Open AccessPositive and negative sequence control of DFIG based wind turbines and its impact on grid voltage profile concerning converter control capability
Author(s) -
Yan Lun,
Yuan Xiaoming
Publication year - 2017
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2017.0599
Subject(s) - grid code , rotor (electric) , control theory (sociology) , grid , overcurrent , induction generator , doubly fed electric machine , computer science , wind power , matlab , fault (geology) , generator (circuit theory) , voltage , ac power , sequence (biology) , power (physics) , engineering , control (management) , electrical engineering , mathematics , physics , geometry , quantum mechanics , artificial intelligence , seismology , geology , operating system , biology , genetics
As grid‐connected doubly fed induction generator (DFIG) based wind turbines have become a significant power source, in order to meet grid code and ensure its safe operation during asymmetrical grid faults, many improved control algorithms have been developed for the rotor‐side converter (RSC). However, most of them did not take the RSC control capability constraint into account and may cause overcurrent problem in the rotor side under serve asymmetric faults. In this study, first a new positive and negative sequence current control scheme for the RSC is designed so that DFIG can operate well during serve asymmetrical faults. Then, due to the RSC capability constraint, the controllable regions of DFIG are analysed while the limitation of DFIG is given. Based on the controllable regions and limitation of DFIG, the limitation and division strategies between DFIG rotor positive and negative sequence current are also developed theoretically. Finally, a typical system of a 45 MW DFIG‐based wind farm connected to power system is used to verify the effectiveness of the developed rotor positive and negative sequence current limitation and division strategies and study their impact on grid voltage profile during various asymmetrical faults in Matlab/Simulink software.