Experimental Study On Arc Characteristics Of DC Contactor

With the rapid development of new energy technologies and electric locomotives,higher requirements are placed on the breaking performance of DC contactors.The arc generated in the process of breaking is the key to determine its reliability and service life.In order to study the influencing factors and regularity of dc breaking arc,a complete set of experimental platform is built,which can realize the periodic automatic breaking of contact,real-time collection,display and storage of the waveform of arc voltage and current.Symmetrical and asymmetric paired breaking arc experiments on AgNi?10?and AgSnO₂?10?material contacts were carried out using the experimental system.The results show that AgSnO₂/AgNi?moving contact/static contact?is more conducive to the circuit.Break.Symmetrical and asymmetrical pairing breaking arc experiments were carried out on the plane and convex surface with AgSnO₂ material contacts.The results show that the convex surface/plane?moving contact/static contact?is beneficial to lengthen the arc,which accelerates the arc heat dissipation and relatively reduces the arcing time short.The arcing experiment of AgSnO₂ material contacts under different electrical parameters shows that the arcing time increases with the increase of voltage when the current is constant.When the voltage is constant,the arcing time is not monotonous with the current.Lateral and longitudinal arcing experiments were carried out under different magnetic field strengths.The arcing time was shortened with the increase of the magnetic field strength.Under the action of the transverse magnetic field,the arc caused ablation due to the ablation of the contacts,but the arcing time was shorter.The arc energy is small,and the degree of ablation of the contact is light;under the same magnetic field strength,the transverse magnetic field is more conducive to the extinction of the arc.