一种BCM Boost PFC电路的VCFF控制策略  

A VCFF Control Strategy of BCM Boost PFC Circuit

作　　者：刘光清 林维明[1] LIU Guangqing;LIN Weiming(College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学电气工程与自动化学院,福建福州350108

出　　处：《电器与能效管理技术》2024年第3期7-14,29,共9页Electrical & Energy Management Technology

摘　　要：临界导通模式Boost功率因素校正(PFC)电路通常采用恒定导通时间(COT)控制策略,导致开关频率的变化与输入电压、输出功率以及电感有关,轻载下过高的开关频率将影响电路的转换效率,故提出一种谷底计数频率反走(VCFF)控制策略。通过检测MOS管两端电压谷底计数,使电路轻载时工作在断续模式,从而降低开关频率以提升轻载效率。实验结果表明,相比于COT控制策略,所提控制策略能够有效提高轻载效率。输入电压为220 Vrms下,10%~50%负载时效率在0.96以上。The control strategy of constant on time(COT)is usually used in Boost power factor correction(PFC)circuits working in boundary conduction mode.The change of switching frequency in this control strategy is related to the input voltage,output power and the inductor.The conversion efficiency of the circuit will be affected by too high switching frequency under light load.Aiming at the above problems,a control strategy of valley count frequency flyback(VCFF)is proposed.By detecting the valley count of the MOS transistor voltage,the circuit works in discontinuous conduction mode during light load to reduce the switching frequency and improve light load efficiency.A prototype experiment is made.The experimental results show that compared with the COT control strategy,the proposed control strategy can effectively improve the light load efficiency.Under the input voltage of 220 Vrms,the 10%~50%load efficiency can be reached up to above 0.96.

关 键 词：LED驱动电源 Boost功率因素校正电路 临界导通模式 轻载效率 

分 类 号：TM46[电气工程—电器]