Gear backlash flexible meshing design method of wind power yaw bearing

Abstract

The invention discloses a gear backlash flexible meshing design method for a wind power yaw bearing, which relates to the technical field of yaw motor control, and comprises the following steps: designing a yaw bearing gear backlash flexible meshing hardware unit, setting a yaw instruction processing unit, processing a yaw instruction, and controlling the yaw bearing gear backlash flexible meshing hardware unit. According to the design method, a yaw bearing backlash flexible meshing hardware principle block diagram is established, and a compensation control algorithm suitable for realizing backlash flexible meshing of a yaw motor in open-loop and closed-loop working modes and a control flow of backlash flexible meshing of the yaw bearing are developed. Compared with a traditional wind power yaw bearing gear backlash flexible meshing design method, flexible matching of a yaw bearing large gear and a yaw speed reducer small gear is achieved by means of a software algorithm, gear backlash detection is not needed, and the risks of gear damage and aggravated mechanical damage caused by overlarge impact force and inter-tooth acting force during yaw starting are effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of yaw motor control, and in particular to a method for designing flexible meshing of tooth side clearance of a wind power yaw bearing. Background Art

[0002] The wind turbine yaw bearing is one of the most important components in the wind turbine generator set. It supports the nacelle, blades, hub, axial and radial loads and overturning moments, and transmits the aerodynamic force on the blades to the tower, so that the nacelle can rotate and adjust according to the change of wind direction to ensure that the wind turbine blades are always in the best windward position. In order to improve the power generation efficiency and extend the service life of the equipment, the design of the yaw bearing must consider a variety of factors, including load capacity, wear resistance, sealing performance and maintenance convenience. The tooth side clearance flexible meshing design method is an important improvement measure for the yaw bearing gear system. After long-term operation, the gears of traditional yaw bearings may have excessive tooth side clearance due to wear or manufacturing errors. By measuring the tooth clearance on the spot, mechanical components are added to compensate for the clearance in places with large clearance. This is a method to solve the tooth gap between the yaw bearing large gear ring and the yaw reducer pinion. However, this method is inefficient and difficult to apply to wind turbines. The flexible meshing design aims to optimize the geometry and material properties of the gears so that the gears can still maintain a good meshing state even if there are slight installation errors or wear. Although the existing wind turbine yaw bearing tooth side clearance flexible meshing design method has made great progress, there are still some problems that need to be optimized: First, during the operation of the wind turbine, the wind turbine yaw bearing is used to adjust the direction according to the wind direction to improve the power generation efficiency. The wind turbine needs to rotate frequently, so that the large gear ring of the yaw bearing rotates continuously. In the long run, there may be a gap between the large gear ring and the small gear of the reducer, resulting in tooth impact, affecting the smoothness and uniformity of the gear transmission. In severe cases, it will cause gear damage and weaken the stability and reliability of the yaw system; secondly, the yaw reducer is connected to the yaw motor, and the yaw motor is adjusted according to the wind direction. In order to improve the control accuracy of the yaw motor, the inverter is used to control it more accurately. In order to control the speed and power of the motor, replacing the original motor in the yaw fan that has been installed and put into use will increase the cost and increase the space limitation. Therefore, the driving mode of the yaw fan is changed. In theory, all motors can be started and stopped and accelerated and decelerated synchronously. However, due to manufacturing differences and load differences, the actual operating speeds of each motor will be different, and the system lacks the function or equipment to correct these differences, resulting in the gradual loss of synchronization between the yaw motors over time; in addition, some yaw motors lack speed and position feedback devices and cannot accurately control their own operation. In the case of the yaw motor without an encoder and open-loop control, the flexible engagement of the yaw bearing large ring gear and the yaw reducer small gear cannot be achieved. Summary of the invention

[0003] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for designing flexible meshing of tooth side clearance of a wind power yaw bearing, comprising the following steps: Step 1: Design a yaw bearing tooth side flexible meshing hardware unit, wherein the yaw bearing tooth side flexible meshing hardware unit includes a yaw system execution unit, a frequency converter processing unit, a yaw deceleration unit and a yaw bearing support unit. The yaw bearing tooth side flexible meshing hardware unit is used to provide power drive for yaw, so that the wind turbine can adjust the direction of the cabin according to the wind direction, accurately control the motor speed and torque, reduce the speed and increase the torque of the motor power, and mobilize the brake disc to brake, so as to achieve smooth and slow rotation of the cabin; Step 2: Design a yaw command processing unit to process yaw commands, realize the start, stop, forward and reverse rotation of the wind turbine yaw bearing, and determine the tooth side clearance flexible meshing compensation control algorithm under different modes; Step 3: Establish a hardware analysis algorithm for the flexible meshing of the yaw bearing tooth side clearance, and analyze the various components required for the flexible meshing control of the yaw bearing tooth side clearance and their connections and working relationships with each other; Step 4: construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the open-loop working mode, and perform torque control and flexible meshing judgment; Step 5: construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the closed-loop working mode, and perform speed control and dynamic adjustment; Step 6: Design a control process for the flexible meshing of the yaw bearing tooth side clearance. This control process can effectively reduce the impact and vibration caused by excessive or insufficient tooth side clearance, reduce the noise during the operation of the yaw system, and improve the meshing accuracy and transmission efficiency of the gears.

