具有混合控制策略的宽输出双全桥LLC谐振变换器
Wide Output Dual-full-bridge LLC Resonant Converter with Hybrid Control Strategy
潘健 1石迪 1刘松林 1熊嘉鑫 1宋豪杰1
作者信息
- 1. 湖北工业大学电气与电子工程学院,武汉 430068
- 折叠
摘要
针对宽输出电压范围应用中传统频率控制的LLC型谐振变换器存在开关频率调节范围宽、循环电流大及难实现高效运行等问题,提出1种具有定频移相-定频PWM混合控制策略的双全桥LLC型谐振变换器,以适用于较宽输出电压范围.其由 2 个全桥LLC型谐振变换器共用 1 个桥臂组合而成,输出电压通过定频移相-定频PWM混合控制进行调节,使该谐振变换器实现 4 倍电压增益范围以获得较宽输出电压,同时解决传统频率控制中循环电流过大及在移相控制移相角小时的软开关不能实现问题,提升系统效率.该转换器开关频率工作在谐振频率点,电压增益与负载无关且有助于磁性元件设计,在全负载范围内实现软开关.最后给出详细的电路工作原理分析并通过仿真进行验证,搭建实验平台验证了所提变换器的可行性和有效性.
Abstract
In the application of wide output voltage range,some problems exist in an LLC resonant converter under the traditional frequency control,such as a wide switching frequency regulation range,a large circulation current and difficulty in high-efficiency operation.To solve these problems,a dual-full-bridge LLC resonant converter under a fixed-frequency phase-shift and fixed-frequency PWM hybrid control strategy is proposed,which is suitable for the wide range of output voltage.This converter is composed of two full-bridge LLC resonant converters sharing one bridge arm,and the output voltage is modulated by the hybrid control,so that a quadruple voltage gain and a wider output voltage range of the resonant converter can be realized.Meanwhile,the problems that the large circulation current exists under the traditional frequency control and the soft switching cannot be realized at a small phase shift angle are solved,thus improving the system efficiency.The switching frequency of the converter is always equal to the resonance frequency,and the voltage gain is independent of load,which is helpful for the design of the magnetic element.At the same time,the soft switching can be realized in the full load range.Finally,a detailed analysis of the circuit principle was given,which was further verified by simulations.An experimental platform was also established to validate the feasibility and effectiveness of the proposed converter.
关键词
双全桥LLC谐振变换器/定频移相-定频PWM混合控制/宽输出范围/零电压开关/零电流关断Key words
Dual-full-bridge LLC resonant converter/fixed-frequency phase-shift and fixed-frequency PWM hybrid control/wide output range/zero voltage switch/zero current 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