Research on 10 kV Nonlinear Materials Terminal Accessories for Polypropylene-Insulated Cables

Power cables are important power equipment in high-voltage power transmission systems. Compared with cross-linked polyethylene (XLPE), polypropylene (PP) is environmentally friendly and has better insulation properties. As a result, PP-insulated cables are gaining traction rapidly. In this paper, the simulation research of 10 kV PP-insulated cable terminal accessories is carried out. The effects of different materials, including conventional semi-conductive materials and various nonlinear materials, on voltage equalization are examined using accessories with a stress cone structure. The results show that appropriate nonlinear materials outperform semi-conductive materials. A novel structure of the accessories with a field grading layer based on nonlinear materials is proposed and the uniformed electric field distribution is obtained. The novel scheme, as compared to the conventional semi-conductive stress cone, considerably simplifies the geometric structure of the accessories while successfully controlling the concentration of internal electrical stress.