[0004] Preferably, in step 1, the process of designing the yaw system execution unit includes: The yaw system execution unit is composed of a yaw motor, which is divided into two types with rated voltages of 400V AC and 690V AC. The yaw motor is equipped with a speed measurement feedback unit, which is generally composed of a speed sensor, an analog-to-digital converter and a communication interface. The speed sensor is installed on the yaw motor shaft and is used to collect analog signals that describe the motor speed in real time. The analog signals are converted into digital signals through the built-in analog-to-digital converter, which are transmitted and fed back through the communication interface.

[0005] Preferably, in step 1, the process of designing the frequency converter processing unit includes: The inverter processing unit is equipped with a dedicated inverter and an input inductor, wherein the dedicated inverter is used to adjust the voltage and frequency of the input yaw motor to control the motor speed and torque; the input inductor is used to suppress the high-order harmonic current generated by the dedicated inverter, and the dedicated inverter is equipped with an energy-consuming braking unit; the energy-consuming braking unit is based on the principle of energy conversion. When braking is required during the inverter's multiple start-stop and acceleration and deceleration processes, the energy-consuming braking unit applies a braking force, and converts the kinetic energy into heat energy for braking through resistance heating and friction movement.

[0006] Preferably, in step 1, the process of designing the yaw reduction unit includes: The yaw reduction unit consists of a yaw reducer and its pinion, wherein the yaw reducer is used to transmit speed data to the yaw reducer through a speed measurement feedback unit after the yaw motor is started and generates a high-speed rotation speed, and the yaw reducer adjusts the reduction ratio to convert the high-speed and low-torque output of the yaw motor into a low-speed and high-torque output; the pinion of the yaw reducer is installed at the output end of the yaw reducer and meshes with the large gear of the yaw bearing. Through the meshing of the large gear and the pinion, the power between the large gear and the pinion is transmitted to control the speed of the yaw action.

[0007] Preferably, in step 1, the process of designing the yaw bearing support unit includes: The yaw bearing support unit consists of a yaw bearing, a yaw bearing gear and a gear brake disc, wherein the yaw bearing is used to support the tower top structure, which includes a nacelle, a hub and blades, and bears its radial and axial loads; the yaw bearing gear is used to mesh with the pinion of the yaw reducer to transmit power from the yaw reducer; the gear brake disc is used to lock the yaw bearing, and when there is a yaw action, only back pressure is retained; when no yaw is required, full pressure braking is applied to lock the position of the motor nacelle.

[0008] Preferably, in step 2, the process of designing a yaw command processing unit to process the yaw command, realizing the start, stop, forward rotation and reverse rotation of the wind turbine yaw bearing, and determining the tooth side clearance flexible meshing compensation control algorithm in different modes includes: A1. The yaw command processing unit is the processing module of the yaw frequency converter itself. The yaw command includes the yaw command including start, stop, forward and reverse; A2. Check whether the yaw motor is equipped with a speed feedback unit and set the control mode of the yaw inverter. If it is equipped with a speed feedback unit, select the speed control mode; if it is not equipped with a speed feedback unit, select the torque control mode; A3. Through the selected control mode, before the meshing is completed, set the torque limit value T0, the operating speed limit value N0 and the acceleration / deceleration time t0. The torque limit value T0 and the operating speed limit value N0 are used to determine the meshing condition of the yaw bearing gear and the reducer pinion. The deceleration time is the time t0 for the yaw motor to accelerate from 0 to the rated speed of the motor. In the speed control mode, the maximum rated torque of the yaw motor is set as the torque limit value, the maximum operating speed is set as the operating speed limit value, and the real-time acceleration / deceleration time is set as the acceleration / deceleration time; in the torque control mode, set the actual operating torque of the yaw motor as the torque limit value, the actual average operating speed as the operating speed limit value, and the real-time acceleration / deceleration time as the acceleration / deceleration time; A4. According to the control mode of the yaw inverter, determine the tooth side clearance flexible meshing compensation control algorithm in different modes.

