Abstract: The discharge between cable connector and box walls directly affects the operational reliability of CRH. Optimized design of the electric field distribution of the connector can improve stability of CRH. The sheath installation position, sheath structure and thickness of the insulation layer were analyzed to see its influence on the distribution of field intensity. The simulation results show that insulating jacket positioned at the high voltage end of cable connector can effectively improve the electric field distribution, insulation sheath should appress to the high voltage fitting end of the cable connector and also extend to the root of first ceramic umbrella. The test result shows that after installing the insulation sheath cling to the high voltage fitting surface, the withstand lightning impulse voltage value of the cable connector can fit the operational requirement at high altitudes.

Key words: China railways high-speed (CRH), high voltage box, insulation optimization, finite element method (FEM), simulation calculation