Study On Contact Bounce Performance Of Contactor Based On Cu-W Alloy Skeleton Structure

For the switchgear with contacts,while ensuring good conductivity,it is necessary to take into account the service life of the switchgear,including electrical life and mechanical life.As the core component of contact switching apparatus,the bouncing performance of electrical contact can not be ignored,and the material and microstructure of electrical contact will greatly affect its service life.Nowadays,composite electrical contacts occupy a dominant position.The special bionic structure in nature shows an orderly arrangement of its internal organization.This kind of bionic structure has high-quality impact resistance.Based on the above composites and microstructure,the copper tungsten alloy skeleton structure is proposed and applied to the electrical contact of contactor to study its bouncing performance.Based on the yield principle of electrical contact materials,this paper simulates the first collision of dynamic and static contacts by using finite element software,studies the effects of commercial disordered skeleton electrical contacts and ordered skeleton electrical contacts on stress,strain and plastic dissipation work under the same load,and considers the influencing factors of isotropy and anisotropy of the material itself through the analysis of section diagrams with different height ratios.The disordered skeleton electrical contact includes block and particle skeleton structure,while the orderly skeleton electrical contact includes quadrilateral,hexagonal,rhombic dodecahedron skeleton structure.The results show that the strain of the ordered skeleton structure is much less than that of the disordered skeleton structure,and the disordered skeleton structure has an obvious large-area depression.The ordered skeleton structure is more suitable for contact electrical appliances;In the ordered skeleton structure,the quadrilateral skeleton structure can bear greater load before failure,the rhombic dodecahedral skeleton structure has better deformation performance,and the hexagonal skeleton structure presents the effect of neutral material.Based on the energy conservation equation in the process of electric contact collision,this paper uses multi-body dynamics software to simulate the bouncing process of contactor contact.Combined with the initial condition theory,the bounce speed of the contact after the first collision is deduced and calculated,and the bounce curves of three ordered skeleton structures are obtained combined with the energy recovery coefficient.The results show that the bounce amplitude of the electric contact of the diamond dodecahedral skeleton structure is small and the action time is short,followed by the hexagonal skeleton structure and the quadrilateral skeleton structure.In addition,the research on reducing the bounce of the electrical contact of the contactor is also a key link to judge its performance.This paper shows that the purpose of reducing contact bounce can be achieved by appropriately increasing the contact preload,increasing the over range spring stiffness coefficient and reducing the moving contact mass.Based on Mises yield principle,Cu-W composite contacts with different ordered skeleton structures were prepared by electron beam selective melting technology combined with infiltration technology,and their mechanical properties and bouncing properties were experimentally studied.The experimental results of mechanical properties show that the three-dimensional interpenetrating network structure of Cu and W is conducive to promote the stress conduction between the two phases in the composite electrical contact,and the cubic w skeleton structure has high strength but low absorption energy;The experimental results of bouncing performance show that the first and second bouncing amplitudes of electric contacts with ordered skeleton structure after collision are less than those with disordered skeleton structure,indicating that the bouncing performance of electric contacts with ordered skeleton structure is better.It provides a new idea to reduce the contact vibration and improve the service life of the contactor.