Torsional Vibration Characteristics Study Of Muti-type Wind Farms

As an environmentally friendly resource, wind energy has been developed quickly in recent years, which has led to the explosive growth of wind turbines connected to grid. However, with obvious disadvantages of Randomness, volatility, intermittent, the large amount of wind turbines integrated to grid will bring a great impact of low-frequency oscillation on power system and wind turbine shaft torsional vibration. Above all, the torsional vibration can cause a reduction in the fatigue life of the wind turbine, even the shaft fault, which contributes critically to the stability and safe operation of power system. Therefore it is of greatly practical significance to study the wind turbine torsional vibration characteristics in deep. According to the below problems, the tasks of this paper are arranged as follows.First of all, the present wind power developments At home and abroad are introduced, as well as the wind power generation technology. Secondly, this paper provides the small-signal union model of the grid-connected fixed-speed induction generator(FSIG), doubly fed induction generator(DFIG) and permanent magnet synchronous generator(PMSG) wind turbines, which consist of the drive train, the generator, the converter controller and the transmission line models. Then this paper employs the modal analysis to study the shaft torsional vibration issues of all type wind turbines. After that, the torsional vibration characteristics with the change of the system parameters are studied. Finally, a typical wind farm based on 24 wind turbines in all three types is taken for example to study the torsional vibration transmission characteristics among the wind turbines.