Low Voltage Ride-Through of high power DFIG wind turbine using three-level NPC converters

Nowadays, there is a tendency to increase the power of wind turbines. Multilevel converter is a realistic alternative in such high power applications. As the most widely used variably speed wind turbine, doubly fed induction generators (DFIG) are very sensitive to grid disturbances. Moreover, grid codes have been revised to require wind turbines to provide Low Voltage Ride-Through (LVRT) ability. This paper proposes a space-vector hysteresis current control strategy of the three-level neutral point clamped (NPC) converter in order to enhance the ride-through ability of the high power DFIG wind turbine system against grid faults. Simulation and experimental results have proven an excellent performance and verified the effects of the strategy.