World Academy of Science, Engineering and Technology
Published January 25, 2011 | Version 13464
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Star-Hexagon Transformer Supported UPQC

Description

A new topology of unified power quality conditioner (UPQC) is proposed for different power quality (PQ) improvement in a three-phase four-wire (3P-4W) distribution system. For neutral current mitigation, a star-hexagon transformer is connected in shunt near the load along with three-leg voltage source inverters (VSIs) based UPQC. For the mitigation of source neutral current, the uses of passive elements are advantageous over the active compensation due to ruggedness and less complexity of control. In addition to this, by connecting a star-hexagon transformer for neutral current mitigation the over all rating of the UPQC is reduced. The performance of the proposed topology of 3P-4W UPQC is evaluated for power-factor correction, load balancing, neutral current mitigation and mitigation of voltage and currents harmonics. A simple control algorithm based on Unit Vector Template (UVT) technique is used as a control strategy of UPQC for mitigation of different PQ problems. In this control scheme, the current/voltage control is applied over the fundamental supply currents/voltages instead of fast changing APFs currents/voltages, thereby reducing the computational delay. Moreover, no extra control is required for neutral source current compensation; hence the numbers of current sensors are reduced. The performance of the proposed topology of UPQC is analyzed through simulations results using MATLAB software with its Simulink and Power System Block set toolboxes.

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References

  • E. W. Gunther and H. Mehta, "A survey of distribution system power quality", IEEE Trans. On Power Delivery, vol.10, No.1, pp.322-329, Jan.1995.
  • A. C. Liew, "Excessive neutral current in three-phase fluorescent lighting circuits," IEEE Trans. Ind. Appl., vol.25, no.4, pp.776- 782.Jul./Aug. 1989.
  • T. M. Gruzs, "A survey of neutral currents in three-phase computer systems, "IEEE Trans. Ind. Appl.,vol.26,no.4,pp.719-725,Jul./Aug.1990.
  • IEEE recommended practices and requirements for harmonic control in electric power system, IEEE Std.519, 1992.
  • IEEE Recommended Practice for Monitoring Electric Power Quality, IEEE Std. 1159, 1995.
  • P. Jayaprakash , B. Singh and D.P. Kothari , Star/Hexagon transformer Based Three-Phase Four-Wire DSTATCOM for Power Quality Improvement," International Journal of Emerging Electric Power Syatem,vol.9,no.8,Article1,Dec.2008.
  • J. Praveen , B. P. Muni, S. Venkateshwarlu and H. V. Makthal , " Review of dynamic voltage restorer for power quality Improvement," Proc.IEEE IECON2004, Nov.2004, vol.1, pp.749-754..
  • B. Han , B. Bae , H. Kim and S. Baek , "Combined operation of unified power-quality conditioner with distributed generation," IEEE Trans. Power Del., vol. 21, no. 1, pp. 330-338, Jan. 2006.M. Young, The Techincal Writers Handbook. Mill Valley, CA: University Science, 1989.
  • T. Zhili , L. Xun , C. Jian , K. Yong and D. Shanxu , "A direct control strategy for UPQC in three-phase four-wire system," in Proc. IEEE Conf. on Power Electron. and Motion Control 2006,vol.2,pp.1-5. [10] V. Khadkikar and A. Chandra , "A Novel Structure for Three-Phase Four-Wire Distribution System Utilizing Unified Power Quality Conditioner (UPQC),"IEEE Trans. Industry Appl.,vol.45,pp.1897- 1902,2009 [11] L. Xun , Z. Guorong , D. Shanxu and C. J. Chen , "Control Scheme for Three-Phase Four-Wire UPQC in a Three-Phase Stationary Frame," in Procd.IEEE/IECON 2007, pp.1732-1736, 2007. [12] A. Ghosh , A. K. Jindal and A. Joshi , "A unified power quality conditioner for voltage regulation of critical load bus," in Proc. IEEE Power Eng. Society General Meeting, June 2004, vol.1, pp471-476. [13] B. Singh and Venkateswarlu, "A Simplified Control Algorithm for Three-Phase Four-Wire Unified Power Quality Conditioner," Journal of Power Electronics, vol.10, No.1, January2010. [14] G. Chen , Y. Chen and K. M. Smedley , "Three-phase four-leg active power quality conditioner without references calculation," in Procd. IEEE APEC '04, vol.1, pp.587-593, 2004. [15] V. Kumar , P. Agarwal and H. O. Gupta , "A Simple Control Strategy for Unified Power Quality Conditioner Using Current Source Inverter," in Procd. IPEC2007, pp.1219-1223. [16] B. Singh, S. Gairola, B. N. Singh, A. Chandar and K. Al-Haddad, "Multipulse AC-DC Converters for improving Power Quality: A Review," IEEE Trans. On Power Electronics, vol.23, no.1, pp.260-281, Jan2008. [17] B. Singh, S. Gairola, B. N. Singh, A. Chandar and K.Al-Haddad, "Power Quality Improvements in Isolated Twelve-Pulse AC-DC Converters using Delta/Double-Polygon transformer," in Procd. of IEEE PESC, June 2007,pp.2848-2853. [18] B. N. Singh , P. Rastgoufard , B. Singh , A. Chandra and K. A. Haddad., "Design, simulation and implementation of the three pole/four pole topologies for active filters," in Inst. Elect. Engg. Proc. Electr. Power Appl., Jul.2004, vol.151, no.4, pp.467-476.