A distributed master-slave coordinated multi-axis drive yaw operation control system and method

Abstract

This invention relates to a distributed master-slave coordinated multi-axis yaw operation control system and method, belonging to the field of wind power generation control technology. This invention utilizes distributed master-slave motion controllers to realize a multi-motor yaw drive coordinated control system, enabling balanced distribution control of the yaw motor motion controllers in the multi-motor yaw drive mechanism of a wind turbine. Simultaneously, by utilizing the following coordinated control of the master and slave yaw motor motion controllers, synchronous motion control of the distributed multi-motor motion controllers is achieved during yaw movement. This avoids the phenomenon of asynchronous tail-chasing among multiple yaw motors during operation, as well as the mechanical losses caused by the force exerted on the small and large yaw teeth of the yaw system.

Description

Technical Field

[0001] This invention relates to a distributed master-slave coordinated multi-axis drive yaw operation control system and method, belonging to the field of wind power generation control technology. Background Technology

[0002] Addressing global climate change is one of the most significant and pressing challenges facing humanity. In recent years, to meet the challenges of climate change and reduce carbon emissions, my country has made numerous efforts in the development of green and low-carbon energy, maintaining its position as the world's largest developer and user of renewable energy. Wind power is one of the fastest-growing green energy sources and a crucial direction for optimizing my country's energy structure. With continuous advancements in wind power technology, the competitive trend towards larger and more scaled wind turbine units is becoming increasingly prominent, while the requirements for economic efficiency and stable operation of these units are also rising.

[0003] The maximum wind energy capture capability of a wind turbine depends on its real-time and precise tracking of wind direction. The yaw system is a key component of a horizontal axis wind turbine for real-time and precise wind alignment. The yaw system mainly consists of a yaw bearing, yaw motor, yaw gearbox, and hydraulic brake. The inner and outer rings of the yaw bearing are bolted to the nacelle and tower of the wind turbine, respectively, and the gear teeth are either external or internal. When yawing, the yaw motor drives the small gear mounted on the yaw gearbox to mesh with the large gear ring, rotating the nacelle and aligning the rotor with the wind direction, maximizing the turbine's wind capture efficiency. With the improvement of design and manufacturing levels in the wind power industry, the capacity of single units is constantly increasing. Currently, the mainstream models for newly installed units have evolved from the original 2MW units to units with a capacity of 6MW and above. To ensure safe and stable yaw alignment for large-capacity units, the drive mechanism of the yaw system has also increased to 12 or more sets.

[0004] Currently, in traditional yaw system control methods, the drive control of the yaw motors mostly uses common soft starters or frequency converters. A PLC controls multiple frequency converters or soft starters in parallel to simultaneously start and stop the motors, achieving the yaw function of the wind turbine. A common control system diagram for multiple yaw motors is shown below. Figure 1 A schematic diagram of the multi-motor control system structure using a frequency converter and soft starter. In the traditional scheme, the yaw control command of the wind turbine generator is directly and simultaneously sent to the frequency converter or soft starter via the PLC. The frequency converter or soft starter then controls the yaw motor to complete the yaw operation.

[0005] Currently, the 6MW wind turbine yaw system has more yaw drive mechanisms, and the load on the yaw bearing during yaw is more demanding than that of a 2MW turbine, requiring greater balance. However, existing technologies control the 12 asynchronous yaw drive motors independently, preventing synchronized control of the multiple yaw drive shafts during yaw. This leads to a "tailgating" phenomenon when the 12 yaw motors are running, causing mechanical damage to the yaw system's gears and the yaw motors themselves.

[0006] The inner and outer rings of the yaw bearing in the yaw system of a wind turbine generator are bolted to the nacelle and tower of the wind turbine generator, respectively. The yaw drive system consists of 12 sets of drive pinions that transmit power to the inner teeth of the large gears of the yaw bearings. Consequently, the gear clearance between the large yaw gear and the drive pinion in the yaw system causes mechanical shock due to the gear clearance. This is because existing control schemes cannot precisely control the speed and torque of gear meshing during wind turbine generator yaw motor startup.

