基于初级控制的高功率因数CRM反激LED驱动器

Flyback LED Driver With High Power Factor Based on Primary Side Regulation

基于临界连续导电模式(CRM)反激功率因数校正(PFC)变换器,分析其通过无需光耦的初级控制(PSR)作为发光二极管(LED)驱动电源的工作原理。针对传统CRM反激PFC变换器输入电压升高或者LED负载电压降低会降低功率因数和增大输入电流谐波,提出了一种新型高功率因数初级控制CRM反激变换器LED驱动电源,通过引入变导通时间(VOT)控制,消除了输入电压和LED负载电压变化对变换器功率因数和输入电流谐波的影响。最后通过实验验证了理论推导的正确性。

A LED driver is analysed which is based on CRM flyback PFC converter without optocoupler through PSR control method.With the increase of input voltage or reduction of LED load voltage of the traditional PSR CRM Flyback LED driver with high PF,the power factor will be reduced and harmonic of input current will be increased.By introducing the variable on time VOT control,a new PSR CRM Flyback LED driver with high PF is proposed,it can realize higher PF and lower input current harmonic.Experimental results verify the correctness of theoretical derivation.