一种开关电源高次谐波的消除方法

A Method for Eliminating High-Order Harmonic of Switching Mode Power Supply

开关电源广泛地应用在各类电子产品上。但很多开关电源的开关管处于硬开关状态。开关管在储能元件开关变压器电感电流不等于零的情况下突然关断,分布电容与变压器的漏感会产生振玲现象或其他高次谐波的干扰,这种高次谐波的频率非常高,一般在几百kHz到几MHz之间,而且通过常规的增加后级滤波电容容量的方法来滤除这种高频干扰的效果不明显,将会严重影响对电源谐波要求比较高的单片机的正常工作。文章在几种抗高频谐波干扰的实验基础上,发现对开关管进行阻容能量的吸收和在有源整流管引脚上串入磁珠的方法能比较有效地抑制开关电源的高次谐波干扰。

Switching mode power supply is widely used in various types of electronic products. But many switching mode power supply switches are in hard switching state. Switch in the energy storage element switching transformer inductor current was not equal to zero in the case of sudden turn off and distributed capacitance and transformer leakage will produce vibration phenomenon or other high-order harmonic interference. The frequency of this high harmonics is very high. It is generally between several hundred k Hz to several MHz,and through the conventional increase in the post-filter capacitor capacity method to filter out the effect of high-frequency interference is not obvious,which will seriously affect the power supply harmonic requirements of relatively high single-chip normal work. In this paper,based on the experiment of several anti-high-frequency harmonic disturbances,it was found that the method of absorbing the energy of the switch and the method of concatenating the beads on the active rectifier pin can effectively suppress switching mode power supply harmonic interference.