I. Structural Components of a Wind Turbine Generator
Rotor blades: They capture the wind and transmit the wind power to the rotor shaft. On a modern 600-kilowatt wind turbine, each rotor blade measures approximately 20 meters in length and is designed much like an airplane wing.
Shaft: The rotor shaft is attached to the low-speed shaft of the wind turbine.
Low-speed shaft: The low-speed shaft of a wind turbine connects the rotor shaft to the gearbox. In modern 600 kW wind turbines, the rotor speed is quite slow, approximately 19 to 30 revolutions per minute. The shaft contains conduits for the hydraulic system, which activates the aerodynamic brakes.
Gearbox: The low-speed shaft is located on the left side of the gearbox, which can increase the speed of the high-speed shaft to 50 times that of the low-speed shaft.
High-speed shaft and its mechanical brake: The high-speed shaft operates at 1500 revolutions per minute and drives the generator. It is equipped with an emergency mechanical brake for use in case the aerodynamic brake fails or the wind turbine is under maintenance.
Generator: Commonly referred to as an induction motor or asynchronous generator. In modern wind turbines, the maximum power output is typically between 500 and 1500 kilowatts.
Yaw mechanism: An electric motor rotates the nacelle to align the rotor with the wind. The yaw mechanism is operated by an electronic controller, which senses wind direction via a wind vane. Typically, the wind turbine yaws only a few degrees at a time as the wind changes direction.
Electronic controller: Contains a computer that continuously monitors the status of the wind turbine and controls the yaw mechanism. To prevent any malfunction (i.e., overheating of the gearbox or generator), the controller can automatically stop the wind turbine from rotating and call the wind turbine operator via telephone modem.
Hydraulic system: Used to reset the aerodynamic brake of the wind turbine.
Cooling components: This includes a fan for cooling the generator. Additionally, it includes an oil cooling element for cooling the oil inside the gearbox. Some wind turbines have water-cooled generators.
Tower: The wind turbine tower houses the nacelle and rotor. Taller towers are generally advantageous because higher elevations result in higher wind speeds. Modern 600 kW wind turbines typically have towers ranging from 40 to 60 meters in height. They can be tubular or lattice-shaped. Tubular towers offer greater safety for maintenance personnel, as they can access the top via internal ladders. Lattice towers are more affordable.
Anemometers and wind vanes: used to measure wind speed and direction.
Tail rudder: Commonly found in small wind turbines (generally 10KW and below) with a horizontal axis facing the wind. Located behind the rotating body and connected to it. Its main functions are: 1) to adjust the turbine's direction of rotation, ensuring the turbine faces the wind; and 2) to deflect the turbine's nose away from the wind direction in strong winds, thereby reducing speed and protecting the turbine.
II. How to repair the wear problem of wind turbine shaft
When wind turbine shafts wear out, many companies encounter difficulties in repairing them. This is because many wind turbines are installed in remote locations with poor transportation access, such as offshore or mountainous areas, making maintenance a significant challenge. Traditional repair methods are simply inadequate to solve this problem effectively.
Solvay's current carbon nanotube polymer material can quickly solve the problem of difficult wind turbine shaft repair. This technology allows for online, non-disassembly repair, and the online repair process does not generate high temperatures, effectively protecting the equipment from damage. Furthermore, the repair process is not limited by the amount of wear. The material does not experience metal fatigue wear during use, and under normal equipment maintenance, its service life after repair can even exceed that of new parts. Simultaneously, utilizing the inherent advantages of carbon nanotube polymer materials, such as compressive strength, bending strength, and elongation, it can effectively absorb external impacts, greatly mitigating and offsetting the radial impact force of the bearing on the shaft, and preventing the possibility of clearance, thus avoiding wear caused by increased clearance.
A wind turbine shaft showed signs of wear. The bearing housing model is 6330M/C3, the motor speed is 1750 r/min, and the bearing housing diameter is φ150mm. Using appropriate repair techniques, the repair was completed in just 8 hours, and the bearing was reinstalled.
Routine inspection and maintenance of wind turbines:
First, carefully check the safety platform and ladder inside the fan to ensure they are secure, the elevator is functioning properly, the lighting inside the tower is working well, the pressure gauges in the hydraulic station are normal, the hydraulic oil and gearbox oil levels are at the correct positions, there is wear between rotating parts, and the gear oil and hydraulic oil filter indicators are at the correct positions and the operating sounds are normal. Second, listen carefully to the control cabinet for any discharge sounds or abnormal noises. Such sounds may indicate loose wiring terminals or poor contact, requiring careful inspection. Listen for normal yaw sounds and any dry grinding noises, abnormal noises from the gearbox, abnormal noises between the brake disc and brake pads, abnormal noises from the generator and bearings, and normal wind-cutting sounds from the blades. Third, clean the work area thoroughly after operation to facilitate future inspection for leaks.
