Research Of Measurement Technology Of The Transient Temperature On High-speed Sliding Electrical Contact Surface

High speed sliding electrical contact as a kind of dynamic electric contact has a wide range of applications in the high speed electrified railway systems, aerospace and aviation industry and other fields. The problem of transient temperature field of high speed sliding electrical contact surface in large high current carrying environment belongs to current-carrying friction and wear problems under special working conditions. In the process of sliding electric contact, sliding contact area in the mutual coupling effect of mechanical friction system and electric contact system produces a variety of heat, resulting in the rapid increase of the surface temperature. This not only strongly affects the conductivity of contact elements, but also produces wear corrosion on the metal alloy contact surface, which can lead to a decrease of wear resistance performance on the metal alloy contact surface, even cause an accident when serious. In order to ensure the safe and reliabel operation of electrical equipment under dynamic conditons, more and more attention has been paid to the study of the influence of electric contact surface temperature.In this thesis, based on the measurement and analysis of the transient temperature field of high speed sliding electrical contact surface in large high current carrying environment, thermal analysis on transient temperature field of contact surface is carried out in combination with the heat transfer theory and finite element analysis to set up the calculation model of transient temperature field of high-speed sliding electrical contact experiment machine. Then, the simulation of the temperature field distribution of the slider contact surface in the process of high speed sliding is made to study the respective influence of the three kinds of heat sources the mechanical friction, thermal contact resistance and heat resistance on contact surface, followed by a systematic analysis of the temperature field distribution and the maximum temperature changes in the established model under the conditions of different current carryings and different speeds. Next, the transient temperature field of high speed sliding electrical contact surface under large high current carrying is measured by means of non-contact radiation measurement using the high speed sliding electric contact testing machine. In combintion with actual measurement data and the finite element simulation, the correctness of the simulation model is verified by the data comparison and the further analysis of results shows that the speed and the changes of electric current carrying load have impact on the temperature field of the contact surface in the process of large high current carrying. Meanwhile, once the sliding electrical contact is completed, the images of the contact rail surface are acquired to make an analysis of the surface morphology, the mass loss and the ablation depth, and a further research is done on the impact of the transient temperature field of the contact surface on the surface of the contact material under large high current carrying.According to the research results of the transient temperature of high speed sliding electrical contact surface under high current carrying, this thesis is expected to provide technique basis for how to reduce the contact surface temperature, select the appropriate material as contact surface and decrease the material wear and tear.