Research On Fuse Link Material Based On Ampere-second Characteristics Of Fuse Link Of High Voltage Transmission And Transformation Equipment

As a common power equipment,fuse undertakes the responsibility of cutting off the circuit and ensuring the safety of electrical components and equipment when the circuit and power grid system fail,and ensures the personal safety of users.It is widely used all over the world.In order to further improve the reliability of fuse protection,fuse links of different materials can be used to replace the existing fuse links for disconnection.At present,the K-type fuse used in high-voltage drop fuse has some problems,such as large fluctuation of ampere second characteristic curve and unstable fusing time.It is necessary to develop a new type of fuse.In order to improve the fusing performance of high-voltage fuse,based on Sn based alloy,this subject has done a series of related research on fuse material,process and performance.The tin based alloy bar ingots with three components of Sn-Cu,Sn-Ag and Sn-Ag-Cu were prepared by using the silicon carbide rod heating furnace controlled by the self-built control cabinet,and then extruded and drawn to prepare the fuse.Through the research,optimization and improvement of three processes of ingot casting,extrusion and wire drawing,the required fuse wires with different diameters are obtained.The physical properties such as conductivity and DTA curve of the fuse are tested.The analysis results show that the melting range of the fuse is220-240 ℃,which is consistent with the service temperature of the fuse,and the conductivity is slightly improved compared with the original fuse.Through the breaking test of three kinds of fuse wires,the results show that the breaking ability of Sn Ag Cu fuse wire is good,and the other two materials are weak.The pre arc ampere second characteristic curve test in the built test circuit shows that among the three kinds of fuse links,the ampere second curve of Sn-Ag-Cu material has small fluctuation and the fusing curve is stable.With the addition and interaction of Ag and Cu elements,the conductivity and thermal conductivity of the fuse link increase,which can improve the fusing ability of the fuse link.For the ampere second curves of Sn Cu and Sn Ag materials,some curves exceed the limited area,so follow-up improvement research is needed.