Analysis of Temperature Conditions Influence on Cables Insulation Operation Life

Abstract

Electrical equipment fault current interruptions reduce is one of the most important problems of electrical power engineering and diagnostics. Power cables operation life is one of the parameters mostly affecting fault current interruptions on cables. The paper describes the research on thermal degradation of low voltage cables insulating materials and its influence on insulation operation life. The known mathematical models of the insulation aging depending on its temperature are considered. Low voltage cables have an insignificant electrical aging influence, so it is assumed that such cables aging mostly caused by their thermal operating conditions. Experimental research of cables insulation temperature monitoring is performed. Seven weeks of the experiment showed a temperature change between 17˚C and 27˚C. The mean temperature was 21.9˚C. Assuming that cable has normal operation life with an average temperature of 20˚C and accounting thermal conditions cable insulation operation life is reduced for about 20%. Such operation life reduce is significant and shows a considerable influence of insulating material thermal deterioration.

Evaluation of Distribution System Reliability Indices Using Fuzzy Reasoning Approach

“…During the period there was building heating the temperature increase cyclic exponential trend appears. According to insulation aging model, cable insulation operation life reduction is about 20% for temperature increase between 1 ºC and 2 ºC over normal [19]. So, a significant influence on operation life reduction of distribution lines has the thermal deterioration of insulating material.…”