In recent years

offshore wind power has experienced rapid development. The submarine cable

as the sole critical link connectinng onshore power grid and the offshore wind farm

is of vital importance. In order to fully utilize transmission capacity of the cable and enhance the economic per

formance of wind power project

in this paper both variability of wind faram output currents and thermal inertia of cables and their surrounding environment are considered simultaneously. Based on actual typical load

the transient temperature rise characteristics of submarine cables are simulated and analyzed. The study results show that the submarine cables directly buried in the sea exhibit significant thermal time constant. For instance

after applying a full-load current for 48 h based on a 50% long-term load

the temperature of the cable core still did not reach 90 ℃. For a 1 000 MW wind farm

transmission power requirement can be achieved via two 330 kV tranmission lines using only 3×1 000 mm

2

submarine cables

whereas conventional design with 100% load factor woudl require 3×1 600 mm

2

cables. In addition

the influence of ambient temperature

soil thermal conductivity

cable burial depth

insulation dielectric loss and metal sheath loss on the transient temperature rise of the cable is discussed

and the key parameters of finite element analysis such as grid size and step interval are determined. The study in this paper provides a theoretical basis and technical method for the optimized selection of submarine cables for wind farm output.