Simulation calculation for total electric field of three-phase power cable

摘要

There are many references about the calculation of the electric field in three-phase cable, and the main method is about line charge simulation, an infinite way. few articles calculate electric field in three-phase cable terminal strip shielding layer of cable. for the stripped part, there may be many arrangements, these arrangements will be discussed for better electric field distribution, the best one is chosen. This paper presents a 3d finite-element analysis for the electric field behavior at the junction of a 10kV, three-phase, three-core cross-linked polyethylene (XLPE) power cable, applying the ANSOFT Maxwell computer program. The calculation configuration is three insulated phase-conductor without the shielding layer contacted at a certain arrangement, such as triangle phase conductors, parallel, cross, 60 degrees, vertically crossed, etc. The aim of this simulation is to investigate how the electric field distributions can be reduced to avoid partial discharge activities by different arrangements. According to the parameters of the yjv22-3*300, and some important settings in the software, the total electric field of three-phase power cable is obtained by simulation and the best arrangement is chosen by the result, and triangle phase conductor model is the best arrangement, Phase conductor at 60 degrees is the most extreme arrangement, which consisted with the trend we had known. However, it is still possible to produce partial discharge phenomenon, so for the arrangement of the phase conductors in parallel, the way of improving the electric field triangle phase conductor model distribution is to change the relative dielectric constant of phase cable, another way is to mount metal shielding layer for the cable. Then the 60 degree arrangement is emphatically discussed, insulation spacer is added to the interphase. The results show that this method can improve the electric field at the interface effectively. Then we examine the error of the contact-point electric field in comparison with practical experience, taking into account the real geometrical and physical cable properties, comparison is given in the literature.