Abstract :
Inference of ageing mechanisms becomes a very complex matter in insulations, where the presence of electrical field concentrations, temperature gradients, various insulating materials, inhomogeneities, etc., complicates tremendously any physical investigation. This paper focuses on recent developments in modeling insulation behavior under thermo-electrical stresses. In particular, a comparison between phenomenological and physical models, with the relevant limits and constraints, is presented. Moreover, a probabilistic approach, which may hold for materials and systems as well, is discussed, referring to both parametric and non-parametric models.
Keywords :
ageing; insulating materials; insulation testing; life testing; ageing; electrical field concentration; electrothermal endurance model; inhomogeneity; insulating material; nonparametric model; parametric model; phenomenological model; physical model; probabilistic model; temperature gradient; thermo-electrical stress; Aging; Degradation; Dielectrics and electrical insulation; Electric breakdown; Electrothermal effects; Insulation testing; Materials testing; Temperature; Thermal stresses; Thermodynamics;