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Current Limit Strategy of Voltage Controller of Delta-Connected H-Bridge STATCOM under Unbalanced Voltage Drop

  • Received : 2017.07.11
  • Accepted : 2017.09.18
  • Published : 2018.03.01

Abstract

This paper presents the current limit strategy of voltage controller of delta-connected H-bridge static synchronous compensator (STATCOM) under an unbalanced voltage fault event. When phase to ground fault happens, the feasibility to heighten the magnitude of sagging phase voltage is considered by using symmetric transformation method in delta-structure STATCOM. And the efficiency to cover the maximum physical current limit of switching device is considered by using vector analysis method that calculate the zero sequence current for balancing the cluster energy in delta connected H-bridge STATCOM. The result is simple and obvious. Only positive sequence current has to be used to support the unbalanced voltage sag. Although the relationship between combination of the negative sequence voltage with current and zero sequence current is nonlinear, the more negative sequence current is supplying, the larger zero sequence current is required. From the full-model STATCOM system simulation, zero sequence current demand is identified according to a ratio of positive and negative sequence compensating current. When only positive sequence current support voltage sag, the least zero sequence current is needed.

Keywords

References

  1. H. Yonezawa, T. Shimato, M. Tsukada, K.Matsuno, I. Iyoda, J. J. Paserba, and G. F. Reed, "Study of a STATCOM application for voltage stability evaluated by dynamic PV curves and time simulations," in Proc. Power Engineering Society Winter Meeting, 2000.
  2. J. Dixon, L. Moran, J. Rodriguez, and R. Domke, "Reactive power compensation technologies : Stateof- the-art review," Proc. IEEE, vol. 93, no. 12, 2005.
  3. J. M. Guerrero, P. C. Loh, T.-L. Lee, and M. Chandorkar, "Advanced control architectures for intelligent microgrids-Part II: Power quality, energy storage, and AC/DC microgrids," IEEE Transactions on Industrial Electronics, vol. 60, no. 4, April 2013.
  4. W. Qiao, G. K. Venayagamoorthy, R. G. L Harley, "Real-time implementation of a STATCOM on a wind farm equipped with doubly fed induction generator," IEEE Transactions on Industry Applications, vol. 45, no. 1, Jan. 2009.
  5. H. Akagi, "Classification, terminology, and application of the modular multilevel cascade converter (MMCC)," IEEE Transaction on Power Electronics, vol. 26, no. 11, April 2011.
  6. G. T. Son, H. -J. Lee, T. S. Nam, Y. -H. Chung, U. - H. Lee, S.-T. Baek, K. Hur, and J.-W. Park, "Design and control of a modular multilevel HVDC converter with redundant power modules for noninterruptible energy transfer," IEEE Transaction on Power Delivery, vol. 27, no. 3, July 2012.
  7. L. Zhang, and L. Dofnas, "A novel method to mitigate commutation failure in HVDC systems," in Proc. 2002 Inter. Conf. on Power System Technology, 2002.
  8. N. Hatano and T. Ise, "Control scheme of cascaded hbridge statcom using zero-sequence voltage and negative-sequence current," IEEE Transactions on Power Delivery, vol. 25, no. 2, April 2010.
  9. R. Teodorescu, M. Liserre, P. Rodriguez, Grid Converters for Photovoltaic and Wind Power Systems: IEEE/Wiley, 2011.
  10. D. Lu, H. Hu, Y. Xing, X. He, K. Sun and J. Yao, "Studies on the clustered voltage balancing mechanism for cascaded H-bridge STATCOM," in Proc. 2016 IEEE Applied Power Electronics Conference and Exposition (APEC), 2016.
  11. H. Akagi, S. Inoue and T. Yoshii, "Control and performance of a transformerless cascade PWM STATCOM with star configuration," Industry Applications, IEEE Transactions on Industrial Electronics, vol. 43, no. 4, July-Aug. 2007.
  12. L. Tan, S. Wang, P. Wang, Y. Li, Q. Ge, H. Ren, and P. Song, "High performance controller with effective voltage balance regulation for a cascade statcom with star configuration under unbalanced conditions," in Proc. of 15th European Conference on Power Electronics and Applications (EPE), 2013.
  13. Q. Song, W. Liu, Z. Yuan, W. Wei, and Y. Chen, "DC voltage balancing technique using multi-pulse optimal PWM for cascade H-bridge inverters based STATCOM," in Proc. IEEE 35th Power Electronics Specialists Conf., 2004.
  14. J. Yutaka Ota, Y. Shibano, and H. Akagi, "A phaseshifted pwm dstatcom using a modular multilevel cascade converter (ssbc); part ii: Zero-voltage-ridethrough capability," IEEE Transactions on Industry Application, vol. 51, no. 1, Jan 2015.
  15. S. Chui, J.-J. Jung, Y. i Lee, and S.-K. Sul, "Principles and dynamics of natural arm capacitor voltage balancing of a direct modulated modular multilevel converter," in Proc. 2015 9th Inter. Conf. on Power Electric and ECCE Asia, 2015.
  16. Peter W. Sauer, and M. A. Pai, Power System Dynamics and Stability: Prentice-Hall International Editions, 1998
  17. J.-J. Jung, J.-H. Lee, S.-K. Sul, G. T. Son, and Y.-H. Chung, "DC capacitor voltage balancing control for delta-connected cascaded h-bridge STATCOM considering the unbalanced grid and load conditions," in Proc. 2016 IEEE Energy Conversion Congress and Exposition, 2016, 1-8.