DFIG Power Generation Capability and Feasibility Regions Under Unbalanced Grid Voltage Conditions

Several strategies have been proposed for operating doubly-fed induction generator (DFIG)-based wind turbine under unbalanced grid voltage conditions. This study focuses on those strategies in which the rotor-side power converter aims at eliminating the oscillations affecting the electromagnetic torque and the stator reactive power. Given the limited size of the DFIG's power converters, and hence their tolerable current and voltage boundaries, this study analyzes which DFIG power generation capability is under unbalanced grid voltage, and therefrom derives rotor current and stator power controllable ranges. Besides, the feasibility regions of the DFIG are also deduced for different types of imbalance. Furthermore, and based on the outcome of previous analysis, a modified rotor current limiter, as also its equivalent stator power limiter, is proposed. In contrast to the conventional ones, the limiters proposed here take into account that imbalances may arise in the grid voltage. As a consequence, system's overall performance is considerably enhanced under unbalanced grid voltage conditions. Finally, simulation results establish the validity of the treated issues.

[1]  Eduard Muljadi,et al.  Understanding the unbalanced-voltage problem in wind turbine generation , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[2]  G. Tapia,et al.  Modeling and control of a wind turbine driven doubly fed induction generator , 2003 .

[3]  Peter Tavner,et al.  Control of a doubly fed induction generator in a wind turbine during grid fault ride-through , 2006 .

[4]  He Yikang,et al.  Dynamic modelling and robust current control of wind-turbine driven DFIG during external AC voltage dip , 2006 .

[5]  Yikang He,et al.  Dynamic modelling and robust current control of wind-turbine driven DFIG during external AC voltage dip , 2006 .

[6]  Lie Xu,et al.  Control of DFIG-Based Wind Generation Systems under Unbalanced Network Supply , 2007, 2007 IEEE International Electric Machines & Drives Conference.

[7]  J. A. Ferreira,et al.  Control of DFIG under Unsymmetrical Voltage Dip , 2007, 2007 IEEE Power Electronics Specialists Conference.

[8]  Lie Xu,et al.  Dynamic Modeling and Control of DFIG-Based Wind Turbines Under Unbalanced Network Conditions , 2007, IEEE Transactions on Power Systems.

[9]  Heng Nian,et al.  Enhanced control of DFIG-used back-to-back PWM VSC under unbalanced grid voltage conditions , 2007 .

[10]  Dan Sun,et al.  Modified DPC for DFIG based wind power generation under unbalanced grid-voltage , 2008, 2008 International Conference on Electrical Machines and Systems.

[11]  Lie Xu,et al.  Dynamic modeling and direct power control of wind turbine driven DFIG under unbalanced network voltage conditions , 2008 .

[12]  S. Arnalte,et al.  Direct Power Control Applied to Doubly Fed Induction Generator Under Unbalanced Grid Voltage Conditions , 2008, IEEE Transactions on Power Electronics.

[13]  J. López,et al.  Wind Turbines Based on Doubly Fed Induction Generator Under Asymmetrical Voltage Dips , 2008, IEEE Transactions on Energy Conversion.

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

[15]  Lie Xu,et al.  Coordinated Control of DFIG's Rotor and Grid Side Converters During Network Unbalance , 2008, IEEE Transactions on Power Electronics.

[16]  D. Santos-Martin,et al.  Providing Ride-Through Capability to a Doubly Fed Induction Generator Under Unbalanced Voltage Dips , 2009, IEEE Transactions on Power Electronics.

[17]  Peng Zhou,et al.  Improved Direct Power Control of a DFIG-Based Wind Turbine During Network Unbalance , 2009, IEEE Transactions on Power Electronics.

[18]  Stavros A. Papathanassiou,et al.  A review of grid code technical requirements for wind farms , 2009 .

[19]  Lie Xu,et al.  Improved rotor current control of wind turbine driven doubly fed induction generators during network unbalance , 2009, 2009 International Conference on Sustainable Power Generation and Supply.

[20]  Jiabing Hu,et al.  Modeling and enhanced control of DFIG under unbalanced grid voltage conditions , 2009 .

[21]  Barry W. Williams,et al.  Improved Control of DFIG Systems During Network Unbalance Using PI–R Current Regulators , 2009, IEEE Transactions on Industrial Electronics.

[22]  Yongdong Li,et al.  A modified vector control strategy for DFIG based wind turbines to Ride-Through voltage dips , 2009, 2009 13th European Conference on Power Electronics and Applications.

[23]  Jie Wu,et al.  Integral Sliding-Mode Direct Torque Control of Doubly-Fed Induction Generators Under Unbalanced Grid Voltage , 2010, IEEE Transactions on Energy Conversion.

[24]  F. Blaabjerg,et al.  Rotor Voltage Dynamics in the Doubly Fed Induction Generator During Grid Faults , 2010, IEEE Transactions on Power Electronics.

[25]  Lie Xu,et al.  Improved rotor current control of wind turbine driven doubly-fed induction generators during network voltage unbalance , 2010 .

[26]  Jiabing Hu,et al.  DFIG wind generation systems operating with limited converter rating considered under unbalanced network conditions – Analysis and control design , 2011 .