Nowadays, when compared with overhead lines, power cables are becoming increasingly attractive for the delivery of electrical power. Their reduced environmental impact complies with the public concern on the compatibility of electrical infrastructures in residential areas. The lower fault rate of high voltage DC (HVDC) cables matches the need of transmission and distribution system operators for high reliability in power delivery [1], [2], and sometimes they are the only solution, e.g., submarine links. In general, the growing demand and dependency on offshore produced renewable energy makes submarine cables essential, and they have become critical infrastructures for the reliable delivery of electrical power [1]-[3].