[0009] Preferably, in step 3, a hardware analysis algorithm for the flexible meshing of the tooth side clearance of the yaw bearing is established, and the process of analyzing various components required for the flexible meshing control of the tooth side clearance of the yaw bearing and their mutual connections and working relationships includes: B1. According to the wind direction information and the feedback information of the yaw motor, the yaw system execution unit generates a yaw command and sends it to the yaw inverter; B2. The yaw frequency converter receives the yaw command issued by the yaw system execution unit, parses and processes the yaw command, generates a control signal to drive the yaw motor according to the command requirements and preset control parameters, and drives the yaw motor to run at the preset speed and torque by converting the input power energy into the voltage and frequency of the yaw motor; B3. The yaw motor receives the electric energy output by the inverter, converts the electric energy into mechanical energy, outputs torque through the motor bearing, and drives the yaw reducer to rotate. The yaw system has more than one yaw motor, and each yaw motor is equipped with an independent control route to work independently; B4. The yaw reducer is driven by the yaw motor to convert the high-speed low-torque output into a low-speed high-torque output, and the small gear attached to the yaw reducer is adjusted to mesh with the large gear of the yaw bearing, so as to transmit the torque of the yaw reducer to the yaw bearing and control the speed of the yaw bearing; B5. The yaw bearing is used to support the nacelle, hub and blades. It adjusts the yaw bearing speed by meshing with the small gear attached to the yaw reducer. The gear brake disc attached to the yaw bearing locks the yaw bearing through the gear brake disc when receiving a brake command.

[0010] Preferably, in step 4, the process of constructing a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of tooth side clearance in an open-loop working mode includes: C1. According to the rated speed N of the yaw motor rated, set the number of gear rings of the yaw reducer ζ1, the number of gear rings of the yaw bearing large gear ζ2, the transmission ratio of the yaw reducer i, and the yaw angular velocity ω0, calculate the angle θ0 between two adjacent teeth of the yaw bearing, and the time t0 for the yaw motor to accelerate from 0 to the rated speed. The calculation formula is: θ0=360 / Z2; t0=θ0*(60*i*Z 2) / (2*N rated *360*Z1); C2. Calculate the yaw motor torque limit value T0 and the step length ΔT of the output torque gradually increasing to the yaw motor torque limit value T0 in the open-loop mode using the yaw motor rated torque PN. The calculation formula is: T0=1.5*PN; ΔT = T0 / t0; C3, the yaw motor is in open-loop working mode, the yaw inverter is placed in torque control mode, the yaw command is issued, the yaw motor is started, and the output torque is gradually increased according to the step length ΔT within the time t0; C4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the output torque of the yaw inverter reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is meshed with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked until the yaw motor speed reaches N0. It is determined that the yaw reduction pinion is meshed with the yaw bearing gear. After the meshing is completed, it continues to operate based on the open-loop torque control mode until the yaw action is completed.

[0011] Preferably, in step 5, the process of constructing a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of tooth side clearance in a closed-loop working mode includes: D1, according to the rated speed N of the yaw motor rated , set the number of gear rings of the yaw reducer ζ1, the number of gear rings of the yaw bearing large gear ζ2, the transmission ratio of the yaw reducer i, and the yaw angular velocity ω0, calculate the angle between two adjacent teeth of the yaw bearing θ0, and the time t0 for the yaw motor to accelerate from 0 to the rated speed; D2. Calculate the yaw motor speed limit value N0 and the step length ΔN of the output torque gradually increasing to the yaw motor torque limit value T0 in the open-loop mode. The calculation formula is: N0=(ω0*60*i*Ζ2) / (360*Ζ1); ΔN=N0 / t0; D3, the yaw motor is in closed-loop working mode, the yaw inverter is placed in speed control mode, after the yaw command is issued, the PID algorithm is used to adjust the speed of the yaw motor according to the deviation between the target position and the actual position, and within the time t0, the yaw motor is uniformly accelerated to the speed limit value N0 of the yaw motor according to the step length ΔN. D4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the output torque of the yaw inverter reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is meshed with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked until the yaw motor speed reaches N0. It is then determined that the yaw reduction pinion is meshed with the yaw bearing gear. After the meshing is completed, the operation continues based on the closed-loop speed control mode. According to the feedback information transmitted by the speed measurement feedback unit in the yaw motor, the speed is adjusted in real time until the yaw action is completed.

[0012] Preferably, in step six, the process of designing the control flow of the yaw bearing tooth side clearance flexible engagement includes: S1. When the yaw command arrives, the yaw command processing unit immediately feeds back a signal to the upper computer to brake the yaw bearing gear brake disc; S2. Detect whether the yaw motor is equipped with a speed feedback unit, and set the control mode of the yaw inverter. If there is a speed feedback unit, select the speed control mode; if there is no speed feedback unit, select the torque control mode; S3, the control mode of the yaw frequency converter is the speed control mode, and the yaw bearing tooth side clearance flexible meshing closed-loop compensation algorithm is executed; the control mode of the yaw frequency converter is the torque control mode, and the yaw bearing tooth side clearance flexible meshing open-loop compensation algorithm is executed; S4, waiting for all yaw motors to complete engagement; S5, the yaw command processing unit feeds back a signal to the upper computer to release the yaw bearing gear brake disc; S6. The flexible meshing of the yaw bearing tooth side clearance is completed and the yaw is started normally.

