Although wind turbines are diverse, they can be divided into two categories: 1 horizontal axis wind turbine, the rotating shaft of the wind wheel is parallel to the wind direction; 2 vertical axis wind turbine, the rotating shaft of the wind wheel is perpendicular to the ground or airflow direction.
Horizontal axis wind turbine
The horizontal axis wind turbines are divided into two types: lift type and resistance type. The lift type wind turbine rotates at a fast speed and the resistance type rotates at a slow speed. For wind power generation, lift-type horizontal-axis wind turbines are often used. Most horizontal axis wind turbines have a windward arrangement that can rotate as the wind direction changes. For small wind turbines, the wind turbine uses a tail rudder, while for large wind turbines, a wind direction sensing element and a servo motor are used.
The wind turbine's wind turbine is called the upwind wind turbine in front of the tower, and the wind turbine is the downwind wind turbine behind the tower. There are many types of horizontal axis wind turbines, some have reversed blades, and some have more than one wind turbine to reduce the cost of the tower under certain conditions of output power. The shaft wind turbine generates eddies around the wind wheel, concentrating the airflow and increasing the airflow speed.
Vertical axis wind turbine
The vertical axis wind turbine does not need to be windy when the wind direction changes. At this point, it is a big advantage compared to the horizontal axis wind turbine. It not only simplifies the structural design, but also reduces the gyroscopic force when the wind wheel is against the wind.
There are several types of vertical-axis wind turbines that use resistance rotation, among which are wind turbines made of flat plates and quilts, which are pure resistance devices; S-type windmills with partial lift, but mainly resistance devices. These devices have a large starting torque, but have a low tip speed ratio and provide a low power output with a certain size, weight and cost of the rotor.