Effect of Metal Oxide Semiconductor Field-Effect Transistor Output Parasitic Capacitance on Efficiency in Full-Bridge LLC DC/DC Converters

Effect of Metal Oxide Semiconductor Field-Effect Transistor Output Parasitic Capacitance on Efficiency in Full-Bridge LLC DC/DC Converters Ming-Hung Chen Department of Electrical Engineering, Ming Chi University of Technology, New Taipei City 243303, Taiwan http://orcid.org/0000-0003-2388-5086 Chia-Wen Hsieh Department of Electrical Engineering, Ming Chi University of Technology, New Taipei City 243303, Taiwan

This study analyzed the efficiency impact of a MOSFET output parasitic capacitance (Coss) on a full-bridge LLC DC/DC converter. The core of the converter was the control chip for a half-bridge LLC DC/DC converter, and the output signal of the chip controlled the first-arm power transistors of the primary side of the converter. The coupling transformer reversed the output signal to control the primary side of the second arm of the power transistor. The full-bridge converter comprises a half-bridge control chip that converts the high-voltage DC power supply to a low-voltage DC power supply, which is then synchronously rectified and supplied to the load. The primary side of the power transistor achieves a zero-voltage switching (ZVS) state through the resonance of the LLC converter. This design gives the converter high power density and a simple structure. Furthermore, to determine the appropriate output parasitic capacitance for improving converter efficiency, this study analyzed the effect of the output parasitic capacitance on the switching loss and conduction loss of the power transistor on the basis of the output parasitic capacitance of the primary-side power transistor. A 1200 W converter prototype was fabricated in this study, and when the output was 300 W, efficiency increased from 92.603% to 93.462%, a 0.859% increase. The empirical results verified the feasibility of the proposed theory.
02 23 2024 309 mi15030309 Ming Chi University of Technology (MCUT), Taiwan http://dx.doi.org/10.13039/ https://creativecommons.org/licenses/by/4.0/ 10.3390/mi15030309 https://www.mdpi.com/2072-666X/15/3/309 https://www.mdpi.com/2072-666X/15/3/309/pdf 10.1109/ICECENG.2011.6057321 Wang, P., Cui, G., and Chen, L. (2011, January 16–18). Analysis and Design of LLC with new Current Driven Synchronous Rectifiers. Proceedings of the 2011 International Conference on Electrical and Control Engineering, Yichang, China. 10.1109/IBCAST.2018.8312292 Ali, R., Faraz, Z.A., Noora, A., Fareed, M.M., and Siyal, S.H. (2018, January 9–13). Computational Analysis of PT/CT Contact Behavior for a Heavy Water Reactor at High Temperature and Pressure. Proceedings of the 2018 15th International Bhurban Conference on Applied Sciences and Technology (IBCAST), Islamabad, Pakistan. 10.1109/APEC.2018.8341164 Li, H., Bai, L., Zhang, Z., Wang, S., Tang, J., Ren, X., and Li, J. (2018, January 4–8). A 6.6kW SiC bidirectional on-board charger. In Proceedings of the 2018 IEEE Applied Power Electronics Conference and Exposition (APEC), San Antonio, TX, USA. Zhang Novel Forward–Flyback Hybrid Bidirectional DC–DC Converter IEEE Trans. Ind. Electron. 2009 10.1109/TIE.2008.2009561 56 1578 10.1109/VPPC.2009.5289663 Wei, X., Zhao, X., and Dai, H. (2009, January 7–10). The application of flyback DC/DC converter in Li-ion batteries active balancing. Proceedings of the 2009 IEEE Vehicle Power and Propulsion Conference, Dearborn, MI, USA. 10.1109/APEC.2019.8721913 Lim, C.Y., Han, J.K., Park, M.H., Kim, K.W., and Moon, G.W. (2019, January 17–21). Phase-Shifted Full-Bridge DC-DC Converter With High Efficiency and Reduced Output Filter Using Center-Tapped Clamp Circuit. Proceedings of the 2019 IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, USA. 10.1109/IICPE.2012.6450415 Dutta, S., Maiti, D., Sil, A.K., and Biswas, S.K. (2012, January 6–8). A Soft-Switched Flyback Converter with Recovery of Stored Energy in Leakage Inductance. Proceedings of the 2012 IEEE 5th India International Conference on Power Electronics (IICPE), Delhi, India. 10.1109/IPEMC.2016.7512686 Vu, H.N., Tran, D.D., and Choi, W. (2016, January 22–26). A Novel Hybrid Soft Switching Full-Bridge PWM and Full-Bridge LLC Converter for On-Board Battery Charger Applications. Proceedings of the 2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), Hefei, China. 10.1109/ECCE.2018.8557734 Yan, J., Zhao, X., Chen, C.W., and Lai, J.S. (2018, January 23–27). Comparison of Secondary Topology of the LLC Converter for Photovoltaic Application. Proceedings of the 2018 IEEE Energy Conversion Congress and Exposition (ECCE), Portland, OR, USA. 10.1109/ITEC-AP.2017.8080765 Lan, G., Zhang, S., and Wu, X. (2017, January 7–10). Analysis and Reduction of Common Mode Current of the Transformer in a Full-bridge LLC Battery Charger. Proceedings of the 2017 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific), Harbin, China. 10.1109/PEDES.2018.8707458 Peter, A.K., and Mathew, J. (2018, January 18–21). A Three-Level Half-Bridge Flying Capacitor Topology for Single-Stage AC-DC LLC Resonant Converter. Proceedings of the 2018 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES), Chennai, India. 10.1109/ICIEA.2014.6931180 Chen, Q., Wang, J., Ji, Y., and Liang, S. (2014, January 9–11). Soft Starting Strategy of Bidirectional LLC Resonant DC-DC Transformer Based on Phase-Shift Control. Proceedings of the 2014 9th IEEE Conference on Industrial Electronics and Applications, Hangzhou, China. Ambatipudi, R., Kotte, H.B., and Bertilsson, K. (2013, January 17–21). High Frequency (MHz) Planar Transformers for Next Generation Switch Mode Power Supplies. Proceedings of the 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, USA. 10.1109/iSPEC50848.2020.9351089 Zhou, K., Wang, X., and Yang, Q. (2020, January 23–25). Research on the performance of LLC resonant converter considering the influence of parasitic parameters. Proceedings of the 2020 IEEE Sustainable Power and Energy Conference (iSPEC), Chengdu, China. 10.1109/ECCE.2016.7855471 Liu, W., Wang, B., Yao, W., Lu, Z., and Xu, X. (2016, January 18–22). Steady-State Analysis of the Phase Shift Modulated LLC Resonant Converter. Proceedings of the 2016 IEEE Energy Conversion Congress and Exposition (ECCE), Milwaukee, WI, USA. 10.1109/TENCON.2015.7372725 Lin, B.R., and Du, Y.K. (2015, January 1–4). Analysis, Design and Implementation of a Wide ZVS Full-Bridge Converter. Proceedings of the TENCON 2015–2015 IEEE Region 10 Conference, Macao, China. 10.1109/PEDSTC.2019.8697825 Yazdani, M.R., and Farzanehfard, M. (2019, January 12–14). Evaluation and Comparison of Conducted EMI in Three Full-Bridge DC-DC Switching Converters. Proceedings of the 2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC), Shiraz, Iran.