Enhanced Trapezoidal Modulation in MMC: Comparative Analysis with Traditional Modulation Methods

Saqib Hussain; Ahtsham Ullah; Jamshed Ansari

Authors

Saqib Hussain Department of Electrical Engineering, Sukkur IBA University, Sukkur, Pakistan
Ahtsham Ullah Department of Electrical Engineering, Sukkur IBA University, Sukkur, Pakistan
Jamshed Ansari Department of Electrical Engineering, Sukkur IBA University, Sukkur, Pakistan

Keywords:

Modular multilevel converter (MMC), nearest level modulation (NLM), Trapezoidal Modulation (TRP), Total Harmonic Distortion (THD), Switching Losses

Abstract

HVDC transmission and renewable energy systems extensively use Modular Multilevel Converters (MMC) because they provide outstanding scalability and modular architectural features. The performance quality of MMCs depends predominantly on which modulation technique engineers implement. This work studies Nearest Level Modulation (NLM) and conventional Trapezoidal Modulation alongside an enhanced Trapezoidal Modulation method to identify the top choice for high-voltage power implementations. The main goal of this research is to optimize modulation techniques for improving MMC harmonic performance and switching efficiency. Each modulation strategy is simulated through MATLAB/Simulink-based testing under identical operating situations. Product testing indicates NLM shows lower switching losses as well as superior power distribution efficiency but the updated Trapezoidal Modulation design combines reduced THD performance with simple implementation methods. The method's innovative aspect depends on the modified trapezoidal waveform synthesis from a fundamental-frequency triangular signal enabling simplified implementation as well as lower THD and avoiding the need for high switching frequencies used in conventional approaches. The research delivers critical knowledge about MMC modulation selection which systems designers and manufacturers can use to optimize converter operation based on specific applications.

References

“An innovative modular multilevel converter topology suitable for a wide power range | IEEE Conference Publication | IEEE Xplore.” Accessed: May 14, 2025. [Online]. Available: https://ieeexplore.ieee.org/document/1304403

M. Guan and Z. Xu, “Modeling and control of a modular multilevel converter-based HVDC system under unbalanced grid conditions,” IEEE Trans. Power Electron., vol. 27, no. 12, pp. 4858–4867, 2012, doi: 10.1109/TPEL.2012.2192752.

S. Rohner, S. Bernet, M. Hiller, and R. Sommer, “Modulation, losses, and semiconductor requirements of modular multilevel converters,” IEEE Trans. Ind. Electron., vol. 57, no. 8, pp. 2633–2642, Aug. 2010, doi: 10.1109/TIE.2009.2031187.

S. Du, A. Dekka, B. Wu, and N. Zargari, “Modular multilevel converters : analysis, control, and applications,” 2018.

G. P. Adam, O. Anaya-Lara, G. M. Burt, D. Telford, B. W. Williams, and J. R. McDonald, “Modular multilevel inverter: pulse width modulation and capacitor balancing technique,” IET Power Electron., vol. 3, no. 5, pp. 702–715, Sep. 2010, doi: 10.1049/IET-PEL.2009.0184.

“On dynamics and voltage control of the Modular Multilevel Converter | IEEE Conference Publication | IEEE Xplore.” Accessed: Apr. 28, 2025. [Online]. Available: https://ieeexplore.ieee.org/document/5278794

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, 2009, doi: 10.1109/TPEL.2009.2014236.

Q. Tu, Z. Xu, and L. Xu, “Reduced Switching-frequency modulation and circulating current suppression for modular multilevel converters,” IEEE Trans. Power Deliv., vol. 26, no. 3, pp. 2009–2017, Jul. 2011, doi: 10.1109/TPWRD.2011.2115258.

K. Ilves, A. Antonopoulos, S. Norrga, and H. P. Nee, “Steady-state analysis of interaction between harmonic components of arm and line quantities of modular multilevel converters,” IEEE Trans. Power Electron., vol. 27, no. 1, pp. 57–68, 2012, doi: 10.1109/TPEL.2011.2159809.

M. Glinka and R. Marquardt, “A new AC/AC multilevel converter family,” IEEE Trans. Ind. Electron., vol. 52, no. 3, pp. 662–669, Jun. 2005, doi: 10.1109/TIE.2005.843973.

