Fixed switching frequency scheme for current predictive control of DFIG

This paper suggests a new current predictive control algorithm for the wind-driven doubly-fed inductiongenerator (DFIG) based on space vector modulation (SVM) with fixed switching frequency. Combiningthe current predictive controller and SVM has the benefits of a predictive controller, and fixing the switchingfrequency improves the output waveform quality. However, if classical predictive control is used, thecomputational burden will still be high. The proposed algorithm uses SVM to fix the switching frequencyof the rotor side converter. Additionally, by using an incremental algorithm, the proposed technique preventsexamining all inputs over the prediction horizon. As a result, in the proposed current predictivealgorithm the computational time is significantly reduced. The detailed state-space model of DFIG androtor side converter are used to execute the predictive algorithm. The proposed algorithm uses the rotorcurrent to predict the next behavior of the DFIG, and then, by using SVM, the duty cycles of 2-level voltagesource inverter are obtained. Finally, the proposed controller’s responses are compared to those of theSVM-based field-oriented control strategy. Simulation results of the proposed controller on a two-levelvoltage source inverter under a balanced three-phase power system illustrate the satisfactory active andreactive power tracking and improved quality of the inverter outputs.