[0007] The yaw process of wind turbine generators differs from typical multi-motor drive applications. Force analysis during the yaw process reveals that the load on the yaw bearing gear ring, and the yaw torque caused by external wind loads, are constantly changing during operation. Because wind loads vary significantly under different wind conditions throughout the yaw process, maintaining the generator's position and yaw stability requires timely adjustment of the yaw drive motor's output torque and damping torque. Traditional parallel control solutions for multiple yaw motors lack precise dynamic adjustment control algorithms and execution units, failing to accurately control torque and position changes during operation and unable to prevent mechanical and electrical shocks. Summary of the Invention

[0008] The purpose of this invention is to provide a distributed master-slave coordinated multi-axis drive yaw operation control system and method to solve the problem that current control schemes cannot accurately control the speed and torque of gear meshing, thus causing mechanical impact due to gear backlash.

[0009] To solve the above-mentioned technical problems, the present invention provides a distributed master-slave coordinated multi-axis drive yaw operation control system. The control system includes a yaw control unit and several master motion controllers. Each master motion controller controls and connects at least two slave motion controllers. The master yaw motors controlled by the master motion controllers are evenly distributed on the yaw bearings, and the slave yaw motors controlled by the slave motion controllers are evenly distributed on both sides of each master yaw motor.

[0010] The yaw control unit is used to send motion control commands to the main motion controller according to the yaw wind command, and receive motion status information of each yaw motor to complete the motion control of the yaw motor and achieve smooth yaw wind.

[0011] The main motion controller is used to receive speed and torque commands from the yaw control unit, and control the main yaw motor according to the received speed and torque commands, while coordinating the following motion state of the corresponding slave motion controllers to complete the synchronous operation of multiple yaw motors; the slave motion controller is used to drive the slave yaw motor to respond to and follow the speed and torque motion state of the main yaw motor according to the motion state information of the main motion controller.

[0012] This invention utilizes a distributed master-slave motion controller to realize a multi-motor yaw drive coordinated control system. This system enables balanced distribution and control of the yaw motor motion controllers in the multi-motor yaw drive mechanism of a wind turbine. Simultaneously, by utilizing the following coordinated control of the master and slave yaw motor motion controllers, the distributed multi-motor motion controllers achieve synchronous motion control during yaw motion. This avoids the phenomenon of tailgating due to asynchronous operation of multiple yaw motors and the mechanical losses caused by the force on the small and large yaw teeth of the yaw system.

[0013] Furthermore, when performing yaw control, the yaw control unit assigns forward and reverse drive commands to the main motion controller, coordinates the main motion controller to gradually increase the speed of the main yaw motor in the yaw direction, and controls other main yaw motors to adjust the reverse speed, so that the yaw pinion of the yaw drive mechanism slowly meshes with the large tooth of the yaw bearing. After the gear backlash compensation is completed, the main motion controller adjusts the output forward and reverse balance torque of each main yaw motor.

[0014] The forward and reverse drive commands employed in this invention enable the yaw drive pinion and yaw slewing bearing large gear of the multi-motor yaw drive mechanism in wind turbine generators to complete a slow and gentle meshing process, avoiding the meshing shock generated during yaw start-up. Simultaneously, the yaw motor also achieves a smooth start-up, avoiding mechanical and electrical shocks. The yaw optimization control method in this scheme achieves a smooth start-up of the yaw drive system, allowing dynamic compensation of the yaw gear backlash during startup, avoiding sudden torque and speed changes during backlash meshing, as well as mechanical shock damage to the yaw motor and reducer.

[0015] Furthermore, once the yaw motors output balanced torque to stabilize the yaw position of the cabin, the yaw control unit drives the yaw motors to accelerate to their rated speed via the main motion controller and enters the yaw operation state.

