Generalized Instantaneous Flux and Current Control for Three-Phase DAB Converters Under Hybrid Modulation Scheme

IEEE Transactions on Power Electronics, vol. 41, pp. 13757–13772

Abstract

The three-phase dual active bridge (DAB3) converter is widely adopted in high-power conversion systems due to its bidirectional power transfer capability, inherent soft-switching features, and reduced filter requirements. Conventional single-phase-shift (SPS) control enables soft-switching under heavy loads, while asymmetrical duty cycle control (ADCC) extends soft-switching to light-load conditions. By combining these two modulation strategies, the soft-switching range can be broadened, improving overall efficiency. However, the modeling and dynamic control of ADCC remains insufficiently understood. Moreover, direct transitions either within a modulation mode or between modes can induce current overshoots and flux bias, which degrade efficiency and may lead to transformer saturation. To address these challenges, this paper presents a unified current and flux control method for hybrid modulation schemes. The proposed method incorporates soft magnetization and soft de-magnetization under ADCC method, as well as instantaneous current and flux control during load transients and inter-mode transitions. This approach ensures full-range dynamic operation with accurate, bias-free, and overshoot-free control of transformer current and flux. The proposed control strategy is validated through both simulations and experiments on a down-scaled hardware prototype.

Authors 5

1. Jingxin Hu

   Nanjing University of Aeronautics and Astronautics

   Affiliation as printed

   College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China

2. Mingwei Lu

   Nanjing University of Aeronautics and Astronautics

   Affiliation as printed

   College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China

3. Haojie Xie

   Nanjing University of Aeronautics and Astronautics

   Affiliation as printed

   College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China

4. Yuying He

   Hohai University

   Affiliation as printed

   Department of Electrical Engineering, Hohai University, Nanjing, China

5. Rik W. De Doncker Aachen Institute for Power Generation and Storage Systems (PGS) E.ON Energy Research Center

   RWTH Aachen University

   Affiliation as printed

   Institute for Power Generation and Storage Systems, E.ON Energy Research Center, RWTH Aachen University, Aachen, Germany