A multi-motor photovoltaic tracking system and method

Abstract

The application relates to the field of photovoltaic tracking technology and discloses a multi-motor photovoltaic tracking system and method, the system comprising a photovoltaic tracking support, a driving motor module, an edge driving module and a master control module; the driving motor module comprises a first driving motor and at least one second driving motor, the first driving motor and the second driving motor are connected with the photovoltaic tracking support respectively; the edge driving module comprises at least one edge driving unit, the edge driving unit is connected with the corresponding second driving motor; the master control module is connected with the first driving motor and the edge driving unit respectively. The application can improve the operation safety of the multi-motor photovoltaic tracking system.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic tracking technology, and specifically to a multi-motor photovoltaic tracking system and method. Background Technology

[0002] Photovoltaic tracking systems can adjust the orientation of photovoltaic modules based on the sun's position to improve their efficiency in utilizing solar radiation. In single-axis photovoltaic tracking systems, multiple drive motors can be used to drive the same tracking bracket while reducing the load on individual drive motors and meeting the driving requirements of long tracking brackets. However, during multi-motor operation, if one drive motor experiences overcurrent or jamming, and the other motors continue to operate, displacement differences can easily occur between different driving positions. This can cause the tracking bracket to bear significant torsional loads, potentially damaging the bracket or transmission structure. The ability of existing multi-motor photovoltaic tracking systems to coordinate shutdown among drive motors in the event of a single drive motor failure still needs improvement. Summary of the Invention

[0003] This invention provides a multi-motor photovoltaic tracking system and method to solve the problem of untimely coordinated shutdown in multi-motor photovoltaic tracking systems in the event of a fault.

[0004] In a first aspect, the present invention provides a multi-motor photovoltaic tracking system, comprising: Photovoltaic tracking bracket; The drive motor module includes a first drive motor and at least one second drive motor, wherein the first drive motor and the second drive motor are respectively connected to the photovoltaic tracking bracket; The edge drive module includes at least one edge drive unit, which is connected to a corresponding second drive motor. The edge drive unit is used to collect the current of the corresponding second drive motor, control the second drive motor connected to it to stop running when the current meets the fault condition, and send a fault alarm information. The main control module is connected to the first drive motor and each edge drive unit respectively. When it receives a fault alarm information sent by the edge drive unit, it controls the first drive motor to stop running and sends a motor stop command to the other edge drive units except the edge drive unit that sent the fault alarm information.

[0005] The photovoltaic tracking system provided by this invention has a main control module that undertakes the overall control of the photovoltaic tracking bracket and the coordinated control between multiple drive positions, and an edge drive unit that undertakes the local drive and status detection of the corresponding second drive motor. This enables multiple drive motors to work together to complete the tracking motion of the photovoltaic tracking bracket, which can reduce the displacement difference between different drive positions after a fault occurs, reduce the risk of the photovoltaic tracking bracket bearing excessive torsional load, and improve the operational safety of the multi-motor photovoltaic tracking system.

[0006] In one optional implementation, the main control module includes a main controller, a first angle detection unit, a first motor drive unit, and a first communication unit. The first angle detection unit, the first motor drive unit, and the first communication unit are respectively connected to the main controller. The first motor drive unit is connected to a first drive motor, and the first communication unit is connected to an edge drive module.

[0007] In this embodiment, the first angle detection unit can provide angle feedback to the main controller at the corresponding position of the first drive motor. The first motor drive unit drives the first drive motor according to the control signal of the main controller, forming a feedback control link for the first drive position. The first communication unit provides a communication path for information interaction between the main control module and the edge drive module, enabling the main control module to take into account both the local control of the first drive motor and the coordinated control between multiple drive positions.

[0008] In one optional implementation, the edge driving unit includes a local controller, a second angle detection unit, a second motor driving unit, a second current acquisition unit, and a second communication unit. The second angle detection unit, the second motor driving unit, the second current acquisition unit, and the second communication unit are respectively connected to the local controller. The second motor driving unit and the second current acquisition unit are respectively connected to their respective second drive motors. The second communication unit is connected to the first communication unit.

[0009] In this embodiment, each edge drive unit has its own angle detection, motor drive and current detection capabilities. It can complete the local adjustment of the corresponding second drive motor according to the target angle and local angle feedback. There is no need for the main controller to directly generate the underlying drive signals of each second drive motor, which reduces the underlying motor control tasks undertaken by the main controller and provides a hardware foundation for the local status judgment and rapid protection of the second drive motor.

[0010] In one optional implementation, both the first communication unit and the second communication unit are isolated CAN transceivers, and the first communication unit and the second communication unit are connected via a CAN bus.

[0011] In this embodiment, the main control module and multiple edge drive units can establish a shared bus communication network, reducing the wiring complexity caused by setting up independent communication lines for multiple nodes; the isolation setting of the communication interface can improve the anti-interference capability of communication connections between different drive positions, providing a foundation for stable information interaction between multiple drive positions.

[0012] In one optional implementation, the main control module further includes a first current acquisition unit and a first limit switch. The first current acquisition unit is connected to the main controller and the first drive motor, respectively, and the first limit switch is connected to the main controller. The edge drive unit further includes a second limit switch, which is connected to the local controller.

[0013] In this embodiment, the main control module and the edge drive unit can respectively obtain the motor current or limit status at the corresponding drive position, enabling abnormal states at each drive position to be detected on the corresponding controller side. For the second drive motor, the local controller can directly obtain current and limit information, eliminating the need to wait for the main control module to poll the corresponding status when overcurrent occurs or the motion limit is reached, which helps to shorten the response time between abnormal detection and motor protection action.

[0014] In one optional implementation, both the first angle detection unit and the second angle detection unit are tilt sensors, and both the first motor drive unit and the second motor drive unit are H-bridge motor drive units.

[0015] In this embodiment, the tilt sensor can directly provide angle feedback for each drive position, enabling the main controller and local controller to adjust the corresponding drive motor according to the actual angle; the H-bridge motor drive unit can meet the needs of the photovoltaic tracking bracket for forward and reverse angle adjustment and motor stop control, providing hardware conditions for angle adjustment at different drive positions.

