Title: Condition monitoring of disconnectors in the electric power transmission grid with temperature sensors

Authors: Per Westerlund; Patrik Hilber; Tommie Lindquist

Addresses: Department of Electromagnetic Engineering, School of Electrical Engineering, KTH Royal Institute of Technology, Teknikringen 33, SE-100 44 Stockholm, Sweden ' Department of Electromagnetic Engineering, School of Electrical Engineering, KTH Royal Institute of Technology, Teknikringen 33, SE-100 44 Stockholm, Sweden ' Svenska kraftnät, Swedish National Grid, Box 1200, SE-172 24 Sundbyberg, Sweden

Abstract: This paper presents a method that can be used to rank disconnectors in the electric power system, according to the condition of one of the most critical parts, the contacts. The temperature of the contacts can be continuously measured by a new type of infrared sensor. For the case study, 54 sensors were placed on six disconnectors together with reference sensors measuring the ambient temperature. The measured temperature at each contact is then regressed against the ambient temperature and the current through the disconnector. Both a linear and a quadratic dependency of the current are tested and the quadratic one explains the data best. The coefficient of the current serves as a measure of the condition of the contact. Then, it becomes possible to identify in which contacts the resistance has increased the most. As a consequence, it is possible to make better maintenance decisions for the disconnectors.

Keywords: electric power transmission; disconnectors; electric contacts; temperature measurement; infrared sensors; reliability; condition monitoring; temperature sensors; disconnector maintenance.

DOI: 10.1504/IJISE.2016.075809

International Journal of Industrial and Systems Engineering, 2016 Vol.23 No.1, pp.90 - 110

Available online: 06 Apr 2016 *

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