Numerical Model Validation and Sensitivity Study of a Transmission-Line Insulator Failure Using Full-Scale Test Data

This paper presents the validation of a numerical model based on the full-scale broken insulator tests on a 138-kV high-voltage steel transmission line. The University of Wisconsin and the Electric Power Research Institute performed these tests in 1978. A finite-element model of the line is developed to perform incremental nonlinear dynamic analysis, carried out in the time domain. Upon validation of the numerical model with the test results, a sensitivity study is carried out for various insulator lengths, ice thicknesses, and initial tensions to determine the effects of these parameters on the impact loads on the tower cross arm. Results of the study show that the impact loads are less sensitive to the change in insulator length but they do vary significantly when the ice loads and the initial tensions are increased. Studies of this type are now possible and are cost effective because of the use of commercial software not available at the time of the original research.