Abstract
Modular multilevel converters (MMCs) are powerful tools of the future for high- and medium-power applications. The system is composed of cascaded connections of individual submodules. Balancing of submodule capacitor voltage is a key issue while designing MMC. The converter’s reliability will suffer because of increased voltage stress on power components due to the imbalanced capacitor voltage. This work addresses that problem using a novel capacitor voltage sensing and balancing technique. Using two control loops one for finding the direction of the arm current and the other for balancing of capacitor voltage with a low-complexity algorithm, the capacitor voltage will be well balanced. The converter dynamics of the aforementioned method have been studied by comparison of parameters like circulating current, grid voltage, submodule capacitor voltage, switching losses, and total harmonic distortion with that of MMC using the conventional sorting algorithm. The submodule capacitor voltage is typically balanced by the conventional sorting approach, but the proposed method adds the feature that the balancing of capacitor voltage is continued till the MMC output voltage matches the required terminal voltage of the high voltage DC (HVDC) line. The proposed model is scalable to any number of submodules without further computational complexity. The proposed system’s simulation results reveal that the circulating current is decreased by 50%, the grid voltage is improved by 13%, switching losses are reduced by 49%, and total harmonic distortion is reduced by 13% compared to conventional MMC. The features of the proposed system are reduced complexity of the balancing algorithm, fast stabilization of output voltage without any external controller, and superior performance which can be utilized to feed HVDC/medium voltage DC systems.
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References
Elsanabary A, Mekhilef S, Seyedmahmoudian M, Stojcevski A (2021) An energy balancing strategy for modular multilevel converter based grid-connected photovoltaic systems. IET Power Electron 14:2115–2126. https://doi.org/10.1049/pel2.12113
Gontijo GF, Sera D, Ricco M, Mathe L, Kerekes T; Teodores R (2021) Dispatchable high-power wind turbine based on a multilevel converter with modular structure and hybrid energy storage integration. IEEE Access 9:152878–152891. https://doi.org/10.1109/ACCESS.2021.3128050
Hassanpoor A, Norrga S, Nami A (2015) Loss evaluation for modular multilevel converters with different switching strategies. In: 2015 9th international conference on power electronics and ECCE Asia (ICPE-ECCE Asia), pp 1558–1563. IEEE, Seoul, Korea
He L, Zhang K, Xiong J, Fan S, Xue Y (2015) Modular multilevel converter with full-bridge submodules and improved low-frequency ripple suppression for medium-voltage drives. In: IEEE applied power electronics conference and exposition, pp 2288–2294. https://doi.org/10.1109/APEC.2015.7104668
Hu P, Teodorescu R, Wang S, Li S Guerrero JM (2019) A currentless sorting and selection-based capacitor-voltage-balancing method for modular multilevel converters. IEEE Trans Power Electron 34:1022–1025. https://doi.org/10.1109/TPEL.2018.2850360
Joshi SD, Ghat MB, Shukla A, Chandorkar MC (2021) Improved balancing and sensing of submodule capacitor voltages in modular multilevel converter. IEEE Trans Ind Appl 57:537–548. https://doi.org/10.1109/TIA.2020.3026664
Liu Y, Peng FZ (2020) A modular multilevel converter with self-voltage balancing part II: Y-matrix modulation. IEEE J Emerg Sel Top Power Electron 8:1126–1133. https://doi.org/10.1109/JESTPE.2019.2923576
Liu Y, Peng FZ (2020) A modular multilevel converter with self-voltage balancing part I: mathematical proof. IEEE J Emerg Sel Top Power Electron 8:1117–1126. https://doi.org/10.1109/JESTPE.2019.2923582
Lizana R, Perez M, Dekka A, Wu B (2017) Capacitor voltage balancing method for modular multilevel converter with flying capacitor submodules. In: 2017 IEEE international conference on industrial technology (ICIT), pp 60–67. IEEE, Toronto,ON
Luo Y, Li Z, Xu L, Xiong X, Li Y, Zhao C (2018) An adaptive voltage-balancing method for high-power modular multilevel converters. IEEE Trans Power Electron 33:2901–29012. https://doi.org/10.1109/TPEL.2017.2703839
Wang Y (2021) Energy & fuels engineering. figshare https://encyclopedia.pub/entry/5863
Wang D, Zhang B (2019) A optimized capacitor voltage balance strategy using binary number sorting algorithm for modular multilevel converter. In: 2019 8th international symposium on next generation electronics (ISNE), pp 1–3. IEEE, Zhengzhou, China
Wang W, Ma K, Cai X (2021) Efficient capacitor voltage balancing method for modular multilevel converter under carrier-phase-shift pulsewidth modulation. IEEE Trans Power Electron 36:1553–1562. https://doi.org/10.1109/TPEL.2020.3009272
Xin Y, Chen C, Sun L, Zhou L, Xiong J, Zhang K (2021) Module selection method with improved capacitor voltage balance for mmc using (2 n + 1) Shepwm. Int J Electric Power Energy Syst 133:107294. https://doi.org/10.1016/j.ijepes.2021.107294
Yue Y, Xu Q, Guo P, Chu X, Shuai Z, Luo A, Guerrero JM (2021) Capacitor voltage predictor-corrector balancing approach with single sensor for single-phase modular multilevel converter. Int J Electric Power Energy Syst 129:106729. https://doi.org/10.1016/j.ijepes.2020.106729
Zeng W, Li R, Cai X (2019) A new hybrid modular multilevel converter with integrated energy storage. IEEE Access 7:172981–172993. https://doi.org/10.1109/ACCESS.2019.2940101
Zhang J, Shao S, Li Y, Zhang J, Sheng K (2020) Arm voltage balancing control of modular multilevel resonant converter. CES Trans Electric Mach Syst 4:303–308. https://doi.org/10.30941/CESTEMS.2020.00037
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Babu, L., Chacko, M. Modular Multilevel Converter with a Sensing and Balancing (SAB) Technique for Capacitor Voltage Balancing. Iran J Sci Technol Trans Electr Eng 48, 251–264 (2024). https://doi.org/10.1007/s40998-023-00659-w
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DOI: https://doi.org/10.1007/s40998-023-00659-w