A design method for flexible meshing of tooth side clearance of wind turbine yaw bearings

Abstract

The present invention discloses a method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing. The present invention relates to the field of yaw motor control technology and comprises the following steps: designing a hardware unit for flexible meshing of tooth side clearance of a yaw bearing, setting a yaw instruction processing unit, processing a yaw instruction, establishing a hardware principle block diagram for flexible meshing of tooth side clearance of a yaw bearing, developing a compensation control algorithm for realizing flexible meshing of tooth side clearance of a yaw motor in open-loop and closed-loop working modes and a control process for flexible meshing of tooth side clearance of a yaw bearing. Compared with the traditional method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing, the method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing achieves flexible fit between a large gear of a yaw bearing and a small gear of a yaw reducer by means of a software algorithm, without the need to detect tooth side clearance, thereby effectively reducing the risk of gear damage and aggravated mechanical damage due to excessive impact force and inter-tooth force during yaw startup.

Description

Technical Field

[0001] The present 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 yaw bearing is a critical component in wind turbines. It supports the nacelle, blades, and hub, and applies axial and radial loads and overturning moments. It transmits aerodynamic forces acting on the blades to the tower, enabling the nacelle to rotate and adjust according to wind direction, ensuring the blades are always in the optimal windward position. To improve power generation efficiency and extend equipment life, the design of the yaw bearing must consider multiple factors, including load capacity, wear resistance, sealing performance, and ease of maintenance. The flexible meshing design method for side clearance is a key improvement in yaw bearing gear systems. Traditional yaw bearing gears can develop excessive side clearance over time due to wear or manufacturing errors. Field measurement of the inter-tooth clearance and the installation of mechanical components to compensate for the gap in areas with large gaps are one solution to address the gap between the yaw bearing ring gear and the yaw reducer pinion. However, this method is inefficient and difficult to implement in wind turbines. Flexible meshing design aims to optimize the gear geometry and material properties to ensure that the gears maintain good meshing even with slight installation errors or wear.

[0003] Although the existing design method of flexible meshing of tooth side clearance of wind turbine yaw bearings 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. Over time, a gap may appear between the large gear ring and the small gear of the reducer, resulting in inter-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 braking motor, replacing the original motor in the yaw fan that has been installed and put into use will increase the cost and increase the adaptability 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 different loads, 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, it is impossible to achieve flexible engagement between the yaw bearing ring gear and the yaw reducer pinion. Summary of the Invention

[0004] 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 turbine yaw bearing, comprising the following steps:

[0005] 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, allowing the wind turbine to adjust the nacelle orientation according to wind direction, accurately control the motor speed and torque, reduce the motor power and increase the torque, and mobilize the brake disc to achieve smooth and slow rotation of the nacelle;

[0006] 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;

[0007] 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;

[0008] Step 4: Construct a compensation control algorithm suitable for achieving flexible meshing of tooth side clearance in the yaw motor in open-loop operation mode, and perform torque control and flexible meshing determination;

[0009] Step 5: Construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of tooth backlash in closed-loop operation mode, and perform speed control and dynamic adjustment;

[0010] 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 yaw system operation, and improve the gear meshing accuracy and transmission efficiency.

[0011] Preferably, in step 1, the process of designing the yaw system execution unit includes:

[0012] 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 an analog signal that describes the motor speed in real time. The analog signal is converted into a digital signal through the built-in analog-to-digital converter, and transmitted and fed back through the communication interface.

[0013] Preferably, in step 1, the process of designing the frequency converter processing unit includes:

[0014] 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 currents 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 energy conversion principle. When braking is required during the inverter's multiple start-stop and acceleration and deceleration processes, the energy-consuming braking unit applies braking force and converts kinetic energy into heat energy for braking through resistance heating and friction motion.

[0015] Preferably, in step 1, the process of designing the yaw reduction unit includes:

[0016] 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. 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.

[0017] Preferably, in step 1, the process of designing the yaw bearing support unit includes:

[0018] The yaw bearing support unit consists of a yaw bearing, a yaw bearing gearwheel and a gear brake disc. 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 gearwheel is used to engage 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. When there is a yaw action, only back pressure is retained; when yaw is not required, full pressure braking is applied to lock the position of the motor nacelle.

[0019] Preferably, in step 2, the process of designing a yaw command processing unit to process yaw commands, realize the start, stop, forward rotation and reverse rotation of the wind turbine yaw bearing, and determine the tooth side clearance flexible meshing compensation control algorithm in different modes includes:

[0020] 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;

[0021] 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.

