Insulation Coordination Considering the Switching Overvoltage Waveshape—Part II: Application and Results

This paper shows the application of a new insulation coordination procedure for phase-to-ground switching overvoltages, which is based on the variable behavior of the insulation strength according to the waveshape of the surges. It is the sequel to a paper which presented the methodology and calculation details of the procedure. After a series of transient simulations is run for two different transmission systems, both the traditional method and the new procedure are applied. Evaluation of the results focuses on the comparison between the two approaches considering the characteristics of the networks and the modeling of the low flashover probability region of the insulation strength curve. The new procedure is a refinement of insulation coordination studies and the results indicate the benefits that can arise from its application.