DOI QR코드

DOI QR Code

Unbalancing Voltage Control of LVDC Bipolar Distribution System for High Power Quality

전력 품질 향상을 위한 LVDC 양극성 배전 시스템의 불평형 전압 제어

  • Received : 2015.09.21
  • Accepted : 2016.09.06
  • Published : 2016.12.20

Abstract

The voltage unbalance of an LVDC bipolar distribution system was controlled for high power quality. Voltage unbalance may occur in a bipolar distribution system depending on the operation of the converter and load usage. Voltage unbalance can damage sensitive load and lead to converter accidents. The conditions that may cause voltage unbalance in a bipolar distribution system are as follows. First, three-level AC/DC converters in bipolar distribution systems can lead to voltage unbalance. Second, bipolar distribution systems can be at risk for voltage unbalance because of load usage. In this paper, the output DC link of a three-level AC/DC converter was analyzed for voltage unbalance, and the bipolar voltage was controlled with algorithms. In the case of additional voltage unbalance according to load usage, the bipolar voltage was controlled using the proposed converter. The proposed converter is a dual half-bridge converter, which was improved from the secondary circuit of a dual half-bridge converter. A control algorithm for bipolar voltage control without additional converters was proposed. The balancing control of the bipolar distribution system with distributed power was verified through experiments.

Keywords

References

  1. A. Sannino, G. Postiglione, M. J. Bollen, "Feasibility of a DC network for commercial facilities," Industry Applications, IEEE Transactions on, Vol. 39, No. 5, pp. 1499-1507, Sep./Oct. 2003. https://doi.org/10.1109/TIA.2003.816517
  2. M. Brenna, G. C. Lazaroiu, G. Superti-Furga, E. Tironi, "Premium power quality with DG integrated DC systems," IEEE Bucharest Power Tech Conference, 2009.
  3. D. Salomonsson, L. Soder, A. Sannino, "An adaptive control system for a DC microgrid for data centers," Industry Applications IEEE Transactions on, Vol. 44, No. 6, pp. 1910-1917, Nov./Dec. 2008. https://doi.org/10.1109/TIA.2008.2006398
  4. P. Salonen, P. Nuutinen, P. Peltoniemi, and J. Partanen, "Protection scheme for an LVDC distribution system", CIRED, 2009.
  5. A. Manuel, V. Evans, "Why low voltage direct current grids," Master of Science Thesis, Delft University of Technology, Jul. 2013.
  6. P. Salonen, T. Kaipia, P. Nuutinen, P. Peltoniemi, J. Partanen, "An LVDC distribution system concept," NORPIE, 2008.
  7. S. Kakigano, Y. Miura, and T. Ise, "Low-voltage bipolar-type DC microgrid for super high quality distribution," IEEE Trans. Power Electron., Vol. 25, No. 12, pp. 3066-3075, Dec. 2010. https://doi.org/10.1109/TPEL.2010.2077682
  8. A. Nabae, I. Takahashi, H. Akagi, "A new neutralpoint- clamped PWM inverter," IEEE Trans. Ind. Appl., Vol. 17, No. 5, pp. 518-523, Sep./Oct. 1981.
  9. A. K. Gupta and A. M. Khambadkone, "A simple space vector PWM scheme to operate a three-level NPC inverter at high modulation index including overmodulation region, with neutral point balancing," IEEE Trans. Ind. Appl., Vol. 43, No. 3, pp. 751-760, May/Jun. 2007. https://doi.org/10.1109/TIA.2007.895766
  10. Y. Lai, Y. Chou, and S. Pai, "Simple PWM technique of capacitor voltage balance for three-level inverter with dc-link voltage sensor only," in Proc. 33rd Annu. Conf. IEEE IECON, pp. 1749-1754, Nov. 2007.
  11. K. H. Bhalodi and P. Agrawal, "Space vector modulation with dc-link voltage balancing control for three-level inverters," in Proc. Int. Conf. PEDES, pp. 1-6. Dec. 2006.