Structural Performance of Porcelain Insulators in Overhead Railway Power Systems: Experimental Evaluations and Findings

This paper addresses the critical knowledge gap in the structural performance of porcelain insulators in overhead railway power systems through experimental evaluations. The focus is on porcelain insulators as part of a contact wire registration assembly (CWRA) in the railway power system. While porcelain insulators are the most widely used high-voltage insulator material, no previous studies have investigated the impact of age on their ultimate load capacity in overhead rail systems. The paper presents the experimental design for tension and a novel 45-degree test setup that replicates field conditions, as well as an overview of the test specimens, which were both new and retired from the field. The results indicate that aging has no impact on the strength of insulators in direct tension tests, but retired insulators in the CWRA show a reduced capacity. Additionally, the location of the drop bracket has a notable influence on the failure mode and stiffness of the assembly. The findings contribute to future improvements in system design and performance. Future research should include material testing, finite element studies, and dynamic testing of the full CWRA setup to further understand insulator performance and support resilient power transmission and distribution systems. Additionally, similar tests should be conducted on polymeric insulators, due to their prevalence.