An investigation on Grounding System of AC Single-core Submarine Cable Based on Multi-conductor Analysis Theory

Submarine cables are now widely used in offshore wind power interconnection. Due to the electromagnetic coupling effect and the large power transmission distance, the submarine cable has the extremely high risk of excessively large accumulation of the induced voltage on the sheath, and the sheath grounding of the submarine cable will also cause sheath loss, leading to a decreasing in the power transmission capacity. Therefore, investigating the induced voltage and loss of submarine cables is of great significance to practical engineering. In this paper, an optimized calculation model of sheath induced voltage and current loss is established. The non-decoupling form of the matrix is introduced to simplify the nodal admittance matrix. The influence of cable characteristics on the induced voltage and loss of the sheath is investigated and the cable loss reduction methods are analyzed and summarized. The results show that the laying mode has little effect on the induced voltage loss of the sheath. When the connection resistance is 0.5$\Omega$, the induced voltage requirement is met, and the total loss is the lowest. When the conductivity of the armor layer is 10
⁸
S/m, the total loss of the submarine cable is the lowest.