[0016] In one optional implementation, the main control module further includes a charging circuit, an energy storage battery, a fuel gauge, and a heating film. The charging circuit and the fuel gauge are connected to the energy storage battery and the main controller, respectively, and the heating film is disposed at the energy storage battery and connected to the main controller.

[0017] In this embodiment, the fuel gauge can provide the main controller with information on the remaining power of the energy storage battery. The charging circuit and the heating film can respectively adjust the charging state and low-temperature operating temperature of the energy storage battery, enabling the main control module to perform energy management according to the actual state of the energy storage battery. In the case of low temperature and abnormal main power supply, it can retain the necessary discharge capacity and provide the power basis for subsequent multi-motor emergency avoidance actions.

[0018] In one optional implementation, the main control module further includes an isolated RS485 transceiver, a wireless communication unit, a clock unit, and a storage unit, which are respectively connected to the main controller.

[0019] In this embodiment, the isolated RS485 transceiver and wireless communication unit can provide the main control module with wired and wireless data interaction channels, the clock unit can provide the time information required for tracking control and operating condition judgment, and the storage unit can save the data required for system operation and control, so that the main control module has relatively complete communication, time management and data storage capabilities, providing a hardware foundation for photovoltaic tracking, weather information acquisition and operating status management.

[0020] In a second aspect, the present invention provides a multi-motor photovoltaic tracking method, applied to a multi-motor photovoltaic tracking system according to the first aspect above or any corresponding embodiment thereof, the method comprising: Determine the target angle of the photovoltaic tracking bracket and send the target angle to each edge drive unit; Obtain the first actual angle corresponding to the position of the first drive motor; Based on the target angle and the first actual angle, control the first drive motor; Receive fault alarm information sent by the edge drive unit. The fault alarm information is sent by the edge drive unit when the current of the corresponding second drive motor meets the fault condition, and the second drive motor connected to it controls itself to stop running. Based on the fault alarm information, the first drive motor is controlled to stop running, and a motor stop command is sent to the remaining edge drive units except for the edge drive unit that sent the fault alarm information.

[0021] The multi-motor photovoltaic tracking method provided by this invention enables the edge drive unit to perform local shutdown processing when the second drive motor malfunctions, and the main control module coordinates the shutdown of other drive motors based on the fault alarm information. This can shorten the fault response path, reduce the displacement difference between different drive positions, reduce the risk of excessive torsional load on the photovoltaic tracking bracket due to asynchronous operation of multiple motors, and improve the system's operational safety.

[0022] In one optional implementation, the target angle is encapsulated in a synchronization command frame and broadcast to each enabled edge drive unit via the CAN bus; the fault alarm information is encapsulated in a fault alarm frame and sent to the main control module via the CAN bus, and the fault alarm frame has a higher CAN bus arbitration priority than other communication frames; the motor stop command is broadcast via the CAN bus; when the CAN bus communication is disconnected, the first drive motor is controlled to stop running, and the edge drive unit controls the second drive motor connected to itself to stop running.

[0023] In this embodiment, CAN broadcasting can reduce the time difference in receiving the target angle by each edge drive unit, local fault protection can shorten the shutdown response path after the second drive motor malfunctions, high-priority fault alarms and global shutdown broadcasts can enable other drive positions to respond to local faults in a timely manner, and overall shutdown when CAN communication is disconnected further avoids new motion differences after the loss of communication coordination, thereby improving the real-time performance of multi-motor synchronous control and fault interlocking.

[0024] In one alternative implementation, the method further includes: Obtain weather warnings, remaining battery power, and ambient temperature; When the main power supply fails and the ambient temperature is below the safety threshold, the energy storage battery is controlled to stop charging. When the remaining power meets the heating conditions, control the heating film to perform pulse heating on the energy storage battery; When the energy storage battery meets the discharge conditions, the first drive motor is controlled and a risk avoidance control command is sent to each edge drive unit.

[0025] In this embodiment, the main control module combines weather warnings, remaining battery power, and ambient temperature for energy scheduling. Under low temperature conditions, the charging circuit is locked, and when the battery power allows, the battery is pulsed preheated. After the battery power is restored, the multiple motors are driven to perform the avoidance action. This can reduce the risk that the system cannot complete the avoidance control when extreme weather, main power supply failure, and low temperature conditions are superimposed. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a structural block diagram of a multi-motor photovoltaic tracking system according to an embodiment of the present invention; Figure 2 This is another structural block diagram of a multi-motor photovoltaic tracking system according to an embodiment of the present invention; Figure 3 This is another structural block diagram of a multi-motor photovoltaic tracking system according to an embodiment of the present invention; Figure 4 This is a structural block diagram of the main control module according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the first process of a multi-motor photovoltaic tracking method according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a second process for a multi-motor photovoltaic tracking method according to an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures: 100. Photovoltaic tracking bracket; 200. Drive motor module; 300. Edge drive module; 400. Main control module; 210. First drive motor; 220. Second drive motor; 310. Edge drive unit; 311. Local controller; 312. Second angle detection unit; 313. Second motor drive unit; 314. Second current acquisition unit; 315. Second communication unit; 316. Second limit switch; 401. Main controller; 402. First angle detection unit; 403. First motor drive unit; 404. First communication unit; 405. First current acquisition unit; 406. First limit switch; 407. Energy storage battery; 408. Fuel meter; 409. Heating film; 410. Charging circuit; 411. Isolated RS485 transceiver; 412. Wireless communication unit; 413. Clock unit; 414. Storage unit. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] In a photovoltaic power generation system, a photovoltaic tracking bracket 100 can be used to drive the photovoltaic modules to adjust their orientation according to the sun's position. For a long, high-load single-axis photovoltaic tracking bracket 100, multiple drive motors can be set up to drive the same photovoltaic tracking bracket 100 together in order to reduce the load on a single drive motor and distribute mechanical stress.

