耦合电感集成型谐振变换器及其自适应频率控制  

Coupled Inductor Integrated Resonant Converter with Adaptive Frequency Control

作　　者：徐菁涛 许国 孙尧[1] 熊文静[1] Xu Jingtao;Xu Guo;Sun Yao;Xiong WenJing(School of Automation Central South University,Changsha 410083 China)

机构地区：[1]中南大学自动化学院,长沙410083

出　　处：《电工技术学报》2023年第4期998-1009,共12页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51907206);湖南省科技创新计划(2020RC4002)资助项目。

摘　　要：该文提出一种宽电压范围的耦合电感集成型串联谐振变换器(CISRC),其电压增益与负载不相关,并且仅含有一个磁性元件与两个开关管。与传统的两级级联结构变换器相比,磁性元件和开关管数量有效减少。在所提出的调制策略下,一次侧开关可以实现零电压开通,二次侧二极管可以实现零电流关断。此外,该文还提出一种无电流传感器的自适应频率控制,通过观测器观测励磁电流平均值,能够在不同功率下自适应调节开关频率,优化电流纹波。该文详细介绍变换器的工作特性与控制方法,并且搭建一台200 W的实验样机,实验结果证明了所提方案的可行性与有效性。Isolated DC/DC converter with wide input voltage or output voltage range is featured in many applications such as renewable energy generation system, electrical vehicle chargers and LED drivers. LLC resonant converter is an attractive topology which has significant advantages, such as soft switching, high efficiency and low EMI issue. Generally, LLC resonant converter adopts pulse frequency modulation(PFM).However, in order to obtain a wide voltage range, the switching frequency of LLC resonant converter needs to be away from the resonant frequency which could generate high circulating energy and reduce the efficiency.In order to realize wide range voltage regulation in a narrow switching frequency range, many improved control schemes have been proposed. Such as the phase-shift modulation(PSM) and pulse width modulation(PWM) scheme. But the peak current of the secondary rectifier is increased. The hybrid control combining PFM and PSM or PWM is also an effective method. This method takes into account the capacity of voltage regulation and working efficiency, but the control strategy becomes more complex. Besides, the reconstruction of circuit can also help to extend the voltage gain range. Mode switching of full bridge and half bridge can obtain a double gain range. However, it is difficult to switch smoothly between the two modes. Auxiliary switches or components are also commonly adopted to extend the voltage range with narrow switching frequency. Unfortunately, the complex of model and control are increased. Although the improvement of modulation or topology can increase the range of voltage regulation to a certain extent, the control and operation modes of the converter become more complex.To deal with this, the two-stage cascade topology consisting of a non-isolated DC/DC converter and an unregulated LLC resonant converter working as DC transformer(DCX) can be used. In this kind of topology, the voltage regulation is only realized by the traditional non-isolated DC/DC converter, and the voltage regulation abi

关 键 词：串联谐振变换器 耦合电感 软开关 自适应频率控制 

分 类 号：TM46[电气工程—电器]