The Transactions of the Korean Institute of Power Electronics (전력전자학회논문지)

The Korean Institute of Power Electronics (전력전자학회)
권호 표지
DOI QR코드

DOI QR Code

Enhancement of Cell Voltage Balancing Control by Zero Sequence Current Injection in a Cascaded H-Bridge STATCOM

STATCOM에서 영상분 전류주입에 의한 셀간 전압평형화 제어의 향상

  • Received : 2015.02.16
  • Accepted : 2015.06.11
  • Published : 2015.08.20
Download PDF
⟨ Previous Next ⟩

Abstract

The static synchronous compensator (STATCOM) of cascaded H-bridge configuration accompanying multiple separate DC sides is inherently subject to the problem of uneven DC voltages. These DC voltages in one leg can be controlled by adjusting the AC-side output voltage of each cell inverter, which is proportional to the active power. However, when the phase current is extremely small, large AC-side voltage is required to generate the active power to balance the cell voltages. In this study, an alternative zero-sequence current injection method is proposed, which facilitates effective cell balancing controllers at no load, and has no effect on the power grid because the injected zero sequence current only flows within the STATCOM delta circuit. The performance of the proposed method is verified through simulation and experiments.

Keywords

References

  1. F. Z. Peng, J. S. Lai, J. McKeever, and J. VanCoevering, "A multilevel voltage-source inverter with separate DC sources for static var generation," in Proc. Conf. Rec. IEEE-IAS Annu. Meeting, pp. 2541-2548, 1995.
  2. F. Z. Peng, J. W. McKeever, and D. J. Adams, "A power line conditioner using cascaded multilevel inverters for distribution systems," IEEE Trans. Ind. Appl., Vol. 34, No. 6, pp. 1293-1298, Nov./Dec. 1998. https://doi.org/10.1109/28.739012
  3. Y. Liang and C. O. Nwankpa, "A new type of STATCOM based on cascading voltage-source inverters with phase-shifted unipolar SPWM," IEEE Trans. Ind. Appl., Vol. 35, No. 5, pp. 1118-1123, Sep./Oct. 1999. https://doi.org/10.1109/28.793373
  4. H. Akagi, S. Inoue, and T. Yoshii, "Control and performance of a transformerless cascade PWM STATCOM with star configuration," IEEE Trans. Ind. Appl., Vol. 43, No. 4, pp. 1041-1049, Jul./Aug. 2007. https://doi.org/10.1109/TIA.2007.900487
  5. N. Hatano and T. Ise, "Control scheme of cascaded H-bridge STATCOM using zero-sequence voltage and negative-sequence current," IEEE Trans. Power Delivery, Vol. 25, No. 2, pp. 543-550, Apr. 2010. https://doi.org/10.1109/TPWRD.2009.2035221
  6. R. E. Betz and T. J. Summers, "Using a cascaded H-bridge STATCOM for rebalancing unbalanced voltages," in Proc. 7th Int. Conf. Power Electron., pp. 1219-1224, 2007.
  7. M. Hagiwara, R. Maeda, and H. Akagi, "Negative-sequence reactive-power control by a PWM STATCOM based on a modular multilevel cascaded converter(MMCC-SDBC)," in Conf. Rec. IEEE-ECCE 2011, pp. 3728-3735, 2011.
  8. J. A. Barrena, L. Marroyo, M. Vidal, and J. Apraiz, "Individual voltage balancing strategy for PWM cascaded H-bridge converter-based STATCOM," IEEE Trans. Ind. Electron., Vol. 55, No. 1, pp. 21-29, Jan., 2008. https://doi.org/10.1109/TIE.2007.906127
  9. Y. Li and B. Wu, "A novel DC voltage detection technique in the CHB inverter-based STATCOM," IEEE Trans. Power Delivery, Vol. 23, No. 3, pp. 1613-1619, Jul. 2008. https://doi.org/10.1109/TPWRD.2008.919251
  10. Z. Liu. B. Liu, S. Duan, and Y. Kang, "A novel dc capacitor voltage balance control method for cascaded multilevel STATCOM," IEEE Trans. Power Electron., Vol. 27, No. 1, pp. 14-27, Jan. 2012. https://doi.org/10.1109/TPEL.2010.2050337
  11. B. K. Kwon, S. K. Jung, and T. H. Kim, "Control of DC-side voltage unbalance among phases in multi-level H-bridge STATCOM with unbalanced load," The Trans. of the Korean Institute of Power Electronics, Vol. 19, No. 4, pp. 332-341, Aug. 2014. https://doi.org/10.6113/TKPE.2014.19.4.332
  12. B. Bahrani, A. Rufer, S. Kenzelmann, and L. Lopes, "Vector control of single-phase voltage-source converters based on fictive-axis emulation," IEEE Trans. Ind. Appl., Vol. 47, No. 2, pp. 831-840, Mar./Apr. 2011. https://doi.org/10.1109/TIA.2010.2101992