Wind power variable pitch driving system

Abstract

The invention discloses a wind power variable pitch driving system which comprises a driving module, a transmission module, a control module, a detection module and a variable pitch bearing. The permanent magnet synchronous motor is matched with the vector control driver, torque-magnetic field decoupling control is achieved, high torque density and excellent dynamic response are achieved, and a rapid variable pitch instruction can be accurately executed to stabilize power fluctuation; the planetary gearbox reduces speed and increases torque, the structure is compact, transmission is stable, a built-in lubricating system guarantees long-term reliable operation of the gear, and the maintenance requirement is lowered. A variable-pitch strategy algorithm is built in the control module, the variable-pitch rate can be dynamically optimized according to real-time signals of the unit, and safety and power generation efficiency are both considered; and the fault diagnosis module realizes predictive maintenance. Meanwhile, the system is provided with a redundant driving module, an emergency braking device and an energy storage unit, under the main driving fault, power failure or emergency working condition, a redundant system can be rapidly switched, blades can be locked, safe blade collection is guaranteed, and the fault ride-through capacity and safety are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, specifically to a wind turbine pitch drive system. Background Technology

[0002] As the global energy structure shifts towards clean energy, wind power, as a mature and widely used renewable energy source, is developing towards larger single-unit capacity, higher hub height, and longer blades. The pitch system is one of the core control units of a wind turbine. Its main function is to adjust the blade pitch angle to achieve maximum power point tracking when the wind speed is below the rated wind speed, and to limit the captured wind energy when the wind speed is above the rated wind speed, thus protecting the safe and stable operation of the unit.

[0003] Traditional wind turbine pitch drive systems often employ asynchronous motors paired with ordinary frequency converters or servo systems, resulting in slow response, insufficient control precision, and low efficiency. Their transmission mechanisms are prone to wear under frequent start-stop cycles and heavy load impacts, leading to a short lifespan. Furthermore, traditional control systems have limited intelligence, making it difficult to dynamically optimize pitch actions based on complex actual operating conditions, and lack comprehensive and accurate condition monitoring and fault self-healing capabilities. The reliability and safety of the system face challenges when encountering grid dips, extreme weather, or sudden component failures. Therefore, there is an urgent need for an advanced wind turbine pitch drive system that integrates high-precision drive, intelligent control, real-time monitoring, and multiple safety redundancies. Summary of the Invention

[0004] The purpose of this invention is to provide a wind turbine pitch drive system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a wind power pitch drive system, comprising a drive module, a transmission module, a control module, a detection module, and a pitch bearing; characterized in that: the drive module is poweredly connected to the input end of the transmission module, the output end of the transmission module is driven by the pitch bearing, the detection module collects pitch operation status signals and transmits them to the control module, and the control module regulates the operation of the drive module according to the signals.

[0006] In a preferred embodiment of the present invention, the drive module is a permanent magnet synchronous motor, the permanent magnet synchronous motor is configured with a vector control driver, and the vector control driver communicates bidirectionally with the control module.

[0007] In a preferred embodiment of the present invention, the transmission module includes a planetary gearbox and a coupling. The input end of the planetary gearbox is connected to the output shaft of the drive module via the coupling, and the output end of the planetary gearbox meshes with the pitch bearing for transmission.

[0008] As a preferred embodiment of the present invention, the control module has a built-in pitch strategy algorithm and a fault diagnosis module. The pitch strategy algorithm can dynamically optimize the pitch rate according to the unit operation signal, and the fault diagnosis module monitors the system operation status in real time. When an abnormality is detected, an alarm is triggered and the system switches to the standby control mode.

[0009] In a preferred embodiment of the present invention, the detection module includes an angle sensor, a torque sensor, and a temperature sensor; the angle sensor is installed at the end of the pitch bearing and has a measurement accuracy of not less than ±0.1°; the torque sensor is located on the power transmission path of the transmission module; and the temperature sensor is arranged in the drive module and the transmission module to monitor the operating temperature of the corresponding components and feed it back to the control module.

