The characteristics of variable speed constant frequency generator is windmills and the wind grid tie inverter

Speed is available in a wide range of change and does not affect the frequency of the output power inverter .

Due to the speed variable windmills, can through the proper control, make the wind speed at or close to the optimal value, so as to maximize the use of power inverter. 

2.3 the characteristics of constant speed constant frequency power inverter 

At present, most of the induction generator in wind power systems with belongs to constant speed constant frequency power inverter unit. 

In order to adapt to the requirement of the size of wind grid tie inverter  speed, generally USES two different capacity and different number of asynchronous generators, low wind speed with small capacity of generators, wind grid tie inverter is high with large capacity generators, usually by variable pitch system at the same time change the Angle of attack of the blade in order to adjust the output wind grid tie inverter. 

But it also can make asynchronous generator under the two wind speed has better output coefficient, unable to effectively use different wind speed of wind grid tie inverter. 

2.4 the implementation of variable speed constant frequency system

Can be used in variable speed constant frequency grid tie inverter system has a variety of: if delivery has been a frequency conversion system, ac excitation generator system, brushless doubly-fed motor system, the switched reluctance generator system, the magnetic field modulated power inverter system, synchronous asynchronous motor variable speed constant frequency system, etc. 

This kind of variable speed constant frequency system have a plenty of through transforming structure and realize variable speed constant frequency generator itself; Others are grid tie inverter and power electronic device, microcomputer control system and the combination of realize variable speed constant frequency.