A modified efficiency‐oriented optimal method for three‐phase interleaved LLC resonant converter in plug‐in hybrid electric vehicle battery chargers

• Published in: IET electric power applications 2021-01, Vol.15 (1), p.114-127
• Main Authors: Shen, Chaochao, Zhong, Hao, Zhang, Yang, Xu, Mai, Zhang, Yining
• Format: Article
• Language: English
• Subjects: battery chargers; battery powered vehicles; hybrid electric vehicles; power capacitors; power transformers; resonant power convertors
• ISSN: 1751-8679; 1751-8660; 1751-8679
• DOI: 10.1049/elp2.12002

Three‐phase interleaved LLC resonant converters are preferably employed to realize high efficiency and high power density in the application of On‐board Charger. The parameter design of LLC resonant converter with wide range output has always been rigorous and difficult. Compared with the common time‐domain model, a high‐accuracy time domain analysis is adopted to analyze the interaction between three phases in detail. This method improves the accuracy of the design results by adding the interaction analysis. According to the operation mode analysis, transformer's turn ratio, resonant inductor, magnetic inductor and resonant capacitor are optimized based on the design principle of minimizing the conduction loss. Finally, the modified efficiency‐oriented optimal method of wide output range LLC resonant converter is proposed and its design results is validated by a 6.6 kW prototype. The efficiency of the design using proposed method is significantly improved than the results of the common time‐domain model.