Open AccessMethod to suppress sub‐synchronous oscillation of DFIG‐based wind farms based on virtual impedance
Author(s) -
Ning Wei,
Wu Xi,
Guan Ya Jing,
Chen Fan
Publication year - 2017
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2017.0715
Subject(s) - control theory (sociology) , controller (irrigation) , electrical impedance , transfer function , computer science , induction generator , frequency domain , rotor (electric) , oscillation (cell signaling) , time domain , impedance parameters , generator (circuit theory) , voltage , engineering , physics , power (physics) , electrical engineering , control (management) , chemistry , biochemistry , artificial intelligence , quantum mechanics , agronomy , computer vision , biology
This study proposes a novel method that can mitigate sub‐synchronous oscillation in the wind farm by adding virtual impedance controller to the rotor side converter (RSC) of doubly‐fed induction generator (DFIG). Firstly, the transfer function of RSC is obtained, taking into account the structure of outer voltage loop in RSC and virtual impedance controller. Then, the design procedure of virtual impedance controller is converted into an optimisation problem for maximising the absolute phase of this transfer function at the resonance frequency. Also genetic algorithm is utiliesd to obtain the optimal parameters of controller. Both the frequency‐domain analysis of this transfer function and time‐domain simulation have validated the effectiveness of this optimal parameters, and the superiority of virtual impedance controller is compared with virtual resistance controller finally.