针对一般照明LED驱动电源中输出滤波电解电容的寿命与LED的长寿命极不匹配的问题.提出了一种有源纹波补偿的Buck型LED驱动电路.电路中用有源纹波补偿支路替代输出滤波电解电容,抵消电感纹波电流,使LED灯组获得恒定直流,达到LED的理想驱动状态.为了减小纹波补偿支路的损耗,必须控制电感电流的峰值和谷值,滞环电流控制可有效地满足这个要求.设计和制作了输出功率为30W的滞环电流控制、有源纹波补偿BUCK型LED驱动电源.仿真和实验验证了上述新型电源的可行性.
The lifespan of the output filter electrolytic capacitor in general lighting LED power supply doesn't match LED's long lifespan.In this regard,this paper proposed the LED driver circuit based on Buck with active ripple compensation.In the circuit,the active ripple compensation branch was used to replace the output filter electrolytic capacitor to offset the inductor ripple current,so that the LED array can obtain a constant DC and achieve the ideal drive state of the LED.In order to reduce the losses of the ripple compensation branch,the peaks and valleys of the inductor current must be controlled and the hysteresis current control can effectively meet that requirement.The LED power supply based on Buck with active ripple compensation and hysteresis current control was designed and made which output power was 30 W.According to the simulation and experiment results,the proposed new power supply is feasible.