[0016] Furthermore, the main motion controller adopts a three-loop control method to control the main yaw motor, consisting of an inner loop for current, a middle loop for speed, and an outer loop for position.

[0017] The motion control of the main yaw motor is achieved through an outer position control loop, an intermediate speed control loop, and an inner current control loop. This allows for precise and dynamic adjustment of the output speed and torque of the main yaw motor, enabling the yaw system to maintain real-time, accurate, and stable wind resistance during yaw.

[0018] Furthermore, the motion controller controls the movement of the yaw motor based on the torque current setpoint of the main motion controller for motor control, and uploads the torque current feedback value of the yaw motor to the main motion controller.

[0019] Furthermore, the yaw control unit and the main motion controller use a POWERLINK bus for data transmission, and the main motion controller and the slave motion controller use a POWERLINK bus for data transmission.

[0020] This invention uses a POWERLINK bus for data transmission between the yaw control unit and the master motion controller, and also uses a POWERLINK bus for data transmission between the master motion controller and the slave motion controller, enabling efficient data transmission between the yaw control unit and the master motion controller, as well as between the master motion controller and the slave motion controller.

[0021] This invention also provides a distributed master-slave coordinated multi-axis drive yaw operation control method, which includes the following steps:

[0022] The yaw motor is divided into a master yaw motor and a slave yaw motor. The master yaw motors are evenly distributed on the yaw bearing, and the slave yaw motors are evenly distributed on both sides of each master yaw motor. A master yaw motor controller is configured for each master yaw motor, and a slave yaw motor controller is configured for each slave yaw motor.

[0023] The main motion controller receives speed and torque commands from the yaw control unit and controls the main yaw motor according to the received speed and torque commands. At the same time, it coordinates the following motion state of the corresponding slave motion controllers to complete the synchronous operation of multiple yaw motors. The slave motion controllers execute response drives to respond to the speed and torque motion state of the slave yaw motors according to the motion state information of the main motion controller.

[0024] Furthermore, when performing yaw control, the yaw control unit assigns forward and reverse drive commands to the main motion controller, coordinates the main motion controller to gradually increase the speed of the main yaw motor in the yaw direction, and controls other main yaw motors to adjust the reverse speed, so that the yaw pinion of the yaw drive mechanism slowly meshes with the large tooth of the yaw bearing. After the gear backlash compensation is completed, the main motion controller adjusts the output forward and reverse balance torque of each main yaw motor.

[0025] Furthermore, the main motion controller adopts a three-loop control method to control the main yaw motor, consisting of an inner loop for current, a middle loop for speed, and an outer loop for position.

[0026] Furthermore, the motion controller controls the movement of the yaw motor based on the torque current setpoint of the main motion controller for motor control, and uploads the torque current feedback value of the yaw motor to the main motion controller. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a multi-motor control system using traditional frequency converters and soft starter solutions.

[0028] Figure 2 This is a schematic diagram of the topology of the distributed master-slave coordinated multi-axis drive yaw operation control system of the present invention;

[0029] Figure 3 This is a structural diagram of the balanced distribution multi-motor yaw drive master-slave coordinated control system in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the master-slave yaw motor motion control structure in this invention;

[0031] Figure 5 This is a schematic diagram of the motion state control principle of the main yaw motor used in this invention. Detailed Implementation

[0032] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0033] Control system example:

[0034] The distributed master-slave coordinated multi-axis drive yaw operation control system of the present invention is as follows: Figure 2 As shown, the system includes a yaw control unit and several master motion controllers, each of which controls at least two slave motion controllers. The master yaw motors controlled by the master motion controllers are evenly distributed on the yaw bearings, while the slave yaw motors controlled by the slave motion controllers are evenly distributed on both sides of each master yaw motor. The master motion controllers receive speed and torque commands from the yaw control unit and control the master yaw motors accordingly, while simultaneously coordinating the following motion states of the corresponding slave motion controllers to achieve synchronous operation of multiple yaw motors. The slave motion controllers, based on the motion state information from the master motion controllers, execute response drives to adjust the speed and torque of the slave yaw motors accordingly. A detailed explanation follows with specific examples.