[0022] A3. According to the selected control mode, before the meshing is completed, the torque limit value T0, the operating speed limit value N0 and the acceleration / deceleration time t0 are set. 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, the actual operating torque of the yaw motor is set as the torque limit value, the actual average operating speed is set as the operating speed limit value, and the real-time acceleration / deceleration time is set as the acceleration / deceleration time.

[0023] A4. According to the control mode of the yaw frequency converter, determine the tooth side clearance flexible meshing compensation control algorithm in different modes.

[0024] Preferably, in step 3, establishing a hardware analysis algorithm for the flexible meshing of the yaw bearing tooth side clearance, and analyzing the components required for the flexible meshing control of the yaw bearing tooth side clearance and their connections and working relationships include:

[0025] B1. Based on wind direction information and feedback from the yaw motor, the yaw system execution unit generates a yaw command and sends it to the yaw inverter.

[0026] B2. The yaw frequency converter receives the yaw command issued by the yaw system execution unit, parses and processes the yaw command, and generates a control signal to drive the yaw motor according to the command requirements and preset control parameters. By converting the input power energy into the voltage and frequency of the yaw motor, the yaw motor is driven to operate at the preset speed and torque;

[0027] B3. The yaw motor receives the electrical energy output by the inverter, converts the electrical 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;

[0028] B4. The yaw reducer is driven by the yaw motor, converting high-speed, low-torque output into low-speed, high-torque output. The small gear attached to the yaw reducer is engaged with the large gear of the yaw bearing, transmitting the torque of the yaw reducer to the yaw bearing and controlling the speed of the yaw bearing.

[0029] B5. The yaw bearing supports the nacelle, hub, and blades. It adjusts the yaw bearing speed by meshing with the pinion attached to the yaw reducer. The gear brake disc attached to the yaw bearing locks the yaw bearing when a brake command is received.

[0030] Preferably, in step 4, the process of constructing a compensation control algorithm suitable for achieving flexible engagement of tooth side clearance in the yaw motor in an open-loop working mode includes:

[0031] C1, according to the rated speed N of the yaw motor rated , set the number of yaw reducer gear rings Ζ1, the number of yaw bearing large gear gear rings Ζ2, the yaw reducer transmission ratio i, and the yaw angular velocity ω0, and 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:

[0032] θ0=360 / Ζ2;

[0033] t0=θ0*(60*i*Ζ 2) / (2*N rated *360*Ζ1);

[0034] C2. Calculate the yaw motor torque limit value T0 and the step length ΔT of gradually increasing the output torque to the yaw motor torque limit value T0 in open-loop mode using the yaw motor rated torque PN. The calculation formula is:

[0035] T0=1.5*PN;

[0036] ΔT= T0 / t0;

[0037] 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 within time t0, the output torque is gradually increased according to the step size ΔT;

[0038] C4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the yaw inverter output torque reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is engaged 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 engaged with the yaw bearing gear. After the engagement is completed, the system continues to operate in open-loop torque control mode until the yaw action is completed.

[0039] Preferably, in step 5, the process of constructing a compensation control algorithm suitable for achieving flexible engagement of tooth side clearance in a closed-loop working mode of the yaw motor includes:

[0040] 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 i of the yaw reducer, 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;

[0041] D2. Calculate the yaw motor speed limit value N0 and the step length ΔN required for the output torque to gradually increase to the yaw motor torque limit value T0 in open-loop mode. The calculation formula is:

[0042] N0=(ω0*60*i*Ζ2) / (360*Ζ1);

[0043] ΔN=N0 / t0;

[0044] 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 size ΔN.

[0045] D4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the yaw inverter output torque reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is engaged 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 engaged with the yaw bearing gear. After the engagement is completed, the closed-loop speed control mode is continued to operate. 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.

[0046] Preferably, in step 6, the process of designing a control flow for flexible meshing of the yaw bearing tooth side clearance includes:

[0047] 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;

[0048] S2. Check whether the yaw motor is equipped with a speed feedback unit and set the control mode of the yaw inverter. If a speed feedback unit is present, select the speed control mode; if no speed feedback unit is present, select the torque control mode.

[0049] S3: The control mode of the yaw frequency converter is 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 torque control mode, and the yaw bearing tooth side clearance flexible meshing open-loop compensation algorithm is executed;

[0050] S4, waiting for all yaw motors to complete engagement;

[0051] S5, the yaw command processing unit feeds back a signal to the upper computer to release the yaw bearing gear brake disc;

[0052] S6. The flexible engagement of the yaw bearing tooth side clearance is completed and the yaw is started normally.

