Three-Level Bidirectional DC–DC Converter with an Auxiliary Inductor in Adaptive Working Mode for Full-Operation Zero-Voltage Switching

  • Deshang Sha
  • Guo Xu
Part of the CPSS Power Electronics Series book series (CPSS)


This chapter proposes a three-level bidirectional DC–DC converter with an auxiliary inductor for full-operation zero-voltage switching (ZVS) in high-output voltage applications. The auxiliary inductor is connected across the middle node of the split flying capacitors and the center tap of the secondary winding in the transformer. In this topology, the outer and inner switches in the three-level stage can generate two independent 50% duty-cycle square waveforms, which is used to control the current in the auxiliary inductor to extend ZVS range from no loads to full loads condition. Considering the phase shift angle in three-level stage, the ZVS range of the converter is analyzed, and the modulation trajectory to maintain the full-operation ZVS range with low conduction loss is proposed. A flowchart implementation can guarantee the seamless transfer in different working modes. Then, the conduction loss in the proposed converter is compared with the previous three-level bidirectional solution, which illustrates that the conduction loss in the proposed converter only increases in light loads. Finally, the experimental results verify the theoretical analyses and ZVS performance across the whole power and voltage range, and the efficiency curves demonstrate the efficiency improvement.


Three-level Dual active bridge Auxiliary inductor Zero-voltage switching 


  1. 1.
    Thomas S, Doncker RD, Lenke R (2015) Bidirectional DC–DC converter. United State Patent No. 9148065B2Google Scholar
  2. 2.
    Sha D, Lin Q, You F, Wang X, Xu G (2016) A ZVS bidirectional three-level dc–dc converter with direct current slew rate control of leakage inductance current. IEEE Trans Ind Appl 52(3):2368–3377CrossRefGoogle Scholar
  3. 3.
    Lu Y, Xing Y, Wu H (2016) A PWM plus phase-shift controlled interleaved isolated boost converter based on semiactive quadrupler rectifier for high step-up applications. IEEE Trans Ind Electron 63(7):4211–4221CrossRefGoogle Scholar
  4. 4.
    Guo Z, Sun K, Sha D (2016) Improved ZVS three-level dc–dc converter with reduced circulating loss. IEEE Trans Power Electron 31(6):6394–6404CrossRefGoogle Scholar
  5. 5.
    Kim J, Kwon J, Kwon B (2018) High-efficiency two-stage three-level grid-connected photovoltaic inverter. IEEE Trans Ind Electron 65(3):2368–2377CrossRefGoogle Scholar
  6. 6.
    Pinheiro JR, Barbi I (1993) The three-level ZVS-PWM DC-to-DC converter. IEEE Trans Power Electron 8(4):486–492CrossRefGoogle Scholar
  7. 7.
    Ruan X, Xu D, Zhou L, Li B, Chen Q (2002) Zero-voltage-switching PWM three-level converter with two clamping diodes. IEEE Trans Ind Electron 49(4):790–799CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.Advanced Power Conversion Center, School of AutomationBeijing Institute of TechnologyBeijingChina

Personalised recommendations