Evaluation of the effects of rotor harmonics in a doubly-fed induction generator with harmonic induced speed ripple

This paper is concerned with the low-frequency harmonics which originate from the rotor inverter of a doubly-fed induction generator (DFIG). By including the mechanical speed response, it expands the transformer approach previously taken to analyze the harmonic transfer in the machine. A numerical method is proposed to calculate the stator current sidebands, which can be used to predict the voltage fluctuation at the system busbar. It is shown that the pulsating torque associated with the rotor harmonics can induce speed ripple depending on the inertia, causing a significant change in the stator current spectrum. Experiment and simulation verify the analysis and the proposed calculation method.

[1]  K. S. Smith,et al.  Torsional Vibrations in Electrical Induction Motor Drives During Start-up , 1996 .

[2]  Z. M. Salameh,et al.  Analysis of the Double Output Induction Generator Using Direct Three-phase Model Part II - Harmonic Analysis , 1987, IEEE Transactions on Energy Conversion.

[3]  A. Larsson,et al.  Flicker Emission of Wind Turbines during Continuous Operation , 2002, IEEE Power Engineering Review.

[4]  Scott D. Sudhoff,et al.  Analysis of Electric Machinery and Drive Systems , 1995 .

[5]  Jawad Faiz,et al.  Harmonic analysis and performance improvement of slip energy recovery induction motor drives , 2001 .

[6]  Li Ran,et al.  Monitoring torsional vibrations of electro-mechanical systems using stator currents , 1998 .

[7]  Li Ran,et al.  Input current harmonic analysis of pseudo 12-pulse 3-phase to 6-phase cycloconverters , 1996 .

[8]  B. R. Pelly,et al.  Thyristor Phase-Controlled Converters and Cycloconverters: Operation, Control, and Performance , 1971 .

[9]  R. D. Ball,et al.  Alternating-current machines. A review of progress , 1962 .

[10]  Pragasen Pillay,et al.  Harmonic analysis of slip energy recovery induction motor drives , 1994 .

[11]  L. Haydock,et al.  Modelling and simulation of a variable speed stand-alone generator system , 2000 .

[12]  Siegfried Heier,et al.  Grid Integration of Wind Energy Conversion Systems , 1998 .

[13]  P. Ashmole.  Quality of supply-voltage fluctuations. II , 2001 .

[14]  Hirofumi Akagi.  The state-of-the-art of power electronics in Japan , 1998 .

[15]  G. A. Putrus,et al.  Analysis of harmonic transfer in an AC excited generator including speed ripple , 2002, IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02.