Voltage Complex Feedback Control for Wind Powered Double Fed Induction Generator Mohamed-Saïd Naït-Saïd 1 , Nasreddine Naït-Saïd 2 , Abdesslem Makouf 3 , Saïd Drid 4 L.S.P.I.E Lab., Electrical Eng. Depart.; Batna University, Rue M.E.H Boukhlof, Algeria, Tel/Fax: +213.33.81.51.23 1 medsnaitsaid@yahoo.fr, 2 n_naitsaid@yahoo.com, 3 a_makouf@yahoo.fr, 4 s_drid@lycos.com ABSTRACT This paper deals with a voltage complex control intended to wind powered doubly fed induction generator in isolate site. Analysis developed in the complex model form of this machine demonstrates that is possible to create a linear decoupling control between rotor and stator voltages. Complex feedback voltage control is utilized in order to compensate the undesired complex coupled terms existing in the constituted voltage complex transfer function established from the complex machine model. The obtained complex feedback control is robust against machine parameters model variation and it is only related to the stator and rotor frequencies where the first one is fixed to its desired rated value and the second one is estimated from the measured speed. Also, a linear controller can be easily employed such as a PI controller designed by the pole placement method. Simulation tests confirm widely the feasibility and the effectiveness of the proposal control, especially, for an isolate electric site when the wind speed and power consumption may be varied. Index Terms— Double fed induction machine, wind powered, complex feedback control, decoupling control, stator voltage control, complex transfer function 1. INTRODUCTION It is established that the renewable wind energy like being a means ecological and economical resources to produce the electricity [1-2]. Actually, electric energy production from this natural and renewable energy knows an important development all over the world since it is supported by very mature technologies, such as the wind turbine technology [3-5]. Total installed capacity of wind energy, since the beginning of 2004, all over the world reached 39 GW with an annual growth rate of about 30% [1]. Some prediction studies give that 12% of the total world electricity demands will be supplied from wind energy by 2020 [2]. In the wind power generation systems, the input power may be considerably varied with wind speed variation. Generally, a maximum power point tracker (MPPT) adjusts a system quantity to track the highest turbine power output [6-9]. Kid of generator functioning directly at the variable speed drive is more adaptive for these particular applications, such as double fed induction machine. But such machine presents an ambivalent character of the synchronous and asynchronous machines and its control is done from a non linear model which is not easy and requires a particular attention. Since the stator frequency may be fixed to its desired rated value, the main advantage of the double fed induction generator (DFIG) is that the rotor may be controlled by ac voltage where its rotor frequency is directly linked to the rotor speed varying with the wind speed. Other particularity of the DFIG is that the rotor may be controlled from a reduced power converter. This work concerns the development of a linear and decoupled control of the stator voltage via the so called complex transfer stator-rotor voltage [6]. It will be seen that using the complex form model of the induction machine, we can obtain this proposed control trough a complex feedback state given by the complex form gains. This complex feedback control can be considered as robust control against machine parameters model variation and it depends to the stator and rotor frequencies where the first one is fixed to its desired rated value while the second one may be easily estimated from the measured rotor speed. Simulation tests attest widely the validation of this proposed control scheme especially when it is utilized for an isolate electric site. 2. DFIG COMPLEX MODEL The complex form state model of the DFIG, described in the Park’s formulation (dq- axis), may be written as follows [10]: ( ) ( ) s s s s s s s r v R sL jL i Ms j i = + + ω + + ω (1) ( ) ( ) r r r r r r r s v R sL jL i Ms j i = + + ω + + ω (2) s r p ω =ω ± Ω (3) 2012 First International Conference on Renewable Energies and Vehicular Technology 978-1-4673-1170-0/12/$31.00 ©2012 IEEE 293