Nonlinear dynamic modeling for fault ride-through capability of DFIG-based wind farm

摘要

Fault ride-through (FRT) is a control model enhanced to protect doubly fed induction generator (DFIG) during voltage dip occurring in grid. In this study, stator and rotor circuit dynamic modeling enhanced in terms of simulation performance and fast system responses during instability in DFIG-based wind farm, besides, a FRT capability strategy were enhanced for nonlinear supercapacitor modeling in DFIG-based wind farm. The transient stability analyses of the DFIG with and without supercapacitor as well as positive-negative-sequence dynamic modeling (PNSDM) were compared for three phases, two phases, two-phase-ground and a-phase-ground faults. Furthermore, variations such as DFIG output voltage, DFIG angular speed, DFIG electrical torque and DFIG d-q axis stator current variations were also evaluated. It was found that the DFIG-based wind farm became stable within a short time using the PNSDM and supercapacitor.