TY - GEN
T1 - Voltage drift mechanism in modular multilevel converter
AU - Shen, Jie
AU - Lei, Qin
AU - Schroder, Stefan
AU - Mechlinski, Marius
N1 - Publisher Copyright:
© 2015 IEEE.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2015/10/27
Y1 - 2015/10/27
N2 - The capacitor voltage drift problem in Modular Multilevel Converter (MMC) system has been widely discussed in the past. It is well known that sometimes the capacitor voltages are balanced, without any active controls. However, due to the uncertainty and lack of theoretical explanations, active capacitor voltage controls are typically preferred for real applications, and the voltage balancing/drift mechanism of MMC topology did not draw much attention in the past. This paper covers this gap: it is explored that the cell voltage drift effect is caused by the sideband overlap effect. Moreover, the requirements of voltage drift effect are discussed systematically. The conclusion is that for high-power applications with limited switching frequencies, low but non-integer carrier ratios are highly preferred to avoid the intrinsic voltage drift between MMC cells. By doing this, active voltage balancing algorithms are only needed as backup.
AB - The capacitor voltage drift problem in Modular Multilevel Converter (MMC) system has been widely discussed in the past. It is well known that sometimes the capacitor voltages are balanced, without any active controls. However, due to the uncertainty and lack of theoretical explanations, active capacitor voltage controls are typically preferred for real applications, and the voltage balancing/drift mechanism of MMC topology did not draw much attention in the past. This paper covers this gap: it is explored that the cell voltage drift effect is caused by the sideband overlap effect. Moreover, the requirements of voltage drift effect are discussed systematically. The conclusion is that for high-power applications with limited switching frequencies, low but non-integer carrier ratios are highly preferred to avoid the intrinsic voltage drift between MMC cells. By doing this, active voltage balancing algorithms are only needed as backup.
KW - carrier ratio
KW - modulation
KW - sideband overlap effect
KW - voltage drift
UR - http://www.scopus.com/inward/record.url?scp=84963579046&partnerID=8YFLogxK
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U2 - 10.1109/ECCE.2015.7310163
DO - 10.1109/ECCE.2015.7310163
M3 - Conference contribution
AN - SCOPUS:84963579046
T3 - 2015 IEEE Energy Conversion Congress and Exposition, ECCE 2015
SP - 3557
EP - 3563
BT - 2015 IEEE Energy Conversion Congress and Exposition, ECCE 2015
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 7th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2015
Y2 - 20 September 2015 through 24 September 2015
ER -