[0013] The beneficial effects of the present invention are as follows: compared with the traditional design method for flexible meshing of tooth side clearance of wind turbine yaw bearing, the flexible meshing design method for tooth side clearance of the wind turbine yaw bearing achieves flexible fit between the yaw bearing gear and the yaw reducer pinion with the help of software algorithm, without the need to detect tooth side clearance, and effectively reduces the risks of gear damage and aggravated mechanical damage caused by impact force and excessive force between teeth during yaw startup; for yaw motors not equipped with speed feedback, the present solution can also ensure the flexible meshing of the yaw bearing gear and the yaw reducer pinion. In the case where such motors are not equipped with speed feedback, the corresponding tooth side clearance flexible meshing compensation control algorithm in both open-loop and closed-loop working modes is used to ensure the motor The normal operation of the machine is ensured, which significantly reduces the system cost and enhances the stability of the yaw system. The scheme also realizes the independent control of multiple yaw motors to prevent the uneven force caused by the synchronous control, such as the excessive tightness or inadequate meshing of some yaw reducer gears and yaw bearing gears. When the reducer gears of multiple yaw motors are flexibly meshed, the motor starting current is small, and they start synchronously after meshing, the system noise is low, and the start-up is smooth. In view of the problem that the yaw bearing gear brake disc of the long-term running wind turbine often fails to brake, the scheme proposes to use the speed limit value and torque limit value as the two judgment criteria to judge whether the flexible meshing of the yaw bearing tooth side clearance is completed, which greatly broadens the application field, has excellent adaptability and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of a method for designing flexible meshing of tooth side clearance of a wind power yaw bearing; Figure 2 This is a block diagram of the hardware components of the yaw bearing tooth side flexible engagement of the present invention; Figure 3 The present invention is a control flow chart of the flexible meshing of the tooth side clearance of the yaw bearing. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] like Figures 1 to 3 As shown, the present invention provides a technical solution: a method for designing flexible meshing of tooth side clearance of a wind power yaw bearing, comprising the following steps: Step 1: Design a yaw bearing tooth side flexible meshing hardware unit, wherein the yaw bearing tooth side flexible meshing hardware unit includes a yaw system execution unit, a frequency converter processing unit, a yaw deceleration unit and a yaw bearing support unit. The yaw bearing tooth side flexible meshing hardware unit is used to provide power drive for yaw, so that the wind turbine can adjust the direction of the cabin according to the wind direction, accurately control the motor speed and torque, reduce the speed and increase the torque of the motor power, and mobilize the brake disc to brake, so as to achieve smooth and slow rotation of the cabin; Step 2: Design a yaw command processing unit to process yaw commands, realize the start, stop, forward and reverse rotation of the wind turbine yaw bearing, and determine the tooth side clearance flexible meshing compensation control algorithm under different modes; Step 3: Establish a hardware analysis algorithm for the flexible meshing of the yaw bearing tooth side clearance, and analyze the various components required for the flexible meshing control of the yaw bearing tooth side clearance and their connections and working relationships with each other; Step 4: construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the open-loop working mode, and perform torque control and flexible meshing judgment; Step 5: construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the closed-loop working mode, and perform speed control and dynamic adjustment; Step 6: Design a control process for the flexible meshing of the yaw bearing tooth side clearance. This control process can effectively reduce the impact and vibration caused by excessive or insufficient tooth side clearance, reduce the noise during the operation of the yaw system, and improve the meshing accuracy and transmission efficiency of the gears.

[0017] In step 1, the process of designing the yaw system actuator includes: The yaw system execution unit is composed of a yaw motor, which is divided into two types with rated voltages of 400V AC and 690V AC. The yaw motor is equipped with a speed measurement feedback unit, which is generally composed of a speed sensor, an analog-to-digital converter and a communication interface. The speed sensor is installed on the yaw motor shaft and is used to collect analog signals that describe the motor speed in real time. The analog signals are converted into digital signals through the built-in analog-to-digital converter, which are transmitted and fed back through the communication interface.

[0018] In step 1, the process of designing the inverter processing unit includes: The inverter processing unit is equipped with a dedicated inverter and an input inductor, wherein the dedicated inverter is used to adjust the voltage and frequency of the input yaw motor to control the motor speed and torque; the input inductor is used to suppress the high-order harmonic current generated by the dedicated inverter, and the dedicated inverter is equipped with an energy-consuming braking unit; the energy-consuming braking unit is based on the principle of energy conversion. When braking is required during the inverter's multiple start-stop and acceleration and deceleration processes, the energy-consuming braking unit applies a braking force, and converts the kinetic energy into heat energy for braking through resistance heating and friction movement.

