Negative sequence control for DC voltage balancing in three-phase cascaded H-bridge rectifiers considering DC-port failures

• Published in: Journal of power electronics Vol. 22; no. 12; pp. 2025 - 2038
• Main Authors: Xinyu, Zhu, Xiao, Liang, Kaiyue, Gong, Xu, Peng, Jun, Cai, Xiaohan, Liu, Chao, Zhou, Siqi, An, Chao, Wu, Pengcheng, Han
• Format: Journal Article
• Language: Korean
• Published: 2022
• Subjects: Three-phase cascaded H-bridge rectifier; Matrix generation modulation; Power electronic transformer; DC-port failure; Negative sequence control
• ISSN: 1598-2092; 2093-4718

As a vital component of power electronic transformers (PET), the reliability of a cascaded H-bridge rectifier (CHBR) is essential. Therefore, in this paper, a DC-port voltage balance strategy considering DC-port failure is researched to ensure the stable operation of a CHBR. However, if the DC-port voltage balance strategy is adopted to realize the single-phase balance of a CHBR, the three-phase currents become unbalanced. This paper uses a negative sequence control (NSC) strategy that is conducive to balancing DC-port voltage to achieve three-phase current balance. For the DC-port voltage balance, the matrix generation modulation (MGM) algorithm is proposed. In addition, the DC-port voltage balance boundary is analyzed to determine the range of the DC-port voltage balance in the CHBR. A 3-module cascading topology is adopted to demonstrate the MGM algorithm and the NSC strategy. Through experiments, results show the correctness and feasibility of the proposed strategy.