Identification of short-wavelength contact wire irregularities in electrified railway pantograph-catenary system

The effect of two common types of short-wavelength irregularities (local imperfections and periodic short-wavelength irregularities) of the railway catenary on the pantograph- catenary interaction performance are studied and their potential identification approaches are explored in this paper. The analysis of the intrinsic mode functions of panhead acceleration indicates that the effect of local imperfection can be reflected in the high-order deformation mode of the contact wire. The cut-off frequency is suggested to cover the wavelength smaller than 1/8 of the dropper to dropper distance, which can be used to identify the local imperfection. The instantaneous energy obtained by the Hilbert transform is used to localise the local imperfection. The effect of periodic short-wavelength irregularities can be recognised as the introduction of non-Gaussian behaviour in the contact force at specific wavelengths. Thus, spectral kurtosis is utilised to identify the deviating wavelength. The short-wavelength irregularity can be localised by the time-frequency analysis of the intrinsic mode function containing the identified deviating wavelength. The examples with measurement data indicate the validation of the present methods with some improvements to the current equipment. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Automated summary

This paper studies the effect of short-wavelength irregularities of the railway catenary on the pantograph-catenary interaction performance, exploring potential identification approaches. The analysis suggests using intrinsic mode functions and the Hilbert transform to identify local imperfections, and utilizing spectral kurtosis to identify deviating wavelengths caused by periodic short-wavelength irregularities. The study validates the methods with some improvements to current equipment.