基于磁控制的双谐振腔LLC谐振变换器

Double Resonant Tanks LLC Resonant Converter Based on Magnetic Control

LLC谐振变换器可以实现原边开关管的零电压开通和副边整流管的零电流关断,变换效率较高,但传统的LLC谐振变换器具有输入电压范围不宽、且在宽输入电压范围下效率较低的缺点。针对这个缺点,本文在拓扑和控制方法上做出改进,提出了一种利用磁控制的可变电感来实现定频模式下输出电压控制与调节的全桥双谐振腔LLC变换器,在没有牺牲效率的前提下,拓宽了输入电压的范围。并且制作了一台输入为120 V~400 V,输出为48 V/5 A的实验样机,验证了理论分析的正确性。

LLC resonant converter can realize the zero voltage switching(ZVS)of primary switching transistor and the zero current switching(ZCS)of the secondary rectifier transistor with high conversion efficiency.However,the traditional LLC resonant converter has the disadvantages of narrow input voltage range and low efficiency in wide input voltage range.In view of this shortcoming,through the improvement of topology and control method,a full-bridge double resonant tanks LLC resonant converter is proposed,which uses variable inductance controlled by magnetism to realize output voltage control and regulation in constant frequency mode,and greatly broadens the input voltage without sacrificing efficiency.An experimental prototype with the input of 120 V-400 V and the output of 48 V/5 A is assembled,which verifies the rationality of the theoretical analysis.