CONTROL OF DOUBLY FED INDUCTION GENERATOR AT GRID VOLTAGE IMBALANCE
More details
Hide details
1
Institute of Control and Industrial Electronics, Warsaw Univ. Of Technology
2
Warsaw Univ. Of Technology
Corresponding author
Grzegorz Iwański
Institute of Control and Industrial Electronics, Warsaw Univ. Of Technology, 75, Koszykowa St.,, 00-662 Warszawa, Poland
Power Electronics and Drives 2017;2 (37)(2):31-48
KEYWORDS
TOPICS
ABSTRACT
The paper presents properties and control of doubly fed induction machine operating under unbalanced grid voltage conditions. The proposed method does not include symmetrical se-quences decomposition and is realized in a rotating frame not synchronized with the grid voltage vector or the stator flux vector. The method uses reference torque and reference q component of instantaneous power for calculation of the reference stator current. Next, calculation of magnetizing current for the given unbalanced grid voltage is used to assign reference rotor current. Due to the fact that reference current contains both positive and negative sequence, the proportional-integral-resonant controller is used. The main strategy is non-oscillatory waveform of torque, whereas other strategies like symmetrical stator current or sinusoidal rotor current can easily be obtained by adequate filtration of the reference values. The paper presents simulation results of 2MW model of doubly fed induction generator and the laboratory tests with the use of small scale 7.5kW machine.