Facts about wind turbines

Renewable energy wind - Wind turbine

Written by Renewable Power   

Facts about wind turbinesWind turbine and wind power
Wind turbine rotors can be divided according to several basic principles:
- by wind action
- returned to the position and axis of rotation
- the speed of rotation.


According to the action of wind, wind turbine rotors can be:
1. Rotor with resistant action are based on the forces of resistance on the rotor blade where they rotate slower than the wind, it even reduces overall efficiency. Rotational speeds are in fact small, and torque on the rotor shaft relatively large. Frequently used in windmills, water mills to drive or pump the water.
2. Rotors with buoyant activity are established by the action of buoyancy forces on the rotor blade, whereby their linear speed is several times greater than wind speed. Rotational speed at the same time is great and the torque on rotor shaft runs. Because of the higher speed of rotation (1000 to 1500 min-1) and greater aerodynamic efficiency they are used in modern wind farms.

According to the position of shaft or axis of rotation, rotor wind turbine can be:
1. Rotors with horizontal axis (Such as the propeller) are much more common in the application of the rule     used in modern wind farms.
2. Rotors with vertical axes are, in fact, started with the first, but they are still a bit abandoned. However they have numerous advantages: does not depend on wind direction and heavy machinery parts can be placed on the ground. Their use is limited for now     (Egg on the principle of work Anemometers).

According to the rotation speed, wind turbine rotors can be:
1. Rotors with variable speed of rotation are commonly used to drive pumps for water and wind energy for charging the battery, whereas the application of wind turbine that are connected to the power grid require transducer frequency.
2. Rotors with constant angular speed very suitable for use in wind farms for needs of the power system (network) as it allows the use of a simple generator which speeds gender specific frequency of the network.

The main parts of wind turbines:
- rotor wind turbine
- shaft with gear
- electric generator and other parts of the electrical system (connection to the network, necessary to power, etc)
- control systems (air and aerodynamic braking, turning housings, control and communications, etc)
- pier
- foundation.

The rotor wind turbine consists of an appropriate number of blades connected to the shaft by one or several hubs (especially in a vertical rotor axis). For use in the wind today is mostly (almost 90% of cases) using the so-called propeller rotors with three blades ('arms') in whose peaks are achieved speeds of 50 to 70 m / s. Besides three-arms, which proved to be most effective, are also bifurcated (whose efficiency is only for 2 to 3% lower), and one-arm rotors.

Blade part of which leads to the conversion of kinetic wind energy into kinetic energy of rotation rotor. Number and performance of blades are determined by the first performance of the rotor or turbine (with horizontal or vertical axis, etc) and numerous other technical and non-technical factors. For example, a smaller number of blades means less production costs, but causes a higher speed, and thus more noise and erosion of beds. For use with wind turbines with the horizontal axis is mostly due to technical and aesthetic reasons, the most commonly used rotors with three blades.

Nave is part of the rotor blades through which the rigid or flexible shaft is connected to. When the rotor with the horizontal axis is only one hub while the vertical axis of the rotor can be more. The hubs are located bearings swivel blades and blade rotation system and connections to the installation (egg electrical heaters to top of the blade or hydraulic powered rotation blades, etc).

Shaft serves to transfer torque from the hub to an electric generator. On the location of its axis is established with one of the most important division of the wind turbines and their rotors in which the shaft can be vertical or with the horizontal axis. In doing so, in fact, a two shafts: slow speed and fast speed which are connected to transmitter (multiplier).

Slow speed shaft is connected directly to the hubs and torque over the entire radial and axial load that is transmitted through the bearings on mounting construction of the pillar and foundation. Speed of slow speed shaft is usually less than 100 min-1.

Fast speed shaft is used to drive electric generators and does not spread the load.
Electric Generator used to convert the kinetic energy of rotation of rapid return to an electrical energy and represents the final element of the conversion of energy in the wind. Generators used in the wind turbines must have a special structure because the torques due to the change of wind power often changes. For wind farms with forces greater than 150 kW is generally used generators AC voltage.
Tags: renewable energy renewable power green power wind energy wind turbine wind turbines wind power wind generator wind farms
 
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