Wind Turbine | Working and Types of Wind Turbine
How Does Wind Turbine Work?
Working of Wind TurbineWhen the wind strikes the rotor blades, blades start rotating. The rotor is directly connected to a high-speed gearbox. Gearbox converts the rotor rotation into high speed which rotates the electrical generator. An exciter is needed to give the required excitation to the coil so that it can generate required voltage. The exciter current is controlled by a turbine controller which senses the wind speed based on that it calculates the power what we can achieve at that particular wind speed. Then output voltage of electrical generator is given to a rectifier and rectifier output is given to line converter unit to stabilize the output AC that is feed to the grid by a high voltage transformer. An extra units is used to give the power to internal auxiliaries of wind turbine (like motor, battery etc.), this is called Internal Supply unit. ISU can take power from the grid as well as from wind. Chopper is used to dissipate extra energy from the RU for safety purpose. An internal Block diagram of a wind turbine
Types of Wind TurbineThere are generally two types of wind turbines. The horizontal axis and vertical axis. The horizontal axis is divided as upwind and downwind whereas vertical axis is divided as a drag based and lift based as shown in below.
- Horizontal Axis Wind Turbine or HAWT - Up wind
- Horizontal Axis Wind Turbine or HAWT - Down wind
- Vertical Axis Wind Turbine or VAWT - Drag based
- Vertical Axis Wind Turbine or VAWT - Lift based
History of Wind TurbineUsing wind energy is not a new concept. It was being used from long past but for different purposes other than producing electricity. It was long before the invention of electricity, the Chinese and Persian people used the windmill for pumping water, breaking up grain and sawing lumber etc. It was long before the invention of electricity.
There are mainly two types of wind turbine, namely vertical axis and horizontal axis turbine. The first wind turbine was designed as a vertical axis where many sails attached around the vertical axes produce ration of the rotor along the vertical axis of the system. The figure below shows a very old design of vertical axis wind turbine.
After that horizontal axis windmill was designed in the British Isles, Northern Europe. Horizontal axis windmills were most popularly utilized in Holland in 14th century. These windmills carried out lots of tasks, for example, timber milling, pumping water for farming etc. The Netherlands is another European country which utilized windmill popularly at that time.
In the late 19th century in the American mid-west farmers came to put your faith in a leaner design characteristic a trestle tower topped by wooden or steel paddle-type blades. Between 1850 and 1970, more than six million mostly small means one horsepower or less mechanical output wind turbines were installed in the U.S. only and the most important use was water-pumping and the major purpose were store water for home water needs. In 1891 Danish meteorologist, Poul La Cour designed an electrical output wind turbine replicating the aerodynamic design principles that were used in European tower mills. In Denmark, 1900 the biggest machines were on 24 meters (79 ft) tower with four-bladed 23 meters (75 ft) diameter rotors and generating 30 MW. In the 1920s, wind-generated electrical systems began to follow the design of aeroplane propellers and monoplane wings.
In 1950’s the world’s first alternating current wind turbines come in the picture and credit goes to Johannes Juul, he is the best student of Paul La Cour (great scientist and known as his work on wind power). After that John Brown & Company in 1951, developed a first convenience grid-connected wind turbine which operated in the UK (United Kingdom). An overview about wind turbines. The figure given below contains some components of wind turbines.