[0032] When multiple motors drive the system together, the motion states of each drive position are interconnected and require good synchronization. Existing multi-motor photovoltaic tracking systems can configure each drive motor with an independent controller, or adopt a master-slave control structure consisting of a master controller 401 and multiple slave drive controllers. The former method requires more control, detection, and power supply hardware, resulting in higher system costs; the latter method typically involves the master controller 401 communicating with multiple slave drive controllers, and when using a polling method to send control information, the response times of different drive motors may differ. When multiple drive motors act on the same photovoltaic tracking bracket 100, if one drive motor experiences a fault such as jamming or overcurrent, and if the fault information needs to be uploaded to the master controller 401 and await its processing, there will be a certain delay in the fault response. During this process, the remaining drive motors may continue to operate, causing displacement differences between different drive positions of the bracket and generating significant mechanical loads on the bracket and transmission structure.

[0033] This invention provides a multi-motor photovoltaic tracking system, such as... Figure 1 As shown, it includes a photovoltaic tracking bracket 100, a drive motor module 200, an edge drive module 300, and a main control module 400; The drive motor module 200 includes a first drive motor 210 and at least one second drive motor 220, wherein the first drive motor 210 and the second drive motor 220 are respectively connected to the photovoltaic tracking bracket 100. The edge driving module 300 includes at least one edge driving unit 310, which is connected to a corresponding second driving motor 220. The edge driving unit 310 is used to collect the current of the corresponding second driving motor 220, control the second driving motor 220 connected to it to stop running when the current meets the fault conditions, and send a fault alarm information. The main control module 400 is connected to the first drive motor 210 and each edge drive unit 310 respectively. When it receives the fault alarm information sent by the edge drive unit 310, it controls the first drive motor 210 to stop running and sends a motor stop command to the other edge drive units 310 except the edge drive unit 310 that sent the fault alarm information.

[0034] Specifically, the photovoltaic tracking bracket 100 can be a support structure for mounting photovoltaic modules and capable of changing the orientation of the photovoltaic modules under the action of driving force, for example, it can be a flat single-axis photovoltaic tracking bracket 100. The first drive motor 210 and the second drive motor 220 can be set at different driving positions of the photovoltaic tracking bracket 100, and apply driving force to the corresponding driving positions respectively, so that multiple drive motors can jointly drive the photovoltaic tracking bracket 100 to move. The first drive motor 210 can be controlled by the main control module 400, and the second drive motor 220 can be controlled by the corresponding edge drive unit 310. The number of second drive motors 220 can be set according to the length of the photovoltaic tracking bracket 100, the load, and the driving force requirements.

[0035] The edge drive unit 310 can be a local control device located on the side of the corresponding second drive motor 220. It can control the operation of the corresponding second drive motor 220 according to the system's tracking control requirements, enabling the corresponding drive position to track the photovoltaic tracking bracket 100. Simultaneously, it can acquire the operating status of the corresponding second drive motor 220 and provide local fault protection for it. For example, the edge drive unit 310 can perform closed-loop control of the corresponding second drive motor 220 based on the target angle sent by the main control module 400 and the angle feedback it collects. The edge drive unit 310 can also collect the current of the corresponding second drive motor 220 and determine whether the second drive motor 220 is malfunctioning based on the collected current. The fault condition can be a current condition corresponding to abnormal operating states such as jamming or overcurrent in the second drive motor 220, for example, determined based on the current magnitude or current changes. When the current meets the fault condition, the edge drive unit 310 can directly control the second drive motor 220 connected to it to stop operating and generate a fault alarm message to notify the main control module 400 of the fault occurring at that drive position.

[0036] The main control module 400 serves as the centralized control device for a multi-motor photovoltaic tracking system. It controls the overall tracking operation of the photovoltaic tracking bracket 100 and coordinates the operation of the first drive motor 210 and each edge drive unit 310. For example, the main control module 400 can calculate the target angle based on the sun's position and the structural parameters of the photovoltaic tracking bracket 100, using an ideal apparent solar tracking algorithm and a three-dimensional inverse tracking algorithm to determine the target angle. The three-dimensional inverse tracking algorithm can combine parameters such as axis azimuth, axis tilt, and cross-axis slope. During normal operation, the main control module 400 controls the first drive motor 210 and interacts with the edge drive units 310, enabling the first drive motor 210 and each second drive motor 220 to jointly drive the photovoltaic tracking bracket 100. In case of a fault, the main control module 400 can determine an abnormal driving position based on the fault alarm information sent by the edge drive units 310 and control its connected first drive motor 210 to stop operating. It can also send motor stop commands to other edge drive units 310 that have not sent the fault alarm information, causing the other second drive motors 220 to stop operating.

[0037] During operation, as the photovoltaic tracking bracket 100 performs normal tracking motion, the first drive motor 210 and each of the second drive motors 220 act on different drive positions of the photovoltaic tracking bracket 100, jointly driving the photovoltaic tracking bracket 100 to move. Each edge drive unit 310 performs local control and status detection on its corresponding second drive motor 220. When the current of a certain second drive motor 220 meets the fault condition, the corresponding edge drive unit 310 can locally trigger the second drive motor 220 to stop running, without waiting for the main control module 400 to complete the fault judgment and then return the stop control command for the second drive motor 220, and send the fault alarm information to the main control module 400. The main control module 400, based on the fault alarm information, stops the first drive motor 210 and the second drive motors 220 corresponding to the other edge drive units 310, so that the multiple drive positions jointly driving the same photovoltaic tracking bracket 100 change from a normal coordinated operation state to a coordinated stop state.

[0038] The photovoltaic tracking system provided in this embodiment of the invention has a main control module 400 that undertakes the overall control of the photovoltaic tracking bracket 100 and the coordinated control between multiple drive positions, and an edge drive unit 310 that undertakes the local drive and status detection of the corresponding second drive motor 220. This enables multiple drive motors to work together to complete the tracking movement of the photovoltaic tracking bracket 100, which can reduce the displacement difference that continues to occur between different drive positions after a fault occurs, reduce the risk of the photovoltaic tracking bracket 100 bearing excessive torsional load, and improve the operational safety of the multi-motor photovoltaic tracking system.

