Method to Mitigate Cable Insulation Defect Caused by Improper Terminal Fabrication Work

[[abstract]]This thesis investigates the cable terminal fault, focusing on the faults caused by improper termination fabrication work which has been recently recognized as the major root cause for cable outage in Taiwan. The thesis presents a new design concept to reduce the probability of cable terminal outage which intends not to cause any variation on the presently existing fabrication work procedure of cable termination. In addition to the improper fabrication work, other root causes for the cable terminal outage have also been studied in this thesis. The new design concept presented in this thesis is by adding an additional semiconductive layer to the cable terminal so that the ununiform distribution of electric field can be effectively reduced. The new design has been tested on the cold-shrinking termination which is presently extensively used in the low and medium voltage of power system. To evaluate the effectiveness of purposed concept, numerical simulation has been done by using the Finite Element Method. Through the simulation, the author intends to find out the optimal design structure for coldly shrunk terminal and also the potential difficulty in future application of the design. This thesis also simulates the electrical field of cable terminals with a variety of improper fabrication works and cable environmental conditions, as well as the ability of the new design to withstand the voltage tests. The evaluation shows that the new structural design of cable terminal can mitigate the ununiform distribution of electrical field under the most common improper fabrication works, no matter the cable is operated under the normal operation condition state or under the withstand voltage test. Although the simulation is done only here to verify the effect of the new design, the simulation results show that the design can indeed reduce the vulnerability of cable terminal caused by the improper fabrication work, and has a high potential in the future application.[[fileno]]2030164030014[[department]]電機工程學