An Isolated Bidirectional Modular Multilevel DC/DC Converter for Power Electronic Transformer Applications

- Journal title : Journal of Power Electronics
- Volume 16, Issue 3, 2016, pp.861-871
- Publisher : The Korean Institute of Power Electronics
- DOI : 10.6113/JPE.2016.16.3.861

Title & Authors

An Isolated Bidirectional Modular Multilevel DC/DC Converter for Power Electronic Transformer Applications

Wang, Zhaohui; Zhang, Junming; Sheng, Kuang;

Wang, Zhaohui; Zhang, Junming; Sheng, Kuang;

Abstract

With high penetration of renewable energies, power electronic transformers (PETs) will be one of the most important infrastructures in the future power delivery and management system. In this study, an isolated bidirectional modular multilevel DC/DC converter is proposed for PET applications. A modular multilevel structure is adopted as switching valves to sustain medium voltages to achieve modular design and high reliability. Only one high-frequency transformer is used in the proposed converter, which significantly simplifies the circuit and galvanic insulation design. A dual-phase-shift modulation strategy is proposed to regulate the output power and achieve a simple voltage balancing control. A down-scaled (2 kW/20 kHz) prototype is constructed to demonstrate the proposed converter and verify the control strategy. The experimental results comply with the theoretical analysis well, with the highest power efficiency reaching 97.6%.

Keywords

DC/DC;Dual active bridge;Modular multilevel converter;Phase shift control;Power electronic transformer;Solid state transformer;Voltage balancing control;

Language

English

References

1.

A. Q. Huang, M. L. Crow, G. T. Heydt, J. P. Zheng, and S. J. Dale, “The future renewable electric energy delivery and management (FREEDM) system: The energy Internet,” Proceedings of the IEEE, Vol. 99, No. 1, pp. 133-148, Jan. 2011.

2.

R.-A. Hooshmand, M. Ataei, and M. H. Rezaei, “Improving the dynamic performance of distribution electronic power transformers using sliding mode control,” Journal of Power Electronics, Vol. 12, No. 1, pp. 145-156, 2012.

3.

X. She, A. Q. Huang, and R. Burgos, “Review of solid-state transformer technologies and their application in power distribution systems,” IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 1, No. 3, pp. 186-198, Sep. 2013.

4.

J. E. Huber and J. W. Kolar, "Volume/weight/cost comparison of a 1MVA 10 kV/400 V solid-state against a conventional low-frequency distribution transformer," in IEEE Energy Conversion Congress and Exposition (ECCE), pp. 4545-4552, Sep. 2014.

5.

E. R. Ronan, S. D. Sudhoff, S. F. Glover, and D. L. Galloway, “A power electronic-based distribution transformer,” IEEE Trans. Power Del., Vol. 17, No. 2, pp. 537-543, Apr. 2002.

6.

N. Hugo, P. Stefanutti, M. Pellerin, and A. Akdag, "Power electronics traction transformer," in European Conference on Power Electronics and Applications, pp. 1-10, Sep. 2007.

7.

M. Steiner and H. Reinold, "Medium frequency topology in railway applications," in European Conference on Power Electronics and Applications, pp. 1-10, Sep. 2007.

8.

H. Iman-Eini, S. Farhangi, M. Khakbazan-Fard, and J.-L. Schanen, “Analysis and control of a modular MV-to-LV rectifier based on a cascaded multilevel converter,” Journal of Power Electronics, Vol. 9, No. 2, pp. 133-145, 2009.

9.

S. Bifaretti, P. Zanchetta, A. Watson, L. Tarisciotti, and J. C. Clare, “Advanced power electronic conversion and control system for universal and flexible power management,” IEEE Trans. Smart Grid, Vol. 2, No. 2, pp. 231-243, Jun. 2011.

10.

Y. Yi, C.-X. Mao, D. Wang, and J.-M. Lu, "Analysis of the internal electrical characteristics of electronic power transformers," Journal of Power Electronics, Vol. 13, No. 5, pp. 746-756, 2013.

11.

D. Dujic, C. Zhao, A. Mester, J. K. Steinke, M. Weiss, S. Lewdeni-Schmid, T. Chaudhuri, and P. Stefanutti, “Power electronic traction transformer-low voltage prototype,” IEEE Trans. Power Electron., Vol. 28, No. 12, pp. 5522-5534, Dec. 2013.

12.

X. She, X. Yu, F. Wang, and A. Q. Huang, “Design and demonstration of a 3.6-kV–120-V/10-kVA solid-state transformer for smart grid application,” IEEE Trans. Power Electron, Vol. 29, No. 8, pp. 3982-3996, Aug. 2014.

13.

C. Gu, H. S. Krishnamoorthy, P. N. Enjeti, Z. Zheng, and Y. Li, “A medium-voltage matrix converter topology for wind power conversion with medium frequency transformers,” Journal of Power Electronics, Vol. 14, No. 6, pp. 1166-1177, Nov. 2014.

14.

