Comparison of Different Control Strategies to Study Power Quality in Variable Speed Wind Turbine

Resumen

In this paper, a Fixed-Speed (FSWT) and a Variable-Speed Wind Turbine (VSWT) are modelled in Matlab/Simulink. The purpose of these models is to analyse the flicker emission of a FSWT and a VSWT in different operating points. First a FSWT is modelled and validated with data of an 180kW Wind Turbine. This model is used to study the wind and the effects of the aerodynamic characteristics on the short-term flicker severity index (Pst). Then a VSWT working with a Doubly Fed Induction Generator is modelled. This model has the same aerodynamic, mechanical and electrical parameters as the FSWT. The analysis of the VSWT working allows understanding the origin of the flicker emission. An advanced control strategy taking into account the cause of flicker emission is then designed to get a lower Pst. The results show, as it was expected, that the flicker emitted by the VSWT is very low and lower than the emitted by the FSWT. From the other hand, it is shown that despite the very low value of the flicker emitted by the VSWT, it is possible to get an even lower Pst by designing an advanced control strategy taking into account the origin of flicker emission.