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
JF - IEEE Transactions on Industrial Electronics
SN - 0278-0046
IS - 1
ER -