[0019] In step 1, the process of designing the yaw reduction unit includes: The yaw reduction unit consists of a yaw reducer and its pinion, wherein the yaw reducer is used to transmit speed data to the yaw reducer through a speed measurement feedback unit after the yaw motor is started and generates a high-speed rotation speed, and the yaw reducer adjusts the reduction ratio to convert the high-speed and low-torque output of the yaw motor into a low-speed and high-torque output; the pinion of the yaw reducer is installed at the output end of the yaw reducer and meshes with the large gear of the yaw bearing. Through the meshing of the large gear and the pinion, the power between the large gear and the pinion is transmitted to control the speed of the yaw action.

[0020] In step 1, the process of designing the yaw bearing support unit includes: The yaw bearing support unit consists of a yaw bearing, a yaw bearing gear and a gear brake disc, wherein the yaw bearing is used to support the tower top structure, which includes a nacelle, a hub and blades, and bears its radial and axial loads; the yaw bearing gear is used to mesh with the pinion of the yaw reducer to transmit power from the yaw reducer; the gear brake disc is used to lock the yaw bearing, and when there is a yaw action, only back pressure is retained; when no yaw is required, full pressure braking is applied to lock the position of the motor nacelle.

[0021] In step 2, the process of designing a yaw command processing unit to process yaw commands, realize the start, stop, forward and reverse rotation of the wind turbine yaw bearing, and determine the tooth side clearance flexible meshing compensation control algorithm under different modes includes: A1. The yaw command processing unit is the processing module of the yaw frequency converter itself. The yaw command includes the yaw command including start, stop, forward and reverse; A2. Check whether the yaw motor is equipped with a speed feedback unit and set the control mode of the yaw inverter. If it is equipped with a speed feedback unit, select the speed control mode; if it is not equipped with a speed feedback unit, select the torque control mode; A3. Through the selected control mode, before the meshing is completed, set the torque limit value T0, the operating speed limit value N0 and the acceleration / deceleration time t0. The torque limit value T0 and the operating speed limit value N0 are used to determine the meshing condition of the yaw bearing gear and the reducer pinion. The deceleration time is the time t0 for the yaw motor to accelerate from 0 to the rated speed of the motor. In the speed control mode, the maximum rated torque of the yaw motor is set as the torque limit value, the maximum operating speed is set as the operating speed limit value, and the real-time acceleration / deceleration time is set as the acceleration / deceleration time; in the torque control mode, set the actual operating torque of the yaw motor as the torque limit value, the actual average operating speed as the operating speed limit value, and the real-time acceleration / deceleration time as the acceleration / deceleration time; A4. According to the control mode of the yaw inverter, determine the tooth side clearance flexible meshing compensation control algorithm in different modes.

[0022] In step 3, a hardware analysis algorithm for the flexible meshing of the yaw bearing tooth side clearance is established. The process of analyzing the various components required for the flexible meshing control of the yaw bearing tooth side clearance and their connections and working relationships includes: B1. According to the wind direction information and the feedback information of the yaw motor, the yaw system execution unit generates a yaw command and sends it to the yaw inverter; B2. The yaw frequency converter receives the yaw command issued by the yaw system execution unit, parses and processes the yaw command, generates a control signal to drive the yaw motor according to the command requirements and preset control parameters, and drives the yaw motor to run at the preset speed and torque by converting the input power energy into the voltage and frequency of the yaw motor; B3. The yaw motor receives the electric energy output by the inverter, converts the electric energy into mechanical energy, outputs torque through the motor bearing, and drives the yaw reducer to rotate. The yaw system has more than one yaw motor, and each yaw motor is equipped with an independent control route to work independently; B4. The yaw reducer is driven by the yaw motor to convert the high-speed low-torque output into a low-speed high-torque output, and the small gear attached to the yaw reducer is adjusted to mesh with the large gear of the yaw bearing, so as to transmit the torque of the yaw reducer to the yaw bearing and control the speed of the yaw bearing; B5. The yaw bearing is used to support the nacelle, hub and blades. It adjusts the yaw bearing speed by meshing with the small gear attached to the yaw reducer. The gear brake disc attached to the yaw bearing locks the yaw bearing through the gear brake disc when receiving a brake command.

