Control and performance analysis of grid-connected variable speed wind turbine with dual stator-winding induction generator for the contribution of both stator windings in active power transmission

Recently, variable speed wind turbines (WTs) employing dual stator-winding induction generators (DSWIGs) have gained interest in related kinds of literature. A DSWIG has two sets of stator windings known as power-winding (PW) and control-winding (CW), where CW is connected to a pulse-width modulation converter called semiconductor excitation controller (SEC). This study, first, presents a topology for connection of DSWIG-based WT to the grid, in which unlike most of the related kinds of literature, both the PW and CW contribute in transmission of active power to the grid. In the study system, PW is connected to the diode rectifier-boost converter and CW to the SEC, and thus PW and CW active powers are controlled by the related boost converter and SEC, respectively. Hence, this study extends theoretical expression and presents a new relation for the generator torque as a function of the CW and boost converter currents, and then develops control structures for the study system. Next, mathematical expressions are presented for the selection of excitation capacitor at the PW terminals. Besides, the presented control strategy of the system is modified to enhance the WT-low voltage ride-through capability. In the end, simulation results are presented for examining the system performance and verifying the theoretical analyses.