The application of silicone grease at the interface of XLPE/silicone rubber is a key step in the production of cable intermediate joints. However

staff members are not sufficiently aware of the importance of application of silicone grease. It’s often to find silicone grease not applied or unevenly smeared. The effect of silicone grease on the interface electric field has not been reported. Therefore

this paper established a three-dimensional finite element model of the 10 kV cable intermediate joint to analyze the electric field distribution under three working situations

that silicon grease is applied or not; silicon grease is distributed evenly and unevenly; and the focus on the inhibitory effect of silicone grease on other defects. The simulation results show that

when no grease is applied

the maximum field strength of the interface is 3.79 times larger than that of when silicon grease is applied

the maximum field strength under the situation that silicon grease is distributed unevenly is 2.8 times larger than that of when the silicon grease is unevenly applied. Absence of silicone grease and unevenly distributed silicon smearing both cause serious distortion of the interface electric field distribution. In addition

when there is a main insulation impurity in the silicone grease

the electric field strength of the coated silicone grease is much lower than that of the uncoated silicone grease. It shows that the application of silicone grease has optimizing function on electric field distribution under impurity defects situation. Applying silicone grease is an indispensable part of on construction.