1.Background and Research:1.1.History of Wind Energy and Wind TurbinesFig1.1 History of Wind TurbinesDuring the last century, due to the rapid development of the energy system, the The use of wind energy has gone through several phases. First, in the infancy of the 1930s and 1940s, hundreds of thousands of wind turbines were built in the United States to produce electricity. These wind turbines provided electricity to farms beyond the reach of power lines and were typically used to charge storage batteries, operate radio receivers, and power a light bulb or two [1]. Then, with the expansion of the public grid, wind energy entered a period of depression. Because of this, wind turbine development remained almost dormant for the next 20 years, until the 1970s. Subsequently, wind energy ushered in a new beginning. In the early 1980s, a new market for wind systems began, called “wind farms.” Furthermore, with the emphasis on renewable energy, more wind farms will be built, but for most countries this is not yet realistic. Recent decades have seen an increasing use of induction generators, particularly in wind energy applications. In generator operation, a prime mover (turbine, motor) drives the rotor above synchronous speed. The stator flux still induces currents in the rotor, but because the opposing rotor flux now cuts the stator coils, active current is produced in the stator coils and the motor now functions as a generator and sends energy to the electrical grid. Based on the reactive power source, induction generators can be classified into two types: stand-alone generator and grid-tied induction generator. In the case of independent insulating assemblies the magnetizing flux is established by a capacitor bank connected to the ma...... middle of paper ......erg "A review of the state of the art in power electronics for the wind turbines sector" IEEE conference on Power Electronics and Machines in Wind Applications, 2009. pp. 1-16 June 2009.[13] Power Electronics and Machines in Wind Applications (PEMWA), 2012 IEEE, issue date: 16-18 July 2012, written by: Arnedo, Luis; Dwari, Suman; Motapon, Souleman; Blasko, Vladimir[14] Matlab. Available at: http://en.wikipedia.org/wiki/MATLAB (accessed: 7 November 2014)[15] Electrical Engineer Jobs in London. Available from: http://www.jobsite.co.uk/jobs/london/electrical-engineer(Accessed: 7 November 2014)[16] Available from: http://www.alibaba.com/product-detail/ac -squirrel-cage-induction-generator_60066504902.html(Accessed: 8 November 2014)[17]Market research and statistics in the wind turbine industry. Available at: http://www.reportlinker.com/ci01341/Wind-Turbine.html(Accessed: November 8 2014)