Abstract
Due to superior static and dynamic performances and low power ratings of associated power converters, doubly-fed induction generators (DFIG) become a new trend for renewable energy technology, especially for wind and hydro pump-storage power generations. By appropriately controlling the magnitude, phase, and frequency of the rotor voltage phasor, the DFIG can be operated in various operating modes, including sub-synchronous modes, synchronous modes, and super-synchronous modes. In this thesis, we will focus on the rotor side control of DFIGs. In order to achieve active power and reactive power decoupled control, a generalized flux oriented control will be investigated in details. It can be shown that the conventional stator flux oriented control, rotor flux oriented control, and air-gap flux oriented control are all special cases of the proposed control algorithm. The MATLAB/Simulink simulation platform has been studied for verifying the feasibility and the correctness of the proposed control algorithms. We also developed a 2.2 kW hardware prototype for the DFIG. The TMS320F2812 digital signal processor is utilized for real-time controller implementations. In order to verify the proposed generalized flux oriented algorithms, the hardware DFIG platform test has been conducted under different operating conditions. Measured waveforms demonstrate excellent performances of the proposed control algorithms.