Analysis and control of modular multilevel converters under asymmetric arm impedance conditions

Rong Zeng, Lie Xu, Liangzhong Yao, Stephen J. Finney

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

This paper presents a detailed analysis and improved control strategy for Modular Multilevel Converters (MMC) under asymmetric arm inductance conditions. Unlike symmetric conditions, the fundamental ac current is not split equally between the upper and lower arms under asymmetric conditions, and the dc and double-frequency components in the common-mode current also flow into the ac side. To solve these issues, a theoretical analysis of the effect of asymmetric conditions on MMC operation is carried out using equivalent circuits at different frequencies. Three control targets are then presented to enhance the operational performance. A control strategy providing the control of differential-mode current, common-mode current and power balance is designed. The feasibility and validity of the proposed analysis and control strategy are demonstrated by simulation results from a threephase MMC system, and simulation and experimental results from a single-phase MMC system.
LanguageEnglish
Pages71-81
Number of pages11
JournalIEEE Transactions on Industrial Electronics
Volume63
Issue number1
Early online date7 Sep 2015
DOIs
Publication statusPublished - 31 Jan 2016

Fingerprint

Equivalent circuits
Inductance

Keywords

  • modular multilevel converter
  • asymmetric conditions
  • common mode current
  • differential mode current
  • power balance

Cite this

@article{1b837e743b494c389e0f6f5842c3b49f,
title = "Analysis and control of modular multilevel converters under asymmetric arm impedance conditions",
abstract = "This paper presents a detailed analysis and improved control strategy for Modular Multilevel Converters (MMC) under asymmetric arm inductance conditions. Unlike symmetric conditions, the fundamental ac current is not split equally between the upper and lower arms under asymmetric conditions, and the dc and double-frequency components in the common-mode current also flow into the ac side. To solve these issues, a theoretical analysis of the effect of asymmetric conditions on MMC operation is carried out using equivalent circuits at different frequencies. Three control targets are then presented to enhance the operational performance. A control strategy providing the control of differential-mode current, common-mode current and power balance is designed. The feasibility and validity of the proposed analysis and control strategy are demonstrated by simulation results from a threephase MMC system, and simulation and experimental results from a single-phase MMC system.",
keywords = "modular multilevel converter, asymmetric conditions, common mode current, differential mode current, power balance",
author = "Rong Zeng and Lie Xu and Liangzhong Yao and Finney, {Stephen J.}",
note = "(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works",
year = "2016",
month = "1",
day = "31",
doi = "10.1109/TIE.2015.2477057",
language = "English",
volume = "63",
pages = "71--81",
journal = "IEEE Transactions on Industrial Electronics",
issn = "0278-0046",
number = "1",

}

Analysis and control of modular multilevel converters under asymmetric arm impedance conditions. / Zeng, Rong; Xu, Lie; Yao, Liangzhong; Finney, Stephen J.

In: IEEE Transactions on Industrial Electronics, Vol. 63, No. 1, 31.01.2016, p. 71-81.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Analysis and control of modular multilevel converters under asymmetric arm impedance conditions

AU - Zeng, Rong

AU - Xu, Lie

AU - Yao, Liangzhong

AU - Finney, Stephen J.

N1 - (c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

PY - 2016/1/31

Y1 - 2016/1/31

N2 - This paper presents a detailed analysis and improved control strategy for Modular Multilevel Converters (MMC) under asymmetric arm inductance conditions. Unlike symmetric conditions, the fundamental ac current is not split equally between the upper and lower arms under asymmetric conditions, and the dc and double-frequency components in the common-mode current also flow into the ac side. To solve these issues, a theoretical analysis of the effect of asymmetric conditions on MMC operation is carried out using equivalent circuits at different frequencies. Three control targets are then presented to enhance the operational performance. A control strategy providing the control of differential-mode current, common-mode current and power balance is designed. The feasibility and validity of the proposed analysis and control strategy are demonstrated by simulation results from a threephase MMC system, and simulation and experimental results from a single-phase MMC system.

AB - This paper presents a detailed analysis and improved control strategy for Modular Multilevel Converters (MMC) under asymmetric arm inductance conditions. Unlike symmetric conditions, the fundamental ac current is not split equally between the upper and lower arms under asymmetric conditions, and the dc and double-frequency components in the common-mode current also flow into the ac side. To solve these issues, a theoretical analysis of the effect of asymmetric conditions on MMC operation is carried out using equivalent circuits at different frequencies. Three control targets are then presented to enhance the operational performance. A control strategy providing the control of differential-mode current, common-mode current and power balance is designed. The feasibility and validity of the proposed analysis and control strategy are demonstrated by simulation results from a threephase MMC system, and simulation and experimental results from a single-phase MMC system.

KW - modular multilevel converter

KW - asymmetric conditions

KW - common mode current

KW - differential mode current

KW - power balance

U2 - 10.1109/TIE.2015.2477057

DO - 10.1109/TIE.2015.2477057

M3 - Article

VL - 63

SP - 71

EP - 81

JO - IEEE Transactions on Industrial Electronics

T2 - IEEE Transactions on Industrial Electronics

JF - IEEE Transactions on Industrial Electronics

SN - 0278-0046

IS - 1

ER -