Posture adjusting system for solar heliostat

Abstract

The invention provides a posture adjusting system for a solar heliostat. The posture adjusting system comprises an azimuth angle adjusting module, an elevation angle adjusting module and a control module. The azimuth angle adjusting module comprises a rotation driving mechanism installed on the stand column, is used for driving the main beam truss to horizontally rotate in the azimuth angle direction and is provided with a position detection unit for calibrating the zero point position. The elevating angle adjusting module comprises two rotation executing mechanisms driven by a motor, each executing mechanism is connected with the corresponding main beam truss and used for adjusting the inclination angle of the main beam truss, and each main beam truss is provided with an angle detection unit for obtaining inclination angle information in real time; the control module is installed on the stand column and controls posture adjustment according to detection data. According to the control method, a master-slave motor cooperative control strategy is adopted, through historical deviation compensation, position feedback verification and a load balancing mechanism, the accuracy and stability of attitude adjustment of the heliostat are ensured, and the utilization efficiency of solar energy is improved.

Description

Technical Field

[0001] This invention relates to solar power generation equipment, and more specifically to an attitude adjustment system for a solar heliostat. Background Technology

[0002] Solar heliostats are core components of tower solar thermal power generation systems, their main function being to reflect sunlight onto a receiver at the top of the receiver tower. To achieve efficient energy conversion, the heliostat needs to adjust its attitude in real time according to changes in the sun's position, ensuring that the reflected light always accurately illuminates the target receiver. Currently, heliostat attitude adjustment systems typically employ a dual-axis tracking mechanism, including azimuth and elevation angle adjustments, to achieve precise tracking of the sun's position.

[0003] In existing technologies, the attitude adjustment system of a heliostat is mainly achieved through a motor-driven mechanism. For example, CN110727293A discloses a tower-type heliostat spot calibration device, which includes a calibrator, a controller, an inclinometer, and an encoder. By collecting the deviation between the actual spot position formed by the heliostat's reflection and the theoretical spot position, and combining it with real-time azimuth and elevation angle data, the device drives a motor to adjust the heliostat's attitude. Although this system can effectively reduce the cost of the control system, in large heliostat applications, the torque output of its drive mechanism is often insufficient.

[0004] CN114353346B discloses a tower-type solar heliostat attitude correction system. This system employs a PLC controller, incorporating elevation and azimuth angle controllers, and uses a neural network-based method to calculate the control law, precisely adjusting the heliostat's azimuth and altitude. However, in practical applications, this system still requires a high-power motor and a high-reduction-ratio reducer to generate sufficient torque, resulting in a complex system structure and increased cost.

[0005] In summary, current heliostat driving technologies primarily rely on dual-motor drives, requiring high-power motors and high-ratio reducers or other reduction devices to generate sufficient torque to rotate the reflector. This results in complex heliostat structures and high manufacturing costs. Furthermore, existing control systems are inadequate in handling issues such as uneven load distribution and angular deviations when dual motors are working together, making it difficult to achieve high-precision and high-reliability attitude adjustment. Moreover, in large-scale heliostat array applications, current technologies lack effective distributed control and data transmission solutions, failing to meet the operational requirements of large-scale solar power plants. Summary of the Invention

[0006] To address the technical problem that most heliostat drive methods on the market rely on dual-motor drives, requiring high-power motors and high-reduction-ratio reducers or other speed reduction devices to generate sufficient torque to drive the reflector rotation, resulting in complex heliostat structures and high manufacturing costs, this invention provides a large-scale heliostat dual-axis three-motor tracking drive device that achieves the technical effect of using a low-power motor to provide sufficient torque to drive the reflector rotation, with a simple structure and low manufacturing cost.

[0007] The technical solution adopted by the present invention to solve its technical problem is: to provide an attitude adjustment system for a solar heliostat, including an azimuth adjustment module, an elevation adjustment module and a control module.

