An Advanced Ceramic Material for Internal Insulation Used in Gas-Insulated HVDC Apparatus

The traditional polymer insulating material has encountered a bottleneck in improving the surface insulation performance in gas-insulated high voltage direct current (HVDC) apparatus. In this article, an advanced ceramic insulating material is proposed, which has great potential to be utilized in HVDC apparatus. The short-time and long-time surface insulation properties of the ceramic material are researched and compared with those of epoxy composite widely used at present. The conductivity and temperature dependence of the ceramic material is significantly lower than the epoxy composite. The surface charge accumulation and trap evolution characteristics of the ceramic can improve the surface electric field distribution. The long-time test further verifies its reliability, where the failure probability of the ceramic is 74% lower than that of the traditional material. This work may provide a basis for the application of the ceramic material in gas-insulated HVDC apparatus and may be helpful in understanding the surface insulation failure mechanisms in electro-thermal conditions.