wind turbines

Wind turbines are windmills used to generate electricity. This wind turbine was originally created to accommodate the needs of farmers in making rice mills, irrigation purposes, etc.. Previous wind turbines were built in Denmark, the Netherlands and other European countries and better known as the Windmill.
Wind turbines are now more widely used to accommodate the electrical needs of the community, using the principle of energy conversion and use of natural resources which can be updated is the wind. Although to date the construction of wind turbines are still not able to compete with power generation konvensonal (Example: diesel, power plant, etc.), wind turbines are still further developed by scientists because in the near future humans will be faced with the problem of shortage of non-renewable natural resources (Example: coal, petroleum) as a base material to generate electricity.
Calculation of power that can be generated by a wind turbine with a diameter fan r is:
P = \ frac {1} {2} \ rho \ pi R ^ 2 v ^ 3 where ρ is the density of the wind at a given time and v is the wind speed at a given time.
Generally effective power that can be harvested by a wind turbine is only 20% -30%. So the above formula can be multiplied by 0.2 or 0.3 to obtain a sufficiently exact results.The basic principles of wind turbines is to change the mechanical energy of wind into energy play in the wheel, then spin wheel used to turn a generator, which will eventually produce electricity.
Actually the process is not that easy, because there are various sub-systems that can improve safety and efficiency of wind turbines, namely:
1. GearboxThis tool serves to change the low round on the mill into high rotation. The gearbox is usually used around 1:60.
2. Brake SystemUsed to keep the rounds on the shaft after the gearbox in order to work safely at the point when there is a big wind. These tools need to be installed because the generator has a safe working point in the operation. This generator will produce electric energy maximum at the point when working on the work that has been determined. The presence of the wind outside diguaan will cause a fairly rapid rotation on the shaft generator, so that if not addressed then this rotation can damage the generator. The impact of damage caused by excessive rounds include: overheated, rotor breakdown, broken wire in the generator because it can not withstand large currents.
3. GeneratorThis is one of the most important component in the manufacture of wind turbine systems. These generators can change the energy of motion into electrical energy. The principle works can be studied using electromagnetic field theory. In short, (referring to the workings of one generator) on the generator shaft fitted with a permanent ferromagnetic material. After that, around the axis of the stator which forms fisisnya there are coils of wire that form a loop. When the generator starts rotating shaft there will be changes in the stator flux is ultimately due to a change of this flux will produce a certain voltage and amperage. Voltages and currents generated electricity is distributed through the electrical network cable to eventually be used by the public. Voltage and electric current generated by the generator in the form of AC (alternating current) which has approximately sinusoidal waveform.
4. Energy storageDue to the limited availability of energy-wind (no wind throughout the day will always be available), the availability of electricity was erratic. Therefore, use of energy storage devices that serve as back-up electrical energy. When the load increases the use of electrical power or when the wind speed of a region are declining, the need for electric power demand will not be met. Therefore we need to store the energy generated when there is excess power at a wind turbine spinning or when the use of power in society decreases. Energy storage is accommodated by using energy storage devices. A simple example which can be referenced as an electrical energy storage device is a car battery. Car battery has a storage capacity large enough energy. Battery 12 volt, 65 Ah can be used to dole households (approximately) for 0.5 h at 780 watts of power.
Constraints in using this tool is the tool requires a power supply DC (Direct Current) to meng-charge/mengisi energy, while the power supply from the generator produced AC (Alternating Current). Therefore, the rectifier-inverter is needed to accommodate this purpose. Rectifier-inverter will be described below.
5. Rectifier-inverterRectifier means rectifier. Wave rectifier can rectify sinusodal (AC) produced by the generator into a DC waveform. Inverter is inverting. When the required power from energy storage (batteries / other) then the supply will be generated by wave-shaped battery DC. Since most household uses AC power supply, it would require an inverter to convert DC waves released by the battery into the AC waveform, so that could be used by the household.