[0035] This invention analyzes the gear ring transmission strength of the yaw bearing of a wind turbine generator set, calculates the distribution of inter-tooth load, contact surface pressure distribution, and stress model. Based on the yaw bearing load analysis and the stress under unbalanced torque load conditions, four evenly distributed yaw drive motors are selected as the main yaw drive motors, and the operation status of the motors is controlled by four main motion controllers. At the same time, the two yaw motors adjacent to each main yaw drive motor are set as their corresponding slave yaw motors, and the following motion status control of the slave yaw motors is completed by the slave motion controller of this invention.

[0036] The yaw motor configuration in this embodiment is as follows: Figure 3 As shown, motors A, B, C, and D are the main yaw motors. These four main yaw motors are equipped with rotary encoders and are directly driven by four main motion controllers, which also feed back the encoder signals to their respective main motion controllers. The motors located on either side of each main yaw motor are its slave yaw motors. Specifically, motors A1 and A2 are slave yaw motors of main yaw motor A; motors B1 and B2 are slave yaw motors of main yaw motor B; motors C1 and C2 are slave yaw motors of main yaw motor C; and motors D1 and D2 are slave yaw motors of main yaw motor D. The motion controllers of the slave yaw motors follow the motion control states of their corresponding main yaw motor motion controllers, thus controlling the motor's motion.

[0037] Master-slave yaw motor motion control structure, such as Figure 4 As shown, the yaw control unit communicates with the main motion controllers of the four main yaw motors via a POWERLINK high-speed bus to achieve real-time control command and motion data transmission; the four main motion controllers also communicate with the corresponding slave yaw motor motion controllers via a POWERLINK high-speed bus to achieve follow control command and motor motion data transmission.

[0038] Based on the aforementioned balanced multi-motor yaw drive master-slave coordinated control system, the yaw control unit distributes forward and reverse drive commands to the main motion controller according to the left and right yaw commands from the control system. First, the main motion controller coordinates the gradual increase in speed of the three main yaw motors in the yaw direction, while another main yaw motor adjusts its reverse speed, causing the yaw pinion of the yaw drive mechanism to slowly and gently mesh with the large teeth of the yaw bearing. After the gear backlash is gradually compensated, the main motion controller adjusts the output forward and reverse balancing torque of the four main yaw motors, while the slave yaw motors synchronize their movements. The yaw control unit coordinates the release of yaw brake pressure to the residual pressure value via the yaw hydraulic solenoid valve, while simultaneously relying on the motor output balancing torque to maintain the yaw position of the engine compartment. Once the system's motors output balancing torque to stabilize the yaw position of the engine compartment, the yaw control unit then drives the yaw motors to gradually accelerate to their rated speed, entering the yaw operation state. Therefore, during the yaw system startup process, the gear meshing clearance between the large teeth of the yaw bearing and the small teeth of the yaw drive can be slowly compensated, reducing mechanical impact on the tooth surfaces. Meanwhile, the method in this scheme controls the output torque of each yaw motor so that the yaw drive mechanism forms a pre-tension force before yaw acceleration and the yaw drive mechanism is dynamically balanced by force, so as to avoid the unit from swaying and vibrating during the yaw start-up process.

[0039] Through the above control process, the yaw drive pinion and yaw slewing bearing large gear of the multi-motor yaw drive mechanism of the wind turbine generator can complete a slow and gentle meshing process, avoiding the meshing shock generated during yaw start-up. At the same time, the yaw motor also completes a flexible start-up, avoiding mechanical and electrical shocks. The yaw optimization control method of this scheme realizes the flexible start-up of the yaw drive system, enabling dynamic compensation of the yaw gear backlash during start-up, avoiding sudden torque and speed changes during backlash meshing, and preventing mechanical shock damage to the yaw motor and reducer.

