脉冲序列调制-脉冲跳周期调制Buck变换器研究

Study of Pulse Train Modulation Pulse Skipping Modulation Buck Converter

脉冲序列调制(Pulse Train Modulation,简称PTM)采用高、低能量脉冲对开关变换器的输出电压进行调整,其动态响应速度快,控制器设计简单,但同时开关变换器轻载效率低,输出电压纹波大。脉冲跳周期调制(Pulse Skipping Modulation,简称PSM)采用ON/OFF控制对输出电压进行调整,虽然提高了开关变换器的轻载效率,但也存在输出电压纹波大的缺点。结合PTM与PSM调制技术,提出了开关变换器的PTM-PSM调制技术,在保留PSM调制轻载效率高的同时,降低了输出电压的纹波。最后设计了基于PTM-PSM调制的Buck变换器,通过实验验证了分析结果。

Pulse train modulation（PTM）control technique uses two preset control pulses with different duty ratio to realize the regulation of the output voltage of switching DC/DC converter.PTM controller is easy to realize,with no compensation network.However,at light load,its efficiency is low and output voltage ripple is large.Pulse skipping modulation（PSM）realize the output voltage regulation of switching dc/dc converter by the ON/OFF control of power switch,at light load,its efficiency is high,but still suffers large output voltage ripple.The PTM-PSM control technique is thus proposed to utilize the advantage of PTM control and PSM control to reduce output voltage ripple and to im-prove light load efficiency.The PTM-PSM controller is designed and experimental results are presented to verify the analysis results.