Processing of collector acceleration data for condition-based monitoring of overhead lines

Abstract

This paper describes a diagnostic system for overhead line monitoring; it is based on the measurement of collector accelerations, and aimed at improving current scheduled methods for catenary and pantograph maintenance, making condition-based maintenance possible. The proposed setup is inexpensive and easy to install on in-service commercial trains. Meaningful indicators of pantograph/catenary interactions are obtained by the processing and analysis of data on collector accelerations; summarized values are computed in real-time during the train run and compared with alarm limits

Identification of the catenary structure wavelength using pantograph head acceleration measurements

“…According to the specification in EN 50317 [3] and the majority of previous studies [9][10][11], a low-pass filter with 20Hz cut-off frequency is prescribed to process the pantograph-catenary contact force data. However, some recent studies noticed that the cut-off frequency is sometimes too low for the purpose of defect detection [4,12,13]. Catenary defects such as contact wire irregularity that can excite high frequency response of pantograph can be overlooked by the conventional treatment.…”

“…In particular, the deformable modes of the collector normally occupy a considerable portion of energy in pantograph vibrations [13]. In some cases, they are observed as the dominant frequencies in pan-head acceleration instead of the CSWs [4]. This brings up a major challenge for the identification of CSWs that is avoiding the submergence and contamination of other frequencies.…”

“…Addressing this cost issue, the pantograph head (pan-head) vertical acceleration has been pointed out to be feasible for catenary condition monitoring as a substitution to the contact force measurement [4]. The pan-head vertical acceleration can reflect the catenary condition for the following two reasons:…”

“…2) It is theoretically proven that the pan-head vertical acceleration can reflect the span-passing and dropper-passing frequencies [4], namely the concept of catenary structure wavelengths (CSWs) proposed in [6] that are the dominant and concerned frequencies in the contact force. Hence, the pan-head vertical acceleration can substitute the contact force in similar methodologies for condition monitoring, in which the frequency components are frequently adopted as the indicator of anomalies.…”

Advances of research on high-speed railway catenary

“…Thus, related measurement and evaluation techniques have been developed in recent years to meet the emerging needs, making the dynamic state evaluation promising and popular for high-speed railway lines. Meanwhile, to improve the effect and reduce the cost of dynamic state evaluation, a shorter inspection interval [122] and a higher sampling frequency [123] than that in current practice are necessary and helpful.…”