基于临界导电模式的BOOST PFC电路开关特性分析与研究

Analysis and research of switching-condition in Boost PFC circuit based on boundary conduction mode

该文基于对临界导电模式BOOST-PFC电路开关管开关特性的分析,提出了一种解决开关管容性开通损耗的新型方案。利用PFC控制芯片的固有输出延迟时间和合理选择谐振参数,使开关管获得零电压或最低电压的开通条件,减少了开关管开通损耗,同时由于外接谐振电容,进一步改善了开关管的关断条件,提高了电路的工作效率。分析了BCM-BOOST-PFC电路的开关损耗以及在不同输入电压情况下开关管获得零电压或最低电压的开通条件,给出了电路参数的设计方法。实验结果验证了所提出的方案是可行的。

Based on the analysis of switching characteristic in BCM-BOOST-PFC circuit, a novel method to solve the capacitive turn-on loss of the switch is proposed in the paper. By using the inherent delay time of universal PFC integrated control circuit and rightly selecting the resonant capacitor, the turn-on condition of zero-voltage or the lowest drain-source voltage for the main switch is obtained , which reduces the turn-on and turn-off loss and increases the circuit efficiency. The switching loss in BCM-BOOST-PFC circuit and the turn-on condition of zero-voltage or the lowest voltage under different input voltages are analyzed measurements are used to verify the theoretical and the design considerations are given in details. The experiment prediction and analytical discussion.