TY - JOUR
T1 - A Postfault Strategy to Control the Modular Multilevel Converter under Submodule Failure
AU - Yang, Qichen
AU - Qin, Jiangchao
AU - Saeedifard, Maryam
N1 - Funding Information:
This work was supported by the National Science Foundation under Grant 1443814. Paper no. TPWRD-00175-2015.
Publisher Copyright:
© 1986-2012 IEEE.
PY - 2016/12
Y1 - 2016/12
N2 - The modular multilevel converter (MMC) has become one of the most promising topologies for high-voltage applications. Although the MMC has a modular and redundant structure, which can significantly enhance its reliability and fault tolerance, its fault handling capability can be further improved by adopting a postfault strategy. In this paper, a postfault strategy based on the neutral-shift method is proposed, which, subsequent to bypassing the faulty submodule(s), aims at improving the maximum attainable line-to-line voltages of the MMC. Based on a newly developed internal variable analysis method, the impact of the neutral-shift strategy on the operation of the MMC is analyzed. In conjunction with the proposed postfault strategy, a modified circulating current suppression (CCS) method is used to mitigate the double-frequency component of the circulating currents. Performance and effectiveness of the proposed neutral-shift strategy with and without the CCS method is evaluated based on time-domain simulation studies in the PSCAD/EMTDC software environment.
AB - The modular multilevel converter (MMC) has become one of the most promising topologies for high-voltage applications. Although the MMC has a modular and redundant structure, which can significantly enhance its reliability and fault tolerance, its fault handling capability can be further improved by adopting a postfault strategy. In this paper, a postfault strategy based on the neutral-shift method is proposed, which, subsequent to bypassing the faulty submodule(s), aims at improving the maximum attainable line-to-line voltages of the MMC. Based on a newly developed internal variable analysis method, the impact of the neutral-shift strategy on the operation of the MMC is analyzed. In conjunction with the proposed postfault strategy, a modified circulating current suppression (CCS) method is used to mitigate the double-frequency component of the circulating currents. Performance and effectiveness of the proposed neutral-shift strategy with and without the CCS method is evaluated based on time-domain simulation studies in the PSCAD/EMTDC software environment.
KW - Modular multilevel converter (MMC)
KW - neutral shift
KW - postfault strategy
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U2 - 10.1109/TPWRD.2015.2449875
DO - 10.1109/TPWRD.2015.2449875
M3 - Article
AN - SCOPUS:85018283765
SN - 0885-8977
VL - 31
SP - 2453
EP - 2463
JO - IEEE Transactions on Power Delivery
JF - IEEE Transactions on Power Delivery
IS - 6
ER -