An Active Hybrid Modulation Strategy for a Si/SiC Hybrid Multilevel Converter

IEEE Open Journal of Power Electronics

Yufei Li¹  Yue Zhao¹  Xinyuan Du¹  Fei Diao¹ 

[1] Power Electronic Systems Laboratory at Arkansas (PESLA), Department of Electrical Engineering, University of Arkansas, Fayetteville, AR, USA;

关键词: Hybrid modulation;    multilevel converter;    space-vector-modulation (SVM);    zero-sequence injection;   

DOI  :  10.1109/OJPEL.2021.3104608

来源: DOAJ

【 摘 要 】

This paper proposes a hybrid modulation strategy for a medium-voltage hybrid seven-level (7-L) converter, which consists of a three-phase silicon (Si) IGBT-based active-neutral-point-clamped (ANPC) stage and a cascaded silicon carbide (SiC) MOSFET-based H-bridge (HB) stage in each phase. Within the framework of the proposed modulation strategy, three floating HB converters are controlled using a high-frequency three-level (3-L) space-vector-modulation (SVM), while a low-frequency modulation is applied to the ANPC converter. To regulate the DC voltages across floating capacitors, a zero-sequence voltage (ZSV) injection method is adopted. The proposed method possesses three major advantages. First, it enables the simplification from a 7-L to a 3-L SVM, which significantly reduces the computational burden. Second, with all the high-frequency switching actions assigned to SiC devices in the HB stage, the power loss of the hybrid 7-L converter is reduced. Third, the hybrid modulation together with the ZSV injection enables a wider stable operating range compared to the existing 7-L SVM method. Finally, both simulation and experimental results performed on the scale-down and the full-scale 1 MVA prototype validate the effectiveness of the proposed hybrid modulation strategy.

【 授权许可】

Unknown