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Transformerless Three-Level DC-DC Buck Converter with a High Step-Down Conversion Ratio

  • Zhang, Yun (School of Electrical Engineering and Automation, Tianjin University) ;
  • Sun, Xing-Tao (School of Electrical Engineering and Automation, Tianjin Polytechnic University) ;
  • Wang, Yi-Feng (School of Electrical Engineering and Automation, Tianjin University) ;
  • Shao, Hong-Jun (School of Electrical Engineering and Automation, Tianjin University)
  • Received : 2011.12.11
  • Published : 2013.01.20

Abstract

For high power high step-down dc-dc conversion applications, conventional three-level dc-dc converters are subject to extreme duty cycles or increased volume and cost due to the use of transformers. In this paper, a transformerless three-level dc-dc buck converter with a high step-down conversion ratio is proposed. The converter comprises two asymmetrical half bridges, which are of the neutral point clamped structures. Therefore, the output pulse voltage of the converter can be obtained in terms of the voltage difference between the two half bridges. In order to realize harmonious switching of the converter, a modulation strategy with capacitor voltages self balance is presented. According to the deduced output dc voltage function, transformerless operation without extreme duty cycles can be implemented. Experimental results from a 1kW prototype verify the validity of the proposed converter. It is suitable for ship electric power distribution systems.

Keywords

References

  1. H. M. Pirouzy and M. T. Bina, "Modular multilevel converter based STATCOM topology suitable for medium-voltage unbalanced systems," Journal of Power Electronics, Vol. 10, No. 5, pp. 572-578, Sep. 2010. https://doi.org/10.6113/JPE.2010.10.5.572
  2. E. Babaei, "Optimal topologies for cascaded sub-multilevel converters," Journal of Power Electronics, Vol. 10, No. 3, pp. 251-261, May 2010. https://doi.org/10.6113/JPE.2010.10.3.251
  3. F. Iturriz and P. Ladoux, "Phase-controlled multilevel converters based on dual structure associations," IEEE Trans. Power Electron., Vol. 15, No. 1, pp. 92-102, Jan. 2000. https://doi.org/10.1109/63.817367
  4. H. Mohammadi and M. T. Bina, "A transformerless medium-voltage STATCOM topology based on extended modular multilevel converters," IEEE Trans. Power Electron., Vol. 26, No. 5, pp. 1534-1545, May 2011. https://doi.org/10.1109/TPEL.2010.2085088
  5. M. L. Heldwein, S. A. Mussa, and I. Barbi, "Three-phase multilevel PWM rectifiers based on conventional bidirectional converters," IEEE Trans. Power Electron., Vol. 25, No. 3, pp. 545-549, Mar. 2010. https://doi.org/10.1109/TPEL.2009.2032365
  6. M. Hagiwara and H. Akagi, "Control and experiment of pulsewidth-modulated modular multilevel converters," IEEE Trans. Power Electron., Vol. 24, No. 7, pp. 1737-1746, Jul. 2009. https://doi.org/10.1109/TPEL.2009.2014236
  7. 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./Apr. 2011. https://doi.org/10.1109/TIA.2010.2102327
  8. Y. Zhang and L. Sun, "An efficient control strategy for a five-level inverter comprising flying-capacitor asymmetric h-bridge," IEEE Trans. Ind. Electron., Vol. 58, No. 9, pp. 4000-4009, Sep. 2011. https://doi.org/10.1109/TIE.2010.2100339
  9. Z. Du, L. M. Tolbert, B. Ozpineci, and J. N. Chiasson, "Fundamental frequency switching strategies of a seven-level hybrid cascaded H-bridge multilevel inverter," IEEE Trans. Power Electron., Vol. 24, No. 1, pp. 25-33, Jan. 2009. https://doi.org/10.1109/TPEL.2008.2006678
  10. A. Nabae, I. Takahashi, and H. Akagi, "A new neutral-point-clamped PWM inverter," IEEE Trans. Ind. Appl., Vol. 1A-17, No. 5, pp. 518-523, Sep./Oct. 1981.
  11. J. R. Pinheiro and I. Barbi, "The three-level ZVS PWM converter a new concept in high-voltage dc-to-dc conversion," in Conf. Rec. IECON, pp. 173-178, 1992.
  12. X. Ruan, B. Li, Q. Chen, S. C. Tan, and C. K. Tse, "Fundamental considerations of three-level dc-dc converters: topologies, analyses, and control," IEEE Trans. Circuits Syst. I, Reg. Papers, Vol. 55, No. 11, pp. 3733-3743, Dec. 2008. https://doi.org/10.1109/TCSI.2008.927218
  13. B. Axelrod, Y. Berkovich, and A. Ioinovici, "Switched-capacitor/switched-inductor structures for getting transformerless hybrid dc-dc PWM converters," IEEE Trans. Circuits Syst. I, Reg. Papers, Vol. 55, No. 2, pp. 687-696, Mar. 2008. https://doi.org/10.1109/TCSI.2008.916403
  14. E. H. Ismail, M. A. Al-Saffar, and A. J. Sabzali, "High conversion ratio dc-dc converters with reduced switch stress," IEEE Trans. Circuits Syst. I, Reg. Papers, Vol. 55, No. 7, pp. 2139-2151, Aug. 2008. https://doi.org/10.1109/TCSI.2008.918195
  15. L. Huber and M. M. Jovanovic, "A design approach for server power supplies for networking applications," in Conf. Rec. IEEE APEC, pp. 1163-1169, 2000.
  16. B. M. Song, R. McDowell, A. Bushnell, and J. Ennis, "A three-level dc-dc converter with wide-input voltage operations for ship-electric-power-distribution systems," IEEE Trans. Plasma Sci., Vol. 32, No. 5, pp. 1856-1863, Oct. 2004. https://doi.org/10.1109/TPS.2004.835485
  17. V. F. Pires and J. F. Silva, "Single-stage double-buck topologies with high power factor," Journal of Power Electronics, Vol. 11, No. 5, pp. 655-661, Sep. 2011. https://doi.org/10.6113/JPE.2011.11.5.655