Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Step-Up Asymmetrical Nine Phase Delta-Connected Transformer for HVDC Transmission

  • Ammar, Arafet Ben (Laboratory of Materials, Measurements and Applications, National School of Engineering of Tunis, University of Tunis) ;
  • Ammar, Faouzi Ben (Laboratory of Materials, Measurements and Applications, National Institute of Applied Sciences and Technology, University of Carthage)
  • Received : 2017.03.30
  • Accepted : 2018.04.16
  • Published : 2018.11.20
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Abstract

In order to provide a source for nine phases suitable for 18-pulse ac to dc power, this paper proposes a new structure for a step-up asymmetrical delta-connected transformer for converting three-phase ac power to nine-phase ac power. The design allows for symmetry between the nine output voltages to improve the power quality of the supply current and to minimize the THD. The results show that this new structure proves the equality between the output voltages with $40^{\circ}-{\alpha}$ and $40^{\circ}+{\alpha}$ phase shifting and produces symmetrical output currents. This result in the elimination of harmonics in the network current and provides a simulated THD that is equal to 5.12 %. An experimental prototype of the step-up asymmetrical delta-autotransformer is developed in the laboratory and the obtained results give a network current with a THD that is equal to 5.35%. Furthermore, a finite element analysis with a 3D magnetic field model is made based on the dimensions of the 4kVA, 400 V laboratory prototype three-phase with three-limb delta-autotransformer with a six-stacked-core in each limb. The magnetic distribution flux, field intensity and magnetic energy are carried out under open-circuit operation or load-loss.

Keywords

References

  1. D. A. Paice, "Power electronic converter harmonics: multipulse methods for clean power," IEEE Press, 1996.
  2. S. Pyakuryal and M. Matin, "Harmonic for a 6-pulse rectifier," IOSR Journal for engineering, Vol. 3, pp. 2278-8719, Mar. 2013.
  3. F. Meng, L. Gao, S. Yang, and W. Yang, “Effect of phaseshift angle on a delta-connected autotransformer applied to a 12-pulse rectifier,” IEEE Trans. Ind. Electron., Vol. 62, No. 8, pp. 4678-4690, Aug. 2015. https://doi.org/10.1109/TIE.2015.2405058
  4. B. Singh, G. Bhuvaneswari, and V. Garg, “Harmonic mitigation using 12-pulse AC-DC converter in vectorcontrolled induction motor drives,” IEEE Trans. Power Del., Vol. 21, No. 3, pp. 1483-1492, Jul. 2006. https://doi.org/10.1109/TPWRD.2005.860265
  5. B. Singh, G. Bhuvaneswari, and R. Kalpana, "Autoconnected transformer-based 18-pulse ac-dc converter for power quality improvement in switched mode power supplies," IET Power Electron., Vol. 3, No.4, pp. 525-541, Jul. 2010. https://doi.org/10.1049/iet-pel.2009.0158
  6. D. A. Paice, "Optimized 18-pulse type ac-dc or dc-ac converter system", U.S. Patent No. 5124904 A, Jun. 23, 1992.
  7. C. Kim and S. Lee, "Redundancy determination of HVDC MMC modules," Electronics, Vol. 4, No. 3, pp 526-537, Aug. 2015, https://doi.org/10.3390/electronics4030526
  8. K. M. Kim, J. H. Kim, D. H. Kim, B. M. Han, and J, Y, Lee, “Improved pre-charging method for MMC-based HVDC systems operated in nearest level control,” J. Power Electron., Vol. 17, No. 1, pp. 127-135, Jan. 2017. https://doi.org/10.6113/JPE.2017.17.1.127
  9. A. Hassanpoor, Y. J Hafner, A. Nami, and K. Vinothkumar, "Cost-effective solutions for handling DC faults in VSC HVDC transmission," EPE, pp. 5-9, 2016.
  10. J. Hafner and B. Jacobson, "Proactive hybrid hvdc breakers a key innovation for reliable hvdc grid," in Cigresymposium, pp. 13-15, Sep. 2011.
  11. A. Mokhberdoran, N. Silva, H. Leite, and A. Carvalho, "Unidirectional protection strategy for multi-terminal HVDC grids," Trans. Environment and Electrical Engineering, Vol. 1, No. 4, 2016.
  12. J. Vobecky, T. Stiasny, V. Botan, K. Stiegler, U. Meier, and M. Bellini, "New thyristor platform for UHVDC (>1 MV) transmission," International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management, pp. 20-22, May. 2014.
  13. B. Sheng, H. O. Bjarme, and H. Johansson, "Reliability enhancement of HVDC transmission by standardization of thyristor valves and valve testing," 6th Int. Conf. on Power T&D Technolog, Nov. 10-12, 2007.
  14. B. L. Sheng, H. O. Bjarme, O. Saksvik, L. Carlsson, and R. Ruderval, "Modern thyristor valves and HVDC transmission technologies," Trans. High Voltage Apparatus, Vol. 39, No. 6, pp.47-50, 2003.
  15. M. B. Baherman and B. K. Johnson, "The ABCs of HVDC transmission technology," IEEE Power Energy Mag., Vol. 5, No. 2, Apr. 2007
  16. B. A. Arafet and B. A. Faouzi, "Auto-connected transformer with $40^{\circ}$ phase shifting for harmonic elimination," Int. J. Signal Imaging Syst. Eng., Vol. 9, Nos. 4/5, pp. 233-241, 2015.
  17. E. N. A. Matus, "Analysis and design of new harmonic mitigation approaches," PhD. thesis, Texas A&M University, 2012.
  18. D. A. Paice, "Nine-phase step-up/step-down autotransformer," U.S. Patent No. 7274280 B1, Sep.25, 1992.
  19. D. Hammond, "Autotransformer", U.S Patent No. 5619407 A, Apr.8, 1997.
  20. G. R. Kamath, "Autotransformer-based system and method of current harmonic reduction in a circuit," U.S. Patent No. 6861936, Mar. 1, 2005.
  21. K. Oguchi, "Autotransformer-based 18-pulse rectifiers without using dc-side interphase transformers: Classification and comparison," International Symposium Power Electronics, Electrical Drives Automation and Motion SPEEDAM, pp.760-765, Jun. 2008.
  22. R. E. Perez, S. V. Kulkarni, N. K. Kodela, and J. C. O. Galvan, "Asymmetry during load-loss measurement of three-phase three-limb transformers," Power Engineering Society General Meeting IEEE, 2007.