A robust STATCOM control to augment LVRT capability of fixed speed wind turbines

In this paper, we propose an algorithm to design a robust output feedback controller for a Static Synchronous Compensator (STATCOM) to enhance the Low-Voltage Ride- Through (LVRT) capability of fixed-speed wind turbines equipped with induction generators. The wind generator is a highly nonlinear system, and in this paper it is modelled as a linear part plus a nonlinear part. The nonlinear part is written as the Cauchy remainder term in Taylor series expansion; this enables us to use the bound of this term in robust control design. Large disturbance simulations demonstrate that the proposed controller enhances voltage stability as well as transient stability of induction generators during low voltage ride through transients and thus enhances the LVRT capability.

[1]  M. J. Hossain,et al.  Excitation control for large disturbances in power systems with dynamic loads , 2009, 2009 IEEE Power & Energy Society General Meeting.

[2]  Ian R. Petersen,et al.  A connection between H∞ control and the absolute stabilizability of discrete-time uncertain linear systems , 1995, Autom..

[3]  T. C. Green,et al.  Benefits and control of STATCOM with energy storage in wind power generation , 2006 .

[4]  P. Kundur,et al.  Power system stability and control , 1994 .

[5]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[6]  J. Sun,et al.  Voltage flicker mitigation using PWM-based distribution STATCOM , 2002, IEEE Power Engineering Society Summer Meeting,.

[7]  Thomas Ackermann,et al.  Wind Power in Power Systems , 2005 .

[8]  Jon Are Suul,et al.  Low Voltage Ride Through of Wind Farms With Cage Generators: STATCOM Versus SVC , 2008, IEEE Transactions on Power Electronics.

[9]  R. Itoh,et al.  Series connected PWM GTO current/source convertor with symmetrical phase angle control , 1990 .

[10]  Poul Ejnar Sørensen,et al.  Design of a wind turbine pitch angle controller for power system stabilisation , 2007 .

[11]  R.G. Harley,et al.  Real-Time Implementation of a STATCOM on a Wind Farm Equipped With Doubly Fed Induction Generators , 2006, IEEE Transactions on Industry Applications.

[12]  Kevin Barraclough,et al.  I and i , 2001, BMJ : British Medical Journal.

[13]  Andrés Feijóo,et al.  A third order model for the doubly-fed induction machine , 2000 .

[14]  B.H. Chowdhury,et al.  Power flow and stability models for induction generators used in wind turbines , 2004, IEEE Power Engineering Society General Meeting, 2004..

[15]  Luis M. Fernández,et al.  Equivalent models of wind farms by using aggregated wind turbines and equivalent winds , 2009 .

[16]  Ian R. Petersen,et al.  Robust Control Design Using H-infinity Methods , 2000 .

[17]  Ian R. Petersen,et al.  Nonlinear versus linear control in the absolute stabilizability of uncertain systems with structured uncertainty , 1995, IEEE Trans. Autom. Control..

[18]  M. Steurer,et al.  Applying a STATCOM for stability improvement to an existing wind farm with fixed-speed induction generators , 2008, 2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century.