[0008] The azimuth adjustment module includes a rotary drive mechanism mounted on the column, used to drive the main beam truss to rotate horizontally in the azimuth direction. The azimuth adjustment module is equipped with a position detection unit for calibrating the zero point position. Specifically, a rotary mechanism driven by a brushless motor is used in the azimuth direction, mounted on the column, to drive the main beam truss to rotate horizontally. The rotary mechanism is equipped with a magnetic Hall sensor to calibrate the zero point position of the azimuth.

[0009] The elevation angle adjustment module includes two motor-driven rotary actuators, each connected to a corresponding main beam truss, for adjusting the tilt angle of the main beam truss. Each main beam truss in the elevation angle adjustment module is equipped with an angle detection unit to acquire its respective tilt angle information in real time. Specifically, in the elevation angle direction, a rotary mechanism driven by two brushless motors through multi-point linkage is used to drive the two main beam trusses. Two external tilt sensors are installed at the center of each of the two main beam trusses to monitor their tilt angles in real time, ensuring the consistency of the tilt angles of the two main beam trusses.

[0010] The control module is mounted on the column and is used to control the azimuth angle adjustment module and the elevation angle adjustment module to adjust the attitude based on the data from the position detection unit and the angle detection unit. Specifically, a tracking controller is installed on the column to drive the three motors to obtain the real-time angle of the heliostat support. It can communicate with the host computer via a wireless communication module or a 485 interface.

[0011] Preferably, the system further includes a terminal relay module and a regional aggregation module. The terminal relay module is installed at the main beam truss and is communicatively connected to the tilt sensor. It receives data to be transmitted from the tilt sensor and acts as an edge route in the Mesh network, establishing dynamic connections with a preset number of adjacent nodes within a preset radius. These adjacent nodes include the control module. The regional aggregation module includes multiple regional relay stations, each corresponding to a preset number of heliostat clusters, and acts as a gateway node in the Mesh network, communicatively connected to the terminal relay module.

[0012] Furthermore, the regional convergence module is communicatively connected to the control center and is used to control the attitude adjustment and data monitoring of each heliostat within the region.

[0013] Preferably, the control method of the control module includes: setting the motor driving the first main beam truss as the master motor and the motor driving the second main beam truss as the slave motor; acquiring the target angle of the master motor, which is determined by adjusting the deviation between the feedback value of the first sensor and the command from the host computer through a PID algorithm; calculating the target angle of the slave motor, which is the sum of the actual angle of the master motor and the historical deviation compensation value; wherein the historical deviation compensation value is the average angle difference between the first sensor and the second sensor during normal operation; and driving the master motor and the slave motor according to the target angle of the master motor and the target angle of the slave motor, respectively. Specifically, a "single sensor + motor encoder" composite control mode is adopted. When one sensor is normal and the other is faulty, the angle of the normal sensor is used as a reference, combined with the encoder data of the two elevation angle motors, to achieve synchronous control.

[0014] Furthermore, the method for calculating the historical deviation compensation value includes: defining a window of fixed length; adding new angle difference data to the window and removing the oldest data each time new angle difference data is acquired; and calculating the statistics of the data within the window in real time as the historical deviation compensation value.

[0015] Preferably, both the main motor and the slave motor are equipped with a position feedback module. The resolution of the position feedback module is not lower than a preset accuracy threshold, and it is used to provide real-time feedback on the motor rotor position. The controller converts the position feedback data into a mechanical structure angle according to the transmission ratio parameter and compares it with the corresponding sensor data. When the deviation between the converted angle and the sensor data does not exceed a first threshold, the target angle of the slave motor is the sum of the actual angle of the main motor and the historical deviation compensation value. Otherwise, an abnormal handling process is executed, which includes reducing the operating speed of the main motor to a preset ratio. Specifically, both elevation angle motors have built-in high-precision encoders to provide real-time feedback on the motor rotor position. The controller converts the encoder data into a truss angle through the motor reduction ratio and transmission mechanism parameters, and compares it with the angle of sensor A.

