Dynamic response of wind power generation based on DFIG under grid fault

This paper analyzes the behavior of DFIG and converter in the case of grid fault including symmetrical and unsymmetrical fault. First, the simple space vector models are presented to estimate the moduli of DFIG stator voltage in different grid fault. Then with the symmetrical components method, the dynamic response of DFIG and converter in grid fault is analyzed in details, and the equations of grid fault are derived. According to the equation, the maximum value and it´s occurred moment of the short-current of DFIG is determined, which can be used to design crowbar precisely. At last, based on the above analysis, the design guidelines for grid fault ride-through are proposed.