperature correction areas have been screened and confirmed, image analysis of the high-temperature correction areas from the surface temperature distribution map can determine the location of the high-temperature areas.

[0126] Step S401: Connect all the high-temperature areas using a preset path planning method to form a flushing path, with the end of the flushing path closest to the water tank 3 as the starting point.

[0127] The flushing path refers to the path of the water flow when the water in the water collection box 4 flushes the dust in the high-temperature area.

[0128] Once the locations of all high-temperature zones are determined, data simulation is performed based on the location of each high-temperature correction zone. A path planning method is then used to connect all the high-temperature zone locations to obtain the flushing path. The path planning method is as follows: all high-temperature zone locations are arranged from highest to lowest ground height. Starting from the location with the highest ground height, all high-temperature zone locations are connected one by one to obtain the optimal path. In this path, water tank 3 is located at the end of reflector 1 with the highest ground height.

[0129] Step S402: Connect the starting point of the flushing path to the preset water tank 3 to form a water guiding path.

[0130] The water guiding path refers to the path of water flow when water in the water tank 3 is directed into the flushing path. The water guiding path is the shortest line segment connecting the starting point of the flushing path and the water tank 3.

[0131] Step S403: Based on the water guiding path matching, guide the water in the water tank 3 to the water guiding state position of the water guiding path.

[0132] The water guiding state position refers to the position of the reflector 1 when the water in the water tank 3 is discharged from the water tank 3 and flows into the water guiding path.

[0133] Water can flow along the water guiding path if the vertical plane containing the water guiding path is perpendicular to the surface of mirror 1. Based on this condition, once the water guiding path is determined, the water guiding state position of mirror 1 can be determined through the water guiding path, provided that the surface of mirror 1 is perpendicular to the vertical plane containing the water guiding path.

[0134] Step S404: Based on the dynamic change information of the attitude of the reflector 1 when the water flows along the flushing path, the flushing path is matched.

[0135] The attitude dynamic change information refers to the real-time attitude information of the reflector 1 when the water flows along the flushing path.

[0136] The method for determining the dynamic attitude change information is similar to the method for determining the water guiding state position in step S403. The difference is that the water guiding path is a straight line, while the flushing path can be regarded as multiple broken line segments connecting the positions of various high-temperature areas. The method for determining the dynamic attitude change information of the line segment path between two adjacent high-temperature areas is the same as the method for determining the water guiding path. Therefore, the flushing path is divided into multiple line segments, and the dynamic attitude change information of the reflector 1 is determined segment by segment.

[0137] Step S405: Control actuator 2 to adjust reflector 1 from the reflection angle to the preset water intake position so that the water tank 3 of reflector 1 is rotated and extended into water collection box 4 to take water.

[0138] The water intake position refers to the angular position of the reflector 1 when the water tank 3 of the reflector 1 is taking water from the water collection box 4. This position is preset by the technicians and will not be elaborated here.

[0139] When it is determined that there is dust on the surface of the reflector 1, the system control actuator 2 adjusts the reflector 1 from the angle of receiving sunlight to the water intake position. At this time, the water tank 3 of the reflector 1 can take out a portion of water from the water collection box 4.

[0140] Step S406: After the reflector 1 completes water intake, the actuator 2 controls the reflector 1 to adjust from the water intake state to the water guiding state, and controls the reflector 1 to adjust its attitude based on the attitude dynamic change information to drive the water flow along the flushing path to flush away the dust in the flushing path.

[0141] After the reflector 1 takes water from the water collection box 4, the system controls the actuator 2 to adjust the reflector 1 to the water guiding position. At this time, the water can flow out of the water tank 3 and into the water guiding path. Then, the system controls the actuator 2 to adjust the attitude of the reflector 1 in real time according to the dynamic change information of the attitude, so that the water can flow along the flushing path. During the water flow, the dust on the flushing path can be washed away.

[0142] The dust removal method also includes the following steps:

[0143] In this embodiment, the dust on the surface of the reflector 1 has different thicknesses, which require treatment by using different water flow rates.