[0016] Furthermore, the angle difference A between the position feedback devices of the master motor and the slave motor is calculated. If the angle difference exceeds the preset angle deviation threshold, the slave motor command is corrected. The target angle of the slave motor is the sum of the master motor angle, the historical deviation compensation value, and the angle difference A.

[0017] Preferably, the control module monitors the real-time current of the main motor and the slave motor through a current sensor and calculates the ratio of the current difference to the rated current. If this ratio exceeds a preset current threshold, it is determined that the mechanical structure is under uneven load. The controller increases the output torque of the motor on the heavier load side by adjusting the PWM duty cycle to compensate for the angle deviation caused by the load deviation. Specifically, when the sensor data is abnormal but not completely failed or the encoder data is interfered with, the rigid linkage characteristics of the mechanical structure can be used to assist in synchronization.

[0018] The beneficial effects of this invention are as follows: 1. By using a brushless motor-driven rotary mechanism in the azimuth direction and two brushless motors electrically linked in the elevation direction for multi-point drive, a small-power motor can replace a large-power motor, which reduces the requirement for reduction ratio and lowers manufacturing costs. 2. By adopting a dual-motor drive and dual external tilt sensor monitoring method, the accuracy of elevation angle operation is improved and the photothermal conversion efficiency is enhanced; 3. The tracking controller can communicate with the host computer via a wireless communication module, which facilitates remote control and monitoring, and improves the operability and maintainability of the system. Attached Figure Description

[0019] Figure 1 This is a system architecture diagram from the embodiment; Figure 2 This is a flowchart of the control method of the control module in the embodiment; Figure 3 This is a flowchart illustrating the calculation method for historical deviation compensation values ​​in the embodiment. Figure 4 This is a schematic diagram of the structure of the solar heliostat in the embodiment. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Example 1: As Figure 1-4 As shown, an attitude adjustment system for a solar heliostat, such as Figure 1 The specific structure of the heliostat in this embodiment shown includes: Column structure 1: The main beam structure 2 set on the top of the column structure 1 and the upper assembly structure connected to the main beam structure 2 through the main beam truss 4. The column structure 1 includes a vertically set column 11 and a slewing support assembly 12 movably installed on the top of the column 11. Slewing support assembly 12: The top is locked and fixed to the middle section of the main beam structure 2 by clamp 13. The main beam structure 2 includes a horizontally arranged main beam 21 and tilt adjustment slewing assemblies 22 symmetrically arranged at both ends of the main beam 21. The tilt adjustment slewing assembly 22 connects the main beam 21 and the main beam truss 4. The upper assembly structure includes an array of mirror structures 3 and purlins 5 horizontally installed on the back of the mirror structures 3. The main beam truss 4 is connected to the purlins 5 by diagonal supports.

[0022] The system in this embodiment includes an azimuth adjustment module, an elevation adjustment module, and a control module.

[0023] The azimuth adjustment module is mounted on the column and includes a rotary drive mechanism that drives the main beam truss to rotate horizontally in the azimuth direction. The azimuth adjustment module is equipped with a position detection unit, which is used to calibrate the zero-point position, ensuring that the system can accurately locate the initial reference point and providing a basis for subsequent precise adjustments.

[0024] The elevation angle adjustment module includes two motor-driven rotary actuators, each connected to a corresponding main beam truss, for adjusting the tilt angle of the main beam truss. Each main beam truss in the elevation angle adjustment module is equipped with an angle detection unit, which can acquire the tilt angle information of its respective main beam truss in real time, providing the system with real-time attitude data.

[0025] The control module, mounted on the column, receives data from the position and angle detection units and controls the azimuth and elevation adjustment modules to adjust the attitude of the heliostat. The control module is the core of the entire system, responsible for coordinating the actions of all actuators to ensure the heliostat accurately tracks the sun's position.