[0023] In step 4, the process of constructing a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the open-loop working mode includes: C1. According to the rated speed N of the yaw motor rated, set the number of gear rings of the yaw reducer ζ1, the number of gear rings of the yaw bearing large gear ζ2, the transmission ratio of the yaw reducer i, and the yaw angular velocity ω0, calculate the angle θ0 between two adjacent teeth of the yaw bearing, and the time t0 for the yaw motor to accelerate from 0 to the rated speed. The calculation formula is: θ0=360 / Z2; t0=θ0*(60*i*Z 2) / (2*N rated *360*Z1); C2. Calculate the yaw motor torque limit value T0 and the step length ΔT of the output torque gradually increasing to the yaw motor torque limit value T0 in the open-loop mode. The calculation formula is: T0=(1.5*rated torque of yaw motor); ΔT = T0 / t0; C3, the yaw motor is in open-loop working mode, the yaw inverter is placed in torque control mode, the yaw command is issued, the yaw motor is started, and the output torque is gradually increased according to the step length ΔT within the time t0; C4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the output torque of the yaw inverter reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is meshed with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked until the yaw motor speed reaches N0. It is determined that the yaw reduction pinion is meshed with the yaw bearing gear. After the meshing is completed, it continues to operate based on the open-loop torque control mode until the yaw action is completed.

[0024] In step 5, the process of constructing a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the closed-loop working mode includes: D1, according to the rated speed N of the yaw motor rated , set the number of gear rings of the yaw reducer ζ1, the number of gear rings of the yaw bearing large gear ζ2, the transmission ratio of the yaw reducer i, and the yaw angular velocity ω0, calculate the angle between two adjacent teeth of the yaw bearing θ0, and the time t0 for the yaw motor to accelerate from 0 to the rated speed; D2. Calculate the yaw motor speed limit value N0 and the step length ΔN of the output torque gradually increasing to the yaw motor torque limit value T0 in the open-loop mode. The calculation formula is: N0=(ω0*60*i*Ζ2) / (360*Ζ1); ΔN=N0 / t0; D3, the yaw motor is in closed-loop working mode, the yaw inverter is placed in speed control mode, after the yaw command is issued, the PID algorithm is used to adjust the speed of the yaw motor according to the deviation between the target position and the actual position, and within the time t0, the yaw motor is uniformly accelerated to the speed limit value N0 of the yaw motor according to the step length ΔN. D4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the output torque of the yaw inverter reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is meshed with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked until the yaw motor speed reaches N0. It is then determined that the yaw reduction pinion is meshed with the yaw bearing gear. After the meshing is completed, the operation continues based on the closed-loop speed control mode. According to the feedback information transmitted by the speed measurement feedback unit in the yaw motor, the speed is adjusted in real time until the yaw action is completed.

[0025] In step 6, the process of designing the control flow of the yaw bearing tooth side clearance flexible meshing includes: S1. When the yaw command arrives, the yaw command processing unit immediately feeds back a signal to the upper computer to brake the yaw bearing gear brake disc; S2. Detect whether the yaw motor is equipped with a speed feedback unit, and set the control mode of the yaw inverter. If there is a speed feedback unit, select the speed control mode; if there is no speed feedback unit, select the torque control mode; S3, the control mode of the yaw frequency converter is the speed control mode, and the yaw bearing tooth side clearance flexible meshing closed-loop compensation algorithm is executed; the control mode of the yaw frequency converter is the torque control mode, and the yaw bearing tooth side clearance flexible meshing open-loop compensation algorithm is executed; S4, waiting for all yaw motors to complete engagement; S5, the yaw command processing unit feeds back a signal to the upper computer to release the yaw bearing gear brake disc; S6. The flexible meshing of the yaw bearing tooth side clearance is completed and the yaw is started normally.

[0026] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing, characterized in that: The following steps are involved: Step 1: Design a yaw bearing tooth side flexible meshing hardware unit, wherein the yaw bearing tooth side flexible meshing hardware unit includes a yaw system execution unit, a frequency converter processing unit, a yaw deceleration unit and a yaw bearing support unit. The yaw bearing tooth side flexible meshing hardware unit is used to provide power drive for yaw, so that the wind turbine can adjust the direction of the cabin according to the wind direction, accurately control the motor speed and torque, reduce the speed and increase the torque of the motor power, and mobilize the brake disc to brake, so as to achieve smooth and slow rotation of the cabin; Step 2: Design a yaw command processing unit to process yaw commands, realize the start, stop, forward and reverse rotation of the wind turbine yaw bearing, and determine the tooth side clearance flexible meshing compensation control algorithm under different modes; Step 3: Establish a hardware analysis algorithm for the flexible meshing of the yaw bearing tooth side clearance, and analyze the various components required for the flexible meshing control of the yaw bearing tooth side clearance and their connections and working relationships with each other; Step 4: construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the open-loop working mode, and perform torque control and flexible meshing judgment; Step 5: construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in a closed-loop working mode, and perform speed control and dynamic adjustment; Step 6: Design a control process for the flexible engagement of the yaw bearing tooth side clearance, and use the control process to regulate the impact and vibration caused by excessive or insufficient tooth side clearance.

