Numerical Analysis of Cable Heat Output for Renewable Energy Transmission Lines

With the development of renewable energy such as wind-power and photovoltaic-power, the first-tier cities supporting high-voltage level transmission lines are mostly used to lay cables along with the pipeline corridor tunnels to save ground space. The continuous heating of the cable operation and the increase of temperature in the tunnel will affect the cable ampacity. For the research of cable heat output in different arrangements and cross-sections, this paper uses CYMCAP to establish a 500kV AC cable tunnel laying model and compare the simulation results. The analyzed results will serve as a reference for cable tunnel laying in actual projects. The results show that as the cable cross-section decreases, the heat output of the cable rises gradually; Horizontal laying heat is significantly less than triangular laying, the former is less than 70% of the latter, horizontal laying each time to adjust the spacing of 50mm, the heat affects the magnitude of about 3% to 5%. Compared with the normal conditions, the heat output is increased by about 27.4% for triangular laying and 23.6% for horizontal laying under N-2 working conditions.