Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Fundamental impedance-based digital synchronous rectification scheme for bidirectional CLLC resonant converters

  • Guopeng Zhang (School of Electrical Engineering and Automation, Henan Polytechnic University) ;
  • Xindi Sun (School of Electrical Engineering and Automation, Henan Polytechnic University) ;
  • Hao Wang (School of Electrical Engineering and Automation, Henan Polytechnic University) ;
  • Yonghui Liu (School of Electrical Engineering and Automation, Henan Polytechnic University) ;
  • Haijun Tao (School of Electrical Engineering and Automation, Henan Polytechnic University) ;
  • Lulu Huang (China Electric Power Research Institute Co., Ltd.)
  • Received : 2022.12.15
  • Accepted : 2023.08.28
  • Published : 2024.01.20
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Abstract

Synchronous rectification (SR) is an effective way to improve the efficiency of CLLC resonant converters. The soft switching of SR is affected by the parasitic capacitance and the zero-crossing point of the current of the secondary inductance. Therefore, based on uncontrolled rectification on the secondary of the converter, the effective range of soft switching for SR under different operating modes is analyzed. A fundamental impedance model is established to obtain the discharge time of the parasitic capacitance and the zero-crossing point of the current of the secondary in the upper resonant frequency mode. The relationship between the SR signals and primary driving signals in different operating modes is summarized, which can improve the operating range of the SR while ensuring soft-switching. This in turn, ensures the operating efficiency of the converter. The calculation method of the turn-ON and turn-OFF times of the SR in different modes is improved. In addition, the proposed SR method can be used in bidirectional CLLC resonant converters that do not have SR functionality. To accomplish this, only the control program needs to be updated. Experimental results on a 200 V 500 W prototype are given to verify the effectiveness of the SR method.

Keywords

Acknowledgement

This work is supported by the Natural Science Foundation of Henan (No. 212300410147), Fundamental Research Funds for the Universities of Henan Province (No. NSFRF210423), and the Henan Provincial Science and Technology Research Project (222102220014)

References

  1. Huang, J.-J., Zhang, X., Shuai, Z.-K., et al.: Robust circuit parameters design for the CLLC-type DC transformer in the hybrid AC-DC microgrid. IEEE Trans. Ind Electron. 66(3), 1906-1918 (2019) https://doi.org/10.1109/TIE.2018.2835373
  2. Huang, J.-J., Zhang, X., Mao, T.: Multitime scale frequency regulation of a general resonant DC transformer in a hybrid AC/DC microgrid. IEEE Trans. Ind Electron. 68(10), 9641-9651 (2021) https://doi.org/10.1109/TIE.2020.3022498
  3. Zhang, Z.-D., Liu, C.-H., Wang, M.-Z., et al.: High-efficiency high-power-density CLLC resonant converter with low-stray-capacitance and well-heat-dissipated planar transformer for EV on-board charger. IEEE Trans. Power Electron. 35(10), 10831-10851 (2020) https://doi.org/10.1109/TPEL.2020.2980313
  4. Pei, L., Jia, L.-X., Wang, L.-L., et al.: A Time-domain-model-based digital synchronous rectification algorithm for CLLC resonant converters utilizing a hybrid modulation. IEEE Trans. Power Electron. 37(3), 2815-2829 (2022)
  5. Zhou, X., Wang, L.-L., Gan, Y.-M., et al.: Accurate analysis and design of the circuit parameters of LLC DC-DC converter with synchronous rectification. IEEE Trans. Power Electron. 37(12), 15051-15065 (2022) https://doi.org/10.1109/TPEL.2022.3194588
  6. Bhardwaj, M., Yu, S.-Y.: Bidirectional CLLLC resonant dual active bridge (DAB) reference design for HEV/EV onboard charger. https://www.ti.com/tool/TIDM-02002#design-products (2020)
  7. Chen, N., Chen, M., Li, B.-D., et al.: Synchronous rectification based on resonant inductor voltage for CLLC bidirectional converter. IEEE Trans. Power Electron. 37(1), 547-561 (2022) https://doi.org/10.1109/TPEL.2021.3100154
  8. Gao, Y.-C., S, K., Lin, X., et al.: A phase-shift-based synchronous rectification scheme for bi-directional high-step-down CLLC resonant converters. In: Proceedings of 2018 IEEE Applied Power Electronics Conference and Exposition (APEC), pp. 1571-1576 (2018)
  9. Li, B.-D., Chen, M., Wang, X.-Q., et al.: An optimized digital synchronous rectification scheme based on time-domain model of resonant CLLC circuit. IEEE Trans. Power Electron. 36(9), 10933-10948 (2021) https://doi.org/10.1109/TPEL.2020.3044297
  10. Chen, H., Sun, K., Shi, H.-X., et al.: A battery charging method with natural synchronous rectification features for full-bridge CLLC converters. IEEE Trans. Power Electron. 37(2), 2139-2151 (2022)
  11. Li, H., Zhang, Z.-L., Wang, S.-D., et al.: A 300-kHz 6.6-kW SiC bidirectional LLC onboard charger. IEEE Trans. Ind. Electron. 67(2), 1435-1445 (2020) https://doi.org/10.1109/TIE.2019.2910048
  12. Liao, J.-R., Hang, L.-J., Dan, Z.-M.: Digital control method of wide-range CLLLC bidirectional synchronous rectification. Trans. China Electrotech. Soc. 37(14), 3632-3642 (2022)
  13. Li, H.R., Wang, S.-D., Zhang, Z.-L., et al.: An impedance-based digital synchronous rectifier driving scheme for bidirectional high-voltage SiC LLC converter. IEEE Trans. Ind. Electron. 69(11), 11314-11323 (2022) https://doi.org/10.1109/TIE.2021.3127037
  14. Li, H.R., Wang, S.-D., Zhang, Z.-L., et al.: A bidirectional synchronous/asynchronous rectifier control for wide battery voltage range in SiC bidirectional LLC chargers. IEEE Trans. Power Electron. 37(5), 6090-6101 (2022) https://doi.org/10.1109/TPEL.2021.3126886
  15. Li, H.R., Sun, Y.-B., Wang, S.-D., et al.: Bidirectional control with fitting model-based synchronous rectification and input ripple current feedforward for SiC bidirectional CLLC EV charger. IEEE Trans. Ind. Electron. 70(9), 9136-9146 (2023) https://doi.org/10.1109/TIE.2022.3212382
  16. Wei, Y.-Q., Luo, Q.-M., Mantooth, A.: Overview of modulation strategies for LLC resonant converter. IEEE Trans. Power Electron. 35(10), 10423-10443 (2020) https://doi.org/10.1109/TPEL.2020.2975392
  17. Lee, S.-Y., Lee, W.-S., Lee, J.-Y., et al.: High-efficiency 11kW bidirectional on-board charger for EVs. J. Power Electron. 22(2), 363-376 (2022)  https://doi.org/10.1007/s43236-021-00344-3