Geometrical approach to multistress endurance of electrical insulation

The geometrical approach to multistress endurance is shown to be a powerful tool for evaluation and classification of electrical insulation materials. Even though its most interesting application is to double stress, this method is suitable for triple stress, where it gives guidance for rational and well-designed tests. Furthermore, this type of approach is very useful in making clearer the relationships between the various quantities involved in the multistress process. Experimental results are reported that are pertinent to models of XLPE (cross-linked polyethylene) insulated cables. These results appear particularly significant for illustrating the practical advantages of the geometrical approach