[0053] Beneficial effects of the present invention: 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 wind turbine yaw bearing achieves flexible fit between the yaw bearing gear and the yaw reducer gear with the help of software algorithm, without the need to detect tooth side clearance, effectively reducing the risk of gear damage and aggravated mechanical damage caused by impact force and excessive force between teeth during yaw startup; for yaw motors that are not equipped with speed feedback, this solution can also ensure the flexible meshing of the yaw bearing gear and the yaw reducer gear. In the case that 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 flexibility of the motor. The normal operation of the machine is ensured, which significantly reduces the system cost and enhances the stability of the yaw system. This solution also realizes the independent control of multiple yaw motors, and prevents the uneven force caused by excessive or inadequate meshing of some yaw reducer gears and yaw bearing gears due to synchronous control. Moreover, when the reducer gears of multiple yaw motors are flexibly meshed, the motor starting current is small, and they start synchronously after meshing, with low system noise and smooth startup. In view of the problem that the yaw bearing gear brake disc of the long-term running wind turbine often fails to brake, this solution 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

[0054] Figure 1 This is a flow chart of a method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to the present invention;

[0055] Figure 2 This is a block diagram of the hardware components of the yaw bearing tooth side flexible engagement of the present invention;

[0056] Figure 3 This is a control flow chart of the flexible engagement of the tooth side clearance of the yaw bearing of the present invention. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0058] like Figures 1 to 3As shown, the present invention provides a technical solution: a method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing, comprising the following steps:

[0059] 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, allowing the wind turbine to adjust the nacelle orientation according to wind direction, accurately control the motor speed and torque, reduce the motor power and increase the torque, and mobilize the brake disc to achieve smooth and slow rotation of the nacelle;

[0060] 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;

[0061] 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;

[0062] Step 4: Construct a compensation control algorithm suitable for achieving flexible meshing of tooth side clearance in the yaw motor in open-loop operation mode, and perform torque control and flexible meshing determination;

[0063] Step 5: Construct a compensation control algorithm suitable for the yaw motor to achieve flexible meshing of tooth backlash in closed-loop operation mode, and perform speed control and dynamic adjustment;

[0064] 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 yaw system operation, and improve the gear meshing accuracy and transmission efficiency.

[0065] In step 1, the process of designing the yaw system actuator includes:

[0066] 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 an analog signal that describes the motor speed in real time. The analog signal is converted into a digital signal through the built-in analog-to-digital converter, and transmitted and fed back through the communication interface.

[0067] In step 1, the process of designing the inverter processing unit includes:

[0068] 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 currents 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 energy conversion principle. When braking is required during the inverter's multiple start-stop and acceleration and deceleration processes, the energy-consuming braking unit applies braking force and converts kinetic energy into heat energy for braking through resistance heating and friction motion.

[0069] In step 1, the process of designing the yaw reduction unit includes:

[0070] 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. 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.

[0071] In step 1, the process of designing the yaw bearing support unit includes:

[0072] The yaw bearing support unit consists of a yaw bearing, a yaw bearing gearwheel and a gear brake disc. 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 gearwheel is used to engage 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. When there is a yaw action, only back pressure is retained; when yaw is not required, full pressure braking is applied to lock the position of the motor nacelle.

[0073] In step 2, the design of the yaw command processing unit processes the yaw command to 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 in different modes. The process includes:

[0074] 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;

[0075] 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.

[0076] A3. According to the selected control mode, before the meshing is completed, the torque limit value T0, the operating speed limit value N0 and the acceleration / deceleration time t0 are set. 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, the actual operating torque of the yaw motor is set as the torque limit value, the actual average operating speed is set as the operating speed limit value, and the real-time acceleration / deceleration time is set as the acceleration / deceleration time.

[0077] A4. According to the control mode of the yaw frequency converter, determine the tooth side clearance flexible meshing compensation control algorithm in different modes.

[0078] 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:

[0079] B1. Based on wind direction information and feedback from the yaw motor, the yaw system execution unit generates a yaw command and sends it to the yaw inverter.

[0080] B2. The yaw frequency converter receives the yaw command issued by the yaw system execution unit, parses and processes the yaw command, and generates a control signal to drive the yaw motor according to the command requirements and preset control parameters. By converting the input power energy into the voltage and frequency of the yaw motor, the yaw motor is driven to operate at the preset speed and torque;

[0081] B3. The yaw motor receives the electrical energy output by the inverter, converts the electrical 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;

[0082] B4. The yaw reducer is driven by the yaw motor, converting high-speed, low-torque output into low-speed, high-torque output. The small gear attached to the yaw reducer is engaged with the large gear of the yaw bearing, transmitting the torque of the yaw reducer to the yaw bearing and controlling the speed of the yaw bearing.

