電氣化鐵道技術(shù)接觸網(wǎng)畢業(yè)論文中英文資料外文翻譯文獻(xiàn)-展示頁
2025-01-26 01:53本頁面
【正文】 pe of materials at contact, operating conditions (sliding speed, contact force and electrical current intensity) and level of sparking and/or arching.The previously mentioned factors mutually interact in determining the level of wear, as shown in Klapas et al. and Becker et al., so that multidimensional maps can be de?ned. For the sake of convenience, wear at the collector–contact wire interface could be divided into mechanically and electrically caused contributions, even though it is clear that they are strongly correlated and mutually in?uencing. In particular, the increasing wear due to current intensity depends also on the level of contact force, since the sparking intensity at the contact, and the related wear, increases as contact force decreases. Moreover, high currents can, in some cases, decrease the overall wear through the so called ‘current lubrication’ effect. Furthermore, increasing the speed will not always result in increasing wear, and the changes in thermal conditions caused by the increased friction power will, under some circumstances, even reduce the wear. A brief summary concerning these topic has been already reported by Diana and colleagues.This paper presents the results of an investigation carried out by means of a test rig on some of the previously mentioned aspects. Several kinds of collector strips have been considered: all copper, metallised carbon with an external envelope of copper (Kasperowski type) and metallised carbon. All the strips are designed for 3 kV . lines. It is worth mentioning that the sliding speeds are quite high (up to 200 km/h), and the currents are higher than in other published research, being up to 1000A .Following a description of the test rig, the main experimental results are presented. A correlation between the wear of collector strips and contact wire with the operating conditions is reported. A correlation between wear rates and indexes of the test severity is also proposed. The relationship is based on the assumption of dependence from the dissipated power, and on the wear of both mechanical and electrical nature.TEST RIG OVERVIEWThe main features of the test rig, are herein recalled. The equipment enables testing of a collector to be performed at speeds up to 220 km/h under the passage of electrical current up to
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