[0039] In some embodiments, such as Figure 2As shown, the main control module 400 includes a main controller 401, a first angle detection unit 402, a first motor drive unit 403, and a first communication unit 404. The first angle detection unit 402, the first motor drive unit 403, and the first communication unit 404 are respectively connected to the main controller 401. The first motor drive unit 403 is connected to the first drive motor 210, and the first communication unit 404 is connected to the edge drive module 300.

[0040] Specifically, the main controller 401 can be a microcontroller with data processing and control functions, used to process the data collected by the first angle detection unit 402, and generate control signals for the first drive motor 210 and information for interaction with the edge drive module 300. The first angle detection unit 402 can be a sensor capable of detecting the angle of the corresponding drive position of the photovoltaic tracking bracket 100, and its detection result can be used as position feedback for the first drive motor 210. The first motor drive unit 403 can be a drive circuit capable of adjusting the operating state of the first drive motor 210 according to the control signals output by the main controller 401, used to provide corresponding drive signals to the first drive motor 210. The first communication unit 404 can be a communication interface with data sending and receiving functions, used to establish a communication connection between the main controller 401 and the edge drive module 300. The main controller 401 can adjust the first drive motor 210 via the first motor drive unit 403 according to the deviation between the actual angle fed back by the first angle detection unit 402 and the target angle corresponding to the photovoltaic tracking bracket 100, so that the drive position of the first drive motor 210 moves towards the target angle.

[0041] In this embodiment, the first angle detection unit 402 can provide angle feedback to the main controller 401 at the corresponding position of the first drive motor 210. The first motor drive unit 403 drives the first drive motor 210 according to the control signal of the main controller 401, forming a feedback control link for the first drive position. The first communication unit 404 provides a communication path for information interaction between the main control module 400 and the edge drive module 300, so that the main control module 400 can take into account both the local control of the first drive motor 210 and the coordinated control between multiple drive positions.

[0042] In some embodiments, such as Figure 2As shown, the edge driving unit 310 includes a local controller 311, a second angle detection unit 312, a second motor driving unit 313, a second current acquisition unit 314, and a second communication unit 315. The second angle detection unit 312, the second motor driving unit 313, the second current acquisition unit 314, and the second communication unit 315 are respectively connected to the local controller 311. The second motor driving unit 313 and the second current acquisition unit 314 are respectively connected to the corresponding second drive motor 220. The second communication unit 315 is connected to the first communication unit 404.

[0043] Specifically, the local controller 311 can be a microcontroller with data processing and motor control functions. The second angle detection unit 312 is used to detect the actual angle of the driving position of the corresponding second drive motor 220 and send the detection result to the local controller 311. The second motor drive unit 313 is used to drive the corresponding second drive motor 220 according to the control signal output by the local controller 311. The second current acquisition unit 314 can acquire the current of the corresponding second drive motor 220 during operation and send the current acquisition result to the local controller 311, so that the local controller 311 can determine the operating status of the corresponding second drive motor 220 according to the current change. The second communication unit 315 is used to interact with the first communication unit 404, so that the local controller 311 can receive the information sent by the main control module 400 and feed back its own operating information to the main control module 400. During normal tracking, the local controller 311 can determine the control quantity of the corresponding second drive motor 220 according to the received target angle and the actual angle fed back by the second angle detection unit 312, and then control the second drive motor 220 to run through the second motor drive unit 313. The post-drive board has a local controller 311, angle detection, motor drive and current acquisition hardware, and can complete position closed loop locally.

[0044] In this embodiment, each edge drive unit 310 has its own angle detection, motor drive and current detection capabilities. It can complete the local adjustment of the corresponding second drive motor 220 according to the target angle and local angle feedback. There is no need for the main controller 401 to directly generate the underlying drive signal of each second drive motor 220, which reduces the underlying motor control task undertaken by the main controller 401 and provides a hardware foundation for the local status judgment and fast protection of the second drive motor 220.

[0045] In some embodiments, such as Figure 2 As shown, both the first communication unit 404 and the second communication unit 315 are isolated CAN transceivers, and the first communication unit 404 and the second communication unit 315 are connected through a CAN bus.

[0046] Specifically, the isolated CAN transceiver can convert signals from the main controller 401 or local controller 311 to differential signals on the CAN bus, and establish electrical isolation between the controller side and the bus side. Each second communication unit 315 can connect to the first communication unit 404 as a communication node on the CAN bus, enabling the main control module 400 to communicate with multiple edge drive units 310 via the same CAN bus. The CAN bus supports multiple nodes sharing the communication medium and can be used to transmit data such as target angle, operating status, fault information, and motor control information. The main control module 400 can broadcast synchronous control information to multiple edge drive units 310 via the CAN bus, enabling multiple edge drive units 310 to simultaneously obtain the target angle.

[0047] In this embodiment, the main control module 400 and multiple edge drive units 310 can establish a shared bus communication network, reducing the wiring complexity caused by setting independent communication lines for multiple nodes; the isolation setting of the communication interface can improve the anti-interference capability of communication connections between different drive positions, providing a foundation for stable information interaction between multiple drive positions.

[0048] In some embodiments, such as Figure 3 As shown, the main control module 400 also includes a first current acquisition unit 405 and a first limit switch 406. The first current acquisition unit 405 is connected to the main controller 401 and the first drive motor 210 respectively, and the first limit switch 406 is connected to the main controller 401. The edge drive unit 310 also includes a second limit switch 316, which is connected to the local controller 311.

[0049] Specifically, the first current acquisition unit 405 can acquire the current during the operation of the first drive motor 210 and send the corresponding current detection signal to the main controller 401, enabling the main controller 401 to obtain the load status of the first drive motor 210. The first limit switch 406 and the second limit switch 316 can be switching devices that can change their output state when the corresponding drive position reaches a preset motion limit. The status signal of the first limit switch 406 is sent to the main controller 401 so that the main controller 401 can identify the limit status of the corresponding position of the first drive motor 210; the status signal of the second limit switch 316 is sent to the local controller 311 so that the local controller 311 can directly identify the limit status of the drive position of the corresponding second drive motor 220. The second drive motor 220 can combine the current information obtained by the second current acquisition unit 314 and the status of the second limit switch 316 to judge abnormal situations such as overcurrent, jamming, or reaching the motion limit.

