The Wavelet Based Detecting of the Signalling Relay Armature Defects
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Date
2019
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Institute of Electrical and Electronics Engineers, IEEE
Abstract
EN: Abstract— The paper discusses the problem of prompt detecting of the armature and contact springs
defects in
railway signalling relays. These relays used for safety-related applications in railway signalling
systems should be properly maintained and monitored to ensure reliable and safely operation
throughout their life. Most of the tests for signalling relays are performed manually, which is
time consuming and very expensive. The method proposed in the paper is based on the digital wavelet
packet transform and wavelet packet energy Shannon entropy analysis of transient currents in relay
coil when it is turned on. In order to extract the features of relay defects the time dependences
of the relays' transient currents during their switching have been measured. The investigations
were performed with neutral signalling relays, some of which were correctly adjusted, and some had
defects in the form of bent contact springs or defects in the coil or magnetic core. The transient
current curve when the relay is turned on is conveniently to divide into three segments in
accordance with the physical processes taking place. In the first and third segments, the armature
does not move, and in the second segment, the armature and contact springs move from one position
to another. The transient current of relay in the first and third segments increases in time
approximately exponentially, and the time constants of the current variation in these segments can
be used to prompt detect the defects of the relay coil and magnetic core. The features of the time
dependence of the wavelet packet transform coefficients in the second segment of the transient
current strongly depend on the armature defects and therefore they are effective for detection of
the defects. The wavelet packet energy Shannon entropy of the relay transient current can be used
for prompt detecting of armature and contact springs defects of the signalling relay.
Description
V. Havryliuk: ORCID 0000-0001-9914-5733
Keywords
signalling relay, wavelet transform, wavelet entropy, КАТ
Citation
Havryliuk V. I. The Wavelet Based Detecting of the Signalling Relay Armature Defects. 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON), July 2–6, 2019. Lviv, 2019. P. 507–512. DOI: 10.1109/UKRCON.2019.8879960. The full text is absent.