Wind Turbine and its Working Principle

Working principle of a horizontal axis wind turbine

Working principle of a horizontal axis wind turbine

In a wind power plant, the kinetic energy of the flowing air mass is transformed into mechanical energy of the blades of the rotor. A gearbox is used in a connection between a low speed rotor and the generator. The generator transforms mechanical energy into electrical energy. New types of horizontal axis turbines use a multipolar generator that is connected directly to the rotor of the turbine instead of using a gearbox.

The main part of the turbine consists of rotor blades. These need to meet stringent criteria with regards to the strength of wind and centrifugal forces they have to withstand. The right profile and angle of attack of the rotor blades is the most important prerequisite if maximum efficiency is to be reached. The minimum wind speed the turbines need to work is between 3 and 4 m/s (6—8 knots). Optimal power output is reached at 15 m/s (30 knots) while at speeds over 25 m/s (50 knots), the turbines are stopped to prevent damage.

Video: 3D model of a horizontal axis wind turbine

The gearbox of a wind turbine, with the electric generator in the rear of the nacelle. (Source: © Composer / stock.adobe.com)

The gearbox of a wind turbine, with the electric generator in the rear of the nacelle.

Generator Room of a Wind Turbine.

Generator Room of a Wind Turbine.

A gearbox of a 2 MW turbine weighs around 15 tonnes.
 
The rotor blades of larger stations are made of laminated composite materials.

An aerodynamically shaped rotor blade of a wind turbine being constructed in Chile. (Source: © abriendomundo / stock.adobe.com)
6 pictures
Blades of giant wind turbines, ready to be fitted. (Source: © pixarno / stock.adobe.com)
Temporary storage of wind turbine blades being transported to their respective construction sites. (Source: © GERARD DUSSOUBS / stock.adobe.com)
The construction of a direct drive (has no gearbox) wind turbine. (Source: © Frédéric Prochasson / stock.adobe.com)
6 pictures

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