[0050] In this embodiment, the main control module 400 and the edge drive unit 310 can respectively obtain the motor current or limit status at the corresponding drive position, so that abnormal states at each drive position can be detected on the corresponding controller side. For the second drive motor 220, the local controller 311 can directly obtain the current and limit information. When overcurrent occurs or the motion limit is reached, there is no need to wait for the main control module 400 to poll the corresponding status, which helps to shorten the response time between abnormal detection and motor protection action.

[0051] In some embodiments, such as Figure 3 As shown, the first angle detection unit 402 and the second angle detection unit 312 are both tilt sensors, and the first motor drive unit 403 and the second motor drive unit 313 are both H-bridge motor drive units.

[0052] Specifically, the tilt sensor can output a corresponding detection signal according to the angle change of the corresponding driving position of the photovoltaic tracking bracket 100, to obtain the actual tilt angle of the photovoltaic tracking bracket 100. The detection result of the first tilt sensor can be provided to the main controller 401, and the detection result of the second tilt sensor can be provided to the corresponding local controller 311. The H-bridge motor drive unit can change the drive state applied to both ends of the corresponding drive motor according to the drive control signal output by the controller, so as to realize the forward rotation, reverse rotation, or stop of the drive motor. Both the main control unit and the subsequent drive board can be configured with tilt sensors and H-bridge motor drive modules.

[0053] In this embodiment, the tilt sensor can directly provide angle feedback for each driving position, enabling the main controller 401 and the local controller 311 to adjust the corresponding drive motor according to the actual angle; the H-bridge motor drive unit can meet the needs of the photovoltaic tracking bracket 100 for forward and reverse angle adjustment and motor stop control, providing hardware conditions for angle adjustment at different driving positions.

[0054] In some embodiments, such as Figure 4 As shown, the main control module 400 also includes a charging circuit 410, an energy storage battery 407, a fuel gauge 408, and a heating film 409. The charging circuit 410 and the fuel gauge 408 are connected to the energy storage battery 407 and the main controller 401, respectively. The heating film 409 is disposed at the energy storage battery 407 and connected to the main controller 401.

[0055] Specifically, the energy storage battery 407 can be a rechargeable battery installed in the main control module 400, such as a 6Ah lithium iron phosphate battery, used to provide power to the main control module 400 and the drive motor for emergency operation when the main power supply is abnormal. The fuel gauge 408 can be a power detection device used to detect the remaining power and battery status of the energy storage battery 407, such as an LTC2944 fuel gauge 408. The main controller 401 can obtain the current remaining power of the energy storage battery 407 based on the data detected by the fuel gauge 408.

[0056] The charging circuit 410 can be a circuit for managing the charging of the energy storage battery 407. The main controller 401 can control the operating state of the charging circuit 410 based on the ambient temperature of the energy storage battery 407. For example, when the ambient temperature is lower than a preset safety threshold, the charging circuit 410 can enter a hardware lockout state to limit the continued charging of the energy storage battery 407 under low-temperature conditions. The heating film 409 can be attached to the surface of the energy storage battery 407 or placed in a position adjacent to the energy storage battery 407 to provide heat to the energy storage battery 407. The main controller 401 can control the operation of the heating film 409 based on the remaining charge of the energy storage battery 407 and the ambient temperature. For example, when the remaining charge meets the heating requirements, the heating film 409 can be controlled to perform intermittent heating, so that the temperature of the energy storage battery 407 gradually recovers to a range that can meet the subsequent discharge requirements.

[0057] In this embodiment, the fuel gauge 408 can provide the main controller 401 with information on the remaining power of the energy storage battery 407. The charging circuit 410 and the heating film 409 can respectively adjust the charging state and low-temperature operating temperature of the energy storage battery 407, so that the main control module 400 can perform energy management according to the actual state of the energy storage battery 407, and retain the necessary discharge capacity in the case of low temperature and abnormal main power supply, so as to provide the power basis for subsequent multi-motor emergency avoidance actions.

[0058] In some embodiments, such as Figure 4 As shown, the main control module 400 also includes an isolated RS485 transceiver 411, a wireless communication unit 412, a clock unit 413, and a storage unit 414, which are respectively connected to the main controller 401.

[0059] Specifically, the isolated RS485 transceiver 411 can be a communication device used to realize data transmission and reception between the main controller 401 and an external RS485 communication network. The isolated RS485 transceiver 411 can convert communication signals from the main controller 401 side into differential signals suitable for RS485 bus transmission and form electrical isolation between the main controller 401 side and the external communication side. In one example, the isolated RS485 transceiver 411 can communicate with the main controller 401 via a serial communication interface.

[0060] The wireless communication unit 412 can be a communication module capable of wireless data interaction with external devices or platforms, such as a LoRa wireless module. In one example, the wireless communication unit 412 can be connected to the main controller 401 via a serial communication interface to receive external information such as weather warnings.

[0061] Clock unit 413 can be a clock device used to provide system time information, such as an RTC clock. The main controller 401 can obtain the time information provided by clock unit 413 to determine the current tracking time, perform time-related tracking control, or determine whether the current operating condition is nighttime.

[0062] Storage unit 414 can be a non-volatile memory capable of storing system operating data and control parameters, such as an off-chip Flash memory. The main controller 401 can write operating parameters, historical states, or other data that needs to be stored long-term to storage unit 414, and can also read corresponding data from storage unit 414. In one example, storage unit 414 can be a 128Mb SPI Flash memory, which can be connected to the main controller 401 via an SPI bus.

[0063] In this embodiment, the isolated RS485 transceiver 411 and wireless communication unit 412 can provide the main control module 400 with wired and wireless data interaction channels, the clock unit 413 can provide the time information required for tracking control and operating condition judgment, and the storage unit 414 can save the data required for system operation and control, so that the main control module 400 has relatively complete communication, time management and data storage capabilities, providing a hardware foundation for photovoltaic tracking, weather information acquisition and operating status management.

[0064] This invention also provides a multi-motor photovoltaic tracking method, applicable to the multi-motor photovoltaic tracking system of any of the above embodiments, such as... Figure 5 As shown, the method includes: Step S501: Determine the target angle of the photovoltaic tracking bracket 100 and send the target angle to each edge drive unit 310.

