Enhanced Direct Torque and Reactive Power Control of a Grid-Connected DFIG Fed by Two-Level Back-To-Back Converter

This paper presents an improvement to direct reactive power control (DRPC) applied to two-level inverter feeds the rotor of doubly fed induction generator (DFIG) driven by variable speed wind turbine (WT). For this purpose, a reference rotor flux is obtained from the stator reactive power regulation to be applied to the direct torque control (DTC). The fuzzy logic approach seems to be a good solution to eliminate the problem of ripples that occur in conventional direct reactive power control (CDRPC). On the other hand, a direct power control (DPC) is applied to the grid side converter (GSC) to enable reactive power control at the grid connection point. The simulation results obtained with the proposed fuzzy direct reactive power control (FDRPC) show satisfactory improvements over CDRPC in terms of torque and stator reactive power ripples reduction.