Method for Detecting Step-shaped Wear on Contact Strips by Measuring Catenary Vibration

Abstract

The contact strip of a pantograph slides directly against the contact wire to collect current. The arcing between the contact wire and contact strip causes wear on the contact strip, leading to the development of step-shaped wear patterns. A contact strip with this step-shaped wear can catch and pull the contact wire, causing breakage. In this paper, a method is developed for detecting step-shaped wear on contact strips by using sensors arrayed on the wire to measure the vibration of the contact wire. Step-shaped wear produces characteristic vertical and lateral vibrations in the contact wire. An experimental test was used to evaluate the proposed method. Results showed that the contact wire moving from the top to the bottom of the step-shaped wear can be detected by using the kurtosis of acceleration, although this method occasionally misses wear for the pantograph passing at high speed. Using standard deviation of filtered lateral acceleration or the standard deviation of the lateral displacement of the hanger allows for the detection of the contact wire moving from the bottom to the top of step-shaped wear. No method produced false detection of step-shaped wear.