A Dual Modular Multilevel Converter with High-Frequency Magnetic Links between Submodules for MV Open-End Stator Winding Machine Drives

Mohamed S. Diab, Ahmed M. Massoud, Shehab Ahmed, Barry W. Williams

Research output: Contribution to journalArticle

13 Citations (Scopus)


This paper presents a dual modular multilevel converter (MMC) topology that utilizes energy exchange between adjacent-arm submodules (SMs), operating with out-of-phase modulation. The proposed configuration is applicable to medium-voltage high-power variable-speed drives incorporating open-end stator winding machines. A novel concept of power decoupling between adjacent-arm SMs in the dual MMC topology is realized through high-frequency transformer-based dc-dc converter modules. This concept offers a significant reduction in the sizing requirement of the SM capacitance and the stored energy in the MMC system, while avoiding the problem of wide voltage fluctuations of SM capacitors, especially at low operating frequencies. The proposed configuration can produce dc voltage; therefore, a machine speed range from zero speed to the rated speed is possible under the rated torque operating condition. The operating principles of the proposed dual MMC configuration are elaborated and necessary mathematical analysis is derived. Simulation and experimental results verify the concept of the proposed drive configuration.

Original languageEnglish
Pages (from-to)5142-5159
Number of pages18
JournalIEEE Transactions on Power Electronics
Issue number6
Publication statusPublished - 1 Jun 2018



  • Dual half bridge (DHB)
  • high-frequency (HF) transformer
  • low motor speed
  • medium-voltage (MV) variable-speed drives
  • modular multilevel converter (MMC)
  • open-end stator winding machines
  • submodule (SM) capacitor voltage ripple

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this