Stator current calculation of DFIG under asymmetrical faults by considering stator resistance and slip frequency

Nowadays doubly fed induction generators (DFIG) are the most popular generator used in wind turbine plants because of their cost effective partly rated power converter and variable speeds. The main drawback of DFIG is their sensitivity to gird perturbation especially voltage dips since the stator is directly connected to the grid. Rapidly increasing contribution of wind energy in power generation made it important to understand the behavior of these machines under fault conditions. In this paper an analytical equation of stator current under asymmetrical voltage dips is attained. Also the impact of the location of this fault is considered. It is shown that different time of the fault occurrence can largely effect on the transient amplitude of the stator current.