526 / 2017-05-11 17:03:03

Quantitatively Determination of M-effect Influence on Overload Current of DC Current Limit Fuse

DC current limit fuse,M-effect,prearc time,diffusion rate

DC current limit fuse is more and more widely used in the field of electric vehicles,urban railway transportation,semiconductor and other emerging technology field.The capacity of short circuit interruption of DC current limit fuse is very strong.However,the capacity of overload current interruption of DC current limit fuse is comparably week.This is very outstanding compared with the overload current interruption of AC current limit fuse.One mainly reason is that the pre-arc time is too long.M-effect is a very efficient method to shorten the pre-arc time.M-effect means soldering a small piece of mental which melting point is lower than fuse element on the fuse element.Though this method is widely used in electric fuse,the quantitively influence range of M-effect is not clear yet.The objective of this paper is to quantitatively determine how M-effect influence the overload current rate of DC current limit fuse.First,using a DC test circuit to acquire the pre-arc time with and without M-effect.In this way, the influence range of M-effect can be determained.Second,using a micro scanner to acquire the shape and diffusion condition of M-effect metal after interruption,through the image,the melting condition and diffusion rate can be acquired.The research can help develop the low overload interruption capacity of DC current limit fuse.