Recent grid codes require a high voltage direct current (HVDC) converter station remains connected and provide reliable operation under various faults. An improved clamp-double submodule (CD-SM) is introduced in this article, which belongs to the modular multilevel converter (MMC) topologies proposed for high voltage direct current (HVDC) systems. The proposed submodule (SM) topology features a reduced number of control switches, lower converter level faults, and DC fault-blocking capability compared to the conventional submodule topologies. A CD-SM consists of five $IGBT$s, two diodes, and two floating capacitors, where capacitor voltages are maintained according to the binary geometric propagation (GP) ratio which enables it to generate a maximum four-level output voltage. The hybrid pulse width modulation (PWM) technique is used to generate desired switching pulses for a converter and the associated voltage balancing control technique maintains the power exchange between the converters. In this article, the dimensioning of the proposed MMC converter, and its performance under different fault conditions is discussed in detail. Further, a quantitative comparison with other submodule topologies in terms of dc fault-blocking capability, output voltage level, and device count is discussed. Simulation in MATLAB/Simulink and their results validate the effectiveness of the proposed topology for MMC based HVDC system.
M. Diez, A. Costabeber, F. Tardelli, D. Trainer, and J. Clare, “Control and experimental validation of the series bridge modular multilevel converter for hvdc applications,” IEEE Trans. Power Electron., vol. 35, no. 3, pp. 2389–2401, 2019.
Banaei, H. Ajdar Faeghi Bonab, and N. Taghizadegan Kalantari, “Analysis and design of a new single switch non-isolated buck-boost dc-dc converter,” J. Oper. Autom. Power Eng., vol. 8, no. 2, pp. 116–127, 2020.
Yinghong, S. Peng, G. Qing, and C. Yu, “Capacitor voltage observation for series-connected-double submodule based modular multilevel converter,” in 2022 4th International Conference on Power and Energy Technology (ICPET), pp. 276–281, IEEE, 2022.
Saleki, S. Rezazade, B. J. Pordanjani, M. Gupta, and M. T. Bina, “A novel protective scheme to improve half-bridge mmc operation against dc fault condition,” in 2022 13th Power Electronics, Drive Systems, and Technologies Conference (PEDSTC), pp. 118–122, IEEE, 2022.
Song, Y. Luo, X. Xiong, F. Blaabjerg, and W. Wang, “An improved submodule topology of mmc with fault blocking capability based on reverse-blocking insulated gate bipolar transistor,” IEEE Trans. Power Delivery, vol. 37, no. 3, pp. 1559–1568, 2021.
Saleki, B. J. Pordanjani, and M. T. Bina, “Dc fault analysis in mmc based hvdc systems along with proposing a modified mmc protective topology for grid stability,” in 2021 25th Electrical Power Distribution Conference (EPDC), pp. 55–59, IEEE, 2021.
Farooq and R. B. Bass, “Frequency event detection and mitigation in power systems: A systematic literature review,” IEEE Access, vol. 10, pp. 61494–61519, 2022.
Prommetta, J. Schindler, J. Jaeger, T. Keil, C. Butterer, and G. Ebner, “Protection coordination of ac/dc intersystem faults in hybrid transmission grids,” IEEE Trans. Power Delivery, vol. 35, no. 6, pp. 2896–2904, 2020.
Yang and M. Saeedifard, “Analysis of the modular multilevel converter under single open-circuit fault in the upper active switch of a submodule,” in 2019 IEEE Applied Power Electronics Conference and Exposition (APEC), pp. 1817–1824, IEEE, 2019.
V. M. Farias, A. F. Cupertino, H. A. Pereira, S. I. Seleme, and R. Teodorescu, “On converter fault tolerance in mmchvdc systems: A comprehensive survey,” IEEE J. Emerging Sel. Top. Power Electron., vol. 9, no. 6, pp. 7459–7470, 2020.
He, Q. Yang, and Z. Wang, “On-line fault diagnosis and fault-tolerant operation of modular multilevel converters—a comprehensive review,” CES Tras. Electr. Mach. Syst., vol. 4, no. 4, pp. 360–372, 2020.
Che, J. Z. Bird, A. Hagmüller, and M. E. Hossain, “An adjustable stiffness torsional magnetic spring with a linear stroke length,” in 2021 IEEE Energy Conversion Congress and Exposition (ECCE), pp. 5944–5948, IEEE, 2021.
Yang, Y. Xue, B. Chen, Z. Lin, T. Q. Zheng, and Y. Li, “Novel modular multilevel converter against dc faults for hvdc applications,” CSEE J. Power Energy Syst., vol. 3, no. 2, pp. 140–149, 2017.
Li, Q. Song, W. Liu, H. Rao, S. Xu, and L. Li, “Protection of nonpermanent faults on dc overhead lines in mmc-based hvdc systems,” IEEE Trans. Power Delivery, vol. 28, no. 1, pp. 483–490, 2012.
