Parallel Operation of DFIGs in Three-Phase Four-Wire Autonomous Wind Energy Conversion System

This paper deals with a control algorithm for two parallel-operated doubly fed induction generators (DFIGs) driven by wind turbines in a three-phase four-wire autonomous system feeding local loads. The proposed autonomous wind energy conversion system (AWECS) is using back-to-back-connected pulsewidth-modulated insulated-gate-bipolar-transistor-based voltage source converters with a battery energy storage system at their dc link. The system utilizes separate rotor-side converters for each DFIG for maximum power tracking (MPT) through its rotor speed control. However, a common dc bus and a battery bank and stator-side converter are used for voltage and frequency control at the stator terminals of the DFIGs. A delta-star transformer is connected between the stator-side converter and the stator terminals of DFIGs for optimizing the voltage of dc bus, and the load-side neutral is connected to the neutral of the star side of the transformer. The proposed electromechanical system is modeled and simulated in MATLAB using Simulink and Sim Power Systems set toolboxes. The performance of the proposed AWECS is presented to demonstrate its capability of MPT, stator voltage and frequency control, harmonic elimination, load balancing, and load leveling.

[1]  Greg Asher,et al.  A doubly fed induction generator using back-to-back PWM converters supplying an isolated load from a variable speed wind turbine , 1996 .

[2]  R. Blasco-Gimenez,et al.  Analytical and experimental evaluation of a WECS based on a Doubly Fed Induction Generator fed by a matrix converter , 2008, 2008 IEEE International Symposium on Industrial Electronics.

[3]  G. Martin.  Renewable energy gets the "green" light in Chicago , 2003 .

[4]  J. Clare,et al.  Wind–Diesel Generation Using Doubly Fed Induction Machines , 2008, IEEE Transactions on Energy Conversion.

[5]  Amit K. Jain,et al.  Wound Rotor Induction Generator With Sensorless Control and Integrated Active Filter for Feeding Nonlinear Loads in a Stand-Alone Grid , 2008, IEEE Transactions on Industrial Electronics.

[6]  J. Clare,et al.  Sensorless control of a doubly- fed induction generator for stand alone operation , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[7]  P. Vas.  Vector control of AC machines , 1990 .

[8]  Ziyad M. Salameh,et al.  A mathematical model for lead-acid batteries , 1992 .

[9]  Roberto Cárdenas,et al.  Vector Control of Front-End Converters for Variable-Speed Wind–Diesel Systems , 2006, IEEE Transactions on Industrial Electronics.

[10]  K. Stunz,et al.  Multilevel energy storage for intermittent wind power conversion: computer system analogies , 2005, IEEE Power Engineering Society General Meeting, 2005.

[11]  H. Polinder,et al.  General Model for Representing Variable-Speed Wind Turbines in Power System Dynamics Simulations , 2002, IEEE Power Engineering Review.

[12]  Alex Van den Bossche,et al.  Autonomous renewable energy conversion system , 2000 .

[13]  Bikash C. Pal,et al.  Modelling adequacy of the doubly fed induction generator for small-signal stability studies in power systems , 2008 .

[14]  B. Singh,et al.  Voltage and Frequency Controller for a Three-Phase Four-Wire Autonomous Wind Energy Conversion System , 2008, IEEE Transactions on Energy Conversion.

[15]  B. Singh,et al.  Battery Based Voltage and Frequency Controller for Parallel Operated Isolated Asynchronous Generators , 2007, 2007 IEEE International Symposium on Industrial Electronics.

[16]  Lie Xu,et al.  Enhanced Control and Operation of DFIG-Based Wind Farms During Network Unbalance , 2008, IEEE Transactions on Energy Conversion.

[17]  M.R. Iravani,et al.  Hybrid Control of a Grid-Interactive Wind Energy Conversion System , 2008, IEEE Transactions on Energy Conversion.

[18]  L.A.C. Lopes,et al.  Wind-driven self-excited induction generator with voltage and frequency regulated by a reduced-rating voltage source inverter , 2006, IEEE Transactions on Energy Conversion.

[19]  B. Singh,et al.  Analysis and design of STATCOM-based voltage regulator for self-excited induction generators , 2004, IEEE Transactions on Energy Conversion.