Frequency Response of a Real Cable Network and its Impact on Field PD Measurements

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Paper number
1492
Working Group Number
Conference name
CIRED 2019
Conference date
3-6 June 2019
Conference location
Madrid, Spain
Peer-reviewed
Yes
Short title
Convener
Authors
Abdul Madhar, Saliha, Haefely Test AG / TU Delft, Switzerland
Mraz, Petr, Haefely Test AG, Switzerland
Barrios Pereira, Sonia Raquel, Ormazabal Corporate Technology, Spain
Akroud, Nabil , Ormazabal Corporate Technology, Spain
Abstract
Asset condition monitoring through Partial Discharge (PD) measurements is widely used for preemptive maintenance especially when it comes to cable networks. This is because the physical structure of the cable is a coaxial waveguide that poses as a one dimensional medium for the discharge pulse propagation; which in turn provides the added advantage of pulse/defect localization. Several monitoring systems rely on measurements in the High Frequency (HF) band using wideband sensors when it comes to PD monitoring. However, they fail to realize the radical attenuation of the higher frequencies by the cable. Therefore, this paper presents some important insights towards PD measurements on real cable networks. Firstly, it provides the values of measured attenuation and limits of measurement when it comes to PD measurements in general. It demonstrates the damping of the High Frequencies merely by the influence of the injection loop inductance. Second, it presents the measurement results from an actual MV cable network showing pulse propagation in various network configurations. It makes detailed analysis of the network’s frequency response to explain crucial features such as pulse reflections from interconnections and interruptions. The results of measurement are compared to create a comprehensive argument towards selection of suitable measuring bands/frequencies and the pertinence of measuring at lower frequencies when it comes to power cables.
Table of content
Keywords
Publisher
AIM
Date
2019-06-03
Permanent link to this record
https://cired-repository.org/handle/20.500.12455/419
http://dx.doi.org/10.34890/646
ISSN
2032-9644
ISBN
978-2-9602415-0-1