电流临界连续时PFC电路分析

ANALYSIS OF PFC CIRCUITS FOR CRITICAL CONTINUOUS CURRENT MODE

本文讨论了峰值电流型功率因数校正电路、电路中电感临界连续时频率变化的规律，分别推导了Ｂｏｏｓｔ、Ｂｏｏｓｔ／Ｂｕｃｋ和反激变换器的导通时间、截止时间与输入电压、输出电压、变换器中电感等参数的关系，指出了电路实用范围，给出了最大和最小开关周期。利用这些关系，就可以进行电路设计。

This paper analyses the input current wave forms and the imput power fac- tor, examines the relations of the frequency range, turn-on time, turu-off time to the out- put voltage, input voltage and inductance in the active PFC circuits with Boost, Boost/Buck and flyback converter, and points out the application range of the active PFC with these power circuits for critical continuous mode.