The modernisation of electrical systems installed on board ships has made the use of high-efficiency electronic power components possible, but has however led to an increased rate of failures in the insulation system of the plant components, presumably due to reduced switching times of the equipment. This required the revision of the design process of these insulating systems in order to include electrical phenomena not currently considered, such as the non-linear distribution of overvoltages which leads to the accelerated and uneven aging of the insulating systems.