A Novel Vector-Based Pulse-Width Modulation for Cascaded H-Bridge ‎Multilevel Inverters

Document Type : Research paper


Department of Electrical Engineering, Urmia University, Urmia, Iran


The conventional space vector pulse-width modulation (SVPWM) for cascaded H-bridge inverters (CHBIs) has problems of computational complexity and memory requirements. Operation in overmodulation mode is the other reason for the complexity in SVPWM. This paper proposes a novel modulation method, named as level vector pulse-width modulation (LVPWM), for voltage control of CHBIs. The concept of the proposed method is similar to the SVPWM but with different vector diagram and dwell times calculations. Unlike the SVPWM, the α and β axes and also their variables are considered separately without gathering in complex variables. The vector diagram has two separated α and β axes each of which contains individual switching vectors and reference vectors. The selection of the vectors to synthesize the reference vectors depends only on the amplitudes of the reference vectors. The computational overhead and memory requirement are independent of the number of cascaded H-bridges. Lower computational overhead and easy and continuous extension to overmodulation region are the advantages of the proposed method compared with the SVPWM-based methods. Moreover, the switching algorithm achieves improved efficiency for the inverter. Simulation and experimental results verify the effectiveness of the proposed algorithm.


  1. Wu, “HIGH-POWER CONVERTERS AND AC DRIVES” New Jersey: John Wiley & Sons; 2006.
  2. Nikpayam et al., “Vector control methods for star-connected three-phase induction motor drives under the open-phase failure”, J. Oper. Autom. Power Eng., vol. 10, no. 2 pp. 155-164, 2022.
  3. Mohammadi et al., “Design of A single-phase transformerless grid connected PV inverter considering reduced leakage current and LVRT grid codes”, J. Oper. Autom. Power Eng., vol. 9, no. 1, pp. 49-59, 2021.
  4. M. Attique, Y. Li and K. Wang, “A survey on space-vector pulse width modulation for multilevel inverters”, CPSS Tran. Power Electron. App., vol. 2, no. 3, pp. 226-236, 2017.
  5. Wu et al., “A simplified space vector pulsewidth modulation scheme for three-phase cascaded h-bridge inverters”, IEEE Trans. Power Electron., vol. 35, no. 4, pp. 4192-4204, 2020.
  6. Rabinovici et al., “Series space vector modulation for multi-level cascaded H-bridge inverters,” IET Power Electron., vol. 3, no. 6, pp. 843–857, 2010.
  7. Mohamed, A. Gopinath and M. R. Baiju, “A Simple space vector PWM generation scheme for any general n-level inverter”, IEEE Trans. Ind. Electron., vol. 56, no. 5, pp. 1649-1656, 2009.
  8. Ahmed et al., “Simplified space vector modulation techniques for multilevel inverters”, IEEE Trans. Power Electron., vol. 31, no. 12, pp. 8483-8499, 2016.
  9. Ovalle, M. Hernández and G. Ramos, “A flexible nonorthogonal reference frame based SVPWM framework for multilevel inverters”, IEEE Trans. Power Electron., vol. 32, no. 6, pp. 4925-4938, 2017.
  10. Chamarthi, P. Chhetri and V. Agarwal, “Simplified implementation scheme for space vector pulse width modulation of n-level inverter with online computation of optimal switching pulse durations”, IEEE Trans. Ind. Electron., vol. 63, no. 11, pp. 6695-6704, 2016.
  11. Ahmed and V. B. Borghate, “simplified space vector modulation technique for seven-level cascaded H-bridge inverter”, IET Power Electron., vol. 7, no. 3, pp. 604-13, 2014.
  12. Zhang et al., “Fast and simple space vector modulation method for multilevel converters”, IET Power Electron, vol. 13 no. 1, pp. 14-22, 2020.
  13. Hu, J. Lin and H. Chen, “A discontinuous space vector PWM algorithm in ABC reference frame for multilevel three-phase cascaded h-bridge voltage source inverters”, IEEE Trans. Ind. Electron., vo. 64, no. 11, 2017.
  14. Yuan, Y. Gao and Y. Li, “A fast multilevel SVPWM method based on the imaginary coordinate with direct control of redundant vectors or zero sequence components”, IEEE Open J. Ind. Electron. Soc., vol. 1, pp. 355-366, 2020.
  15. Lin et al., “A fast and flexible nearest-level-equivalent space vector modulation algorithm for three-phase multilevel converters”, Elec. Power Energy Sys., vol. 118, pp.1-10, 2020.
  16. A. Menon and B. Jacob, “A simplified space vector pulse density modulation scheme without coordinate transformation and sector identification”, IEEE Trans. Ind. Electron., vol. 69, no. 5, pp. 4431-4439, 2022.
  17. Guo, M. He and Y. Yang, “Over modulation strategy of power converters: a review”, IEEE Access, vol. 6, pp. 69528-69544, 2018.
  18. K. Gupta and A. M. Khambadkone, “A general space vector pwm algorithm for multilevel inverters, including operation in overmodulation range”, IEEE Trans. Power Electron., vol. 22, no. 2, pp. 517-526, 2007.
  19. Pramanick et al., “Extending the linear modulation range to the full base speed using a single DC-Link multilevel inverter with capacitor-fed h-bridges for IM drives”, IEEE Trans. Power Electron., vol. 32, no. 7, pp. 5450-5458, 2017.
  20. D. Manjrekar, P. K. Steimer and T. A. Lipo, “Hybrid multilevel power conversion system: a competitive solution for high-power applications”, IEEE Trans. Ind. App., vol. 36, no. 3, pp. 834-841, 2000.
  21. Perez et al., “Power distribution in hybrid multi-cell converter with nearest level modulation”, IEEE Int. Symp. Ind. Electron., 2007.
  22. Qanbari and B. Tousi, “Single-source three-phase multilevel inverter assembled by three-phase two-level inverter and two single-phase cascaded h-bridge inverters”, IEEE Trans. Power Electron., vol. 36, no. 5, pp. 5204-5212, 2021.
  23. Kumar and M. Lokhande, “Analysis of PWM techniques on multilevel cascaded H-Bridge three phase inverter”, Recent Develop. Control Autom. Power Eng., 2017.
Volume 11, Issue 2
August 2023
Pages 113-122
  • Receive Date: 07 December 2021
  • Revise Date: 07 March 2022
  • Accept Date: 07 April 2022
  • First Publish Date: 23 April 2022