Analysis of electrical contact resistance models for substation connectors

The contact resistance is a key parameter that has a great impact on the thermal behavior, stable performance and efficiency of electrical devices containing electrical contacts thus greatly influencing the useful life of such devices. The study and minimization of the contact resistance is especially critical when dealing with contact surfaces made of aluminum, due to the insulating nanometric alumina layer formed when the aluminum is in contact with atmospheric air. This is the case of substation connectors, most of which are made of aluminum alloy. When applying procedures to eliminate this insulating layer, the only component of the contact resistance is the electrical constriction resistance or ECR. This paper analyzes the accuracy of different available ECR models. The study is carried out by comparing the results of the theoretical models with experimental data, obtained when analyzing different substation connectors and aluminum conductors. The results of this work can be very useful during the optimal design stage of such devices, to ensure a suitable thermal behavior.