This paper explains the principal aspects of vector control of a variable-speed wind turbine based on an induction controlled with power electronics connected to the stator. The power-electronic converter consistis of two voltage-source inverter controls the angular speed of the induction generator. The other one conrols the active-power and reactive-power flow to the grid, independently. Both inverters implement some form of vector control. This configuration is easily applicable to low-power wind turbines (hundreds of kW’s) with a single inverter at both sides of the d.c. link. The paper also investigates the application of the same control principales to high-power turbines using several voltage-source inverters connected in series at each side of the d.c. link to achieve low output-voltage distortion with a reasonably-low switching frequency in the PWM control. Furthermore, the same control philosophy when applied to two back-to-back-connected inverters should also work for the rotor-power control of doubly-fed induction generators. The main contributions of the paper are illustrated with a prototype.
Keywords: Wind energy conversion system, wind turbine, voltage-source inverters, induction generator, vector control
2003 EWEA - European Wind Energy Conference and Exhibition. 16-19 June, 2003. Madrid, Spain.
Published: June 2003.