Wind turbine internal structure description
Wind turbine structure:
Cabin: The cabin contains key equipment for the wind turbine, including the gearbox and generator. Maintenance personnel can enter the cabin through the wind turbine tower. The left end of the nacelle is the rotor of the wind turbine, ie the rotor blades and the shaft.
Rotor blades: catch wind and transmit wind power to the rotor shaft. On modern 600 kW wind turbines, each rotor blade has a measured length of approximately 20 meters and is designed to resemble an airplane's wing.
Axis: The rotor axis is attached to the low speed shaft of the wind turbine.
Low speed shaft: The low speed shaft of the wind turbine connects the rotor shaft to the gearbox. On modern 600 kW wind turbines, the rotor speed is quite slow, about 19 to 30 revolutions per minute. There are conduits for the hydraulic system in the shaft to activate the operation of the aerodynamic brake.
Gearbox: The left side of the gearbox is the low speed shaft, which increases the speed of the high speed shaft to 50 times the low speed shaft.
High-speed shaft and its mechanical brake: The high-speed shaft runs at 1500 rpm and drives the generator. It is equipped with an emergency mechanical brake for when the aerodynamic brake fails or when the wind turbine is being serviced.
Generator: Usually called induction motor or asynchronous generator. On modern wind turbines, the maximum power output is typically between 500 and 1500 kW.
Yaw device: Rotate the nacelle with the motor so that the rotor is facing the wind. The yaw device is operated by an electronic controller that can sense the wind direction through the wind vane. The figure shows the yaw of the wind turbine. Usually, when the wind changes its direction, the wind motor will only deflect a few degrees at a time.
Electronic controller: Contains a computer that continuously monitors the state of the wind turbine and controls the yaw device. To prevent any malfunction (ie overheating of the gearbox or generator), the controller can automatically stop the rotation of the wind turbine and call the wind turbine operator via the telephone modem.
Hydraulic system: The aerodynamic brake used to reset the wind turbine.
Cooling element: Contains a fan for cooling the generator. In addition, it contains an oil cooling element for cooling the oil in the gearbox. Some wind turbines have water cooled generators.
Wind tower: The wind turbine tower carries the organic cabin and rotor. Usually tall towers have an advantage because the higher the ground, the greater the wind speed. Modern 600 kW wind turbines have tower heights of 40 to 60 meters. It can be a tubular tower or a lattice tower. Tubular towers are safer for maintenance personnel as they can reach the top of the tower through an internal ladder. The advantage of a latticed tower is that it is relatively inexpensive.
Anemometer and wind vane: used to measure wind speed and direction.
Wind turbine generators: Wind turbine generators convert mechanical energy into electrical energy. The generator on the wind turbine is a bit different than the power generation equipment you usually see on the grid. The reason is that the generator needs to operate under fluctuating mechanical energy conditions.
The output voltage
Large wind turbines (100-150 kW) typically produce 690 volts of three-phase AC. The current then passes through the transformer next to the wind turbine (or inside the tower) and the voltage is increased to 10,000 to 30,000 volts, depending on the local grid standard.
Large manufacturers can offer 50 Hz wind turbine types (for most of the world's power grids) or 60 Hz types (for US power grids).
