A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines

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

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

Abstract

This paper proposes a new modular multilevel converter (MMC) configuration as a medium-voltage drive for variable-speed applications incorporating symmetrical six-phase machines. The proposed topology employs six MMC phase-legs feeding two isolated groups of three-phase machine windings, each with 60° spatial phase-displacement. A novel concept of sharing one capacitor between each pair of adjacent-arm submodules (SMs) of MMC phase-legs, while feeding machine windings in a spatial phase-opposition, is realized through a new integrated SM arrangement. The integrated SM allows the shared capacitor to absorb and release the same energy amount in a consecutive switching scheme, where the capacitor is experiencing both charging and discharging arm currents, one after another. This results in a limited voltage variation across the SM shared capacitor, independent of the operating frequency. Also, the proposed approach allows the MMC to utilize half the number of the SM capacitors, compared to a traditional MMC topology, while further diminishes the SM capacitance requirement, reducing the volume of the MMC system and its stored energy. The proposed configuration can efficiently operate at near zero frequency, therefore a machine speed-range from zero speed to the rated speed is possible under rated torque operating condition. The proposed MMC topology is elucidated in detail, and its effective performance is verified using simulation.
LanguageEnglish
Title of host publication2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL)
Place of PublicationPiscataway, NJ
PublisherIEEE
Number of pages6
ISBN (Electronic)9781538655412
DOIs
Publication statusPublished - 13 Sep 2018

Fingerprint

Capacitors
Machine windings
Topology
Electric potential
Capacitance
Torque

Keywords

  • capacitors
  • topology
  • windings
  • torque
  • modular multilevel converter
  • shared capacitor

Cite this

Diab, M. S., Williams, B. W., Massoud, A. M., & Ahmed, S. (2018). A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines. In 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL) Piscataway, NJ: IEEE. https://doi.org/10.1109/COMPEL.2018.8459951
Diab, Mohamed S. ; Williams, Barry W. ; Massoud, Ahmed M. ; Ahmed, Shehab. / A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines. 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL). Piscataway, NJ : IEEE, 2018.
@inproceedings{055fbf665b1c4bf684142b83f1c84288,
title = "A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines",
abstract = "This paper proposes a new modular multilevel converter (MMC) configuration as a medium-voltage drive for variable-speed applications incorporating symmetrical six-phase machines. The proposed topology employs six MMC phase-legs feeding two isolated groups of three-phase machine windings, each with 60° spatial phase-displacement. A novel concept of sharing one capacitor between each pair of adjacent-arm submodules (SMs) of MMC phase-legs, while feeding machine windings in a spatial phase-opposition, is realized through a new integrated SM arrangement. The integrated SM allows the shared capacitor to absorb and release the same energy amount in a consecutive switching scheme, where the capacitor is experiencing both charging and discharging arm currents, one after another. This results in a limited voltage variation across the SM shared capacitor, independent of the operating frequency. Also, the proposed approach allows the MMC to utilize half the number of the SM capacitors, compared to a traditional MMC topology, while further diminishes the SM capacitance requirement, reducing the volume of the MMC system and its stored energy. The proposed configuration can efficiently operate at near zero frequency, therefore a machine speed-range from zero speed to the rated speed is possible under rated torque operating condition. The proposed MMC topology is elucidated in detail, and its effective performance is verified using simulation.",
keywords = "capacitors, topology, windings, torque, modular multilevel converter, shared capacitor",
author = "Diab, {Mohamed S.} and Williams, {Barry W.} and Massoud, {Ahmed M.} and Shehab Ahmed",
year = "2018",
month = "9",
day = "13",
doi = "10.1109/COMPEL.2018.8459951",
language = "English",
booktitle = "2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL)",
publisher = "IEEE",

}

Diab, MS, Williams, BW, Massoud, AM & Ahmed, S 2018, A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines. in 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL). IEEE, Piscataway, NJ. https://doi.org/10.1109/COMPEL.2018.8459951

A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines. / Diab, Mohamed S.; Williams, Barry W.; Massoud, Ahmed M.; Ahmed, Shehab.

2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL). Piscataway, NJ : IEEE, 2018.

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

TY - GEN

T1 - A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines

AU - Diab, Mohamed S.

AU - Williams, Barry W.

AU - Massoud, Ahmed M.

AU - Ahmed, Shehab

PY - 2018/9/13

Y1 - 2018/9/13

N2 - This paper proposes a new modular multilevel converter (MMC) configuration as a medium-voltage drive for variable-speed applications incorporating symmetrical six-phase machines. The proposed topology employs six MMC phase-legs feeding two isolated groups of three-phase machine windings, each with 60° spatial phase-displacement. A novel concept of sharing one capacitor between each pair of adjacent-arm submodules (SMs) of MMC phase-legs, while feeding machine windings in a spatial phase-opposition, is realized through a new integrated SM arrangement. The integrated SM allows the shared capacitor to absorb and release the same energy amount in a consecutive switching scheme, where the capacitor is experiencing both charging and discharging arm currents, one after another. This results in a limited voltage variation across the SM shared capacitor, independent of the operating frequency. Also, the proposed approach allows the MMC to utilize half the number of the SM capacitors, compared to a traditional MMC topology, while further diminishes the SM capacitance requirement, reducing the volume of the MMC system and its stored energy. The proposed configuration can efficiently operate at near zero frequency, therefore a machine speed-range from zero speed to the rated speed is possible under rated torque operating condition. The proposed MMC topology is elucidated in detail, and its effective performance is verified using simulation.

AB - This paper proposes a new modular multilevel converter (MMC) configuration as a medium-voltage drive for variable-speed applications incorporating symmetrical six-phase machines. The proposed topology employs six MMC phase-legs feeding two isolated groups of three-phase machine windings, each with 60° spatial phase-displacement. A novel concept of sharing one capacitor between each pair of adjacent-arm submodules (SMs) of MMC phase-legs, while feeding machine windings in a spatial phase-opposition, is realized through a new integrated SM arrangement. The integrated SM allows the shared capacitor to absorb and release the same energy amount in a consecutive switching scheme, where the capacitor is experiencing both charging and discharging arm currents, one after another. This results in a limited voltage variation across the SM shared capacitor, independent of the operating frequency. Also, the proposed approach allows the MMC to utilize half the number of the SM capacitors, compared to a traditional MMC topology, while further diminishes the SM capacitance requirement, reducing the volume of the MMC system and its stored energy. The proposed configuration can efficiently operate at near zero frequency, therefore a machine speed-range from zero speed to the rated speed is possible under rated torque operating condition. The proposed MMC topology is elucidated in detail, and its effective performance is verified using simulation.

KW - capacitors

KW - topology

KW - windings

KW - torque

KW - modular multilevel converter

KW - shared capacitor

U2 - 10.1109/COMPEL.2018.8459951

DO - 10.1109/COMPEL.2018.8459951

M3 - Conference contribution book

BT - 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL)

PB - IEEE

CY - Piscataway, NJ

ER -

Diab MS, Williams BW, Massoud AM, Ahmed S. A modular multilevel converter with integrated shared capacitor sub-module for MV motor drives incorporating symmetrical six-phase machines. In 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL). Piscataway, NJ: IEEE. 2018 https://doi.org/10.1109/COMPEL.2018.8459951