TY - GEN
T1 - Modeling and Defect Analysis of Transformer-Less Multilevel Back-to-Back Cascaded H-Bridge Converter
AU - Lai, Zhenhong
AU - Zhao, Kexu
AU - Yi, Hao
AU - Wang, Zhenxiong
AU - Zhuo, Fang
AU - Zhuang, Haoyan
N1 - Publisher Copyright:
© 2023 IEEE.
PY - 2023
Y1 - 2023
N2 - Back-to-back (B2B) soft open point (SOP) is a widely adopted solution for connecting distribution networks with different phases. In medium voltage networks, two commonly used topologies are modular multilevel converters (MMC) and cascaded H-bridge converters (CHB). However, these schemes require a large number of semiconductor devices, which hinders the widespread adoption of B2B-type SOP in medium voltage networks. In this paper, the scheme of the addition of inductance to the transformer-less B2B-CHB topology to mitigate the short-circuit current is proposed. This modification shows promise in reducing the cost and size of the medium voltage B2B-type SOP. A single-phase model is established and the control system is designed to ensure stable operation. Using the mathematical model of the system, certain drawbacks of the transformer-less B2B-CHB topology are identified. Specifically, the output current range of the converters is significantly influenced by the grid voltage of both sides, and there is a sharp variation in the current distribution among the semiconductors. The theoretical reasons are analyzed for these phenomena and verified through simulations.
AB - Back-to-back (B2B) soft open point (SOP) is a widely adopted solution for connecting distribution networks with different phases. In medium voltage networks, two commonly used topologies are modular multilevel converters (MMC) and cascaded H-bridge converters (CHB). However, these schemes require a large number of semiconductor devices, which hinders the widespread adoption of B2B-type SOP in medium voltage networks. In this paper, the scheme of the addition of inductance to the transformer-less B2B-CHB topology to mitigate the short-circuit current is proposed. This modification shows promise in reducing the cost and size of the medium voltage B2B-type SOP. A single-phase model is established and the control system is designed to ensure stable operation. Using the mathematical model of the system, certain drawbacks of the transformer-less B2B-CHB topology are identified. Specifically, the output current range of the converters is significantly influenced by the grid voltage of both sides, and there is a sharp variation in the current distribution among the semiconductors. The theoretical reasons are analyzed for these phenomena and verified through simulations.
KW - Transformer-less
KW - back-to-back
KW - mathematical model
KW - multilevel cascaded H-bridge converter
KW - soft open point
UR - https://www.scopus.com/pages/publications/85187245270
U2 - 10.1109/PEAS58692.2023.10395396
DO - 10.1109/PEAS58692.2023.10395396
M3 - 会议稿件
AN - SCOPUS:85187245270
T3 - PEAS 2023 - 2023 IEEE 2nd International Power Electronics and Application Symposium, Conference Proceedings
SP - 2198
EP - 2202
BT - PEAS 2023 - 2023 IEEE 2nd International Power Electronics and Application Symposium, Conference Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2nd IEEE International Power Electronics and Application Symposium, PEAS 2023
Y2 - 10 November 2023 through 13 November 2023
ER -