[0144] Step S500: Calculate the difference between the extreme temperature and the reference reflection temperature at each high-temperature region location, and define it as the high-temperature difference.

[0145] The extreme temperatures at high-temperature zones correspond to the areas with the thickest dust. By calculating the temperature difference between the extreme temperatures and the reference reflection temperature, the dust accumulation at each high-temperature zone can be determined.

[0146] Step S501: Determine the dust thickness at the location of the high-temperature area based on the high temperature difference.

[0147] Within a certain thickness range, the thicker the dust, the higher the temperature of the high-temperature area of ​​the reflector 1, and the greater the temperature difference. The two are directly proportional, so the dust thickness can be determined by the temperature difference.

[0148] Step S502: Match the water flow velocity when the water flows through the high-temperature area based on the dust thickness.

[0149] In areas with thicker dust, the water flow rate needs to be reduced to accumulate more water flow while impacting the dust. Therefore, the water flow rate is inversely proportional to the dust thickness. The dust thickness can be used to determine the water flow rate when passing through high-temperature areas.

[0150] Step S503: Match the tilt angle of mirror 1 based on the water flow velocity.

[0151] The tilt angle refers to the real-time tilt angle of reflector 1 as the water flows along the flushing path. The tilt angle is directly proportional to the water flow velocity; the greater the water flow velocity, the greater the required tilt angle of reflector 1.

[0152] Step S504: When the water flows through each high-temperature zone, the actuator 2 adjusts the elevation angle of the reflector 1 according to the tilt angle to control the speed of the water flow when it passes through the high-temperature zone.

[0153] When dealing with dust of varying thicknesses, the tilt angle of reflector 1 needs to be adjusted according to the dust thickness, thereby changing the water flow speed. As the water flows along the flushing path, the system controls actuator 2 to adjust the attitude of reflector 1 in real time according to the tilt angle, thus changing the water flow speed to flush dust of different thicknesses.

[0154] The water stains on the surface of mirror 1 need to be dried. The water stain drying method includes the following steps:

[0155] In this embodiment, the actuator 2 is a multi-axis device, and the reflector 1 can revolve 360 ​​degrees around the actuator 2 as the rotation center, and can also rotate around itself as the center.

[0156] Step S600: Control the reflector 1 to rotate horizontally around the actuator 2 as the rotation center at a preset circumferential rotation speed, and obtain the rotational wind force of the reflector 1 in each circumferential direction.

[0157] The circumferential rotation speed is the rotation speed of the reflector 1 when it revolves, as set by the technicians, and will not be elaborated here.

[0158] Rotational wind force refers to the magnitude of the wind force experienced by reflector 1 during its revolution. This rotational wind force includes the effect of wind generated by the revolution itself and the effect of wind forces present in the environment. The rotational wind force can be acquired by a pressure sensor mounted on actuator 2. When reflector 1 rotates horizontally in the circumferential direction, the pressure sensor collects pressure information in real time, thus obtaining the rotational wind force of reflector 1 in all circumferential directions.

[0159] Step S601: Match the reference wind force based on the circumferential rotation speed and the area of ​​reflector 1.

[0160] The reference wind force refers to the wind force generated by the revolution of reflector 1 in the absence of ambient wind.

[0161] The reference wind force can be obtained by looking up the circular rotation speed and the area of ​​reflector 1 in a preset force table. The force table was obtained in advance by technicians through experimental measurements, and will not be described in detail here.

[0162] Step S602: Determine whether the rotating wind force is consistent with the reference wind force.

[0163] The presence of ambient natural wind is determined by checking whether the rotating wind force matches the reference wind force. The presence of ambient natural wind will affect the system's drying method for reflector 1.

[0164] Step S6021: When the rotating wind force is consistent with the reference wind force, continue to rotate the reflector 1 horizontally at a circular rotation speed.

[0165] If the rotating wind force is consistent with the reference wind force, it means that there is no wind in the external environment at this time, and the water stains on the surface of the reflector 1 cannot be dried by the natural wind. At this time, the actuator 2 is continued to drive the reflector 1 to rotate horizontally to generate wind force, thereby drying the surface of the reflector 1.

