The design and manufacture of wind turbines is a complex engineering task. Due to their large size, different components of the turbines need to be transported separately to the wind farm and assembled on-site. Each component has its own characteristics and requires special tools for transportation or installation. 

We will analyze the characteristics of each part of the fan, as well as the specific equipment required during transportation, installation and maintenance. 

What are the main components of a wind turbine? 

The wind turbine is composed of five main components and many secondary components. The main components include the foundation, the tower, the rotor and the hub (which consists of three blades), the nacelle and the generator. 

The installation of all these components requires specific wind turbine-specific installation equipment. 

The foundation of the wind turbine 

The foundation of the onshore wind turbine is located on the ground; it is invisible because it is covered by the soil. It is a large and heavy concrete block that must be able to support the entire wind turbine and the forces acting on the fan. 

In an offshore fan, its foundation underwater is invisible. For offshore fans located far from land, their foundation is in a floating state, but it has sufficient mass to support and maintain the weight of the fan and the various forces acting upon it. 

2. Wind turbine tower 

The towers of most modern fans are made of circular steel tubes. One rule of thumb for fan towers is that their height is the same as the diameter of the circle formed by the rotation of the fan blades. Generally speaking, the higher the fan, the easier it is to capture the high-speed wind. Because the farther we are from the ground, the stronger the wind is (wind speed varies at different heights). 

3. The rotor and hub of the wind turbine 

The rotor is the rotating component of a turbine; it consists of three blades and a central part that connects the blades, namely the hub. 

Although three-bladed fans are the most common, they are not necessarily three-bladed. However, three-blade rotors have the advantage of the highest efficiency. The blades are not sturdy; they are hollow and are made of lightweight and strong composite materials. The trend is to make them larger (to obtain greater power), lighter and stronger. For aerodynamics, the shape of the blades is like an airplane wing (like the wing of an aircraft). In addition, they are not flat; there is a twisted design between their roots and tips. The blades can rotate 90 degrees around their own axis. This movement is called pitch change. 

The function of the hub is to hold the blades and allow them to rotate along with the rest of the fan body. 

4. Fan housing 

The cabin accommodates all the components that need to be installed on the top of the fan. 

The fan compartment is a complex electromechanical system with numerous components that can operate accurately and normally. The key fan components are the generator and the main shaft. The main shaft transmits the energy collected from the wind to the generator through a gearbox. The gearbox is another important component of the wind turbine. 

Since the fan must operate with the wind and needs to adjust its direction according to the wind direction, its rotor must be able to rotate relative to the tower. This rotation is called yawing. 

5. Fan Generator 

A generator is a component that converts the mechanical energy of the rotor (obtained from the wind) into electrical energy. The structure of a generator is the same as that of an electric motor. 

Although there are many types of wind turbines, they can be classified into two categories. 

Horizontal-axis wind turbines have the rotation axis of the wind turbine parallel to the wind direction. 

② Vertical-axis wind turbines, in which the rotation axis of the rotor is perpendicular to the ground or the direction of the airflow. 

Horizontal-axis wind turbine

Horizontal-axis wind turbines are classified into lift-type and drag-type. 

The lift-type wind turbine rotates at a faster speed while the resistance rotates at a slower speed. For wind power generation, lift-type horizontal-axis wind turbines are mainly used. Most horizontal-axis wind turbines have a wind device that can rotate according to the change of wind direction. For small wind turbines, this wind device adopts a tail rudder, while for large wind turbines, a transmission mechanism consisting of a wind direction sensor element and a servo motor is used. 

The wind turbine blades of a wind turbine are called upwind wind turbines when they are located in front of the tower, and downwind wind turbines when they are located behind the tower. There are many types of horizontal-axis wind turbines. Some have reversed-rotating blades for the wind turbine blades, some install multiple wind turbine blades on the tower to reduce the cost of the tower under certain output power conditions, and some horizontal-axis wind turbines generate vortices around the wind turbine blades, concentrating the airflow and increasing the air flow speed. 

Vertical-axis wind turbine 

Vertical-axis wind turbines do not need to adjust to the wind direction when the wind direction changes. This is a significant advantage compared to horizontal-axis wind turbines. It not only simplifies the structural design but also reduces the gyroscopic force exerted by the rotor on the wind. 

There are several types of vertical-axis wind turbines that use resistance rotation, including wind wheels made of flat plates and blankets, which is a purely resistance device; the S-type windmill has some lift but is mainly a resistance device. These devices have a larger starting torque, but their tip speed is relatively low. When the size, weight and cost of the wind wheel are fixed, the power output provided is relatively low.