Enhancing Low-Voltage Ride-Through Capability of Wind Turbine Based Double-Fed Induction Generator Using ANFIS Controller and Crowbar Circuit

The main target of this paper is to increase the low-voltage ride-through (LVRT) of the Doubly fed induction generator (DFIG) driven by wind turbine. Two steps are suggested to achieve this goal, firstly, by inserting a crowbar circuit (CB) into rotor circuit, in case of voltage dip (VD), to protect it from excessive current and excessive voltage that could result from the transient flux produced by the VD. It is worth to note that simulation results proved that if no CB circuit is used, the system may be vulnerable to instability. Next, an ANFIS-controller is proposed to control both the rotor side converter (RSC) and the grid side converter (GSC). The GSC is controlled such that the suggested controller will enhance LVRT by injecting the needed system reactive power. While the RSC controller regulates the electromagnetic torque, the GSC controller control both the real power and reactive power delivered to the system during normal operating conditions beside with it keeps the value of the dc link voltage fixed. From the results, it is clear that the hybrid ANFIS and CB circuit are capable of sustaining the DFIG stability and provide an improved LVRT responses in challenging operating conditions and within the acceptable criterions.