[0166] Step S6022: When the rotating wind force is inconsistent with the reference wind force, analyze the rotating wind force to determine the maximum pressure, and determine the wind direction based on the maximum pressure.

[0167] If the rotating wind force is inconsistent with the reference wind force, it indicates that there is ambient natural wind. When ambient natural wind is present, its magnitude needs to be measured to determine whether it is sufficient to dry the surface of reflector 1.

[0168] When there is ambient natural wind, the rotational wind force experienced by reflector 1 during its horizontal circumferential rotation is not the same in different directions. By analyzing the rotational wind force, the maximum wind force can be determined. When reflector 1 is facing the direction of the wind, the rotational wind force is at its maximum. Therefore, based on the circumferential position of the maximum wind force within the rotational wind force, the wind direction can be determined, which is the direction of the ambient natural wind.

[0169] Step S60221: Calculate the difference between the maximum pressure and the reference wind force, which is defined as the wind force difference.

[0170] Wind force difference refers to the strength of the ambient natural wind. Wind force difference is the difference between the maximum pressure and the reference wind force.

[0171] Step S60222: If and only if the wind force difference is greater than the reference wind force, the control actuator 2 adjusts the reflector 1 to face the wind direction and rotates at a preset rotation speed.

[0172] By comparing the wind force difference with the reference wind force, if the wind force difference is not greater than the reference wind force, it means that the ambient natural wind force is small and not as strong as the wind force generated when the reflector 1 revolves. In this case, the ambient natural wind is not used to dry the surface of the reflector 1. Instead, the actuator 2 is controlled to drive the reflector 1 to rotate horizontally to generate wind force, thereby drying the surface of the reflector 1.

[0173] If the wind difference is greater than the reference wind force, it indicates that the ambient natural wind is stronger than the wind generated by the revolution of reflector 1. Therefore, when this occurs, the system controls actuator 2 to rotate reflector 1 towards the wind direction, allowing the ambient natural wind to blow across the surface of reflector 1. Furthermore, during this process, the system controls actuator 2 to drive reflector 1 to rotate at its own rotational speed, thus drying the water on its surface. The rotational speed is a control parameter of actuator 2 preset by technicians and will not be elaborated upon here.

[0174] The method for removing adhesive residue includes the following steps:

[0175] Step S700: Identify and determine the location of the low-temperature correction area on the surface of the mirror from the surface temperature distribution map.

[0176] The low-temperature region refers to the actual location on mirror 1 covered with adhesive. The temperature of mirror 1 below the adhesive is lower than the area not covered by the adhesive. The method for determining the location of the low-temperature region is the same as in step S400, and will not be repeated here.

[0177] Step S701: Connect the low-temperature area to the water tank 3 to form an immersion path.

[0178] The wetting path refers to the flow path of water when it is introduced from the water tank 3 into the low-temperature zone. The wetting path is the shortest line segment connecting the low-temperature zone and the water tank 3.

[0179] Step S702: Heat the water in the water collection box 4, and control the actuator 2 to adjust the reflector 1 from the reflection angle to the water intake position so that the water tank 3 of the reflector 1 can be rotated and inserted into the water collection box 4 to obtain hot water.

[0180] In this embodiment, for the adhesive adhering to the surface of the reflector 1, the system controls the water tank 3 of the reflector 1 to obtain hot water from the water collection box 4, and then uses the hot water to treat the adhesive. The water collection box 4 originally contains cold water. The method of obtaining hot water is: by analyzing the position of the water collection box 4, the state position of the adjacent reflector 1 is determined, and the adjacent reflector 1 is controlled to focus sunlight into the water collection box 4 to heat the water.

[0181] Step S703: After the reflector 1 completes water intake, the actuator 2 is controlled to adjust the reflector 1 from the water intake state position to the water guiding state position so as to guide the hot water into the wetting path to wet the adhesive and reduce the adhesion force.

[0182] After the water tank 3 of the reflector 1 receives hot water from the water collection box 4, the system controls the reflector 1 to adjust to the water guiding position so that the hot water in the water tank 3 is directed to the wetting path and flows to the adhesive in the low-temperature correction area. After the adhesive is wetted by the hot water, the adhesion between the adhesive and the reflector 1 is reduced.

