ABSTRACT
The multiphysical processes at a strong electric field perturbation in local areas of XLPE insulation near water micro-inclusions of different shapes, sizes and mutual disposition were studied. The water micro-inclusions of shapes: spheres, spheroids, spheres and spheroids with water treeing on the surface were considered. The influence regularities of the inclusions characteristic parameters on the increase degree of maximum values of field strength, electromechanical pressure and total current density in the insulation micro-volumes were determined. Not only sizes and shapes of separate inclusions were taken into account, but also their mutual disposition and orientation with respect to the field lines. The comparison of multiphysical processes of ageing and degradation of XLPE insulation for extra-high voltage cables was made both taking into account its nonlinear properties (in particular, the specific conductivity dependence on the field strength) and without one.
