DocumentCode :
35995
Title :
Direct power control of doubly fed induction generator without phase-locked loop in synchronous reference frame during frequency variations
Author :
Heng Nian ; Peng Cheng ; Ziqiang Zhu
Author_Institution :
Coll. of Electr. Eng., Zhejiang Univ., Hangzhou, China
Volume :
9
Issue :
6
fYear :
2015
fDate :
8 2015
Firstpage :
576
Lastpage :
586
Abstract :
This study presents a direct power control strategy for a grid-connected doubly fed induction generator (DFIG) without phase-locked loop (PLL) in a synchronous reference frame. In the proposed control system, a virtual phase angle, produced by a fixed angular speed, is used to replace the actual one of the network voltage for synchronous coordinate transformations, thus, PLL can be eliminated. The steady-state and dynamic behaviours of DFIG active and reactive powers are analysed with the potential grid frequency variations. It is found that the natural components of the flux linkages are the root cause of power and torque pulsations during the transient frequency variations. Thus, an auxiliary demagnetising current control scheme is proposed and designed to damp the natural flux linkages caused by the transient frequency variations. Then, based on the mathematic model, the control system performance is theoretically analysed. Finally, the simulation and experimental results are provided to demonstrate that the developed control system is adaptive to frequency deviations and achieve a decoupling control of both active and reactive powers.
Keywords :
asynchronous generators; control system synthesis; electric current control; machine control; power control; reactive power control; DFIG; active powers; auxiliary demagnetising current control scheme; decoupling control; direct power control strategy; dynamic behaviours; fixed angular speed; flux linkages; grid frequency variations; grid-connected doubly fed induction generator; mathematic model; network voltage; power pulsations; reactive powers; steady-state behaviours; synchronous coordinate transformations; synchronous reference frame; torque pulsations; transient frequency variations; virtual phase angle;
fLanguage :
English
Journal_Title :
Renewable Power Generation, IET
Publisher :
iet
ISSN :
1752-1416
Type :
jour
DOI :
10.1049/iet-rpg.2014.0307
Filename :
7181835
Link To Document :
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