电力电子装置滤波电容容量的设计方法

由于工作在高频电力电子装置中的滤波电容等效容量会随着工作频率的增加而减小,而由滤波电容的等效电阻和纹波电流产生的发热量会随之增加。因此,合理选择高频电力电子装置的滤波电容容量是电力电子装置设计的一个必要环节。提出了根据纹波电流大小设计电力电子装置的滤波电容容量的一般方法,针对滤波电容中纹波电流与开关频率的关系,纹波电流与电容发热量的关系以及纹波电流对电容器寿命的影响,给出了详细的计算公式。这种滤波电容容量的选择方法对于通用变频器、大功率开关电源等应用场合具有一定的实用参考价值。

Design of Filter Capacitance used in Power Electronic System

The filter capacitors placed in power electronic arrangement need working at high frequency.Due to working at hign frequency,the equivalent capacity of the filter capacitors reduces as the switching frequency increasing, meanwhile the heat radiation caused by the equality resistance and the ripple current increases.Thus,how to select the capacity of the filter capacitors is one of the necessary process for designing power and electric device. This paper presents a usual design method of filter capacitors according to the ripple current, and gives special calculating formulas in view of the influences of ripple current on switching frequence, heat radiation and life-span of filter capacitors.The design method of filter capacitors is referential to the same thing in the universal inverter and high power switch power supply.