[0065] Specifically, the target angle can be a predetermined angle to which the photovoltaic tracking bracket 100 needs to rotate at the current moment, used to determine the target orientation of the photovoltaic module within the current tracking cycle. The target angle can be determined based on the sun's position and the layout parameters of the site where the photovoltaic tracking bracket 100 is located. For example, the sun's position can be obtained based on the current time and geographical location, and combined with parameters such as the axial azimuth, axial tilt, and cross-axis slope of the photovoltaic tracking bracket 100, the target position of the photovoltaic tracking bracket 100 can be calculated. In application scenarios with terrain undulations or the influence of shading from adjacent photovoltaic modules, the target angle can also be adjusted by combining inverse tracking calculations.

[0066] Determining the target angle involves the main control module 400 calculating the required bracket angle based on the current tracking conditions. Since the first drive motor 210 and each of the second drive motors 220 work together on the same photovoltaic tracking bracket 100, and each drive position needs to move around the same bracket target, the main control module 400, after determining the target angle, sends it to each edge drive unit 310, enabling each edge drive unit 310 to obtain the unified target corresponding to this tracking movement. Upon receiving the target angle, the edge drive unit 310 can control the second drive motor 220 based on the actual state of its corresponding drive position, causing all drive positions to jointly drive the photovoltaic tracking bracket 100 towards the target angle.

[0067] Step S502: Obtain the first actual angle at the position corresponding to the first drive motor 210.

[0068] Specifically, the first actual angle can be the angle actually reached by the driving position corresponding to the first drive motor 210, which reflects the actual motion state of the driving position relative to the target angle. The position corresponding to the first drive motor 210 can be the position in the photovoltaic tracking bracket 100 where the first drive motor 210 applies driving force or a position that can indicate the motion state of that position.

[0069] The first actual angle can be obtained by the main control module 400 receiving angle data collected by the angle detection component set at the corresponding position of the first drive motor 210. As the first drive motor 210 drives the photovoltaic tracking bracket 100 to move, the first actual angle changes accordingly. The main control module 400 can continuously or periodically obtain the first actual angle during the tracking process, so that the subsequent motor control can be adjusted according to the actual movement position of the photovoltaic tracking bracket 100.

[0070] Step S503: Based on the target angle and the first actual angle, control the first drive motor 210.

[0071] Specifically, the operating state of the first drive motor 210 may be determined according to the relationship between the target angle and the first actual angle. When the first actual angle has not yet reached the target angle, the movement direction of the first drive motor 210 and the corresponding control quantity may be determined according to the angle deviation between the two, so that the first drive motor 210 drives the corresponding driving position to move towards the target angle; as the first actual angle gradually approaches the target angle, the driving state of the first drive motor 210 may be adjusted correspondingly. When the first actual angle reaches the target angle or falls within the allowable angle error range, the first drive motor 210 may be controlled to stop further adjustment.

[0072] By forming position feedback from the target angle and the actual angle, the control of the first drive motor 210 can be adjusted along with the change of the actual position of the photovoltaic tracking support 100. At the same time, each edge drive unit 310 controls the corresponding second drive motor 220 according to the target angle obtained in step S501, so that the first drive motor 210 and each second drive motor 220 jointly drive the photovoltaic tracking support 100 to complete the current tracking movement around the same target angle.

[0073] In step S504, a fault alarm message sent by the edge drive unit 310 is received, where the fault alarm message is sent by the edge drive unit 310 after controlling the connected second drive motor 220 to stop operating when the current of the corresponding second drive motor 220 meets a fault condition.

[0074] Specifically, the fault alarm message may be information for indicating that an abnormality occurs in the corresponding second drive motor 220 or the corresponding driving position, and may at least be used to enable the main control module 400 to determine that there is a driving position requiring linkage processing. The current of the second drive motor 220 may reflect the load state of the drive motor during operation. When an abnormality such as stalling or overload occurs in the second drive motor 220, its operating current may increase or change abruptly. Therefore, the fault condition may be set according to the current characteristic of the second drive motor 220 in an abnormal operating state, for example, it may be that the current reaches a preset overcurrent condition or a preset abnormal change occurs.

[0075] The edge drive unit 310 may locally acquire the current of the corresponding second drive motor 220 and perform fault determination. When the current meets the fault condition, the edge drive unit 310 controls the connected second drive motor 220 to stop operating, and sends the fault alarm message to the main control module 400. The stopping operation and sending may be triggering the shutdown control of the second drive motor 220 and the sending of the fault alarm message after the fault is detected, without requiring waiting for the second drive motor 220 to be completely mechanically stationary before sending the fault alarm message. In this way, the abnormal second drive motor 220 can be locally processed first at the position where the fault occurs, and the fault state can be promptly provided to the main control module 400.

[0076] In step S505, based on the fault alarm information, the first drive motor 210 is controlled to stop running, and a motor stop command is sent to the other edge drive units 310 except for the edge drive unit 310 that sent the fault alarm information.

[0077] Specifically, the motor stop command can be control information used to instruct the edge drive unit 310 to stop the operation of the corresponding second drive motor 220. After receiving the fault alarm information, the main control module 400 can determine that an abnormal drive position has occurred during the multi-motor joint drive process and control its corresponding first drive motor 210 to stop running. For other second drive motors 220 that have not experienced the fault, the main control module 400 sends a motor stop command to the corresponding edge drive unit 310, causing these edge drive units 310 to stop continuing to drive the corresponding second drive motor 220.

[0078] For example, when one of the multiple second drive motors 220 fails, the corresponding edge drive unit 310 first triggers the second drive motor 220 to stop and sends a fault alarm message. After receiving the fault alarm message, the main control module 400 controls the first drive motor 210 to stop running and causes the other edge drive units 310 to stop their respective connected second drive motors 220, so that the multiple drive positions acting on the same photovoltaic tracking bracket 100 change from the tracking operation state to the coordinated shutdown state.

