Application of Pulse Doubling in Star-Connected Autotransformer Based 12-Pulse AC-DC Converter for Power Quality Improvement

This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMD-s) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse ac-dc converters each of them consisting of three-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6- pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.





References:
[1] B. K. Bose, Modern Power Electronics and AC Drives. Singapore:
Pearson Education, 1998.
[2] IEEE Standard 519-1992, IEEE Recommended Practices and
Requirements for Harmonic Control in Electrical Power Systems.
NewYork: IEEE Inc., 1992.
[3] IEC Standard 61000-3-2:2004, Limits for harmonic current emissions,
International Electromechanical Commission. Geneva, 2004.
[4] D. A. Paice, Power Electronic Converter Harmonics: Multipulse
Methods for Clean Power. New York: IEEE Press, 1996.
[5] Bin Wu, High-Power Converters and AC Drives, IEEE Press, Wiley-
Interscience, 2006.
[6] S. Choi, P. N. Enjeti, and I. J. Pitel, "Polyphase transformer
arrangements with reduced kVA capacities for harmonic current
reduction in rectifier type utility interface", IEEE Trans. on Power
Electronics, Vol. 11, No. 5, pp. 680-689, September 1996.
[7] P. W. Hammond, "Autotransformer", U.S. Patent No. 5619407, April 8,
1997.
[8] B. Singh, G. Bhuvaneswari, and V. Garg, "Harmonic mitigation
using12-pulse ac-dc converter in vector-controlled induction motor
drives," IEEE Trans. Power Delivery, vol. 21, no. 3, pp. 1483-1492, Jul.
2006.
[9] S. Choi, B. S. Lee, and P. N. Enjeti, "New 24-pulse diode rectifier
systems for utility interface of high power ac motor drives," IEEE Trans.
Ind. Appl., vol. 33, no. 2, pp. 531-541, Mar.-Apr. 1997.
[10] B. Singh, G. Bhuvaneswari, V. Garg, and S. Gairola, "Pulse
multiplication in ac-dc converters for harmonic mitigation in vector
controlled induction motor drives," IEEE Trans. Energy Conv., vol. 21,
no. 2, pp.342-352, Jun. 2006.
[11] B. Singh, V. Garg, and G. Bhuvaneswari , "Polygon-Connected
Autotransformer-Based 24-Pulse AC-DC Converter for Vector-
Controlled Induction-Motor Drives" IEEE Transactions on Industrial
Electronics , vol. 55, no. 1, pp.197-208, January 2008.
[12] B. Singh, G. Bhuvaneswari, and V. Garg, "Harmonic Mitigation in AC-
DC Converters for Vector Controlled Induction Motor Drives" IEEE
Transactions on Energy Conversion , Vol. 22, no. 3, pp. 637 - 646 ,
Sept. 2007.
[13] B. Singh, G. Bhuvaneswari, and V. Garg, "Harmonic Mitigation in AC-
DC Converters for Vector Controlled Induction Motor Drives"in Proc.
IEEE Conf. Power Electron. Drives Syst. PEDS, 2005.
[14] [10] B. Singh, G. Bhuvaneswari, V. Garg, "Power-quality improvements
in vector-controlled induction motor drive employing pulse
multiplication in AC-DC converters", IEEE Trans. on Power Delivery,
vol. 21 no. 3, pp. 1578 - 1586, July 2006.
[15] B. Singh, G. Bhuvaneswari, V. Garg, "24-Pulse AC-DC Converter for
Power Quality Improvement in Vector Controlled Induction Motor
Drives", Electric Power Systems and Components, vol. 34, no. 10, pp.
1077 - 1098, October 2006.
[16] B. Singh, and S. Gairola, "Pulse Multiplication in Autotransformer
Based AC-DC Converters using a Zigzag Connection," Journal of Power
Electronics, Vol. 7, No. 3, July 2007.
[17] S. Miyairi, S. Iida, K. Nakata, and S. Masukawa, "New method for
reducing harmonics involved in input and output of rectifier with
interhase transformer," IEEE Trans. Ind. Appl., vol. 22, no. 5, pp. 790-
797, Oct.- Nov. 1986.
[18] M. E. Villablanca and J. A. Arrilaga, "Pulse multiplication in parallel
converters by multi tap control of interphase reactor," in Proc. Inst.
Elect. Eng.ÔÇöB, vol. 139, no. 1, Jan. 1992, pp. 13-20.
[19] S. Choi, B. S. Lee, and P. N. Enjeti, "New 24-pulse diode rectifier
systems for utility interface of high power ac motor drives," IEEE Trans.
Ind. Appl., vol. 33, no. 2, pp. 531-541, Mar.-Apr. 1997.
[20] S. Miyairi, S. Iida, K. Nakata, and S. Masubawa, "New method for
reducing harmonics involved in input and output of rectifier with
interphase transformer," IEEE Trans. Ind. Appl., vol. IA-22, no. 5, pp.
790-797, Sep./Oct. 1986.
[21] P. Qijun, M. Weiming, L. Dezhi, Z. Zhihua, and M. Jin, "A New Critical
Formula and Mathematical Model of Double-Tap Interphase Reactor in
a Six Phase Tap-Changer Diode Rectifier" IEEE Transactions on
Industrial Electronics , vol. 54, no. 1, pp.479-485, February 2007.
[22] F. Meng, S. Yang, W. Yang, and X. Jin," Comments and Further Results
on A New Critical Formula and Mathematical Model of Double Tap
Interphase Reactor in a Six-Phase Tap-Changer Diode Rectifier" IEEE
Transactions on Industrial Electronics , vol. 57, no. 3, pp.950-953,
March 2010.
[23] J. Arrilaga and M. Villablance, "24-pulse HVDC conversion," Proc. Inst.
Elect. Eng., vol. 138, no. 1, pp. 57-64, Jan. 1991
[24] IEEE Guide for Application and Specification of Harmonic Filters, IEEE
Std. 1573, 2003.