Study on Propagation Characteristics of Electrical Trees in different Electrode System

The electrical tree discharge channel will be formed at concentrate of electric field in solid insulation dielectric, in order to study the difference of electrical tree under different electrical field, the short-cable electrode system with actual XLPE cable was designed, experiments were performed under 12 kV, 15 kV, 18 kV, 21 kV compare to the needle-plate electrode system. Experiment results show that the electrical tree of short-cable electrode system have the same growth trend with the needle-plate electrode system in the growing characteristic, the dense of electrical tree increase with the addition of voltage level, electrical tree of short-cable electrode system growth slower than the needle-plate electrode system at the same voltage; To get the same shape of electrical tree, the voltage of short-cable electrode system must higher than needle-plate electrode system, the results show that the semiconductor layer and the copper shield layer outside of XLPE cable have very important affection on the electrical trees degradation.