Technical principle of wind power generation

The basic principle of wind power generation is to convert the kinetic energy of wind into mechanical energy through a wind generator, and then drive the generator to generate electricity and convert it into electrical energy. The dominant wind turbine is generally a horizontal axis wind turbine, which consists of blades, hubs, speed-increasing gearbox, generator, main shaft, yaw device, control system, tower and other components. The role of the wind wheel is to convert wind energy into mechanical energy, which is composed of blades with excellent aerodynamic performance installed on the hub. The low-speed rotating wind wheel is accelerated by the speed-increasing gearbox and then transmits the power to the generator. These components are arranged in the engine room, and the whole engine room is supported by the tower. In order to make effective use of wind energy, the yaw device is controlled by the controller according to the wind direction signal measured by the wind direction sensor, which drives the pinion engaged with the big gear on the tower to rotate, so that the engine room always faces the wind. Because the gearbox is a component with high overload and premature damage rate in megawatt wind turbines, direct-drive wind turbines (also known as gearless wind turbines) have been developed abroad. This kind of wind turbine is driven by multi-stage asynchronous motor and impeller directly, and no gear is needed to adjust the speed or power to track the optimal tip speed ratio, so that the wind turbine can obtain the optimal power output in a large wind speed range. There are two commonly used adjustment methods: one is stall adjustment, and the other is variable pitch adjustment, that is, the blade can rotate around the shaft on the blade to change the aerodynamic data of the blade and realize power adjustment.

Wind power generation technology

Wind turbine is generally composed of wind wheel, generator (including device), direction regulator (tail wing), tower, speed limit safety mechanism and energy storage device. The working principle of wind turbine is relatively simple. The wind wheel rotates under the action of the wind, which converts the kinetic energy of the wind into the mechanical energy of the wind wheel shaft. The generator is driven by the wind wheel shaft to rotate and generate electricity. Wind wheel is a kind of wind collecting device, whose function is to convert kinetic energy of flowing air into mechanical energy of wind wheel rotation. Usually, the rotor of a wind turbine consists of two or three blades. In wind turbines, there are three kinds of generators, namely DC generators, synchronous alternators and asynchronous alternators. The role of the deflector in the wind turbine is to make the wind wheel of the wind turbine face the wind direction at any time, so as to maximize the wind energy. Generally speaking, almost all wind turbines use the tail wing to control the windward direction of the wind wheel. The material of the tail wing is usually galvanized steel plate. Speed limiting safety mechanism is used to ensure the safe operation of wind turbines. The speed-limiting safety mechanism can keep the speed of the fan basically unchanged within a certain wind speed range. Tower is the supporting mechanism of wind turbine, and the larger tower of wind turbine generally adopts truss structure composed of angle steel or round steel. The output power of wind turbine is related to wind speed. Because the wind speed in nature is extremely unstable, the output power of wind turbines is also extremely unstable. Generally, the electric energy generated by wind turbines cannot be directly used for electrical appliances, and must be stored first. The batteries used in wind turbines are mostly lead-acid batteries.