CLLLC谐振变换器变频移相混合控制方法

针对CLLLC谐振变换器存在脉冲频率调制的电压增益范围不足、相移调制的效率较低的问题,提出了一种可同时调节开关管占空比与开关频率的变频移相混合控制方法.该方法可以根据输入电压范围与负载功率变化范围自由切换混合控制模态以实现宽范围软开关与高运行效率,具有极高的调节自由度,且通过移相控制降低了启动时的冲击电流从而实现了软启...

PFM+PSM hybrid control of CLLLC resonant converter

Aiming at the problem of CLLLC resonant converter, such as insufficient voltage gain range with pulse-frequency modulation and low efficiency with phase-shift modulation, a PFM+PSM(Pulse-Frequency Modulation and Phase-Shift Modulation) hybrid control method is proposed, which can adjust the duty ratio of switch tube and the switching frequency at the same time. This method can freely switch the hybrid control mode according to the input voltage range and load power variation range to achieve wide-range soft switching and high operating efficiency, with very high freedom degree of regulation. The soft start is achieved by reducing the impulse current during start-up stage with phase-shift control. Finally, the model of CLLLC resonant converter is established based on time-domain analysis, and the experimental platform of 1 kW CLLLC resonant converter based on SiC(Silicon Carbide) is built. Experimental results verify the feasibility and superiority of the proposed hybrid control method, and the efficiency of the whole machine can reach 96 % in a wide range.