In recent years

the explosion of 110 kV cable intermediate joint has happened for many times during the closing operation of circuit breaker.For studying the over voltage characteristic of 110 kV cable joint at closing operation of the circuit breaker for power transmission

the RLC equivalent model of cable intermediate joint is set up firstly

then

the cable line model containing the intermediate joint is set up in PSCAD software

the influence of closing angle

the length of cable and the number of joints on over-voltage of the joint is analyzed and the joint with the most serious overvoltage is found.Additionally

the internal electric field distribution of joint with the most serious overvoltage is simulated by Ansys software.The results show that the overvoltage of the joint at 60%～90% of cable in phase B is the most serious.During the closing period

the voltage in the joint shielding layer contains high frequency component over 40 kHz.Moreover

the maximum electric field strength on the interface between silicone rubber and cross-linked polyethylene and the maximum field strength at the end of the high voltage shielding tube are doubled than when there is no overvoltage and the maximum value of the interface field strength exceeds the security threshold.The sudden increase of field strength on the composite interface and at the end of high voltage shielding tube and the high frequency oscillation in the shielding layer due to the joint withstanding multiple times of the over voltage

which is caused by asynchronous closing of circuit breaker

is likely to cause fault of the joint.