[0079] The multi-motor photovoltaic tracking method provided in this embodiment of the invention enables the edge drive unit 310 to perform local shutdown processing when the second drive motor 220 malfunctions, and the main control module 400 to coordinate the shutdown of other drive motors based on the fault alarm information. This can shorten the fault response path, reduce the displacement difference between different drive positions, reduce the risk of excessive torsional load on the photovoltaic tracking bracket 100 due to asynchronous operation of multiple motors, and improve the system's operational safety.

[0080] In some embodiments, the target angle is encapsulated in a synchronization command frame and broadcast to each enabled edge drive unit 310 via the CAN bus; the fault alarm information is encapsulated in a fault alarm frame and sent to the main control module 400 via the CAN bus, and the fault alarm frame has a higher CAN bus arbitration priority than other communication frames; the motor stop command is broadcast via the CAN bus; when the CAN bus communication is disconnected, the first drive motor 210 is controlled to stop running, and the edge drive unit 310 controls the second drive motor 220 connected to itself to stop running.

[0081] Specifically, after the main control module 400 completes the calculation of the target angle, it can encapsulate the target angle in a synchronization command frame and broadcast the synchronization command frame to each currently enabled edge drive unit 310 via the CAN bus. When using the broadcast method, each edge drive unit 310 can receive the same synchronization command frame within a relatively small time window. After receiving the synchronization command frame, the edge drive unit 310 can trigger a local synchronization flag, read the actual angle of its corresponding drive position, and perform local closed-loop control on the corresponding second drive motor 220 based on the target angle and the actual angle. In one example, the local controller 311 can use a proportional-integral-derivative (PID) control algorithm to calculate the PWM control quantity and control the second motor drive unit 313 according to the PWM control quantity, so that each second drive motor 220 tracks and drives around the same target angle.

[0082] During fault protection, the edge drive unit 310 can acquire the real-time transient current of the corresponding second drive motor 220 at high frequency and obtain the status of the second limit switch 316. When a local jamming overcurrent is detected, such as a sudden jump in motor current, the edge drive unit 310 can directly cut off the PWM output of the corresponding second motor drive unit 313, causing the second drive motor 220 to brake. This local protection process can be completed on the edge drive unit 310 side without waiting for the main control module 400 to perform fault query.

[0083] When the edge drive unit 310 triggers local fault protection, it can also encapsulate the fault alarm information into a fault alarm frame and send it to the main control module 400 via the CAN bus. The CAN bus adopts a non-destructive arbitration mechanism, and the fault alarm frame can be set to have a higher arbitration priority than the normal communication frame. For example, it can be set to the highest priority in the current communication network, so that the fault alarm frame can obtain communication opportunities first. After receiving the fault alarm frame, the main control module 400 can broadcast the motor stop command to other edge drive units 310 via the CAN bus, so that the second drive motor 220, which is still in normal operation, will stop, and control the first drive motor 210 to stop running, thereby reducing the time that the different drive positions continue to generate motion differences after the local motor jams.

[0084] The communication status of the CAN bus can also serve as a basis for judging system fault protection. When a physical disconnection or other communication breakdown occurs on the CAN bus, the main control module 400 and the edge drive unit 310 can detect the corresponding communication anomaly. The main control module 400 controls the first drive motor 210 to stop running, and each edge drive unit 310 controls its connected second drive motor 220 to stop running, so that multiple drive positions enter a shutdown state when communication coordination is lost, preventing each drive motor from continuing to run independently after communication interruption.

[0085] In this embodiment, CAN broadcasting can reduce the time difference between each edge drive unit 310 receiving the target angle, local fault protection can shorten the shutdown response path after the second drive motor 220 malfunctions, high-priority fault alarm and global shutdown broadcasting can enable other drive positions to respond to local faults in a timely manner, and overall shutdown when CAN communication is disconnected further avoids new motion differences after losing communication coordination, thereby improving the real-time performance of multi-motor synchronous control and fault interlocking.

[0086] In some embodiments, such as Figure 6 As shown, the multi-motor photovoltaic tracking method also includes: Step S601: Obtain weather warning information, remaining power of energy storage battery 407, and ambient temperature.

[0087] Specifically, this embodiment can be applied to nighttime operating conditions involving extreme winds, heavy snow, and main power outages. Weather warning information can indicate meteorological conditions such as strong winds and heavy snow that may affect the safe operation of the photovoltaic tracking bracket 100. The main control module 400 can acquire weather warning information using the wireless communication unit 412, for example, through a LoRa wireless module. The remaining power of the energy storage battery 407 can be determined based on the battery status detected by the fuel gauge 408, for example, using an LTC2944 fuel gauge 408. The energy storage battery 407 can be a 6Ah lithium iron phosphate battery. Ambient temperature can be used to indicate the current low-temperature environment of the energy storage battery 407. The main control module 400 can combine weather warning information, remaining power, and ambient temperature to determine subsequent charging, heating, and emergency control states.

[0088] In step S602, when the main power supply is cut off and the ambient temperature is below the safety threshold, the energy storage battery 407 is controlled to stop charging.

[0089] Specifically, the safety threshold can be a temperature threshold set according to the temperature range during which the energy storage battery 407 is allowed to charge. When the main power supply is interrupted and the ambient temperature is lower than the safety threshold, controlling the energy storage battery 407 to stop charging can be achieved by implementing a hardware interlock on the charging circuit 410 to limit the energy storage battery 407 from continuing to charge at low temperatures.

[0090] In step S603, when the remaining power meets the heating conditions, the heating film 409 is controlled to perform pulse heating on the energy storage battery 407.

[0091] Specifically, the heating condition can be that the remaining charge of the energy storage battery 407 is sufficient to support the current low-temperature preheating process. The main control module 400 can determine whether to allow heating to start based on the remaining charge obtained in step S601. When the remaining charge meets the heating condition, the heating film 409 located on the energy storage battery 407 can be controlled to perform pulse heating, so that the heating film 409 preheats the energy storage battery 407 in an intermittent manner. During the pulse heating process, a portion of the charge in the energy storage battery 407 can be retained for subsequent multi-motor safety actions after the energy storage battery 407 recovers its discharge activity.

