Predictive direct power control of grid-connected voltage-sourced converters under unbalanced grid voltage conditions

This paper proposed a modified predictive direct power control (P-DPC) strategy for a grid-connected voltage-sourced converter under unbalanced grid voltage conditions. The proposed P-DPC strategy is implemented in the stationary reference frame without the necessity of either the space vector modulation or the synchronous speed d-q transformation. A compensation method is adopted in the conventional P-DPC to eliminate the negative sequence component of gird current for the purpose of obtaining the symmetrical and sinusoidal grid current under unbalanced grid voltage conditions. Positive and negative sequence components extraction is also avoided in the proposed method. Simulation results verified that the modified P-DPC strategy is effective to obtain symmetrical and sinusoidal grid currents under unbalanced grid voltage conditions.

[1]  Miguel Ángel Rodriguez Vidal,et al.  Predictive Control Strategy for DC/AC Converters Based on Direct Power Control , 2007, IEEE Transactions on Industrial Electronics.

[2]  J. Eloy-Garcia,et al.  Extended direct power control of a three-level Neutral Point Clamped Voltage Source Inverter with unbalanced voltages , 2008, 2008 IEEE Power Electronics Specialists Conference.

[3]  Mariusz Malinowski,et al.  A comparative study of control techniques for PWM rectifiers in AC adjustable speed drives , 2003 .

[4]  P. Cartwright,et al.  VSC transmission operating under unbalanced AC conditions - analysis and control design , 2005, IEEE Transactions on Power Delivery.

[5]  J. L. Rodriguez-Amenedo,et al.  Direct power control of voltage source inverters with unbalanced grid voltages , 2008 .

[6]  V. Blasko,et al.  A novel control method of a VSC without AC line voltage sensors , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[7]  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 .

[8]  Jiabing Hu,et al.  Modeling and Control of Grid-Connected Voltage-Sourced Converters Under Generalized Unbalanced Operation Conditions , 2008, IEEE Transactions on Energy Conversion.

[9]  Lie Xu,et al.  Direct active and reactive power control of DFIG for wind energy generation , 2006, IEEE Transactions on Energy Conversion.

[10]  Liangzhong Yao,et al.  Direct Power Control of Grid Connected Voltage Source Converters , 2007, 2007 IEEE Power Engineering Society General Meeting.