Effect of water trees ′string of pearls′ configuration on the distribution of electric field, current and stressed volume in XLPE insulation
The processes originating in local areas of cross-linked polyethylene (XLPE) insulation of extra-high voltage cables during water tree germination between closely disposed water micro-inclusions in insulation have been studied. According to current experimental data, water trees in XLPE have not solid cylindrical shape, as it was thought previously, but they consist of closely spaced nanoscale inclusions of spheroid form and nanoscale thin water channels between them (so-called "string of pearls" configuration).