[0010] As a preferred embodiment of the present invention, it further includes a redundant drive module, which is configured in parallel with the main drive module. The control module can automatically switch to the redundant drive module according to the operating status of the main drive module, and the redundancy switching response time is ≤50ms.

[0011] As a preferred embodiment of the present invention, the drive module is provided with an intelligent heat dissipation device, which includes a heat dissipation structure and a speed-regulating heat dissipation component. The control module regulates the operation of the speed-regulating heat dissipation component according to the temperature sensor signal, so that the working temperature of the drive module is maintained in the range of -40℃ to 85℃.

[0012] As a preferred embodiment of the present invention, it further includes a braking device, which is linked to the pitch bearing. When the system loses power or an emergency fault is detected, the braking device automatically locks the pitch bearing.

[0013] In a preferred embodiment of the present invention, the control module is connected to an energy storage unit, which is an energy storage capacitor bank. When the power supply to the unit is interrupted, the energy storage unit provides emergency power to the control module and the drive module.

[0014] As a preferred embodiment of the present invention, the planetary gearbox of the transmission module has a built-in lubrication system, which includes an oil delivery component and an oil circuit structure, and can deliver a lubricating medium to the gear meshing surface at regular intervals.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. This invention employs a permanent magnet synchronous motor and a vector control driver, achieving decoupled control of torque and magnetic field. It features high torque density and excellent dynamic response characteristics, enabling precise execution of rapid pitch commands and effectively mitigating power fluctuations. A planetary gearbox is used for speed reduction and torque amplification, resulting in a compact structure, high load-bearing capacity, and smooth transmission. The built-in lubrication system ensures long-term reliable gear operation, reducing maintenance requirements. The pitch strategy algorithm built into the control module dynamically optimizes the pitch rate based on real-time unit operating signals, improving power generation efficiency while ensuring safety. The fault diagnosis module enables predictive maintenance.

[0017] 2. The system in this invention is equipped with redundant drive modules, an emergency braking device, and an energy storage unit. In the event of a main drive failure, it can seamlessly switch to the redundant system within 50ms. In the event of a power outage or emergency, the braking device can quickly lock the propeller blades, and the energy storage unit provides power for safe propeller retraction, greatly improving the system's fault-tolerant capability and safety. High-precision angle, torque, and temperature sensors provide comprehensive real-time monitoring of the system's operating status, offering a precise data foundation for intelligent control and fault diagnosis, enabling the system's status to be known and controlled. The intelligent heat dissipation device ensures that the drive module operates stably within a wide temperature range, allowing it to adapt to harsh natural environments such as extreme cold and heat. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the system flow of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. "Multiple" means two or more, and unless otherwise explicitly limited, all such meanings fall within the scope of protection of this invention.

[0022] Example 1:

[0023] This invention provides a pitch drive system suitable for 2.5MW onshore wind turbine units:

[0024] Drive Module: Both the main drive unit and the redundant drive unit use a 55kW permanent magnet synchronous motor with a rated speed of 1500rpm and a rated torque of 353.7N·m. Each motor is equipped with a high-performance vector control driver based on DSP, supporting three control modes: position, speed, and torque, and communicating bidirectionally with the control module via the CANopen bus.

[0025] Transmission module: A single-stage planetary gearbox is used, with its input end connected to the output shaft of the drive motor via a flexible coupling. The speed ratio of the planetary gearbox is 1:50, and the external gear ring at the output end directly meshes with the internal gear ring of the pitch bearing, achieving a transmission efficiency of no less than 96.5%.

[0026] Control Module: An embedded control board based on an STM32H7 series microcontroller. The built-in pitch strategy algorithm dynamically adjusts the pitch rate based on wind speed and turbine power signals to achieve maximum power point tracking. Fault Diagnosis Module: Real-time monitoring of motor current, voltage, temperature, gearbox temperature, and signals from various sensors. Upon detecting abnormalities such as motor overcurrent or over-temperature, an audible and visual alarm is immediately triggered, and a switch to the redundant drive unit is completed within 50ms.

