高压大功率LLC谐振变换器死区时间优化设计方法研究
Research on Optimal Design Method of Dead Time for High-voltage High-power LLC Resonant Converter
张捷频1
作者信息
- 1. 中国铁道科学研究院集团有限公司机车车辆研究所,北京 100081;北京纵横机电科技有限公司,北京 100094
- 折叠
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.
Abstract
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.
关键词
LLC谐振变换器/死区时间/高压大功率/软开关Key words
LLC resonant converter/dead time/high-voltage high-power/soft-switching引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据