[0040] Main yaw motor motion controller: The main yaw motor adopts synchronous control of position loop, speed loop and current loop, such as... Figure 5 As shown, the main motion controller uses the rotary encoder on the main yaw motor to obtain the motor position information. Through the speed setpoint and feedback value, it completes PI regulation to obtain the torque current setpoint of the main yaw motor. The main motion controller outputs three-phase current detection, and calculates the motor's excitation current and torque current feedback values ​​through the three-phase current coordinate changes. The main motion controller uses a coordinated control algorithm of the main yaw motor's position loop, speed loop, and current loop to control the dynamic output driving torque of the yaw motor.

[0041] The yaw motor motion controller relies on a current loop to control motion. Specifically, the slave motion controller obtains the torque and current setpoint from the master motion controller via the POWERLINK high-speed bus and uses this torque and current setpoint as the torque and current setpoint for motor control to move the slave yaw motor. The slave motion controller then uploads the torque and current feedback value from the slave yaw motor to the master motion controller. The master yaw motor motion control is calibrated based on the torque and current feedback values ​​from both the master and slave yaw motors and the torque and current setpoint derived from the outer loop speed control.

[0042] This invention relates to a multi-motor yaw drive master-slave coordinated control system for large wind turbine generators of 6MW and above, capable of enabling yaw system wind-following functionality for 12 or more yaw drive motors. Compared to current traditional yaw control systems, this invention first proposes utilizing a distributed master-slave motion controller to achieve a multi-motor yaw drive coordinated control system, ensuring synchronous and coordinated movement of all motors in the yaw system. Secondly, based on the application of the multi-motor yaw drive master-slave coordinated control system, dynamic compensation of the meshing clearance between the large gear of the yaw bearing and the small gear of the yaw drive is achieved, forming pre-tensioning between the yaw drive shaft and the yaw bearing, avoiding mechanical shocks generated during the start-up and shutdown of the yaw motors. Simultaneously, during system operation, the torque and speed of the multiple yaw motors can be precisely and dynamically adjusted through a distributed master-slave coordinated yaw motor motion state control algorithm, achieving dynamic coordinated torque control of the multiple motors during yaw, avoiding unbalanced load changes in the yaw system caused by wind speed environmental variations, thus preventing unbalanced overload damage to the yaw motors. This achieves precise yaw wind-following control, reduces the occurrence of mechanical and electrical failures in the yaw system, lowers system maintenance costs, and increases the power generation of the wind turbine generator.

[0043] Control method example:

[0044] The control method of this invention divides the yaw motor into master yaw motors and slave yaw motors, with the master yaw motors evenly distributed on the yaw bearings and the slave yaw motors evenly distributed on both sides of each master yaw motor. A master yaw motor controller is configured for each master yaw motor, and a slave yaw motor controller is configured for each slave yaw motor. The master motion controller receives speed and torque commands from the yaw control unit and controls the master yaw motors accordingly, while simultaneously coordinating the following motion states of the corresponding slave motion controllers to achieve synchronous operation of multiple yaw motors. The slave motion controllers, based on the motion state information of the master motion controllers, execute response drives to adjust the speed and torque motion states of the slave yaw motors accordingly. The specific implementation process of this method has been described in detail in the embodiments of the method and will not be repeated here.