[0026] The system also includes a terminal relay module, installed at the main beam truss, which communicates with the tilt sensor. The terminal relay module receives data from the tilt sensor and acts as an edge route for the mesh network, establishing dynamic connections with a predetermined number of adjacent nodes within a preset radius. These adjacent nodes include control modules. The terminal relay module enables distributed data transmission, improving communication efficiency and reliability.

[0027] The system is also equipped with a regional aggregation module, which includes multiple regional relay stations. Each regional relay station corresponds to a preset number of heliostat cluster configurations and acts as a gateway node in the Mesh network, communicating with the terminal relay module. The regional aggregation module communicates with the control center to control the attitude adjustment and data monitoring of each heliostat within the region, enabling centralized management of large-scale heliostat arrays.

[0028] The control module employs a master-slave structure, designating the motor driving the first main beam truss as the master motor and the motor driving the second main beam truss as the slave motor. The control process first acquires the target angle of the master motor, determined by adjusting the deviation between the feedback value from the first sensor and the command from the host computer using a PID algorithm. Then, the target angle of the slave motor is calculated, which is the sum of the actual angle of the master motor and the historical deviation compensation value. The historical deviation compensation value is the average angle difference between the first and second sensors during normal operation. Finally, the master motor and slave motor are driven according to their respective target angles.

[0029] The historical deviation compensation value is calculated using the sliding window method. First, a window of fixed length is defined. Each time new angle difference data is acquired, it is added to the window while the oldest data is removed. Then, the statistics of the data within the window are calculated in real time as the historical deviation compensation value. This method can smooth out short-term fluctuations and provide a more stable compensation reference.

[0030] Both the master motor and the slave motor are equipped with position feedback modules. These modules have a resolution no less than a preset accuracy threshold and are used to provide real-time feedback on the motor rotor position. The controller converts the position feedback data into mechanical structural angles based on the transmission ratio parameters and compares it with corresponding sensor data. When the deviation between the converted angle and the sensor data does not exceed a first threshold, the target angle of the slave motor is the sum of the actual angle of the master motor and the historical deviation compensation value; otherwise, an anomaly handling process is executed, including reducing the operating speed of the master motor to a preset ratio to prevent mechanical damage caused by excessive angle deviation.

[0031] The system also calculates the angle difference A between the position feedback devices of the master motor and the slave motor. If this angle difference exceeds a preset angle deviation threshold, the slave motor command is corrected, and the target angle of the slave motor is adjusted to the sum of the master motor angle, the historical deviation compensation value, and the angle difference A. This dynamic adjustment mechanism can compensate for any asynchrony that may occur between the two actuators in real time.

[0032] The control module monitors the real-time current of the main motor and the slave motor using current sensors and calculates the ratio of the current difference to the rated current. If this ratio exceeds a preset current threshold, the system determines that the mechanical structure is under uneven load. The controller then adjusts the PWM duty cycle to increase the output torque of the motor on the heavier load side to compensate for the angular deviation caused by the load imbalance. This load balancing mechanism based on current monitoring can effectively cope with unbalanced loads caused by external factors such as wind loads and snow accumulation, improving the stability and reliability of the system.

[0033] Through the above design, the solar heliostat attitude adjustment system achieves high-precision solar tracking, and also has the characteristics of distributed communication, master-slave coordination control, anomaly handling and load balancing, which can meet the stable operation requirements in complex environments.

[0034] A multi-point drive structure, employing a single brushless motor to drive the rotary mechanism in the azimuth direction and two brushless motors electrically linked in the elevation direction, achieves coordinated control of the large rotary shaft system. By utilizing dual motors equipped with independent feedback systems, the rotation angles at both ends of the main shaft are adjusted in real time, minimizing the angular displacement difference between the two ends of the inclined beam and effectively preventing positioning deviations caused by torsional deformation of the main shaft (i.e., excessive deflection). Compared to the traditional scheme of setting a single-point rotation control only at the column head, this structure significantly improves the torsional stiffness and rotation synchronization accuracy of the shaft system, thereby ensuring the geometric accuracy of the equipment during on-site installation and operation. Simultaneously, the multi-point drive distributes the load torque, allowing smaller motors to meet the drive requirements, reducing the requirement for a reduction ratio, and further reducing the specifications of transmission components and overall manufacturing costs.