[0027] Detection module: The angle sensor adopts a high-precision absolute encoder, which is installed on the non-drive end cover of the pitch bearing. The measurement range is 0-360° and the accuracy is ±0.05°.

[0028] The torque sensor is a strain gauge type torque sensor, connected in series on the input shaft of the planetary gearbox, with a range of 0-500 N·m, used for real-time monitoring of transmission load.

[0029] The temperature sensor uses a PT100 platinum resistance thermometer and is installed on the motor stator winding, motor housing, and planetary gearbox housing, with a measurement range of -50℃ to 150℃.

[0030] Redundant drive module: This module is identical in model and specifications to the main drive module and is configured in parallel with it. The control module achieves seamless switching by comparing the status words and feedback signals of the main and backup drives.

[0031] Intelligent heat dissipation device: Dense aluminum alloy heat dissipation fins are cast on the drive motor housing, and a 48V DC inverter fan controlled by the PWM signal of the control module is installed at the tail of the motor. When the motor housing temperature exceeds 45℃, the fan starts and adjusts its speed according to the temperature change; when the temperature is below 30℃, the fan stops.

[0032] Braking system: A normally closed hydraulic disc brake is used, which is installed on the brake disc of the pitch bearing. When the system is running normally, the hydraulic system provides pressure to release the brake; when the system loses power or receives an emergency stop command, the hydraulic pressure is released, and the brake quickly engages under the action of the spring force, locking the blades in the feathering position.

[0033] Energy storage unit: Employs a supercapacitor module with a capacity of 100F and a rated voltage of 400V. This module is connected to the DC bus of the drive via a bidirectional DC / DC converter. When the power grid fails, the supercapacitor can provide sufficient energy to the control module and drive unit for a short time to complete an emergency feathering operation.

[0034] Lubrication system: A small electric grease pump and an oil circuit are integrated into the planetary gearbox. The control module starts the lubrication pump at regular intervals (e.g., every 2 hours of operation) based on running time or gearbox temperature, delivering a specific type of grease to the gear meshing surfaces and bearings. The amount of grease injected each time can be precisely controlled.

[0035] Example 2:

[0036] This invention provides a pitch drive system suitable for 5MW offshore wind turbines. Its structure is basically the same as that of Embodiment 1, but some components have been reinforced to adapt to the harsh marine environment of high humidity, high salt spray, and strong corrosion.

[0037] Drive module: Both the main and redundant drive units use a 75kW high-protection permanent magnet synchronous motor, and their housings and fasteners are made of corrosion-resistant stainless steel or treated with a special anti-corrosion coating.

[0038] Transmission module: The planetary gearbox features a reinforced design, with gears and bearings made of higher-strength materials, and gear parameters optimized to improve load-bearing capacity and impact resistance. The coupling is made of marine-grade stainless steel.

[0039] Control Module: The control box adopts a double-sealed design and is equipped with a dehumidifier and an anti-condensation heater to ensure stable operation of electronic components in high-humidity environments. The fault diagnosis algorithm includes predictive logic for potential faults such as poor contact caused by salt spray corrosion.

[0040] Detection Module: All sensors are selected to meet IP68 protection standards and are encapsulated in corrosion-resistant materials. The signal cables for angle and torque sensors are shielded and properly grounded to resist complex electromagnetic interference at sea.

[0041] Intelligent heat dissipation system: The cooling fan is designed to be resistant to salt spray and waterproof. Additionally, an anti-corrosion coating has been added to the heat dissipation paths of the drive unit and gearbox to prevent seawater and salt spray corrosion from reducing heat dissipation efficiency.

[0042] Braking system: The hydraulic oil used in the hydraulic braking system is a synthetic oil suitable for a wide temperature range, and the hydraulic lines and joints are subjected to strict anti-corrosion and sealing treatment to prevent leakage.

[0043] Energy storage unit: The supercapacitor module also has a high protection level and is installed in a sealed metal cabinet. The cabinet is equipped with temperature and humidity monitors that are connected to the control module.

