临界导电模式下BOOST变换器功率因数校正电路设计

针对临界导电模式下功率因数校正的问题,以BOOST电路为研究对象,推导了临界导电模式下功率因数校正电路的输入电流表达式,并详细分析了临界导电模式功率因数校正BOOST开关变换器的稳态特性.给出了开关频率与输入电压及功率的关系.提出了采用专用PFC控制芯片来调整开关管的开通时间,改善其关断条件,提高整个电路的工作效率,以...

Design on PFC circuit of BOOST convertor under critical conduction mode

Aiming at the problem of power factor correction（PFC） in critical conduction mode, taking the BOOST electric circuit as object of study, the input current formula of PFC circuit in the critical conduction mode was deduced, a detailed analysis of steady characteristics of BOOST switch convertor was made for power factor correction in the critical conduction mode, the relation of switching frequency with input voltage and power was concluded. It was proposed that special IC simplifies PFC control chip was used to adjust the opening time of switch tube, its shutoff conditions were improved and the working efficiency of the whole circuit was enhanced, and the purpose of improving power factor was achieved. The study results indicate that the constant switch conduction time in the half work cycle of input power can realize the converter unity power factor work, which provides a theoretical basis for the convertor design.