Impact on Operating Constraints of DFIG-Based Wind-Driven System Under Symmetrical and Unsymmetrical Fault Conditions

Doubly fed induction generators (DFIGs) are becoming increasingly popular for generating wind power at variable speeds. However, as the stator is directly connected to the grid, it makes wind turbines more vulnerable to grid disturbances, particularly during voltage failures. Symmetrical and asymmetrical faults, such as single-line-to-ground (LG), double-line-to-ground (LLG), and three-phase fault (LLL), can cause severe issues and require careful analysis to understand how wind turbines behave under such conditions. This paper presents a mathematical model of a generic vector-controlled DFIG-based wind energy conversion system with grid interfacing. It also provides an overview of various voltage faults that can cause grid disturbances, followed by several simulation results for operating constraints like stator current, rotor current, and DC-link voltage. These simulations have been conducted in the MATLAB Simulink environment to demonstrate the behavior of wind turbines under symmetrical and asymmetrical fault conditions.