Calculation of initial discharge voltage on insulator surface based on the simulation analysis of distorted electric field

The calculation of initial discharge voltage is the difficulty of insulator performance evaluation. Based on the theory of streamer and the finite element simulation analysis of distorted electric field, the gas discharge model of polluted insulator surface is established in this paper. The electric field distribution in the gap of the dry band was calculated, and the impact of environmental factors such as pollution degree, humidity and temperature on the distribution of distorted electric field is studied. The dynamic process of the initial discharge of streamer is analyzed quantitatively by the finite element methods such as space electric field partition quantification and dynamic accumulation, and the calculation method of the initial discharge voltage on insulator surface is proposed. The calculation method of this paper is verified by the surface discharge experiment of polluted insulator. The experimental results show that the calculation method based on the simulation analysis of distorted electric field and considering the environmental factors can accurately quantify the streamer initial discharge voltage on insulators, which can provide useful reference for the operation and maintenance of power transmission and transformation projects.