[0044] Lubrication System: The lubricating grease used is a specialized grease with excellent water resistance, corrosion resistance, and extreme pressure properties. The lubrication pump and oil piping are made of stainless steel and are regularly inspected via the control system to ensure the reliability of the lubrication system in harsh environments.

[0045] Working principle:

[0046] When using,

[0047] S1. System Initialization and Standby:

[0048] After the wind turbine is powered on, the pitch system begins initialization. The control module performs a self-test, including communication and status checks on key components such as its own hardware, drive module, detection module, redundancy module, braking device, and energy storage unit.

[0049] The detection module starts working, the angle sensor reads the initial pitch angle of the current blade, and the temperature sensor and other sensors start collecting ambient and component temperatures.

[0050] If all conditions are normal, the system enters standby mode, waiting for pitch control commands from the main control system. At this time, the hydraulic brake is released, and the blades maintain their initial angle without external force.

[0051] S2. Signal Acquisition and Command Reception:

[0052] During normal system operation, the detection module continues to work:

[0053] Angle sensor: Real-time acquisition of the rotation angle of the pitch bearing, i.e. the actual pitch angle of the blade, and feeds the signal back to the control module.

[0054] Torque sensor: Monitors the load torque of the transmission system in real time, reflecting the magnitude of the current wind load.

[0055] Temperature sensors: monitor the operating temperature of key components such as drive motors and planetary gearboxes.

[0056] The control module simultaneously receives operating signals such as wind speed and power from the unit's main control system, as well as pitch angle commands.

[0057] S3. Control Decision and Drive Command Generation:

[0058] The fault diagnosis module of the control module performs real-time analysis on all collected signals. For example, it determines whether the motor current exceeds the limit, the temperature is too high, the angle feedback is normal, or the torque changes abruptly.

[0059] If no fault is detected, the control module's pitch strategy algorithm calculates the required pitch speed and direction based on the received target pitch angle command and the actual pitch angle, combined with information such as wind speed and power, and generates corresponding control commands (such as speed or torque commands).

[0060] The instruction is sent to the vector control driver of the main drive module.

[0061] S4, Power Drive and Redundancy Switching:

[0062] The vector control driver of the main drive module drives the permanent magnet synchronous motor to run at the set speed and direction according to the received instructions.

[0063] The power output from the motor is transmitted to the planetary gearbox via a coupling.

[0064] After the planetary gearbox reduces the speed and increases the torque of the motor at high speed and low torque, it drives the pitch bearing to rotate by meshing the external gear ring at its output end with the internal gear ring of the pitch bearing.

[0065] If the fault diagnosis module detects an abnormality in the main drive module (such as motor overcurrent, driver failure, etc.), the control module will immediately trigger an alarm and automatically switch to the redundant drive module within ≤50ms according to the preset logic. The redundant drive unit will seamlessly take over the work to ensure that the pitching action is not interrupted.

[0066] S5, Pitch Execution and State Closed Loop:

[0067] The rotation of the pitch bearing directly drives the wind turbine blades to change their pitch angle.

[0068] The angle sensor feeds back the actual blade angle collected in real time to the control module, forming a position closed-loop control system.

[0069] The control module continuously adjusts the commands output to the drive module based on the deviation between the actual angle and the target angle until the blade reaches and stabilizes at the target pitch angle.

[0070] S6. Ensure system collaboration:

[0071] Intelligent heat dissipation: The control module adjusts the speed of the variable-speed fan in the intelligent heat dissipation device in real time based on feedback from the temperature sensor. When the temperature of the drive unit rises, the fan accelerates; when the temperature drops, the fan decelerates or stops, ensuring that the drive unit operates within the optimal temperature range of -40℃ to 85℃.

[0072] Automatic lubrication: The control module activates the built-in lubrication system of the planetary gearbox at preset time intervals or the operating temperature of the gearbox to deliver grease to the gear meshing surfaces and bearings to reduce friction and wear.

