Current Control Reference Calculation Issues for the Operation of Renewable Source Grid Interface VSCs Under Unbalanced Voltage Sags

This paper analyzes the current reference calculation for the control of grid-connected voltage source converters meant to operate under voltage unbalanced sags produced by grid faults. The well-known reference calculation method that allows to control the active power ripple produced by the existence of negative-sequence components in the grid voltage is extensively analyzed. A type of voltage sag that produces unfeasible current reference values is identified and a possible workaround is proposed. Also, the need to compensate the power ripple produced by the filter inductance of the converter is demonstrated and an extension of the calculation method to compensate for this is introduced. The theoretical results are confirmed using simulation tools and experimental tests.

[1]  C. Fortescue Method of Symmetrical Co-Ordinates Applied to the Solution of Polyphase Networks , 1918, Transactions of the American Institute of Electrical Engineers.

[2]  P. Rioual,et al.  Regulation of a PWM rectifier in the unbalanced network state using a generalized model , 1996 .

[3]  V. Blasko,et al.  A new mathematical model and control of a three-phase AC-DC voltage source converter , 1997 .

[4]  Math Bollen,et al.  Understanding Power Quality Problems: Voltage Sags and Interruptions , 1999 .

[5]  Hong-Seok Song,et al.  Dual current control scheme for PWM converter under unbalanced input voltage conditions , 1999, IEEE Trans. Ind. Electron..

[6]  Antti J. Koivo,et al.  Nonlinear predictive control with application to manipulator with flexible forearm , 1999, IEEE Trans. Ind. Electron..

[7]  O. Gomis,et al.  A laboratory test bed for PM brushless motor control , 2005, 2005 European Conference on Power Electronics and Applications.

[8]  J. Morren,et al.  Ridethrough of wind turbines with doubly-fed induction generator during a voltage dip , 2005, IEEE Transactions on Energy Conversion.

[9]  Paolo Mattavelli,et al.  Digital Control in Power Electronics , 2006, Digital Control in Power Electronics.

[10]  M. Karimi-Ghartemani,et al.  Processing of Symmetrical Components in Time-Domain , 2007, IEEE Transactions on Power Systems.

[11]  Hirofumi Akagi,et al.  Instantaneous power theory and applications to power conditioning , 2007 .

[12]  P.W. Lehn,et al.  Control and Power Management of Converter Fed Microgrids , 2008, IEEE Transactions on Power Systems.

[13]  O. Gomis-Bellmunt,et al.  Ride-Through Control of a Doubly Fed Induction Generator Under Unbalanced Voltage Sags , 2008, IEEE Transactions on Energy Conversion.

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

[15]  I. Erlich,et al.  Enhanced Fault Ride-Through Method for Wind Farms Connected to the Grid Through VSC-Based HVDC Transmission , 2009, IEEE Transactions on Power Systems.

[16]  Sergio Busquets-Monge,et al.  Control Strategies Based on Symmetrical Components for Grid-Connected Converters Under Voltage Dips , 2009, IEEE Transactions on Industrial Electronics.

[17]  J.A. Ferreira,et al.  Operation of Grid-Connected DFIG Under Unbalanced Grid Voltage Condition , 2009, IEEE Transactions on Energy Conversion.

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

[19]  Ping Wang,et al.  Control of Three-Phase Boost-Type PWM Rectifier in Stationary Frame Under Unbalanced Input Voltage , 2010, IEEE Transactions on Power Electronics.

[20]  Andreas Sumper,et al.  Modeling and control of the doubly fed induction generator wind turbine , 2010, Simul. Model. Pract. Theory.

[21]  Jun Liang,et al.  Topologies of multiterminal HVDC-VSC transmission for large offshore wind farms , 2011 .