Wear Modes of Contact Wire and Contact Strip under Electric Current Condition

Abstract

To suggest measures for reducing wear of current collecting materials such as contact wires and contact strips, it is necessary to understand actual phenomena generated at the point of electric contact. For this study on classification of wear modes and transition conditions between hard drawn copper contact wire and iron-based sintered alloy contact strips, a linear wear testing method was newly introduced. As a result, it was found that the contact temperature which was estimated from the contact voltage depended on electric current and contact load. Consequently it was possible to classify wear modes of the current collecting materials under electric current conditions into three types depending on the maximum contact temperature.

<b>Wear Mechanism of Current Collecting Materials under the Effect of Flowing Electric Current</b>

“…In this chapter, the wear phenomena which could not be clarified in the previous report [1] is explained using the wear mode map, and the wear mechanism of the current collecting materials is discussed. Figure 11 shows the plots of the wear mode and the contour of the contact voltage obtained in wear tests [1].…”

“…Figure 11 shows the plots of the wear mode and the contour of the contact voltage obtained in wear tests [1].…”

“…Then if α falls below 0.8, the contact wire melts and the wear mode must be the contact wire melting wear mode. Since the wear tests were carried out in the open air [1], an oxide film and wear particles on the contact surface could not be ignored. Therefore, in Fig.…”

“…The results were reported in a paper [1] and demonstrated that there were multiple wear modes under the effect of flowing current which govern the wear of the current collecting materials. In the same paper, the author calculated the maximum temperature for the contact spot, based on the contact voltage measured during the wear tests, and found that the transition phenomena between wear modes were caused by the melting of contact members by Joule heating.…”

Analysis of the evolvement of contact wire wear irregularity in railway catenary based on historical data

“…Accordingly, some methodologies and experiments are carried out to predict the contact wire wear [10,11], which can provide general predictions of contact wire wear rate under the influence of pantograph passages. To understand how the contact wire wear are formed under electric current, the wear mechanism between contact strip and contact wire are experimentally analysed in [12][13][14][15]. It is believed that the contact temperature induced by sliding friction and arcing determines the wear modes between contact strip and contact wire.…”