Effects of Different Load on Temperature and Electric Field Distribution of Flexible DC Cable Terminal

Flexible DC cable is the most important carrier of flexible DC transmission, while the flexible DC cable terminal is the weakest part of the whole cable system. When the load applied in the flexible DC cable system is different, the stable operation temperature of flexible DC cable conductor will be different, each part of the terminal insulating material temperature changes, which makes the conductivity changes. Therefore, the electric field distribution of the DC cable terminal also presents difference with the change of load. Due to the conductivity is a function of changing with temperature and electric field, using analytic method to solve the electric field distribution in terminal insulating layer is very difficult. This paper has compared the calculation results of analytical method and finite element method by calculating DC cable. The results show the consistency of analytical method and finite element method. Through the research on the temperature field and the electric field distribution of flexible DC cable terminal insulation, fully grasp the law of the electric field distribution of terminal insulation layer, provide the research foundation of flexible DC cable terminal structure design and optimization, and also provide technical support for China's ± 535kV and ± 800kV UHVDC transmission project.