[0092] In step S604, when the energy storage battery 407 meets the discharge conditions, the first drive motor 210 is controlled to send a risk avoidance control command to each edge drive unit 310.

[0093] Specifically, the energy storage battery 407 can meet the discharge conditions by restoring itself to a state capable of providing the necessary electrical energy for the system's emergency response drive after low-temperature preheating. After confirming that the energy storage battery 407 has regained its discharge activity, the main control module 400 controls the first drive motor 210 to perform emergency response actions and sends emergency response control commands to each edge drive unit 310. Each edge drive unit 310 controls its connected second drive motor 220 according to the emergency response control commands, causing the first drive motor 210 and each of the second drive motors 220 to jointly drive the photovoltaic tracking bracket 100 to perform emergency response actions. This process enables the system to utilize the remaining charge of the energy storage battery 407 to complete necessary low-temperature preheating and multi-motor emergency response even in extreme weather, nighttime power outages, and when low temperatures affect the performance of the energy storage battery 407.

[0094] In this embodiment, the main control module 400 combines weather warnings, the remaining power of the energy storage battery 407, and the ambient temperature to perform energy scheduling. Under low temperature conditions, the charging circuit 410 is locked, and when the power allows, the energy storage battery 407 is pulsed preheated. After the energy storage battery 407 recovers its discharge capacity, the multi-motor is driven to perform the avoidance action. This can reduce the risk that the system cannot complete the avoidance control when extreme weather, main power supply failure, and low temperature conditions are superimposed.

[0095] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A multi-motor photovoltaic tracking system, characterized in that, include: Photovoltaic tracking bracket; The drive motor module includes a first drive motor and at least one second drive motor, wherein the first drive motor and the second drive motor are respectively connected to the photovoltaic tracking bracket; An edge driving module includes at least one edge driving unit, which is connected to a corresponding second driving motor. The edge driving unit is used to collect the current of the corresponding second driving motor, control the second driving motor connected to it to stop running when the current meets the fault condition, and send a fault alarm information. The main control module is connected to the first drive motor and each of the edge drive units respectively. When it receives the fault alarm information sent by the edge drive unit, it controls the first drive motor to stop running and sends a motor stop command to the other edge drive units except the edge drive unit that sent the fault alarm information.

2. The multi-motor photovoltaic tracking system according to claim 1, characterized in that, The main control module includes a main controller, a first angle detection unit, a first motor drive unit, and a first communication unit. The first angle detection unit, the first motor drive unit, and the first communication unit are respectively connected to the main controller. The first motor drive unit is connected to the first drive motor, and the first communication unit is connected to the edge drive module.

3. The multi-motor photovoltaic tracking system according to claim 2, characterized in that, The edge driving unit includes a local controller, a second angle detection unit, a second motor driving unit, a second current acquisition unit, and a second communication unit. The second angle detection unit, the second motor driving unit, the second current acquisition unit, and the second communication unit are respectively connected to the local controller. The second motor driving unit and the second current acquisition unit are respectively connected to the corresponding second drive motors. The second communication unit is connected to the first communication unit.

4. The multi-motor photovoltaic tracking system according to claim 3, characterized in that, Both the first communication unit and the second communication unit are isolated CAN transceivers, and the first communication unit and the second communication unit are connected via a CAN bus.

5. The multi-motor photovoltaic tracking system according to claim 3, characterized in that, The main control module further includes a first current acquisition unit and a first limit switch. The first current acquisition unit is connected to the main controller and the first drive motor respectively, and the first limit switch is connected to the main controller. The edge drive unit further includes a second limit switch, which is connected to the local controller.

6. The multi-motor photovoltaic tracking system according to claim 3, characterized in that, Both the first angle detection unit and the second angle detection unit are tilt sensors, and both the first motor drive unit and the second motor drive unit are H-bridge motor drive units.

7. The multi-motor photovoltaic tracking system according to claim 2, characterized in that, The main control module also includes a charging circuit, an energy storage battery, a fuel gauge, and a heating film. The charging circuit and the fuel gauge are respectively connected to the energy storage battery and the main controller. The heating film is disposed at the energy storage battery and connected to the main controller.

8. The multi-motor photovoltaic tracking system according to claim 2, characterized in that, The main control module also includes an isolated RS485 transceiver, a wireless communication unit, a clock unit, and a storage unit, which are respectively connected to the main controller.

9. A multi-motor photovoltaic tracking method, characterized in that, The method, applied to the multi-motor photovoltaic tracking system according to any one of claims 1-8, comprises: Determine the target angle of the photovoltaic tracking bracket and send the target angle to each edge drive unit; Obtain the first actual angle corresponding to the position of the first drive motor; Based on the target angle and the first actual angle, control the first drive motor; The edge driving unit receives fault alarm information sent by the edge driving unit. The fault alarm information is sent by the edge driving unit when the current of the corresponding second driving motor meets the fault condition, and the edge driving unit controls the second driving motor connected to it to stop running. Based on the fault alarm information, the first drive motor is controlled to stop running, and a motor stop command is sent to the other edge drive units except the edge drive unit that sent the fault alarm information.

10. The multi-motor photovoltaic tracking method according to claim 9, characterized in that, The target angle is encapsulated in a synchronization command frame and broadcast to each enabled edge drive unit via the CAN bus; the fault alarm information is encapsulated in a fault alarm frame and sent to the main control module via the CAN bus, and the fault alarm frame has a higher CAN bus arbitration priority than other communication frames; the motor stop command is broadcast via the CAN bus; when the CAN bus communication is disconnected, the first drive motor is controlled to stop running, and the edge drive unit controls the second drive motor connected to it to stop running.

11. The multi-motor photovoltaic tracking method according to claim 9, characterized in that, The method further includes: Obtain weather warnings, remaining battery power, and ambient temperature; When the main power supply is interrupted and the ambient temperature is below the safety threshold, the energy storage battery is controlled to stop charging. When the remaining power meets the heating conditions, the heating film is controlled to perform pulse heating on the energy storage battery; When the energy storage battery meets the discharge conditions, the first drive motor is controlled and a risk avoidance control command is sent to each of the edge drive units.

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