Study on current-carrying tribological characteristics of C-Cu sliding electric contacts under water accumulation from rainfall condition

Abstract

Pantograph-OCS system sliding electrical contact is the only way for train energy transmission, which determines the safety and stability of energy transfer. And the current-carrying wear is the core factor that affecting the service performance of C-Cu contact pairs. It is shown that the carbon contact strip of the pantograph exhibits abnormal wear in rainfall conditions, resulting in a significant decrease in service performance and lifespan. This article uses the spray method to simulate rainfall conditions and studies the mechanism of the influence of different currents and rainfall levels on the current-carrying tribological characteristics of C-Cu contact pairs. The results show that under low rainfall levels, the lubrication and cooling effects of water film help C-Cu contact pairs achieve lower friction coefficient and contact resistance; but when the rainfall level exceeds a certain range, the thick water film at the C-Cu contact interface seriously hinders current transmission, increasing discharge erosion, deteriorates the performance of the carbon sliding plate, and causes abnormal wear of the sliding plate. By the simulation experiment of the entire process of rainfall, it was found that the tribological performance and electrical contact performance of carbon skateboards are positively correlated with rainfall levels, proving that the lubrication effect of water film can be restored during the process of rainfall from much to little. The research can help to provide a suitable maintenance policyfor pantograph and catenary system during the rainy season.