Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers
Title Converter Control Method of DFIG Wind Turbine for Fast Transient Flux Attenuation Under Voltage Dips
Authors 김태형(Tae-Hyeong Kim) ; 송승호(Seung-Ho Song)
DOI https://doi.org/10.5370/KIEE.2020.69.1.50
Page pp.50-59
ISSN 1975-8359
Keywords DFIG(Doubly Fed Induction Generator); Voltage dip; Reactive Current; Injection of Rotor current; LVRT(Low Voltage Ride-Through)
Abstract The high penetration of large power capacity of wind power plants connected to the grid directly can lead to serious problem of power system stability. Wind turbines should control active and reactive power according to the requirements of grid code and should stay connected to the grid during grid voltage disturbance. Doubly fed induction generator(DFIG) provides the advantage of variable speed operation and control of rated active and reactive power using a small rated power of converter approximately 30% power capacity of the generator. But the main drawback of this type of wind turbine is large sensitivity to the grid voltage disturbance, because the stator of a DFIG is directly connected to the grid. In this paper, based on theoretical study, the dynamic behavior of DFIG under grid voltage dips is analyzed and a control method of rotor current injection is proposed for the fast decrease of the transient natural stator flux. The proposed control strategy focuses on the mitigation of the transient natural stator flux for the reduction of high voltage on rotor-side and the injection of the reactive current for grid voltage support simultaneouly.
For the verification of the proposed control strategy, a complete simulation model for 2MW DFIG is implemented and its performance is extensively examined using PSCAD.