ZCS-QRC同步Buck变换器的特性与效率

分析了ZCS-QRC同步Buck变换器的基本特性,对开关管的导通时间、断开时间和延时进行了计算,提出了变换器的周期平均模型。仿真和实验电路测试结果表明,在负载电流全程变化时,变换器开关频率基本保持不变(变化约1%),占空比的变化也很小(约8%)。变换器有较低的电磁辐射干扰和很好的模型精度,在输出电流不是很小时有很高的转换效率。变换器高精度的对象模型,有利于数字控制方案的设计与实现。

Characteristics and Efficiency of ZCS-QRC Synchronous Buck Converter

We analyse the basic characteristics of ZCS-QRC synchronous buck converter,calculates the accurate value of on time,off time and delay time of switching MOSFETs,and puts forward an period averaging model of the converter.Simulations and experiments show that,when load current changes from zero to maximum,the switching frequency of the converter changes slightly(about 1%) and the duty cycle of the switching power only changes about 8%.The converter has a lower EMI and higher precision of period averaging model,and has a very good transform efficiency when the condition of the load current is not very low.It will be helpful for the design and implementation of the digital control system with the precise period averaging model.