一种高功率因数交流LED驱动电路的设计

Design of AC LED Driver Circuit with High Power Factor

传统的LED驱动电路由于采用AC-DC变换器,需要大的电感和电解电容,导致LED驱动电路存在体积大、成本高、寿命短等问题,提出一种新型交流电压直接驱动的LED驱动电路。该驱动电路仅需要MOSFETs和运放等有源器件,输入电流能跟随输入电压呈正弦波形变换,以获得高功率因数和低THD。仿真和实验验证该驱动电路的电气特性。

Conventional LED drivers consist of AC- DC converters which require passive components such as high value inductors and electrolytic capacitors for their operation,the use of such components increases the size and cost of the LED system while decreasing the overall life time,a novel driver circuit that can directly run from AC voltage is presented. The proposed driver circuit only needs active devices like MOSFETs and op- amps for power processing,the input current is selectively controlled to follow a sinusoidal waveform to achieve low harmonic distortion and high power factor. The efficiency of the proposed system is around80% for a 1. 5W converter with 8% total harmonic distortion and 0. 97 power factor,both simulation and experimental results have been presented to verify the operation of the proposed circuit.