Self healing character of smart grid in presence 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. On the other hand, wind energy is one of the most important renewable energy sources in smart grid this means that it will broadly implement on smart distribution network. The main issue 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 where the self healing character of smart grid should be considered while any contingency occur in system. 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. In addition the behavior of system in traditional distribution network and smart distribution grid is evaluated. It is shown that different time of the fault occurrence can largely effect on the transient amplitude of the stator current and self healing character of smart grid help the system to continue supplying demand without interruption in fault occurrence situation.