Study on temperature field modeling and operation optimization of soil buried double-circuit cables

Cable conductor temperature is the key condition to determine whether current in operation reaches to cable's ampacity. In order to optimize cable operation, it is important to calculate cable conductor temperature with high accuracy. A simple and quick method of calculating temperature field for double-circuit underground cables is introduced in this paper. The superpose principle is applied to establish a calculation model of conductor temperature, and the conductor temperature is divided into three parts: initial temperature decided by environment temperature, temperature rise caused by its loss, and conductor temperature rise generated by other cable heat sources. Theoretical calculating models are established by combinating analytical method and the finite element method, then the formula of conductor temperature is deduced. On this basis, double-circuit soil buried cables' ampacity is calculated and optimized. Finally, the validity of conductor temperature field model and calculation formula proposed in this paper is verified by calculation examples.