2. The method for designing the flexible meshing of the tooth side clearance of a wind turbine yaw bearing according to claim 1, characterized in that: In the step 1, the process of designing the yaw system execution unit includes: The yaw system execution unit is composed of a yaw motor, which is divided into two types: 400V AC and 690V AC rated voltage. A speed measurement feedback unit is provided for the yaw motor, which is composed of a speed sensor, an analog-to-digital converter and a communication interface. The speed sensor is installed on the yaw motor shaft and is used to collect analog signals that describe the motor speed in real time. The analog signals are converted into digital signals through a built-in analog-to-digital converter, which are transmitted and fed back through a communication interface.

3. The method for designing the flexible meshing of the tooth side clearance of a wind turbine yaw bearing according to claim 2, characterized in that: In the step 1, the process of designing the inverter processing unit includes: The inverter processing unit is equipped with a dedicated inverter and an input reactor, wherein the dedicated inverter is used to adjust the voltage and frequency of the input yaw motor to control the motor speed and torque; The input reactor is used to suppress the high-order harmonic current generated by the dedicated frequency converter, and the dedicated frequency converter is equipped with an energy-consuming braking unit; The energy-consuming braking unit is based on the energy conversion principle. When braking is required during the inverter's multiple starts, stops, accelerations and decelerations, the energy-consuming braking unit applies a braking force and converts kinetic energy into heat energy for braking through resistance heating and friction movement.

4. The method for designing the flexible meshing of the tooth side clearance of a wind turbine yaw bearing according to claim 3 is characterized in that: In the step 1, the process of designing the yaw speed reduction unit includes: The yaw reduction unit is composed of a yaw reducer and a pinion thereof, wherein the yaw reducer is used to transmit speed data to the yaw reducer through a speed measurement feedback unit after the yaw motor is started and generates a high-speed rotation speed, and the yaw reducer adjusts the reduction ratio to convert the high-speed and low-torque output of the yaw motor into a low-speed and high-torque output; The pinion gear of the yaw reducer is installed at the output end of the yaw reducer and meshes with the large gear of the yaw bearing. The power between the large gear and the pinion gear is transmitted through the meshing of the large gear and the small gear to control the speed of the yaw action.

5. The method for designing flexible meshing of the tooth side clearance of a wind turbine yaw bearing according to claim 4, characterized in that: In the step 1, the process of designing the yaw bearing support unit includes: The yaw bearing support unit is composed of a yaw bearing, a yaw bearing gear and a gear brake disc thereof, wherein the yaw bearing is used to support the tower top structure, which includes a nacelle, a hub and blades, and bears its radial and axial loads; The yaw bearing large gear is used to mesh with the small gear of the yaw reducer to transmit power from the yaw reducer; The gear brake disc is used to lock the yaw bearing. When there is a yaw action, only back pressure is retained; when there is no need for yaw, full pressure braking is applied to lock the position of the motor cabin.

6. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 5, characterized in that: In the step 2, the process of designing a yaw command processing unit, processing a yaw command, realizing the start, stop, forward and reverse rotation of the wind turbine yaw bearing, and determining the tooth side clearance flexible meshing compensation control algorithm in different modes includes: A1. The yaw command processing unit is a processing module of the yaw frequency converter itself. The yaw command includes the yaw command including start, stop, forward and reverse; A2. Check whether the yaw motor is equipped with a speed feedback unit and set the control mode of the yaw inverter. If it is equipped with a speed feedback unit, select the speed control mode; if it is not equipped with a speed feedback unit, select the torque control mode; A3. Through the selected control mode, before the meshing is completed, set the torque limit value T0, the operating speed limit value N0 and the acceleration / deceleration time t0. The torque limit value T0 and the operating speed limit value N0 are used to determine the meshing condition of the yaw bearing gear and the reducer pinion. The deceleration time is the time t0 for the yaw motor to accelerate from 0 to the rated speed of the motor. In the speed control mode, the maximum rated torque of the yaw motor is set as the torque limit value, the maximum operating speed is set as the operating speed limit value, and the real-time acceleration / deceleration time is set as the acceleration / deceleration time; in the torque control mode, set the actual operating torque of the yaw motor as the torque limit value, the actual average operating speed as the operating speed limit value, and the real-time acceleration / deceleration time as the acceleration / deceleration time; A4. According to the control mode of the yaw inverter, determine the tooth side clearance flexible meshing compensation control algorithm in different modes.

