Novel dc flashover model for predicting flashover voltage of the iced insulators

• Main Authors: Caijin Fan, Xingliang Jiang, Yanbin Xie, Jianlin Hu, Zhijin Zhang, Qin Hu, Maoqiang Bi
• Format: Article
• Language: English
• Published: Wiley 2021-02-01
• Series: High Voltage
• Online Access: https://doi.org/10.1049/hve.2020.0005

Abstract This work first proposes a novel flashover model based on the deduced residual resistance of the ice layer. The most important finding of the field icing tests is that the double‐layer ice‐melting water film exists on the inner and outer surfaces of the ice layer. The conductivity of melting water on the inner and outer surface of the ice layer has been measured, and the corresponding surface conductivity has been calculated. According to the proposed flashover model, the ratio η of the resistance of the ice layer to that of the pollution layer gradually increases with the increase of the ratio k of the resistance of the outer surfaces to that of inner surfaces, and eventually approaches saturation. Furthermore, the icing flashover criterion has been modified, and the voltage gradient of the inner surface is less than that of the outer surface. Test results show that the ice flashover voltage is lower than the pollution flashover voltage between 2.18–9.69% and 14.75–20.32% under light ice and semi‐cylindrical ice, respectively. The simulation results based on the proposed model and the classic model are compared with the field test data. Results show that the proposed model could attain a high accuracy of dc flashover voltage and demonstrate the effectiveness of the proposed model.