Research on the operating state of power cable accessories based on confidence intervals

With a large number of cables are used in distribution network in the city, the fault of power distribution network caused by power cable accessories has a significant increase. Based on IEC-60853, this paper establishes a transient thermal circuit model for a cable terminal, and calculates the conductor temperature, the skin temperature and the load current of the cable terminal by using Matlab, and obtains the relationship between them. Then the paper establishes a 3D model of the cable terminal by using the heat-electricity coupling field in ANSYS, and simulates each layer temperature of the cable terminal under the different current load. Finally by using the data of the above, the confidence intervals for the operating states of cable terminal can be obtained. According to the confidence interval for the normal load current of the terminal, the power supply department can adjust the running current of the cable line in time, ensuring the reliability of the power distribution network.