Abstract
Hexverter is a direct AC–AC modular multilevel converter based on cascaded full-bridge sub-modules, which is well suited to connect two systems operating at different frequencies. However, its operating range is limited by the capacitor voltage of sub-modules. A strategy based on the optimal neutral voltage and circulating current is proposed in this paper to limit the capacitor voltage within a specific range while minimizing the switching loss. First, the capacitor voltage's general fluctuation law is studied, and the detailed mathematical expression of the capacitor voltage is given. After that, constant neutral voltage and circulating current are introduced to limit its magnitude. In addition, the optimal values of neutral voltage and circulating current are calculated by minimizing switching loss, and the complete suppression strategy is put forward. Finally, it is verified by simulation that the proposed strategy suppresses the magnitude of the capacitor ripple voltage and reduces the switching loss.
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References
Tang, Y., Zhang, Z., Xu, Z.: DRU based low frequency AC transmission scheme for offshore wind farm integration. IEEE Trans. Sustain. Energy. 12(3), 1512–1524 (2021)
Huang, M.-H., Wang, X.-L., Liu, S.-Q., et al.: Technical and economic analysis on fractional frequency transmission system for integration of long-distance offshore wind farm. Autom. Elect. Power Syst. 43(05), 167–174 (2019)
Lin, J.-T., Ni, X.-J., Qiu, P.: Review of flexible low-frequency AC transmission technology. Zhejiang Elect. Power 40(10), 42–50 (2021)
Feng, S., Wei, C.-F., Lei, J.-X., et al.: Hybrid modeling and control of modular multilevel matrix converter for offshore fractional frequency transmission system. Proc. CSEE 42(04), 1546–1558 (2021)
Karwatzki, D., Baruschka, L., Mertens, A.: Survey on the Hexverter topology — a modular multilevel AC/AC converter. In: 2015 9th International Conference on Power Electronics and ECCE Asia (ICPE 2015-ECCE Asia), pp. 1075–1082. IEEE, Seoul, Korea (South) (2015)
Ilves, K., Bessegato, L., Norrga, S.: Comparison of cascaded multilevel converter topologies for AC/AC conversion. In: 2014 International Power Electronics Conference (IPEC-Hiroshima 2014 ECCE-ASIA), pp. 1087–1094. IEEE, Hiroshima, Japan (2014)
Baruschka, L., Mertens, A.: A new 3-phase direct modular multilevel converter. In: European Conference on Power Electronics and Applications, pp. 1–10. IEEE, Birmingham, UK (2011)
Robles-Campos, H.R., Mancilla-David, F.: A control scheme in the dq reference frame for Hexverter-based systems. In: 2019 North American Power Symposium (NAPS), pp. 1–6. IEEE, Wichita, KS, USA (2019)
Karwatzki, D., Baruschka, L., von Hofen, M., et al.: Branch energy control for the modular multilevel direct converter Hexverter. In: 2014 Energy Conversion Congress and Exposition(ECCE), pp. 1613–1622. IEEE, Pittsburgh, PA, USA (2014)
Baruschka, L., Karwatzki, D., von Hofen, M., et al.: Low-speed drive operation of the modular multilevel converter Hexverter down to zero frequency. In: 2014 Energy Conversion Congress and Exposition(ECCE), pp. 5407–5414. IEEE, Pittsburgh, PA, USA (2014)
Karwatzki, D., Baruschka, L., von Hofen, M., et al.: Optimised operation mode for the Hexverter topology based on adjacent compensating power. In: 2014 Energy Conversion Congress and Exposition(ECCE), pp. 5399–5406. IEEE, Pittsburgh, PA, USA (2014)
Robles-Campos, H.R., Mancilla-David, F.: A comparative evaluation of modulation strategies for Hexverter–based Modular Multilevel Converters. In: 2019 IEEE International Conference on Industrial Technology (ICIT), pp. 1465–1470. IEEE, Melbourne, VIC, Australia (2019)
Robles-Campos, H.R., Mancilla-David, F.: Detailed assessment of modulation strategies for Hexverter–based modular multilevel converters. Energies 15(6), 2132 (2022)
Xiong, S.-T., Liu, Z.-X., Liao, X.-C., et al.: Generalized control method of modular multilevel converter topology. Power Electron. 56(01), 115–120 (2022)
Fan, B., Wang, K.., Li, Y., et al.: A branch energy control method based on optimized neutral-point voltage injection for a hexagonal modular multilevel direct converter (Hexverter). In: 2015 18th International Conference on Electrical Machines and Systems (ICEMS), pp. 1889–1893. IEEE, Pattaya, Thailand (2015)
Zhang, C., Li, K.-H., Zhang, X., et al.: Analysis and calculation of loss characteristics for hexagonal modular multilevel AC/AC converter. Autom. Elect. Power Syst. 43(13), 9 (2019)
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Yang, F. et al. (2023). Analysis and Suppression of the Capacitor Voltage Ripple for Hexverter-Based Modular Multilevel Converters. In: Cao, W., Hu, C., Chen, X. (eds) Proceedings of the 3rd International Symposium on New Energy and Electrical Technology. ISNEET 2022. Lecture Notes in Electrical Engineering, vol 1017. Springer, Singapore. https://doi.org/10.1007/978-981-99-0553-9_13
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DOI: https://doi.org/10.1007/978-981-99-0553-9_13
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