Open AccessCompound frequency modulation strategy of DFIG‐based wind turbines dealing with stator winding inter‐turn short‐circuit fault
Author(s) -
Sun Liling,
Hu Lanqing,
Xu Boqiang
Publication year - 2017
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2017.0735
Subject(s) - control theory (sociology) , stator , decoupling (probability) , automatic frequency control , induction generator , fault (geology) , wind power , frequency multiplier , frequency grid , computer science , engineering , bandwidth (computing) , voltage , electrical engineering , control engineering , control (management) , artificial intelligence , seismology , geology , computer network
Stator winding inter‐turn short‐circuit fault (SWITSC) is a kind of common and high risk fault of doubly fed induction generator (DFIG), which would cause mutation of motor power. DFIG‐based wind turbine is common in weak grid and its power fluctuation triggers the drop of system frequency. However, due to the decoupling control between speed and frequency, it is difficult to provide dynamic response to the system when the frequency fluctuation. To solve the above problems, two kinds of frequency control are proposed: integrated inertial and improved pitch angle control frequency modulation (FM). The effects of the FM of the two methods dealing with the frequency drop caused by SWITSC fault are analysed and compared, and results show: integrated inertial FM reduces the rate of change of frequency and provides the dynamic support of frequency; improved pitch angle control raises the lowest frequency and reduces the amplitude of frequency fluctuation. Finally, a new composite frequency control strategy considering the integrated inertial control and improved pitch angle control is proposed, which can elevate the transient and steady‐state performance of system frequency and ameliorate the problem of frequency drop in weak grid under SWITSC fault effectively. These methods are applied to models developed in Matlab/Simulink and indicative results are presented.