MOSFET反向恢复特性对临界导通模式图腾柱Boost PFC的影响

Influence of MOSFET reverse recovery on boundary conduction mode totem pole Boost PFC

针对传统的临界导通模式计算方法没有考虑反向恢复,导致图腾柱Boost PFC实验结果与计算不符的问题,将线性拟合的方法应用到反向恢复的预测中。开展了考虑反向恢复的临界导通模式图腾柱Boost PFC的模态分析,建立了电感电流正向峰值和负向电荷之间的关系,提出了线性拟合实验测量结果从而预测反向恢复的方法;在600 W临界导通模式图腾柱Boost PFC上,对预测反向恢复的方法进行了评价,进行了反向恢复对PFC影响的试验。研究结果表明:该方法能精确计算临界导通模式图腾柱Boost PFC的反向恢复,验证了反向恢复会显著增加电感电流,减小开关频率,并有助于拓展零电压开通范围。

Aiming at the problem that traditional boundary conduction mode（ BCM） design methodology does not consider the effect of reverse recovery causing the error between calculation and experimental result of totem pole boost PFC,the linear fit method was investigated.After the mode analysis of BCM totem pole Boost PFC with reverse recovery,the relationship between inductor current positive peak value and negative charge was established. A method was presented to predict negative charge. The influence of reverse recovery was evaluated on the600 W totem pole Boost PFC with two different MOSFETs. The experimental results indicate that the proposed design methodology is more accurate,and the reverse recovery increases the inductor current,decreases switching frequency and expands ZVS-ON zone.