全输入电压范围高功率因数脉冲序列控制DCM Boost PFC变换器

Pulse Train Controlled DCM Boost PFC Converter With High Power Factor for Universal Input-voltage-range Applications

定占空比控制DCM Boost PFC变换器的开关管导通占空比固定,存在输入电流畸变,导致输入功率因数较低。为实现DCM Boost PFC变换器的单位功率因数,需要根据输入电压与输出电压调整占空比,由于运算复杂,低成本的数字控制难以实现。提出了一种DCM Boost PFC变换器的脉冲序列(pulse train,PT)控制方法,以离散化的方式拟合变占空比函数,运算量小,适用于采用低成本的数字控制芯片。实验结果表明,PT控制DCM Boost PFC变换器具有比定占空比控制DCM Boost PFC变换器更高的PF和更低的输出电压纹波。

Constant duty cycle controlled discontinuous conduction mode(DCM)Boost power factor correction(PFC)converter suffers from low power factor over wide input voltage range,especially when input voltage is high,power factor will decrease.In order to achieve unit power factor(PF),the duty cycle should be varied according to input voltage and output voltage,which is difficult for low cost digital controller because of complex operation.A digital pulse train(PT)control technique for power factor correction was proposed,PF close to 1 can be achieved over whole input voltage range.The operation principle of PT controlled DCM Boost PFC converter was analyzed.The experiments results show that the PF and output voltage ripple of PT controlled DCM Boost PFC converter are better than these of constant duty cycle controlled DCM Boost PFC converter.