A Zero Sequence Voltage Injection Method for Cascaded H-bridge D-STATCOM

  • Received : 2016.12.28
  • Accepted : 2017.03.26
  • Published : 2017.07.20


Load variations on a distribution line result in voltage fluctuations at the point of common coupling (PCC). In order to keep the magnitude of the PCC voltage constant at its rated value and obtain zero voltage regulation (ZVR), a D-STATCOM is installed for voltage correction. Moreover, the ZVR mode of a D-STATCOM can also be used to balance the source current during unbalanced loading. For medium voltage and high power applications, a D-STATCOM is realized by the cascaded H-bridge topology. In the ZVR mode, the D-STATCOM may draw unbalanced current and in this process is required to handle different phase powers leading to deviations in the cluster voltages. Zero sequence voltage needs to be injected for ZVR mode, which creates circulating power among the phases of the D-STATCOM. The computed zero sequence voltage and the individual DC capacitor balancing controller help the DC cluster voltage follow the reference voltage. The effectiveness of the control scheme is verified by modeling the system in MATLAB/SIMULINK. The obtained simulations are further validated by the experimental results using a dSPACE DS1106 and five-level D-STATCOM experimental set up.


  1. T. H. Nguyen, D.-C. Lee, T. L. Van, and J.-H. Kang, "Coordinated control of reactive power between STATCOMs and wind farms for PCC voltage regulation," Journal Power Electronics, Vol. 13, No. 5, pp. 909-917, Sep. 2013.
  2. B. H. Chowdhury and C. W. Taylor, "Voltage stability analysis: V-Q power flow simulation versus dynamic simulation," IEEE Trans. Power Syst., Vol. 15, No. 4, pp. 1354-1359, Nov. 2000.
  3. H. Fujita, S. Tominaga, and H. Akagi, "Analysis and design of a DC voltage-controlled static VAr compensator using quad-series voltage-source inverters," IEEE Trans. Ind. Appl., Vol. 32, No. 4, pp. 970-978, Jul./Aug. 1996.
  4. F. Z. Peng, J.-S. Lai, J. W. McKeever, and J. VanCoevering, "A multilevel voltage-source inverter with separate DC sources for static VAr generation," IEEE Trans. Ind. Appl., Vol. 32, No. 5, pp. 1130-1138, Sep./Oct. 1996.
  5. H. Akagi, "Classification, terminology, and application of the modular multilevel cascade converter (MMCC)," IEEE Trans. Power Electron., Vol. 26, No. 11, pp. 3119-3130, Nov. 2011.
  6. K. Yang, Y. Wang, and G. Chen, "Design and research on high-reliability HPEBB Used in cascaded DSTATCOM," Journal Power Electronics, Vol. 15, No. 3, pp. 830-840, May 2015.
  7. H. Akagi, Y. Kanazawa, and A. Nabae, "Instantaneous reactive power compensators comprising switching devices without energy storage components," IEEE Trans. Ind. Appl., Vol. IA-20, No. 3, pp. 625-630, May 1984.
  8. S. Bhattacharya and D. Divan, "Design and implementation of a hybrid series active filter system," in Proceedings of PESC '95 - Power Electronics Specialist Conference, Vol. 1, pp. 189-195, 1995.
  9. B. Singh and V. Verma, "Selective compensation of power-quality problems through active power filter by current decomposition," IEEE Trans. Power Del., Vol. 23, No. 2, pp. 792-799, Apr. 2008.
  10. G. D. Marques, "A comparison of active power filter control methods in unbalanced and non-sinusoidal conditions," in IECON '98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.98CH36200), Vol. 1, pp. 444-449, 1998.
  11. B. Singh and J. Solanki, "An improved control approach for DSTATCOM with distorted and unbalanced AC mains," Journal of Power Electronics, Vol. 8, No. 2, pp. 131-140, Apr. 2008.
  12. M. H. Karimi, H. Zamani, K. Kanzi, and Q. V. Farahani, "Implementation of a 35KVA converter base on the 3-phase 4-wire STATCOMs for medium voltage unbalanced systems," Journal Power Electronics, Vol. 13, No. 5, pp. 877-883, Sep. 2013.
  13. B. Singh, S. S. Murthy, and S. Gupta, "Analysis and design of STATCOM-based voltage regulator for self-excited induction generators," IEEE Trans. Energy Convers., Vol. 19, No. 4, pp. 783-790, Dec. 2004.
  14. K. Hasegawa and H. Akagi, "A new DC-voltage-balancing circuit including a single coupled inductor for a five-level diode-clamped pwm inverter," IEEE Trans. Ind. Appl., Vol. 47, No. 2, pp. 841-852, Mar. 2011.
  15. R. Betz, T. Summers, and T. Furney, "Symmetry compensation using a H-bridge multilevel STATCOM with zero sequence injection," in IEEE Industry Applications Conference Forty-First IAS Annual Meeting, Vol. 4, pp. 1724-1731, 2006.
  16. R. E. Betz and T. J. Summers, "Using a cascaded H-bridge STATCOM for rebalancing unbalanced voltages," in 2007 7th Internatonal Conference on Power Electronics, pp. 1219-1224, 2007.
  17. N. Hatano and T. Ise, "Control scheme of cascaded H-bridge STATCOM using zero-sequence voltage and negative-sequence current," IEEE Trans. Power Del., Vol. 25, No. 2, pp. 543-550, Apr. 2010.
  18. C. Lee, B. Wang, S. Chen, S. Chou. J. Huang, P. Cheng, H. Akagi, and P. Barbosa, "Average power balancing control of a STATCOM based on the cascaded H-bridge PWM converter with star configuration," IEEE Trans. Ind. Appl., Vol. 50, No. 6, pp. 3893-3901, Nov. 2014.
  19. Q. Song and W. Liu, "Control of a cascade STATCOM with star configuration under unbalanced conditions," IEEE Trans. Power Electron., Vol. 24, No. 1, pp. 45-58, Jan. 2009.
  20. P. Sochor and H. Akagi, "Theoretical comparison in energy-balancing capability between star- and delta-configured modular multilevel cascade inverters for utility-scale photovoltaic systems," IEEE Trans. Power Electron., Vol. 31, No. 3, pp. 1980-1992, Mar. 2016.
  21. J. I. Y. Ota, Y. Shibano, and H. Akagi, "A phase-shifted PWM D-STATCOM using a modular multilevel cascade converter (SSBC); Part II: zero-voltage-ride-through capability," IEEE Trans. Ind. Appl., Vol. 51, No. 1, pp. 289-296, Jan. 2015.