C. Zhao, D. Dujic, A. Mester, J. K. Steinke, M. Weiss, and S. Lewdeni-Schmid, T. Chaudhuri, P. Stefanutti, “Power electronic traction transformer – Medium voltage prototype,” IEEE Trans. Ind. Electron., Vol. 61, No. 7, pp. 3257-3268, Jul. 2014.

15.

Z. Li, P. Wang, Z. Chu, H. Zhu, Z. Sun, and Y. Li, "A three-phase 10 kVAC-750 VDC power electronic transformer for smart distribution grid," in 15th European Conference on Power Electronics and Applications (EPE), pp. 1-9, 2013.

16.

H. Fan and H. Li, “High-frequency transformer isolated bidirectional DC–DC converter modules with high efficiency over wide load range for 20 kVA solid-state transformer,” IEEE Trans. Power Electron., Vol. 26, No. 12, pp. 3599-3608, Dec. 2011.

17.

L. Yang, T. Zhao, J. Wang, and A. Q. Huang, "Design and analysis of a 270kW five-level DC/DC converter for solid state transformer using 10kV SiC power devices," in IEEE Power Electronics Specialists Conference (PESC), pp. 245-251, 2007.

18.

S. Madhusoodhanan, A. Tripathi, D. Patel, K. Mainali, A. Kadavelugu, S. Hazra, S. Bhattacharya, and K. Hatua, “Solid state transformer and MV grid tie applications enabled by 15 kV SiC IGBTs and 10 kV SiC MOSFETs based multilevel converters,” IEEE Trans. Ind. Appl., Vol. 51, No. 4, pp. 3343-3360, Jul./Aug. 2015.

19.

K. Vechalapu, A. K. Kadavelugu, and S. Bhattacharya, "High voltage dual active bridge with series connected high voltage silicon carbide (SiC) devices," in IEEE Energy Conversion Congress and Exposition (ECCE), pp. 2057-2064, 2014.

20.

K. Siri, M. Willhoff, and K. Conner, “Uniform voltage distribution control for series connected DC–DC converters,” IEEE Trans. Power Electron., Vol. 22, No. 4, pp. 1269-1279, Jul. 2007.

21.

G. Ortiz, J. Biela, D. Bortis, and J. W. Kolar, "1 megawatt, 20 kHz, isolated, bidirectional 12kV to 1.2kV DC/DC converter for renewable energy applications," in International Power Electronics Conference (IPEC), pp. 3212-3219, 2010.

22.

D. Sha, Z. Guo, and X. Liao, “Digital control strategy for input-series-output-parallel modular DC/DC converters,” Journal of Power Electronics, Vol. 10, No. 3, pp. 245-250, 2010.

23.

S. P. Engel, M. Stieneker, N. Soltau, S. Rabiee, H. Stagge, and R. W. De Doncker, “Comparison of the modular multilevel DC converter and the dual-active bridge converter for power conversion in HVDC and MVDC grids,” IEEE Trans. Power Electron., Vol. 30, No. 1, pp. 124-137, Jan. 2015.

24.

A. Lesnicar and R. Marquardt, "An innovative modular multilevel converter topology suitable for a wide power range," in IEEE Power Tech Conference Proceedings, Vol. 3, pp. 23-26, Jun. 2003.

25.

H. M. Pirouz 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, 2010.

26.

F. Sasongko, M. Hagiwara, and H. Akagi, "A front-to-front (FTF) system consisting of two modular multilevel cascade converters based on double-star chopper-cells," in 1st International Future Energy Electronics Conference (IFEEC), pp. 488-493, 2013.

27.

Y. Cui, Y. Chen, Y. Chen, Y. Kang, X. Wei, and X. Wang, "DC/DC modular multilevel converter with high frequency transformer for transportation applications," in IEEE Conference and Expo Transportation Electrification Asia-Pacific (ITEC Asia-Pacific), pp. 1-6, 2014.

28.

S. Kenzelmann, A. Rufer, D. Dujic, F. Canales, and Y. R. De Novaes, “Isolated DC/DC structure based on modular multilevel converter,” IEEE Trans. Power Electron., Vol. 30, No. 1, pp. 89-98, Jan. 2015.

29.

I. A. Gowaid, G. P. Adam, A. M. Massoud, S. Ahmed, D. Holliday, and B. W. Williams, “Quasi two-level operation of modular multilevel converter for use in a high-power DC transformer with DC fault isolation capability,” IEEE Trans. Power Electron., Vol. 30, No. 1, pp. 108-123, Jan. 2015.

30.

Z. Wang, J. Zhang, and K. Sheng, "Modular multilevel power electronic transformer," in 9th International Conference on Power Electronics and ECCE Asia (ICPE-ECCE Asia), 2015.

31.

R. W. A. A. De Doncker, D. M. Divan, and M. H. Kheraluwala, “A three-phase soft-switched high-power-density DC/DC converter for high-power applications,” IEEE Trans. Ind. Appl., Vol. 27, No. 1, pp. 63-73, Jan./Feb. 1991.