摘要
LLC谐振变换器在输出限流时会工作于PWM控制模式,而现有文献缺乏对PWM控制LLC谐振变换器的分析。为此,本文针对LLC变换器,比较了对称和不对称PWM控制策略,提出了一种新型的PWM控制策略—跟随PWM控制。论文分析了其工作原理,讨论了占空比大小对变换器软开关特性的影响,给出了控制策略的实现方法。最后针对350V～400V输入、48V/480W输出的供电电源,进行了主要参数设计,完成了样机的制作与实验。实验结果与理论分析一致,初步论证了该新型PWM控制策略应用于LLC谐振变换器的可行性。
LLC resonant converter will work with PWM control mode during current-limiting condition. But few literatures address the characteristics of LLC resonant converter with PWM control mode. In this paper, symmetrical PWM control strategy and asymmetrical PWM control strategy ＂are discussed and a novel PWM control strategy is proposed. Based on the illustration of the operating principles, the soft-switching characteristic of the duty cycle is analyzed in detail. The results of analysis and experiment on a 48V/480W converter verify that this control scheme could realize the soft-switch control under the constant duty cycle to the converter.
出处
《电工电能新技术》
CSCD
北大核心
2011年第4期40-45,共6页
Advanced Technology of Electrical Engineering and Energy
基金
国家自然科学基金资助项目(51077069)
江苏省自然科学基金资助项目(BK2009372)