[0083] B5. The yaw bearing supports the nacelle, hub, and blades. It adjusts the yaw bearing speed by meshing with the pinion attached to the yaw reducer. The gear brake disc attached to the yaw bearing locks the yaw bearing when a brake command is received.

[0084] In step 4, the process of constructing a compensation control algorithm for achieving flexible engagement of tooth backlash in the yaw motor in open-loop operation mode includes:

[0085] C1. According to the rated speed N of the yaw motor rated , set the number of yaw reducer gear rings Ζ1, the number of yaw bearing large gear gear rings Ζ2, the yaw reducer transmission ratio i, and the yaw angular velocity ω0, and 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:

[0086] θ0=360 / Ζ2;

[0087] t0=θ0*(60*i*Ζ 2) / (2*N rated *360*Ζ1);

[0088] C2. Calculate the yaw motor torque limit value T0 and the step length ΔT at which the output torque gradually increases to the yaw motor torque limit value T0 in open-loop mode. The calculation formula is:

[0089] T0=(1.5*rated torque of yaw motor);

[0090] ΔT= T0 / t0;

[0091] 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 within time t0, the output torque is gradually increased according to the step size ΔT;

[0092] C4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the yaw inverter output torque reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is engaged 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 engaged with the yaw bearing gear. After the engagement is completed, the system continues to operate in open-loop torque control mode until the yaw action is completed.

[0093] In step 5, the process of constructing a compensation control algorithm for achieving flexible engagement of tooth backlash in the closed-loop operation mode of the yaw motor includes:

[0094] 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 i of the yaw reducer, 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;

[0095] D2. Calculate the yaw motor speed limit value N0 and the step length ΔN required for the output torque to gradually increase to the yaw motor torque limit value T0 in open-loop mode. The calculation formula is:

[0096] N0=(ω0*60*i*Ζ2) / (360*Ζ1);

[0097] ΔN=N0 / t0;

[0098] 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 size ΔN.

[0099] D4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the yaw inverter output torque reaches T0, the yaw bearing gear and its gear brake disc are braked, and the yaw reduction pinion is engaged 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 engaged with the yaw bearing gear. After the engagement is completed, the closed-loop speed control mode is continued to operate. 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.

[0100] In step 6, the process of designing the control flow for the flexible meshing of the yaw bearing tooth side clearance includes:

[0101] 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;

[0102] S2. Check whether the yaw motor is equipped with a speed feedback unit and set the control mode of the yaw inverter. If a speed feedback unit is present, select the speed control mode; if no speed feedback unit is present, select the torque control mode.

[0103] S3: The control mode of the yaw frequency converter is 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 torque control mode, and the yaw bearing tooth side clearance flexible meshing open-loop compensation algorithm is executed;

[0104] S4, waiting for all yaw motors to complete engagement;

[0105] S5, the yaw command processing unit feeds back a signal to the upper computer to release the yaw bearing gear brake disc;

[0106] S6. The flexible engagement of the yaw bearing tooth side clearance is completed and the yaw is started normally.

