Effect of Nano-MgO Doping in XLPE on Charge Transport and Electric Field Distribution in Composite Insulation of HVDC Cable Joint

The space charge characteristics of cross-linked polyethylene (XLPE) can be improved to some extent by doping the appropriate amount nano-MgO. In this study, in order explore influence nano-MgO on and electric field distributions composite insulation high voltage direct current (HVDC) cable joints, effect concentration depth density deep traps MgO/XLPE was first analyzed. On basis, transport simulation model a 320 kV HVDC joint established with as insulation, under different temperature conditions were simulated. It found that radial distribution shows trends change concentration. There is significant difference both sides (MgO/XLPE)/EPDM interface, decreased then increased increase When 0.5 wt%, number charges direction fewest, maximum value only 0.42 C/m−3. changed abruptly at it homogenized certain time. highest interface root stress cone, which weakest point insulation. cone lowest, 13.38 kV/mm. A comprehensive comparison maintain better when wt% compared other concentrations. results provide basis for further improving properties joints through nano technology.