DocumentCode :
3197824
Title :
A study on the impact of control on PV curve associated with doubly fed induction generators
Author :
Lin, Chenxi ; Jiang, John N. ; Tang, Choon Yik ; Runolfsson, Thordur
Author_Institution :
Sch. of Electr. & Comput. Eng., Univ. of Oklahoma, Norman, OK, USA
fYear :
2011
fDate :
20-23 March 2011
Firstpage :
1
Lastpage :
7
Abstract :
The Power/Voltage characteristics (PV curve) of a Doubly Fed Induction Generator (DFIG) is not as well understood as those of synchronous generators. This is becoming a serious concern because of the fast growth of large-scale wind generation, which uses the DFIG technology. A PV curve describes the relation between injected active (real) power and voltage at a receiving bus, taking into consideration the dynamics of generator(s). A PV curve is often used for the characterization of the stable operating region for both generator and transmission systems. Although possessing some characteristics of a synchronous generator, by nature a DFIG is an induction machine, which means it has more complicated active and reactive power dynamics due to the coupling between its electrical and mechanical systems, and between the double feedings of its active and reactive powers from both its stator and rotor circuits. This paper presents the results of a study on the impact of rotor voltage control on the PV curve of a DFIG. Voltage dynamics, power angle dynamics, and the dynamics of the electro-mechanical system are modeled as a third-order nonlinear differential equation. A PV curve controller is also proposed, which uses an exact nonlinear cancellation strategy, as opposed to the commonly used “linear approximation” that is less accurate. This controller is used to study the impact of rotor voltage control on a PV curve. It is found that the unstable operating region of the PV curve, which exhibits bifurcation, can be circumvented through appropriate and timely regulation of the rotor voltage of the DFIG. This finding suggests that an advanced control technology not only provides an improved stable operating region for wind generation, it also enables effective real-time control during emergency.
Keywords :
asynchronous generators; synchronous generators; transmission networks; wind power; DFIG; PV curve; PV curve controller; doubly fed induction generator; generator system; induction machine; large scale wind generation; nonlinear cancellation strategy; power angle dynamic; power-voltage characteristic; synchronous generator; transmission system; voltage dynamic; Bifurcation; Mathematical model; Power system dynamics; Power system stability; Rotors; Voltage control; DFIG; Nonlinear Control; PV curve; Wind Generation;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Power Systems Conference and Exposition (PSCE), 2011 IEEE/PES
Conference_Location :
Phoenix, AZ
Print_ISBN :
978-1-61284-789-4
Electronic_ISBN :
978-1-61284-787-0
Type :
conf
DOI :
10.1109/PSCE.2011.5772583
Filename :
5772583
Link To Document :
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