[0107] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprise," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations. The phrase "includes an element defined by..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0108] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the 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 by: 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, allowing the wind turbine to adjust the nacelle orientation according to wind direction, accurately control the motor speed and torque, reduce the motor power and increase the torque, and mobilize the brake disc to achieve smooth and slow rotation of the nacelle; 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 in different modes; 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 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. According to the selected control mode, before the meshing is completed, the torque limit value T0, the operating speed limit value N0 and the acceleration / deceleration time t0 are set. 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, the actual operating torque of the yaw motor is set as the torque limit value, the actual average operating speed is set as the operating speed limit value, and the real-time acceleration / deceleration time is set as the acceleration / deceleration time. A4. According to the control mode of the yaw frequency converter, determine the tooth side clearance flexible meshing compensation control algorithm in 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; Step 4: Constructing a compensation control algorithm suitable for achieving flexible meshing of tooth side clearance in the yaw motor in an open-loop working mode, and performing torque control and flexible meshing determination. In step 4, the process of constructing a compensation control algorithm suitable for achieving flexible meshing of tooth side clearance in the yaw motor in an open-loop working mode includes: C1, according to the rated speed N of the yaw motor rated , set the number of yaw reducer gear rings Ζ1, the number of yaw bearing large gear gear rings Ζ2, the yaw reducer transmission ratio i, and the yaw angular velocity ω0, and 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 / Ζ2; 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 gradually increasing the output torque to the yaw motor torque limit value T0 in 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 within time t0, the output torque is gradually increased according to the step size ΔT; C4. Real-time monitoring of the yaw motor speed ω. When ω = 0° / s and the yaw inverter output torque reaches T0, the yaw bearing gear and its gear brake disc are braked to a stop, and the yaw reduction pinion engages with the yaw bearing gear. When ω > 0° / s, the yaw bearing gear and its gear brake disc cannot be braked to a stop. Until the yaw motor speed reaches N0, it is determined that the yaw reduction pinion is engaged with the yaw bearing gear. After engagement is completed, the system continues to operate in open-loop torque control mode until the yaw action is completed. Step 5: Constructing a compensation control algorithm suitable for achieving flexible meshing of tooth side clearance in a closed-loop operating mode of the yaw motor, and performing speed control and dynamic adjustment. In step 5, the process of constructing a compensation control algorithm suitable for achieving flexible meshing of tooth side clearance in a closed-loop operating mode of the yaw motor 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 i of the yaw reducer, 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; D2. Calculate the yaw motor speed limit value N0 and the step length ΔN required for the output torque to gradually increase to the yaw motor torque limit value T0 in 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 operation mode, and the yaw inverter is placed in speed control mode. After the yaw command is issued, the PID algorithm is used to adjust the yaw motor speed according to the deviation between the target position and the actual position. Within time t0, the yaw motor is uniformly accelerated to the yaw motor speed limit value N0 according to the step size ΔN; D4. Real-time monitoring of the yaw motor speed ω. When ω=0° / s and the yaw inverter output torque reaches T0, the yaw bearing gear and its gear brake disc are braked to a stop, and the yaw reduction pinion engages with the yaw bearing gear. When ω>0° / s, the yaw bearing gear and its gear brake disc cannot be braked to a stop. Until the yaw motor speed reaches N0, it is determined that the yaw reduction pinion is engaged with the yaw bearing gear. After engagement is completed, the closed-loop speed control mode is continued. 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. 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 and insufficient tooth side clearance.

2. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 1, characterized in that: 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 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, and are transmitted and fed back through the communication interface.

3. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 2, characterized in that: 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 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 equip the dedicated frequency converter with an energy-consuming braking unit; The dynamic braking unit is based on the energy conversion principle. When braking is required during the inverter's multiple start-stop and acceleration / deceleration processes, the dynamic braking unit applies braking force and converts kinetic energy into thermal energy through resistance heating and friction movement for braking.

4. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 3, characterized in that: In step 1, the process of designing the yaw 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. The yaw reducer adjusts the reduction ratio and converts 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. The meshing of the large gear and the pinion transmits power between the large gear and the pinion to control the speed of the yaw action.

5. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 4, characterized in that: 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 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 yaw action, only back pressure is retained; when yaw is not required, full pressure brake 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 step 3, a hardware analysis algorithm for the flexible meshing of the yaw bearing tooth side clearance is established, and 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. Based on wind direction information and feedback from 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, and generates a control signal to drive the yaw motor according to the command requirements and preset control parameters. By converting the input power energy into the voltage and frequency of the yaw motor, the yaw motor is driven to operate at the preset speed and torque; B3. The yaw motor receives the electrical energy output by the inverter, converts the electrical 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, converting high-speed, low-torque output into low-speed, high-torque output. The small gear attached to the yaw reducer is engaged with the large gear of the yaw bearing, transmitting the torque of the yaw reducer to the yaw bearing and controlling the speed of the yaw bearing. B5. The yaw bearing supports the nacelle, hub, and blades. It adjusts the yaw bearing speed by meshing with the pinion attached to the yaw reducer. The gear brake disc attached to the yaw bearing locks the yaw bearing when a brake command is received.

7. The method for designing flexible meshing of tooth side clearance of a wind turbine yaw bearing according to claim 6, characterized in that: In step 6, 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. Check whether the yaw motor is equipped with a speed feedback unit and set the control mode of the yaw inverter. If a speed feedback unit is present, select the speed control mode; if no speed feedback unit is present, select the torque control mode. S3: The control mode of the yaw frequency converter is 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 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 engagement of the yaw bearing tooth side clearance is completed and the yaw is started normally.

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