[0073] Emergency braking and emergency power supply:

[0074] Power outage: When a power outage is detected, the energy storage unit (supercapacitor bank) immediately provides emergency power to the control module and drive unit through a DC / DC converter.

[0075] Emergency Faults: If a serious fault such as blade overspeed or excessive vibration is detected, or if an emergency shutdown command is received from the main control system, the control module will immediately issue a command.

[0076] In both of the above situations, the control module will drive the braking device to automatically lock the pitch bearing in the shortest possible time, and at the same time use the electrical energy provided by the energy storage unit to drive the blades to perform an emergency feathering action, adjusting the blades to the pneumatic brake position to ensure the safety of the unit.

[0077] S7. Cyclic Operation and Shutdown:

[0078] The system operates in a loop from S2 to S6, continuously adjusting the blade angle according to wind conditions and master control commands, while simultaneously performing status monitoring and fault diagnosis.

[0079] When the unit needs to be shut down normally, the main control system issues a shutdown command, the control module drives the blades to feather to the 90° position, and after the blades have completely stopped rotating, the braking device locks, and the system enters a safe shutdown state.

[0080] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A wind turbine pitch drive system, comprising a drive module, a transmission module, a control module, a detection module, and a pitch bearing; characterized in that: The drive module is powered to the input of the transmission module, and the output of the transmission module is driven by the pitch bearing. The detection module collects the pitch operating status signal and transmits it to the control module. The control module regulates the operation of the drive module according to the signal.

2. The wind turbine pitch drive system according to claim 1, characterized in that: The drive module is a permanent magnet synchronous motor, which is equipped with a vector control driver, and the vector control driver communicates bidirectionally with the control module.

3. The wind power pitch drive system according to claim 1, characterized in that: The transmission module includes a planetary gearbox and a coupling. The input end of the planetary gearbox is connected to the output shaft of the drive module through the coupling, and the output end of the planetary gearbox meshes with the pitch bearing for transmission.

4. The wind turbine pitch drive system according to claim 1, characterized in that: The control module has a built-in pitch strategy algorithm and a fault diagnosis module. The pitch strategy algorithm can dynamically optimize the pitch rate according to the unit's operating signals. The fault diagnosis module monitors the system's operating status in real time, and triggers an alarm and switches to standby control mode when an abnormality is detected.

5. A wind turbine pitch drive system according to claim 1, characterized in that: The detection module includes an angle sensor, a torque sensor, and a temperature sensor. The angle sensor is installed at the end of the pitch bearing and has a measurement accuracy of not less than ±0.1°. The torque sensor is located on the power transmission path of the transmission module. The temperature sensor is arranged in the drive module and the transmission module to monitor the operating temperature of the corresponding components and feed it back to the control module.

6. A wind turbine pitch drive system according to claim 1, characterized in that: It also includes a redundant drive module, which is configured in parallel with the main drive module. The control module can automatically switch to the redundant drive module according to the operating status of the main drive module, and the redundancy switching response time is ≤50ms.

7. A wind turbine pitch drive system according to claim 1, characterized in that: The drive module is equipped with an intelligent heat dissipation device, which includes a heat dissipation structure and a speed-regulating heat dissipation component. The control module regulates the operation of the speed-regulating heat dissipation component according to the temperature sensor signal, so that the working temperature of the drive module is maintained in the range of -40℃ to 85℃.

8. A wind turbine pitch drive system according to claim 1, characterized in that: It also includes a braking device that works in conjunction with the pitch bearing. When the system loses power or an emergency fault is detected, the braking device automatically locks the pitch bearing.

9. A wind turbine pitch drive system according to claim 1, characterized in that: The control module is connected to the energy storage unit, which is an energy storage capacitor bank. When the power supply to the unit is interrupted, the energy storage unit provides emergency power to the control module and the drive module.

10. A wind turbine pitch drive system according to claim 1, characterized in that: The planetary gearbox of the transmission module has a built-in lubrication system, which includes an oil delivery component and an oil circuit structure, and can deliver lubricating medium to the gear meshing surface at regular intervals.

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