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Μελέτη αποσυζευγμένου ελέγχου ενεργού – αέργου ισχύος ανεμογεννήτριας διπλής τροφοδότησης χωρίς αισθητήρες ταχύτητας/θέσης του δρομέα (Master thesis)

Γιαννάκης, Ανδρέας/ Giannakis, Andreas

The subject of this thesis is the study-simulation of a grid-connected wind turbine based on a doubly fed induction generator (DFIG). The Matlab/Simulink program was used to simulate the above system. More specifically, the control of such a system, which consists of two control strategies, is thoroughly studied and analyzed. The first refers to the decoupled active-reactive power control of the generator, which is based on calculation methods for the speed and the rotor position estimation instead of using mechanical sensors. This alternative has many advantages, which are described below. The estimation method of the speed and the rotor position is based on a Modified PLL (MPLL). Moreover, an under-scale experiment was conducted to validate the accuracy of the proposed method. Subsequently, the second control strategy is analyzed, which concerns the use of an intelligent control system and more specifically the fuzzy logic controllers instead of the classic PI controllers for (i) the speed regulation, (ii) the active power regulation, (iii) the reactive power regulation and (iv) the voltage regulation in the DC link. The implementation of the fuzzy controllers was based on Takagi-Sugeno’s method. Finally, many simulation results are presented for a more complete understanding of the system under study, emphasizing on the significance of the proposed control approach, making a comparative study between the proposed and other two control strategies.