Study on the Uniformity of Ion Current Density in the Calibration device of DC Total Electric Fields

The total electric field beneath HVDC transmission lines is an important parameter for the research and evaluation of electromagnetic environment characteristic. The DC ion flow field generator plays an important role in the calibration of the DC total electric field sensor under the ion flow environment. In this paper, a finite element simulation model of a total electric field calibration apparatus coupled with space charge is established, and the influence of different meshes on the uniformity of the ion current density is analyzed based on the model. In addition, a DC total electric field calibration apparatus is designed and manufactured, and the uniformity of ion current density of the apparatus is characterized using Wilson plate. Experiment results show that the mesh of the high-voltage control layer has an important influence on the uniformity of the ion current density distribution on the surface of the calibration apparatus’s grounded lower plate. The research provides valuable reference for the design of a DC total electric field calibration apparatus and the accurate calibration of rotating field mill.