How does cable oil contribute to the insulation of underground power cables?

In underground power cables, cable oil fills the spaces within the cable’s insulation system, providing a uniform insulating medium around the conductors. It prevents the formation of air pockets, which can lead to partial discharges and insulation breakdowns. The oil’s high dielectric strength ensures that electrical fields are evenly distributed, reducing stress on the solid insulation materials and enhancing the overall insulation performance of the cable.