Research On The Method To Calculate The Temperature Field And Ampacity Of Bridge Cables

The cable in tray has been widely used in the field of city power distribution system, Which is necessary to keep to run safety. Because its complex installation environment, it will directly affect the economy and reliability of the cable in tray to determine the temperature and ampacity of cable in tray quickly with high accuracy. Furthermore, it is important to research on the method to calculate the temperature and ampacity of cables in tray.The main work and conclusion drawn correspondingly are listed as follow:The electromagnetic loss FEM model of cable in tray was build and the loss of single circuit, two circuit and three circuit were calculated. Because the tray is metal, the loss of the tray was calculated too.The temperature FEM model of cable in tray was established. Under given current, the temperature field coupled with heat conduction, heat radiation and natural convection was calculated. The temperature field distribution and fluent distribution were given out.Iteration method was used to calculate the ampacity of cable in tray based on the temperature calculation. The simulation result is compared with the ampacity of cable buried in soil.At last, the factor to affect the temperature and ampacity of cable in tray, such as wind velocity and air temperature, was simulated. The ampacity increased with the increase of wind velocity and decreased with the increase of the air temperature.FEM is a useful method to calculate the temperature field and ampacity of cable in tray with high accuracy. The simulation result is important to keep the cable in tray safety.