Four-Switch Three-Phase Operation of Grid-Side Converter of Doubly Fed Induction Generator With Three Vectors Predictive Direct Power Control Strategy

Abstract

A predictive power control for a four-switch three-phase (FSTP) grid-side converter (GSC) of doubly fed induction generators (DFIG) is presented in this paper. In this new method, three voltage vectors are employed to ensure that the proposed strategy maintains the switching frequency constant while the ripple of the active and reactive powers of the GSC is minimized. Moreover, a compensation power to eliminate the dc voltage deviation in the capacitors is presented, and it can be estimated without using any low-pass filter. The proposed method can be implemented in a microcontroller very easily. First, the proposed strategy has been evaluated in MATLAB/Simulink environment and afterward it was implemented in a laboratory prototype. The simulation and experimental results of the proposed predictive strategy show that it is capable to suppress the dc-link voltage offset, featuring balanced currents and a fast dynamic response while the GSC current total harmonic distortion is low. Furthermore, the performance of the proposed method is compared to two other predictive controls. The results prove that the proposed method is well suitable for the FSTP GSC of a DFIG.