Claims

1. A distributed master-slave coordinated multi-axis drive yaw operation control method, characterized in that, The control method includes the following steps: The yaw motor is divided into a master yaw motor and a slave yaw motor. The master yaw motors are evenly distributed on the yaw bearing, and the slave yaw motors are evenly distributed on both sides of each master yaw motor. A master yaw motor controller is configured for each master yaw motor, and a slave yaw motor controller is configured for each slave yaw motor. The main motion controller receives speed and torque commands from the yaw control unit and controls the main yaw motor according to the received speed and torque commands. At the same time, it coordinates the following motion state of the corresponding slave motion controllers to complete the synchronous operation of multiple yaw motors. The slave motion controllers execute response drives to respond to the speed and torque motion state of the slave yaw motors according to the motion state information of the main motion controller. When performing yaw control, the yaw control unit assigns forward and reverse drive commands to the main motion controller, coordinates the main motion controller to gradually increase the speed of the main yaw motor in the yaw direction, and controls other main yaw motors to adjust the reverse speed, so that the yaw pinion of the yaw drive mechanism slowly meshes with the large tooth of the yaw bearing. After the gear backlash compensation is completed, the main motion controller adjusts the output forward and reverse balance torque of each main yaw motor.

2. The yaw operation control method for distributed master-slave coordinated multi-axis drive according to claim 1, characterized in that, The main motion controller uses a three-loop control method to control the main yaw motor, with the inner loop being the current loop, the middle loop being the speed loop, and the outer loop being the position loop.

3. The yaw operation control method for distributed master-slave coordinated multi-axis drive according to claim 1, characterized in that, The slave motion controller controls the movement of the slave yaw motor based on the torque current setpoint of the master motion controller, and uploads the torque current feedback value of the slave yaw motor to the master motion controller.

4. A distributed master-slave coordinated multi-axis drive yaw operation control system, characterized in that, The control system includes a yaw control unit and several master motion controllers. Each master motion controller controls at least two slave motion controllers. The master yaw motors controlled by the master motion controllers are evenly distributed on the yaw bearings, and the slave yaw motors controlled by the slave motion controllers are evenly distributed on both sides of each master yaw motor. The yaw control unit is used to send motion control commands to the main motion controller according to the yaw wind command, and receive motion status information of each yaw motor to complete the motion control of the yaw motor and achieve smooth yaw wind. The main motion controller is used to receive speed and torque commands from the yaw control unit, and control the main yaw motor according to the received speed and torque commands, while coordinating the following motion state of the corresponding slave motion controllers to complete the synchronous operation of multiple yaw motors; the slave motion controller is used to drive the slave yaw motor to respond to and follow the speed and torque motion state of the main yaw motor according to the motion state information of the main motion controller. When performing yaw control, the yaw control unit assigns forward and reverse drive commands to the main motion controller, coordinates the main motion controller to gradually increase the speed of the main yaw motor in the yaw direction, and controls other main yaw motors to adjust the reverse speed, so that the yaw pinion of the yaw drive mechanism slowly meshes with the large tooth of the yaw bearing. After the gear backlash compensation is completed, the main motion controller adjusts the output forward and reverse balance torque of each main yaw motor.

5. The distributed master-slave coordinated multi-axis drive yaw operation control system according to claim 4, characterized in that, Once the yaw motors output balanced torque to stabilize the yaw position of the cabin, the yaw control unit drives the yaw motors to accelerate to their rated speed via the main motion controller and enters the yaw operation state.

6. The distributed master-slave coordinated multi-axis drive yaw operation control system according to claim 5, characterized in that, The main motion controller uses a three-loop control method to control the main yaw motor, with the inner loop being the current loop, the middle loop being the speed loop, and the outer loop being the position loop.

7. The distributed master-slave coordinated multi-axis drive yaw operation control system according to claim 5, characterized in that, The slave motion controller controls the movement of the slave yaw motor based on the torque current setpoint of the master motion controller, and uploads the torque current feedback value of the slave yaw motor to the master motion controller.

8. The distributed master-slave coordinated multi-axis drive yaw operation control system according to claim 4, characterized in that, Data transmission between the yaw control unit and the main motion controller is performed via a POWERLINK bus, as is data transmission between the main motion controller and the slave motion controller.

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