Original scientific paper
An improved three-level direct torque control method of brushless doubly-fed machine based on the fixed synthesizing vector
Yan Liu
Xu Wang
Yan Xing
Abstract
With the rapid growth of an AC adjusted speedsystem application, it is necessary to controland reduce harmonic pollution since theproblem brought about by the device of powerelectronics not only blocks the development ofpower electronics technology, but also causessevere harm in an electric power system. In thispaper an improved three-level direct torquealgorithm for brushless doubly-fed machines hasbeen developed for reducing the torque and fluxripples in a brushless doubly-fed machine. Thismethod based on 48 fixed synthesizing vectors isimplemented in the brushless doubly-fed machine.Compared with the traditional two-level directtorque control algorithm, this new methodbroadens the selection range on voltage vectors. Italso effectively reduces the torque ripples andimproves the properties of the magnetic chaintrack. In addition, this algorithm improves thedynamic performance and robustness of both thebrushless doubly-fed machine and its controlsystem. To validate the proposed method, somemathematic simulations have been done so that thesimulation results have shown the effectiveness ofthe proposed method. Moreover, this proposedmethod has been implemented in the brushlessdoubly-fed machine system showing anenhancement in the motor performance.
Keywords
brushless doubly-fed machine; direct torque Ccntrol; fixed synthesizing vector; three level inverter; torque ripples; flux linkage ripples
Hrčak ID:
111108
URI
Publication date:
25.11.2013.
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