An algorithm for prioritizing the maintenance of power transformers

Abstract

This report presents an algorithm that takes into account power transformer (PT) technical conditions and their potential for failure risk assessment to help determine maintenance precedence. The technical condition integrated index is assessed through the weighted average of condition indexes determined by the results of PT traditional and special control methods. Each control type index is the three-dimensional space vector where the coordinates are next: X - damage seriousness, Y - damage development speed, Z - damage development duration. The traditional control method defect identification and coordinate determination are carried out by an expert system without any specialist participation. Risk failure assessment includes: damages of suppliers and to consumers of electricity; transformer design features; lifetime; ES transformer unit (system) failure potential. The PT unit failure potentials were calculated using the flows of failures and damage statistics of 350 reliable facts of PT damage accumulated by the ES for 20 years of operation. Firstly, priority ranking for serviceable transformer operational activities are excluded from the sample. Then there are calculated coordinates on each of the remaining transformers. It coordinates the points, which are marked by the PT plane. The plane includes three zones: additional scheduled inspections and emergency repairs. The ES ranks PT by the distance from the origin within each zone. © 2014 WIT Press.