Stability Analysis and Control of DFIG Based Wind Turbine Using FBC Strategy

Subject Areas : Renewable energy

Majid Tavoosi ¹ , Bahador Fani ² , Ehsan Adib ³

1 - MSc /Science & Research of Isfahan, Branch, Islamic Azad University
2 - Assistant Professor /Najafabad Branch, Islamic Azad University
3 - Assistant Professor /Isfahan University of Technology

Received: 2013-01-13 Accepted : 2013-09-22 Published : 2013-11-01

Keywords: Doubly-fed induction generator, small signal analysis, flatness based control,

Abstract :

Doubly fed induction generator has numerous advantages in wind power generation over other types of generators. Once a DFIG is subjected to a large voltage dip, a large rotor voltage induces in the rotor windings. This leads to a large transient current in rotor circuit and the dc-link overvoltage, and may block power electronic converter operation. This paper first discusses dynamic modeling of  DFIG wind turbines with the stator flux orientation. Then, by small signal analysis, it is found that the dynamic behavior of the DFIG based WT during voltage dip, is strongly affected by the stator dynamics. Next, a nonlinear control strategy based on flatness is proposed to improve the DFIG transient performance. The main interest of this control method is the possibility to define the behavior of the state variable system in the steady state as well as in transients. Since the DFIG electrical dynamics are nonlinear; better control performance is achieved with nonlinear control, compared with the linear control scheme. The proposed approach stabilizes the stator dynamics through rotor and grid side filter voltage control. The results of time domain simulations validate the effectiveness the nonlinear control strategy during voltage dip of generator terminal.

References:

[1] GWEC. 2012. Global Wind Energy Council. Available from: http://www.gwec.net.

[2] M. Tazil, V. Kumar, R.C. Bansal, S. Kong, Z.Y. Dong, W. Freitas, H.D. Mathur, "Three-phase doubly fed induction generators: an overview",  IET Electric Power Applications, No.4,  pp.75-89, 2010.

[3] A. Petersson, L. Harnefors, T. Thiringer, "Evaluation of current control methods for wind turbines using doubly-fed induction machines", IEEE Trans. Power Electronics, Vol. 20, No. 1, pp. 227–235, 2005.

[4] M. Rahimi, M. Parniani, "Transient Performance Improvement of Wind Turbine With Doubly Fed Induction Generators Using Nonlinear Control Strategy", IEEE Trans. Energy Conversion, Vol. 25, No. 2, pp.514-525, 2010.

[5] L. Yang, G.Y. Yang, Z. Xu, Z.Y. Dong, K.P. Wong, X. Ma, "Optimal controller design of a doubly-fed induction generator wind turbine system for small signal stability enhancement", IET Generation, Transmission & Distribution, No. 4, pp.579-597, 2010.

[6] J.P.A. Vieira, M.V.A. Nunes, U.H. Bezerra, A.C. Nascimento, "Designing optimal controllers for DFIGs using a genetic algorithm", IET Generation, Transmission & Distribution, No.3, pp. 472-484, 2009.

[7] X.P. Wu, K. Zhang, P. Ju. Godfrey, "Small signal stability analysis and optimal control of a wind turbine with doubly fed induction generator", IET Generation, Transmission & Distribution, No.1, pp. 751-760, 2007.

[8] Y. Mishra, S. Mishra, M. Tripath, N. Senroy, Z. Dong, "Improving stability of a DFIG-based wind power system with tuned damping controller", IEEE Trans. Energy Conversion, Vol. 24, No. 3, pp. 650-660, 2009.

[9] M.H. Variani, K. Tomsovic, "Distributed automatic generation control using flatness-based approach for high penetration of wind generation", IEEE Trans. Power Sys., Vol. 1, No.1, pp. 1-8, 2013.

[10] P. Ledesma, J. Usaola, "Doubly fed induction generator model for transient stability analysis", IEEE Trans. Energy Conversion, Vol. 20, No. 2, pp.388-397, 2005.

[11] T. Ackerman, Wind Power in Power Systems. New York: Wiley, 2005.

[12] A. Houari, H. Renaudineau, J.P. Martin, S. Pierfederici, F. Meibody Tabar, "Flatness-based control of three-phase inverter with output LC filter", IEEE Trans. Industrial Elec., Vol. 59, No.7, pp. 2890-2897, 2012.

[13] M. Fliess, J.L. Evine, P.H. Martin, P. Rouchon, "Flatness and defect of nonlinear systems: Introductory theory and examples", Int. J. Cont., No. 6, pp. 1327–1361, 1995.