7. The method for designing the flexible meshing of the tooth side clearance of a wind turbine yaw bearing according to claim 6, characterized in that: In the step 3, a hardware analysis algorithm for the flexible meshing of the tooth side clearance of the yaw bearing is established, and the process of analyzing the various components required for the flexible meshing control of the tooth side clearance of the yaw bearing and their connections and working relationships with each other includes: B1. According to the wind direction information and the feedback information of the yaw motor, the yaw system execution unit generates a yaw command and sends it to the yaw inverter; B2. The yaw frequency converter receives the yaw command issued by the yaw system execution unit, parses and processes the yaw command, generates a control signal to drive the yaw motor according to the command requirements and preset control parameters, and drives the yaw motor to run at the preset speed and torque by converting the input power energy into the voltage and frequency of the yaw motor; B3. The yaw motor receives the electric energy output by the inverter, converts the electric energy into mechanical energy, outputs torque through the motor bearing, and drives the yaw reducer to rotate; B4. The yaw reducer is driven by the yaw motor to convert the high-speed low-torque output into a low-speed high-torque output, and the small gear attached to the yaw reducer is adjusted to mesh with the large gear of the yaw bearing, so as to transmit the torque of the yaw reducer to the yaw bearing and control the speed of the yaw bearing; B5. The yaw bearing is used to support the nacelle, hub and blades. It adjusts the yaw bearing speed by meshing with the small gear attached to the yaw reducer. The gear brake disc attached to the yaw bearing locks the yaw bearing through the gear brake disc when receiving a brake command.

8. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 7, characterized in that: In the step 4, the process of constructing a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the open-loop working mode includes: C1. According to the rated speed N of the yaw motor rated , set the number of gear rings of the yaw reducer ζ1, the number of gear rings of the yaw bearing large gear ζ2, the transmission ratio of the yaw reducer i, and the yaw angular velocity ω0, calculate the angle θ0 between two adjacent teeth of the yaw bearing, and the time t0 for the yaw motor to accelerate from 0 to the rated speed. The calculation formula is: θ0=360 / Z2; t0=θ0*(60*i*Ζ 2) / (2*N rated *360*Z1); C2. Calculate the yaw motor torque limit value T0 and the step length ΔT of the output torque gradually increasing to the yaw motor torque limit value T0 in the open-loop mode using the yaw motor rated torque PN. The calculation formula is: T0=1.5*PN; ΔT = T0 / t0; C3, the yaw motor is in open-loop working mode, the yaw inverter is placed in torque control mode, the yaw command is issued, the yaw motor is started, and the output torque is gradually increased according to the step length ΔT within the time t0; C4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the output torque of the yaw inverter reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is meshed with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked until the yaw motor speed reaches N0. It is determined that the yaw reduction pinion is meshed with the yaw bearing gear. After the meshing is completed, it continues to operate based on the open-loop torque control mode until the yaw action is completed.

9. The method for designing flexible meshing of the tooth side clearance of a wind turbine yaw bearing according to claim 8, characterized in that: In the step 5, the process of constructing a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of the tooth side clearance in the closed-loop working mode includes: D1, according to the rated speed N of the yaw motor rated , set the number of gear rings of the yaw reducer ζ1, the number of gear rings of the yaw bearing large gear ζ2, the transmission ratio of the yaw reducer i, and the yaw angular velocity ω0, calculate the angle between two adjacent teeth of the yaw bearing θ0, and the time t0 for the yaw motor to accelerate from 0 to the rated speed; D2. Calculate the yaw motor speed limit value N0 and the step length ΔN of the output torque gradually increasing to the yaw motor torque limit value T0 in the open-loop mode. The calculation formula is: N0=(ω0*60*i*Ζ2) / (360*Ζ1); ΔN=N0 / t0; D3, the yaw motor is in closed-loop working mode, the yaw inverter is placed in speed control mode, after the yaw command is issued, the PID algorithm is used to adjust the speed of the yaw motor according to the deviation between the target position and the actual position, and within the time t0, it is uniformly accelerated to the yaw motor speed limit value N0 according to the step length ΔN; D4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the output torque of the yaw inverter reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is meshed with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked until the yaw motor speed reaches N0. It is then determined that the yaw reduction pinion is meshed with the yaw bearing gear. After the meshing is completed, the operation continues based on the closed-loop speed control mode. According to the feedback information transmitted by the speed measurement feedback unit in the yaw motor, the speed is adjusted in real time until the yaw action is completed.

10. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 9, characterized in that: In step 6, the process of designing the control flow of the yaw bearing tooth side clearance flexible meshing includes: S1. When the yaw command arrives, the yaw command processing unit immediately feeds back a signal to the upper computer to brake the yaw bearing gear brake disc; S2. Detect whether the yaw motor is equipped with a speed feedback unit, and set the control mode of the yaw inverter. If there is a speed feedback unit, select the speed control mode; if there is no speed feedback unit, select the torque control mode; S3, the control mode of the yaw frequency converter is the speed control mode, and the yaw bearing tooth side clearance flexible meshing closed-loop compensation algorithm is executed; the control mode of the yaw frequency converter is the torque control mode, and the yaw bearing tooth side clearance flexible meshing open-loop compensation algorithm is executed; S4, waiting for all yaw motors to complete engagement; S5, the yaw command processing unit feeds back a signal to the upper computer to release the yaw bearing gear brake disc; S6. The flexible meshing of the yaw bearing tooth side clearance is completed and the yaw is started normally.

Images