Title :
Control of DFIG-based wind farms for network unbalance compensation
Author :
Wang, Yi ; Xu, Lie ; Williams, Barry W.
Author_Institution :
Dept. of Electron.&Electr. Eng., Univ. of Strathclyde, Glasgow
Abstract :
This paper investigates the control of doubly-fed induction generator (DFIG) based wind farms for compensating voltage unbalance in weak networks. A DFIG system model containing the generator and its back-to-back converters suitable for analyzing system operation under unbalanced conditions is developed. A control strategy for compensating grid voltage unbalance using DFIG systems is proposed. The negative sequence current injected into the transmission line for the rebalancing control can be provided by either the grid-side or the rotor-side converter. Various methods for coordinating these two converters and their impact on system operation are analyzed. The capabilities of the converters with a DFIG system for negative sequence current compensation are also discussed. The validity of the proposed control strategy is demonstrated by Matlab/Simulink simulations. With the proposed strategy, DFIG based wind farms can provide voltage unbalance compensation for the connected weak grid to improve the performance and stability of the whole wind energy system.
Keywords :
asynchronous generators; machine control; power convertors; wind power plants; back-to-back converters; doubly-fed induction generator; grid-side converter; negative sequence current; negative sequence current compensation; rebalancing control; rotor-side converter; transmission line; voltage unbalance compensation; wind energy system; wind farms; Control systems; Induction generators; Mathematical model; Mesh generation; Power transmission lines; Stability; Voltage control; Wind energy; Wind energy generation; Wind farms;
Conference_Titel :
Power Electronics Specialists Conference, 2008. PESC 2008. IEEE
Conference_Location :
Rhodes
Print_ISBN :
978-1-4244-1667-7
Electronic_ISBN :
0275-9306
DOI :
10.1109/PESC.2008.4591909