[0183] Step S704: Use a concentrated light heating method to control the adjacent reflector 1 to concentrate light on the adhesive in the low temperature region to dry the adhesive.

[0184] After the adhesive is soaked in hot water, the system uses a focused heating method to control the adjacent reflector 1 to heat and dry the adhesive. Under the dual effects of soaking and drying, the physical properties of the adhesive can change, thereby further reducing the adhesive force. The focused heating method will not be described in detail here, but will be described in detail in subsequent embodiments.

[0185] Step S705: Control the actuator 2 to vibrate the reflector 1 with a preset vibration force to shake off the adhering material.

[0186] Actuator 2 includes a telescopic structure. By controlling actuator 2 to reciprocate, a vibration effect can be generated. The vibration intensity is the magnitude of the vibration generated by actuator 2 as set by the technician, which will not be elaborated here.

[0187] After the adhesive has been dried, the system finally shakes off the adhesive from the surface of the reflector 1 by controlling the actuator 2 to vibrate.

[0188] The concentrated heating method includes the following steps:

[0189] Step S800: Identify the location of the low-temperature region from the surface temperature distribution map and determine the outline of the low-temperature region.

[0190] The low-temperature region outline is the contour of the low-temperature region's location, which is the surface contour of the adhered material. Once the location of the low-temperature region is determined, image analysis of the low-temperature region's location is performed from the surface temperature distribution map. Based on the temperature value changes within the image, the low-temperature region outline can be determined.

[0191] Step S801: Based on the preset spot area, the low-temperature region outline is rasterized, and the area of ​​each grid is no larger than the spot area.

[0192] In this embodiment, the system uses adjacent reflectors 1 to focus and heat the adhesive. The area of ​​the focused light spot is the size of the light spot generated by the adjacent reflectors 1 as set by the technician, and will not be elaborated here.

[0193] To ensure that the sunlight reflected by adjacent reflectors 1 can heat every location within the low-temperature region outline, the system grids the low-temperature region outline, allowing the light spot to heat each grid sequentially, thereby achieving the effect of heating all areas within the low-temperature region outline. The area of ​​each grid is no larger than the area of ​​the focused light spot so that the light spot can completely cover the location within each grid.

[0194] Step S802: Determine the relative height of each grid cell based on the water guiding status position, and number each grid cell from low to high relative height to obtain the focusing number.

[0195] Since the reflector 1 wets the adhesive in the water-guiding state position, the subsequent drying process of the adhesive does not change the state position of the reflector 1. Therefore, the position of each grid is determined by the reflector 1 in the water-guiding state position.

[0196] The relative height of each grid cell refers to the height of each grid cell relative to the ground, used to compare the height differences between adjacent grid cells.

[0197] The spotlight numbering refers to the numbering obtained by arranging the grid in ascending order of relative position, which is the order in which the light spots are concentrated and dried.

[0198] Step S803: Form a concentrating heating path based on the concentrating number.

[0199] The concentrating heating path refers to the movement path of the sunlight spot reflected by the adjacent reflector 1 on the adhesive, and the sunlight spot dries the adhesive along the concentrating heating path.

[0200] Once the number of each grid is determined, the grids are connected in the order of their spotlight numbers to obtain the spotlight heating path.

[0201] Step S804: Determine the focusing angle of the adjacent reflector 1 based on the focusing heating path and the solar azimuth angle.

[0202] The concentrating angle refers to the angular position at which adjacent reflectors 1 can reflect sunlight onto the concentrating heating path. Based on the principle of reflected light, the angle of incidence equals the angle of reflection, thus the concentrating angle can be determined based on the location of the concentrating heating path and the solar azimuth. The concentrating angle is a variable and needs to change according to the changes in the concentrating heating path.

[0203] Step S805: Control the adjacent actuator 2 to adjust the angle of the reflector 1 at the focusing angle so as to dry the adhesive along the focusing heating path.

