摘要
LLC谐振变换器由于具有良好的软开关特性和电气隔离能力,在近年来被广泛应用于高压、大功率、中/高频电能变换领域。现有的高压器件受开关特性的制约,需要选取较大的死区时间保证电路中开关桥臂的安全可靠工作,从而会对LLC谐振变换器的软开关实现产生影响。主要研究了大死区时间对LLC谐振变换器软开关特性的影响规律,分别从开关管安全工作、结电容放电和反并联二极管续流3个因素出发,定量推导确保全功率范围内软开关实现的死区设置区间,进而提出死区时间的优化设计方法。最后,搭建了基于6.5 kV/250 A IGBT的150 kW大功率电力电子变压器样机,通过分析和测量不同功率等级下LLC谐振变换器的软开关实现情况,验证所提死区时间设计方法的有效性。
In recent years,LLC resonant converters have been widely applied in the fields of high-power,high-voltage,and medium-and high-frequency power conversion owing to their characteristics of soft-switching and capability of electric isolation.Due to the constraints on the existing high-voltage devices,a large dead time is necessary to guarantee the safe and reliable operation of bridge legs in the circuit,which may affect the soft-switching performance of LLC resonant converters.In this paper,the influence of a large dead time on the soft-switching characteristics of an LLC resonant converter is studied.A quantitative calculation method is given to determine the range of dead time under full-power conditions from the perspectives of safe switching,discharging of junction capacitor and anti-parallel diode freewheeling,respectively.Then,an optimal design method of dead time is proposed accordingly.Finally,a 150 kW high-power power electronic transformer prototype with 6.5 kV/250 A IGBT was built.Through the analysis and measurement of soft-switching conditions for the LLC resonant converter at different power levels,the validity of the proposed design method of dead time was verified.
作者
张捷频
ZHANG Jiepin(Locomotive&Car Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;Beijing Zongheng Electromechanical Technology Co.,Ltd.,Beijing 100094,China)
出处
《电源学报》
CSCD
北大核心
2024年第S01期1-8,共8页
Journal of Power Supply
基金
中国国家铁路集团有限公司科技研究开发计划资助项目(J2021J003)。
