Robust vector controllers for brushless doubly-fed wind turbine generators

Abstract

The paper is concerned with field-oriented control (FOC) and vector control (VC) of a promising brushless doublyfed reluctance generator (BDFRG) technology for adjustable speed wind turbines with maximum power point tracking. The BDFRG has been receiving increasing attention because of the low capital and operation & maintenance costs afforded by using partially-rated power electronics and the high reliability of brushless design, while offering performance competitive to its wellknown slip-ring counterpart, a doubly-fed induction generator (DFIG). The preliminary studies have evaluated the performance of the two parameter independent control algorithms on a custom-made BDFRG under the maximum torque per inverter ampere (MTPIA) conditions for the improved efficiency of the generator and the entire wind energy conversion system (WECS). mutual flux [Wb] and 3-phase inductance [H] ω p,s primary, secondary winding frequencies [rad/s] ω rm rotor angular velocity [rad/s] ω syn synchronous speed = ω p /p r [rad/s] P m mechanical (shaft) power [W] P p,s primary, secondary mechanical power [W] T e electro-magnetic torque [Nm] P, Q primary real [W] and reactive [VAr] power T * e , Q * control reference values for T e and Q σ leakage factor = 1 − L 2 ps /(L p L s )