基于ML4841的具有APFC功能的AC/DC变换器设计

The Design of AC/DC Converter Based on ML4841 with the APFC Function

AC/DC变换器具有体积小、重量轻、变换效率高等优点 ,而被广泛地应用到从工业到民用的各个领域。但随之而来的对供电系统的污染的缺点也越来越引起人们的广泛关注 ,最主要的是由于谐波电流的增加从而使电网的功率因数降低 ,无功功率增加。本文简要分析了造成这种问题的原因及解决方法 ,以及采用ML4841构成具有有源功率因数校正功能的AC/DC变换器的设计方法 ,并给出了典型电路。采用这种电路可使功率因数提高到接近于

AC/DC converter is widely used in both areas of industry and civil because of its small size,light weight and high efficiency.But the shortcoming of the polluting to the electricity supply system is more and more concerned also.The worse thing is that the decrease of power factor by the increase of harmonic current.In this article we briefly analyse the reason of causing this problem and the method to solve it,and the method of designing a AC/DC converter based on ML4841 with the function of active power factor controller,a typical circuit is given.By using of this circuit,the power factor can reach to 1 approximately.