[0035] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations that are directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. An attitude adjustment system for a solar heliostat, characterized in that, include: The azimuth adjustment module includes a rotary drive mechanism mounted on a column for driving the main beam truss to rotate horizontally in the azimuth direction. The azimuth adjustment module is equipped with a position detection unit for calibrating the zero point position. The elevation angle adjustment module includes two motor-driven rotary actuators, each connected to a corresponding main beam truss, for adjusting the tilt angle of the main beam truss. Each main beam truss in the elevation angle adjustment module is equipped with an angle detection unit for real-time acquisition of its respective tilt angle information. The control module, installed on the column, is used to control the azimuth angle adjustment module and the elevation angle adjustment module to adjust the attitude based on the data from the position detection unit and the angle detection unit.

2. The system according to claim 1, characterized in that, The system also includes: The terminal relay module is installed at the main beam truss and is connected to the tilt sensor for communication. It is used to receive the data to be transmitted from the tilt sensor and serves as the edge route of the Mesh network. It establishes dynamic connections with a preset number of adjacent nodes within a preset radius. The adjacent nodes include the control module. The regional aggregation module includes multiple regional relay stations. Each regional relay station corresponds to a preset number of heliostat cluster configurations and acts as a gateway node in the Mesh network, communicating with the terminal relay module.

3. The system according to claim 2, characterized in that, The regional convergence module is communicatively connected to the control center and is used to control the attitude adjustment and data monitoring of each heliostat within the region.

4. The system according to claim 1, characterized in that, The control method of the control module includes: The motor driving the first main beam truss is designated as the master motor, and the motor driving the second main beam truss is designated as the slave motor. The target angle of the main motor is obtained, and the target angle of the main motor is determined by adjusting the deviation between the feedback value of the first sensor and the command of the host computer through a PID algorithm. Calculate the target angle from the motor, which is the sum of the actual angle of the main motor and the historical deviation compensation value; wherein, the historical deviation compensation value is the average angle difference between the first sensor and the second sensor during normal operation; The main motor and the slave motor are driven to run according to the target angle of the main motor and the target angle of the slave motor, respectively.

5. The system according to claim 4, characterized in that, The calculation method for the historical deviation compensation value includes: Define a window of fixed length; Each time new angle difference data is acquired, it is added to the window and the oldest data is removed; The statistics of the data within the real-time calculation window are used as historical deviation compensation values.

6. The system according to claim 4, characterized in that, Both the main motor and the slave motor are equipped with a position feedback module. The resolution of the position feedback module is not lower than a preset accuracy threshold, and it is used to provide real-time feedback on the motor rotor position. The controller converts the position feedback data into mechanical structure angles based on the transmission ratio parameters and compares them with the corresponding sensor data. When the deviation between the conversion angle and the sensor data does not exceed the first threshold, the target angle of the slave motor is the sum of the actual angle of the master motor and the historical deviation compensation value. Otherwise, an exception handling procedure is executed, which includes reducing the operating speed of the main motor to a preset ratio.

7. The system according to claim 6, characterized in that, Calculate the angle difference A between the position feedback devices of the master motor and the slave motor. If the angle difference exceeds the preset angle deviation threshold, correct the slave motor command. The target angle of the slave motor is the sum of the master motor angle, the historical deviation compensation value, and the angle difference A.

8. The system according to claim 7, characterized in that, The control module monitors the real-time current of the main motor and the slave motor through a current sensor and calculates the ratio of the current difference to the rated current. If the ratio exceeds the preset current threshold, it is determined that the mechanical structure is unbalanced. The controller increases the output torque of the motor on the heavier side by adjusting the PWM duty cycle to compensate for the angle deviation caused by the load deviation.

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