What is wind turbine and how does it generate electricity ???

Wind turbine

Wind power components accidents wind turbines are devices that converts the wind kinetic energy into electrical energy we can simply describe the wind as a moving air caused by a difference in atmospheric pressure between the different region of our planet differences in atmospheric pressure arise on a result of a temperature differences when the air moves from a high pressure region into a low pressure region. We will feel the moving air as a wind and the other hand we can describe the wind energy as the process in which wind is used to generate a mechanical energy or electricity since the beginning of a civilization man has always it took advantage of wind energy from the simple sail boats to the grinding  of grain and with the wind mills up to the actual production of electricity.

Thanks to the wind energy  converters also known as wind turbine there are different types and a different size of wind turbines in this video we will focus on the most common horizontal axis turbine we will find out which are the main components of this particular type wind turbine we will understand how these devices are able to transform wind energy into electric current we will see why wind turbines doesn't have a more than a three blades through the observations of the their air foil shape and we will also see what are the main causes of accident that occur during the operation of their devices the first wind turbines built toward the end of the 19th century with the aim off supplying electricity to the small isolated villages. in the following years the gradual structural and technological improvements of these devices allowed the creations of real wind farm entirely dedicated to the production of electricity nowadays there are about the 26 companies in a while specialise in the production of a wind turbine.Wind turbines transform mechanical energy into electrical energy the wind caught by the wind turbine is infect transferred, thanks to a mechanical shaft to a generator, The generator transform the rotational energy into electrical energy which in turn is transferred to a transformer usually places at the base of the wind tower the transformers acts as a link between the wind turbine and the distribution grid it steps up the low output voltage from the generator to a higher distribution voltage level. let’s take a look at various components of a wind turbine this is the tower one of the most important part, it represent the supporting structure of the wind turbines and has a function of observing the vibration generated by the rotary motions of the blades.

Blades.

There are blades which are aerodynamically optimised to capture the maximum power from the wind and transfer it to the rotor hub, each blade is usually 20 metres or more in length depending on the power level.

Rotor.

The rotor is the rotating part of the Wind turbine, the rotor hub hold the wind blades while connecting to the gearbox via the low speed shaft here we can find the pitch control system thanks to the pitch control blades are turned in their longitudinal case to change the angles of attack, according to the wind directions this mechanism also blocks the rotation of the rotor. when the wind is too strong or two week.

Nacelle.

Nacelle

The nacelle  is instead the enclosure of the wind turbine that houses all of the generating components including the gearbox ,the braking system and the generator but also pitch control system and the yaw system which is responsible for the orientation of wind turbine rotor towards the wind.

Anemometer.

Anemometer placed at the rear of the nacelle ,infect constantly detects the wind direction where ever there is a change in the wind direction. the anemometers send a signal to a system that provides to rotate the entire nacelles and consequentially the rotor and the blades to meet the wind at the best angle.

Action.

What happens when the wind turbine goes into action the blades start to turn when the wind reaches the so-called cut in a wind speed that point at which the turbine start generate generation electricity from a turning the rotor is connected to the drive shaft which rotates inside nacelle.

Generator.

Wind turbine generator

The rotational energy of a drive shaft is transformed into electrical energy by the generator.

The generator infect device that uses electromagnetic induction to produce electrical voltage.

Speed multiplier.

One of the main element of a power transmission of the wind turbine is the speed multiplier, since the rotor blade rotating is low  the speed multiplier inside the gearbox is used with the aim to reach higher level of a rotational speed needed by a electric generator. in order to produce the electrical power most wind farms are also equipped with inverter that convert a DC current into AC current at 220 volts.

Inverter.

making it a suitable for a grid feeding or self consumption, if the wind speed increase there will be a gradual increase in the instantaneous power of the turbine until reaching the rated wind speed.

Rated wind speed.

That is the wind speed in which generator reach its rated power out put, as the speed increase above The rated wind speed the force on a turbine structures continue to rise and at some point there is a risk of damage to the rotor ,as a result the braking system is employed to bring the rotor to standstill this is called the cut-out speed and this usually around at 25 metre per second. we have already said that the turbine blade start to turn when they are hit by a wind if we look closely we can notice that the blades had a lots of airfoils cross-sectional consisting of a different sizes and shapes from the roots to tip. The teardrop shape of the blade is a very similar to the aerodynamics of the wings of aircraft in that case the airflow hitting the wings followed precise, trajectories allowing the molecules of a lower surface to have a higher density than those of the upper surface the difference in the pressures between the two parts allowed the wings and  consequentially the whole aircrafts to lift up.

More blades allow you to achieve a more power but the more blades there are on the turbine .when the higher will be the torque which is the force that created rotation and thus lower the rotational speed because of the increasing a drag caused by wind flow resistance so a wind turbine with many blades will  be more powerful but less efficient than one with the less blades, a wind turbine with 3 blades placed ar 120 degrees from each other representing a good compromise between power and efficiency.A turbine with the four blades mean more weight and therefore more cost, also wind turbine with the two blades will obtain similar performance but would require a bigger dimensions and therefore higher cost, we have seen so far that the designe and implementations of a wind turbine involve a series of structural choices that are not directly linked to the power of the wind turbine.

Cost and maintenanc.

But take into account the factors such as a cost maintenance noise pollution landscape assessments and many other maintenance still represent are found fundamental elements .many damage occurs when irregularly maintenance activity does not performed. 

Fire burn by main internal components of a lubrication system.

Foreign objects can also impact the blades.

In the case of bad weather condition thunder cause a damage of turbine. 

Published by Science tube 15 September 2020