Minimum-Current-Stress Scheme of Three-Level Dual-Active-Bridge DC-DC Converters with the Particle Swarm Optimization

Yi Wang, Huiqing Wen*, Yinxiao Zhu, Haochen Shi, Qinglei Bu, Yihua Hu, Yong Yang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Current stress is essential for the reliability of power switching devices, especially for high-voltage applications, such as three-level NPC-based dual-active-bridge (3LNPC-DAB) converters. With the conventional single phase shift (SPS) control, the current stress of power devices in 3LNPC-DAB converters is high, which not only affects the conversion efficiency for a wide operating range but also endangers the power devices, which is harmful for the healthy operation of 3LNPC-DAB converters. To solve this problem, this article proposes a minimum-current-stress scheme using particle swarm optimization (PSO) strategy with the aim to reduce the current stress and improve the efficiency of 3LNPC-DAB converters. Different from SPS, two phase shift variables are adopted in the proposed algorithm: one is set between the primary and secondary bridges, and the other is set within the same bridge. Thus, not only the control flexibility is expanded, but also main performance indexes, such as the transmission power, the current stress of each switch, and the efficiency for the whole operating range, are improved. Moreover, the PSO strategy requires fewer parameters to adjust, less computational burden, and faster convergence speed, which simplifies the theoretical calculation and the practical implementation. Finally, the main experimental results for various operating conditions are provided to validate the proposed scheme.

Original languageEnglish
Pages (from-to)2067-2084
Number of pages18
JournalIEEE Transactions on Transportation Electrification
Issue number4
Early online date16 Apr 2021
Publication statusPublished - Dec 2021

Bibliographical note

Funding Information:
This work was supported in part by the National Natural Science Foundation of China under Grant 51977136, in part by the Research Development Fund of Xi’an Jiaotong-Liverpool University (XJTLU) under Grant RDF-16-01-10 and Grant RDF-17-01-28, in part by the Research Enhancement Fund of XJTLU under Grant REF-17-01-02, in part by the Suzhou Prospective Application Program under Grant SYG202016, and in part by the XJTLU Key Program Special Fund under Grant KSFA-08, Grant KSF-E-13, and Grant KSF-T-04.


  • Current stress
  • improved phase shift control
  • particle swarm optimization (PSO)
  • three-level NPC-based dual-active-bridge (3LNPC-DAB) converters

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