[0204] Once the focusing angle of the adjacent reflector 1 is determined, the system controls the adjacent reflector 1 to adjust its position in real time according to the focusing angle, so as to reflect and focus sunlight onto the adhesive, thereby drying the adhesive.

[0205] Based on the same inventive concept, embodiments of the present invention provide a control system for a linear actuator of a photovoltaic tracking bracket, comprising:

[0206] The acquisition module is used to acquire solar azimuth angle, solar irradiance, photovoltaic power generation, temperature values ​​at various points on the reflector surface, and wind force during the reflector's rotation in various circumferential directions.

[0207] The memory is used to store the program for the control method of the linear actuator of the photovoltaic tracking bracket.

[0208] The processor and the program in the memory can be loaded and executed by the processor to implement the control method of the linear actuator of the photovoltaic tracking bracket.

[0209] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a linear actuator of a photovoltaic tracking bracket, characterized in that, include: S100: Collects solar azimuth and solar irradiance; S101: Determine the reflection angle of the reflector (1) based on the solar azimuth angle and the preset location of the heat absorption tower; S102: Control the preset actuator (2) to adjust the reflector (1) to the reflection angle to receive the light and collect the photovoltaic power generation; S103: Power generation benchmark based on matching solar irradiance and preset reflector area; S104: Based on the fact that the photovoltaic power generation is less than the reference power generation, it is defined that there is a foreign object on the surface of the reflector. The actuator (2) is controlled to tilt the reflector (1) at a preset tilt angle and then reset it to obtain the photovoltaic power generation again. S105: If and only if the photovoltaic power generation is less than the reference power generation, the foreign object is defined as an attached foreign object, the attached foreign object is located and the actuator (2) is controlled to process the attached foreign object. The back of the reflector (1) is arrayed with temperature sensors; the methods for locating foreign objects on the reflector surface include: S200: Collects temperature values ​​at various points on the surface of the reflector and generates a surface temperature distribution map; S201: Determine the reflection temperature region enclosed by a preset reference reflection temperature from the surface temperature distribution map; S202: Identify and determine abnormal temperature areas outside the reflected temperature areas from the surface temperature distribution map; S203: Remove the transition region bounded by the preset transition temperature range from the abnormal temperature region to obtain the correction region; S204: Determine the location of the correction area on the surface of the mirror based on the surface temperature distribution map, and output the location of the area; Foreign matter includes dust and large pieces of adhesive material. Methods for distinguishing between these two different types of foreign matter include: S300: Determine the extreme temperatures in the correction zone from the surface temperature distribution map; S301: Determine whether the extreme temperature is greater than the reference reflection temperature; S3011: When the extreme temperature is greater than the reference reflection temperature, the correction area is defined as the high temperature correction area. The foreign matter attached in the high temperature correction area is dust. The dust on the surface of the reflector is removed by the preset dust removal method. S3012: When the extreme temperature is not greater than the reference reflection temperature, the correction area is defined as the low temperature correction area. The foreign matter attached in the low temperature correction area is a large piece of adhesive. The adhesive on the surface of the reflector is removed by the preset adhesive removal method. The actuator (2) is equipped with a water collection box (4), and the edge of the reflector (1) has a water groove (3); the dust removal method includes: S400: Identify and determine the location of all high-temperature correction areas on the surface of the reflector (1) from the surface temperature distribution map; S401: Connect all the high-temperature areas using a preset path planning method to form a flushing path, with the end of the flushing path closest to the water tank (3) as the starting point; S402: Connect the starting point of the flushing path to the preset water tank (3) to form a water guiding path; S403: Based on the water guiding path matching, guide the water in the water tank (3) to the water guiding path and determine the water guiding state position; S404: Dynamic attitude change information of the reflector (1) when the water flows along the flushing path based on the flushing path matching; S405: The control actuator (2) adjusts the reflector (1) from the reflection angle to the preset water intake position so that the water tank (3) of the reflector (1) is rotated and extended into the water collection box (4) to take water; S406: After the reflector (1) completes water intake, the control actuator (2) adjusts the reflector (1) from the water intake state position to the water guiding state position, and controls the reflector (1) to adjust its attitude with attitude dynamic change information to drive the water flow along the flushing path to flush away the dust in the flushing path.

