新型软开关切换反激式变换器的研究

Research of Soft-switching Flyback Converter

针对现有的软开关切换反激式变换器辅助开关无法达到软切换及轻载时不能实现软切换的问题,提出了一种新型软开关切换反激式变换器,借助所加入的软开关辅助电路,和辅助开关上串联二极管,不仅能使主开关工作在零电压状态下切换,其辅助开关亦能在零电流状态下切换,也能避免辅助变压器的饱和。此外,所加入之辅助开关并非浮接而是和主开关共地,所以辅助开关的控制信号无需隔离,因而降低了控制电路的复杂度。实验结果表明:提出电路的主、辅开关在满载和轻载时都工作在软性切换状态,提高了电路在整个负载范围内的工作效率。

For existing soft switch flyback converter, the auxiliary switch and the light load can not be achieved the soft switching, the paper presents a novel soft switching flyback converter. With the added soft-switching auxiliary circuit, and auxiliary switch in series with the diode, the converter can not only make the work of the main switch to switch at zero voltage state and so is the auxiliary switch, but also avoid the auxiliary transformer saturation. In addition, the accession is not a floating auxiliary switch and main switch instead of the ground, so no auxiliary switch control signal isolation, thus reducing the complexity of the control circuit. The results show that： the circuit of the main and auxiliary switches in the full load and light load switch are working in the soft state to improve the circuit in the entire load range of efficiency.