Event under the auspices of the Ministry of Economy of Slovak Republic

Identification of power cable conditions based on broadband powerline communication characteristics in distribution grids

Nikolai Hopfer
University of Wuppertal, Wuppertal, Germany

Markus Zdrallek
University of Wuppertal, Wuppertal, Germany

Ulrik Dietzler
Energieversorgung Leverkusen GmbH & Co. KG, Leverkusen, Germany

Markus Krampf
Energieversorgung Leverkusen GmbH & Co. KG, Leverkusen, Germany

Christoph Raquet
Power Plus Communications AG, Mannheim, Germany

Marilen Ronczka
Power Plus Communications AG, Mannheim, Germany

Hamed Rezaei
Nexans Power Accessories Germany GmbH, Hof, Germany


     Last modified: 2017-06-16

Abstract
Broadband powerline (BPL) communication systems meet the growing demand for communications technologies in electrical distribution grids. Since this technology uses the existing electrical grid infrastructure as transmission media, in particular power cables fulfill two functions: first of all the reliable distribution of electrical energy with mains frequency, essentially and as originally planned, and additionally the data transmission. For the last purpose, BPL communication uses 917 independent carriers in the frequency range from 1.8 to 30 MHz according to the corresponding standard IEEE Std 1901-2010. To satisfy the demand for high quality electrical energy supply, maintenance of power cables according to the actual condition is fundamental.

Nevertheless, the actual condition of cables is widely unknown, because diagnostic measurements, which are conventionally applied offline, are performed neither extensively nor continuously in the course of condition assessments.

A new research project is investigating, how BPL communication can deliver new insights into power cable conditions using data transmission characteristics. During normal operation, the characteristics of link quality between several modems are automatically determined on a regular basis. The most significant parameter is the signal-to-noise ratio that is gathered at any modem and can be used as input data for further analyses. This parameter contains valuable information about the attenuation of the transmission line, i.e. power cable, and the noise level. Using the influence on the attenuation and the noise the condition of the cable can be determined.

The paper will present theoretical background and the results of laboratory tests in order to draw conclusions for condition assessment. Hence, the necessary relation between cable conditions and their high frequency characteristics are examined. Whereas losses of low frequency signals occur mainly due to the resistance of conductors, high frequency signals are attenuated mainly due to dielectric losses in power cable insulation systems. Laboratory tests show that thermal ageing of medium voltage cable dielectric increases the attenuation per unit length of the corresponding cable in particular at the upper frequency range. Another effect of degradation is the presence and intensity of partial discharges. The typical frequency spectrum of partial discharges overlaps with that of considered broadband powerline communication systems. It is consistent that partial discharges can intensify the noise at modem inputs and reduce the achievable data rate dependent on their intensity.

Thus, broadband powerline communication characteristics can be analyzed in order to determine the cable condition. This procedure will benefit condition assessments of power cables in distribution grids since it will be applied during service and generates valuable information with low effort.

 

Proceedings Indexing

Recent proceedings have been recognized by Thomson Reuters for including in Conference Proceedings Citation Index - Science (CPCI-S).

View More

Original Research Reporting

We recognize international reporting standards. Authors of reports of original research should present an accurate account of the work performed as well as an objective discussion of its significance. .

View More

Call for Papers Announcement

We call for papers that address theoretical, experimental, systems-related and power network management issues...

View More