Research And Performance Analysis Of Power Electrical Connection Technology Based On Low Melting Point Alloy

The abnormal connection of the electrical connection of the transmission and distribution line is a common problem.This kind of defect involves all aspects of power transmission,from small distribution equipment to hair heat,to ultra-high voltage transmission and transformation equipment and line joint overheating failure.Abnormal heating of the electrical connector not only increases the line loss,but also causes a power supply accident,causing major economic losses and casualties.According to the wettability,electrical properties,mechanical properties,electrochemical properties and thermal properties required for the cable joint materials of transmission and distribution equipment,this paper proposes a low melting point alloy as the electrical connection material,which utilizes its high electrical conductivity and high thermal conductivity.The rate and nano-scale pore filling characteristics are attempted to solve the problem of overheating and deterioration of the original electrical joint.Firstly,the interface wettability is the main evaluation index of electrical connection interface materials.The low melting point alloys of different alloy systems are studied,and four low melting point alloy materials Sn-3.5Ag,Sn-1.6Cu,Sn-with excellent comprehensive performance are selected.Zn-0.7Cu,Sn-8Zn-3Bi,and analysis of the properties of the substrate(melting point,conductive heat conduction,potential).Secondly,the T2 copper specified in the electrical connection standard was used as the research substrate to study the wettability of the alloy in the copper cable joint.The spreadability of the alloy at the copper interface,the optimum spreading temperature and the micro-morphology and micro-region of the joint interface were analyzed.ingredient.The results show that the interface between the alloy Sn-3.5Ag,Sn-1.6Cu,Sn-Zn-0.7Cu and the copper substrate is reliably connected,and there are no interfacial connection defects such as porosity,slag inclusion and crack.The spreadability of Sn-8Zn-3Bi at the copper interface is poor,and there are obvious pores at the interface,and the wettability is poor.Finally,the low melting point alloy is applied to the electrical connection interface,the connection process of the alloy in theelectrical connection is designed,and the reliability analysis of the interface after the connection is combined with the ERESCO MF4 portable X-ray machine.The performance of the sample in the electrical connection was studied under the premise of ensuring the reliability of the connection sample.In the performance study applied in electrical connection,the mechanical properties analysis and simulation of the electrical connection specimens are first carried out to determine the shear strength and tensile strength of the interface between the low melting point alloy and the copper.Combined with COMSOL solid-flow coupling simulation analysis,the filling is low.The tension of the splice metal after the melting point alloy is verified,and the feasibility of applying the low melting point alloy to the electric power fitting is verified.Secondly,the SLQ-2000 A upflow experimental platform was built,and the thermal stability analysis method of the actual working condition was used to study the temperature rise of the sample under different load conditions and rated load conditions.The results show that after the low melting point alloy is used as the electrical connection interface material,the calorific value of the test piece is lower than the electric composite grease electrical connection sample and the copper busbar direct connection sample commonly used in the electric power industry,and the low melting point alloy Sn-1.6Cu has the lowest calorific value.It can effectively alleviate the problem of electrical connection hair heat and has the advantage of solving the problem of abnormal heating of electrical connectors.Finally,the research work of this thesis is the basic research of the first application of low melting point alloys in electrical connection.It can provide theoretical basis for the development,modification research and connection process design of alloy materials with excellent high-voltage electrical connection interface performance.Experimental guidance.