Hu, Y. Zhu, J. Zhang, F. Deng, and Z. Chen, “Unipolar double-star submodule for modular multilevel converter with dc fault blocking capability,” IEEE Access, vol. 7, pp. 136094–136105, 2019.
Tang, Z. Xu, and Y. Zhou, “Impacts of three mmc-hvdc configurations on ac system stability under dc line faults,” IEEE Trans. Power Syst., vol. 29, no. 6, pp. 3030–3040, 2014.
V. Iyer, A. K. Sahoo, and N. Mohan, “Asymmetrical modular mutilevel converter (a-mmc) based hvdc system,” in 2015 IEEE Energy Conversion Congress and Exposition (ECCE), pp. 4693–4699, IEEE, 2015.
Seifi Najmi, A. Ajami, and A. Rajaei, “A generalized modular multilevel current source inverter,” J. Oper. Autom. Power Eng., vol. 5, no. 2, pp. 181–190, 2017.
Hosseinpour, S. Mansoori, and H. Shayeghi, “Selective harmonics elimination technique in cascaded h-bridge multilevel inverters using the salp swarm optimization algorithm,” J. Oper. Autom. Power Eng., vol. 8, no. 1, pp. 32–42, 2020.
Srivastav, A. K. Sahoo, K. V. Iyer, and N. Mohan, “Modulation, control, and performance analysis of asymmetric modular multilevel converter (a-mmc),” IET Power Electron., vol. 11, no. 5, pp. 834–843, 2018.
Rahimian, M. Hosseinpour, and A. Dejamkhooy, “A modified phase-shifted pulse width modulation to extend linear operation of hybrid modular multi-level converter,” J. Oper. Autom. Power Eng., vol. 6, no. 2, pp. 183–192, 2018.
Liu, C. Zhang, L. Xu, X. Sun, S. Gu, and X. Li, “Voltage balancing control strategy for mmc based on nlm algorithm,” in 2019 14th IEEE Conference on Industrial Electronics and Applications (ICIEA), pp. 1075–1079, IEEE, 2019.
Zeng, W. Lin, and J. Liu, “Switched-capacitor-based active-neutral-point-clamped seven-level inverter with natural balance and boost ability,” IEEE Access, vol. 7, pp. 126889– 126896, 2019.
S. Lee, C. S. Lim, Y. P. Siwakoti, and K.-B. Lee, “Hybrid 7-level boost active-neutral-point-clamped (h-7lbanpc) inverter,” IEEE Trans. Circuits Syst. II: Express Briefs (Early Access), vol. 67, no. 10, pp. 2044–2048, 2019.
Guo, H. Wang, Q. Song, J. Zhang, T. Wang, B. Ren, and Z. Wang, “Hb and fb mmc based onshore converter in series-connected offshore wind farm,” IEEE Trans. Power Electron., vol. 35, no. 3, pp. 2646–2658, 2019.
Marquardt, “Modular multilevel converter: An universal concept for hvdc-networks and extended dc-bus-applications,” in The 2010 International Power Electronics ConferenceECCE ASIA-, pp. 502–507, IEEE, 2010.
N. Chaudhari and P. B. Darji, “Asymmetrical modular multilevel converter (a-mmc) with mixed cell sub-modules (sm) for improved dc fault blocking capability and reduced component count,” Majlesi J. Electr. Eng., vol. 17, no. 1, pp. 63–74, 2023.
Chaudhari, H., & Darji, P. (2025). A Modified Clamp-Double Submodule (CD-SM) Based Modular Multilevel Converter (MMC) With Reduced Component Count for HVDC Application. Journal of Operation and Automation in Power Engineering, 13(2), 149-156. doi: 10.22098/joape.2023.12917.1982
MLA
Himanshu Chaudhari; Pranav Darji. "A Modified Clamp-Double Submodule (CD-SM) Based Modular Multilevel Converter (MMC) With Reduced Component Count for HVDC Application", Journal of Operation and Automation in Power Engineering, 13, 2, 2025, 149-156. doi: 10.22098/joape.2023.12917.1982
HARVARD
Chaudhari, H., Darji, P. (2025). 'A Modified Clamp-Double Submodule (CD-SM) Based Modular Multilevel Converter (MMC) With Reduced Component Count for HVDC Application', Journal of Operation and Automation in Power Engineering, 13(2), pp. 149-156. doi: 10.22098/joape.2023.12917.1982
VANCOUVER
Chaudhari, H., Darji, P. A Modified Clamp-Double Submodule (CD-SM) Based Modular Multilevel Converter (MMC) With Reduced Component Count for HVDC Application. Journal of Operation and Automation in Power Engineering, 2025; 13(2): 149-156. doi: 10.22098/joape.2023.12917.1982