2. The control method for the linear actuator of the photovoltaic tracking bracket according to claim 1, characterized in that, Also includes: S500: Calculate the difference between the extreme temperature and the reference reflection temperature at each high-temperature region location, and define it as the high-temperature difference; S501: Determine the dust thickness at the location of the high-temperature area based on the temperature difference; S502: Matching water flow velocity when water passes through a high-temperature area based on dust thickness; S503: The tilt angle of the mirror (1) is based on the water flow velocity matching. S504: When the water flows through each high-temperature zone, the actuator (2) adjusts the elevation angle of the reflector (1) according to the tilt angle to control the speed of the water flow when it passes through the high-temperature zone.

3. The control method for the linear actuator of the photovoltaic tracking bracket according to claim 1, characterized in that, The water stains on the surface of the reflector (1) need to be dried. The methods for drying water stains include: S600: Control the reflector (1) to rotate horizontally around the actuator (2) with a preset circumferential rotation speed, and obtain the rotational wind force of the reflector (1) in each circumferential direction; S601: Based on the circumferential rotation speed and the area of ​​the reflector (1) to match the reference wind force; S602: Determine whether the rotating wind force is consistent with the reference wind force; S6021: When the rotating wind force is consistent with the reference wind force, continue to rotate the reflector (1) horizontally at a circular rotation speed; S6022: When the rotating wind force is inconsistent with the reference wind force, the rotating wind force is analyzed to determine the maximum pressure, and the wind direction is determined based on the maximum pressure; S60221: Calculate the difference between the maximum pressure and the reference wind force, which is defined as the wind force difference; S60222: If and only if the wind force difference is greater than the reference wind force, the control actuator (2) adjusts the reflector (1) to face the wind direction and rotates at a preset rotation speed.

4. The control method for the linear actuator of the photovoltaic tracking bracket according to claim 1, characterized in that, Methods for removing adhesive residues include: S700: Identify and determine the location of the low-temperature correction area on the surface of the mirror from the surface temperature distribution map; S701: Connect the low-temperature area to the water tank (3) to form an immersion path; S702: Heat the water in the water collection box (4) and control the actuator (2) to adjust the reflector (1) from the reflection angle to the water intake position so that the water tank (3) of the reflector (1) can be rotated and inserted into the water collection box (4) to obtain hot water; S703: After the reflector (1) completes water intake, the actuator (2) is controlled to adjust the reflector (1) from the water intake state position to the water guiding state position so as to guide the hot water into the wetting path to wet the adhering material and reduce the adhesion force. S704: The adjacent reflector (1) is controlled by a concentrated heating method to heat the adhesive in the low temperature region by concentrated heating to dry the adhesive; S705: Control the actuator (2) to vibrate the reflector (1) with a preset vibration force to shake off the adhering material.

5. The control method for the linear actuator of the photovoltaic tracking bracket according to claim 4, characterized in that, Concentrated heating methods include: S800: Identify the location and contour of low-temperature regions from the surface temperature distribution map; S801: The low-temperature region outline is rasterized based on the preset spot area, and the area of ​​each grid is no larger than the spot area. S802: Determine the relative height of each grid cell based on the water guiding status position, and number each grid cell from low to high relative height to obtain the focusing number; S803: Concentrating heating path is formed based on the concentrator number; S804: Determine the focusing angle of adjacent reflectors (1) based on the focusing heating path and solar azimuth angle; S805: Control the adjacent actuator (2) to adjust the angle of the reflector (1) at the focusing angle to dry the adhesive along the focusing heating path.

6. A control system for a linear actuator of a photovoltaic tracking bracket, characterized in that, include: The data acquisition module is used to acquire solar azimuth angle, solar irradiance, photovoltaic power generation, temperature values ​​at various points on the surface of the reflector, and wind force of the reflector (1) in various circumferential directions. A memory for storing a program for controlling the linear actuator of the photovoltaic tracking bracket as described in any one of claims 1 to 5; The processor and the program in the memory can be loaded and executed by the processor to implement the control method of the linear actuator of the photovoltaic tracking bracket.

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