L. A. M. Barros, A. P. Martins, and J. G. Pinto, “A Comprehensive Review on Modular Multilevel Converters, Submodule Topologies, and Modulation Techniques,” Energies 2022, Vol. 15, Page 1078, vol. 15, no. 3, p. 1078, Feb. 2022, doi: 10.3390/EN15031078.

K. Wang, Y. Li, Z. Zheng, and L. Xu, “Voltage balancing and fluctuation-suppression methods of floating capacitors in a new modular multilevel converter,” IEEE Trans. Ind. Electron., vol. 60, no. 5, pp. 1943–1954, 2013, doi: 10.1109/TIE.2012.2201433.

M. Saeedifard and R. Iravani, “Dynamic performance of a modular multilevel back-to-back HVDC system,” IEEE Trans. Power Deliv., vol. 25, no. 4, pp. 2903–2912, Oct. 2010, doi: 10.1109/TPWRD.2010.2050787.

M. A. Perez, S. Bernet, J. Rodriguez, S. Kouro, and R. Lizana, “Circuit topologies, modeling, control schemes, and applications of modular multilevel converters,” IEEE Trans. Power Electron., vol. 30, no. 1, pp. 4–17, 2015, doi: 10.1109/TPEL.2014.2310127.

M. S. Ansari, A. Shukla, and H. J. Bahirat, “Modeling of MMC Based High Power DC-DC Converter Controlled Using Trapezoidal Modulation,” ECCE 2020 - IEEE Energy Convers. Congr. Expo., pp. 5716–5722, Oct. 2020, doi: 10.1109/ECCE44975.2020.9236301.

A. Nami, J. Liang, F. Dijkhuizen, and G. D. Demetriades, “Modular multilevel converters for HVDC applications: Review on converter cells and functionalities,” IEEE Trans. Power Electron., vol. 30, no. 1, pp. 18–36, 2015, doi: 10.1109/TPEL.2014.2327641.

J. Badar et al., “An MMC based HVDC system with optimized AC fault ride-through capability and enhanced circulating current suppression control,” Front. Energy Res., vol. 11, p. 1190975, May 2023, doi: 10.3389/FENRG.2023.1190975/BIBTEX.

J. B. Soomro, F. Akhter, S. Ali, S. S. H. Bukhari, I. Sami, and J. S. Ro, “Modified Nearest Level Modulation for Full-Bridge Based HVDC MMC in Real-Time Hardware-in-Loop Setup,” IEEE Access, vol. 9, pp. 114998–115005, 2021, doi: 10.1109/ACCESS.2021.3105690.

L. Lin, Y. Lin, Z. He, Y. Chen, J. Hu, and W. Li, “Improved Nearest-Level Modulation for a Modular Multilevel Converter With a Lower Submodule Number,” IEEE Trans. Power Electron., vol. 31, no. 8, pp. 5369–5377, Aug. 2016, doi: 10.1109/TPEL.2016.2521059.

M. Jeong, S. Fuchs, and J. Biela, “High Performance LQR Control of Modular Multilevel Converters with Simple Control Structure and Implementation,” 2020 22nd Eur. Conf. Power Electron. Appl. EPE 2020 ECCE Eur., Sep. 2020, doi: 10.23919/EPE20ECCEEUROPE43536.2020.9215617.

W. Lin, D. Jovcic, S. Nguefeu, and H. Saad, “Full-Bridge MMC Converter Optimal Design to HVDC Operational Requirements,” IEEE Trans. Power Deliv., vol. 31, no. 3, pp. 1342–1350, Jun. 2016, doi: 10.1109/TPWRD.2015.2475130.

N. Flourentzou, V. G. Agelidis, and G. D. Demetriades, “VSC-based HVDC power transmission systems: An overview,” IEEE Trans. Power Electron., vol. 24, no. 3, pp. 592–602, 2009, doi: 10.1109/TPEL.2008.2008441.

I. A. Gowaid, G. P. Adam, S. Ahmed, D. Holliday, and B. W. Williams, “Analysis and Design of a Modular Multilevel Converter With Trapezoidal Modulation for Medium and High Voltage DC-DC Transformers,” IEEE Trans. Power Electron., vol. 30, no. 10, pp. 5439–5457, Oct. 2015, doi: 10.1109/TPEL.2014.2377719.