Dynamic Behavior of Doubly Fed Induction Generator Considering Protection and Control Strategy During Symmetrical Faults

Control and protection strategies take significant effect on dynamic behavior of doubly fed induction generators (DFIGs) during failure, thereby raising a conundrum for relay protection design especially as the penetration of DFIGs based wind turbines (WTs) increases. This paper takes a mathematical viewpoint, considering protection and control strategies, and analyzes the dynamic behavior of DFIG under two different faults as well as the fault steady-state model. The analysis and calculation proceed in the s-domain (complex frequency domain), and thus complex feedback loops are able to be processed. Dynamic behaviors of DFIG are studied with the math model, and fault current expressions reveal the influence of voltage dip, rotor speed as well as control parameters.