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Transient performance improvement of wind turbines with doubly fed induction generators using nonlinear control strategy

Rahimi, M ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1109/TEC.2009.2032169
  3. Publisher: 2010
  4. Abstract:
  5. This paper first discusses dynamic characteristics of wind turbines with doubly fed induction generator (DFIG). Rotor back electromotive force (EMF) voltages in DFIG reflect the effects of stator dynamics on rotor current dynamics, and have an important role on rotor inrush current during the generator voltage dip. Compensation of these voltages can improve DFIG ride-through capability and limit the rotor current transients. It is found that the electrical dynamics of the DFIG are in nonminimum phase for certain operating conditions. Also, it is shown that the dynamics of DFIG, under compensation of rotor back EMF and grid voltages, behave as a partially linearizable system containing internal and external dynamics. The internal and external dynamics of DFIG include stator and rotor dynamics, respectively. It is found that under certain operating conditions, the internal dynamics, and thus, the entire DFIG system becomes unstable. This phenomenon deteriorates the DFIG postfault behavior. Since the DFIG electrical dynamics are nonlinear; the linear control scheme cannot properly work under large voltage dips. We address this problem by means of a nonlinear controller. The proposed approach stabilizes the internal dynamics through rotor voltage control, and improves the dynamic behavior of the DFIG after clearing the fault
  6. Keywords:
  7. Doubly fed induction generator (DFIG) ; Wind turbine (WT) ; Back electromotive force ; Back-emf ; Doubly fed induction generators ; Doubly-fed induction generator ; Dynamic behaviors ; Dynamic characteristics ; External dynamics ; Grid voltage ; In-rush current ; Internal dynamics ; Linear controls ; Non linear control ; Non-linear controllers ; Non-minimum phase ; Operating condition ; Ridethrough capability ; Rotor current ; Rotor dynamic ; Rotor voltage ; Transient performance ; Voltage dip ; Asynchronous generators ; Dynamics ; Electric generators ; Electric potential ; Electromotive force ; Linear control systems ; Stators ; Voltage regulators ; Wind power ; Wind turbines ; Electric fault currents
  8. Source: IEEE Transactions on Energy Conversion ; Volume 25, Issue 2 , 2010 , Pages 514-525 ; 08858969 (ISSN)
  9. URL: http://ieeexplore.ieee.org/document/5306105/?reload=true