3D Electric Field Reconstruction inside GIL by Induced Charge Tomography

Grasping the electric field distribution is critical for the safe operation of gas insulated transmission lines (GIL). Defects in GIL, especially those located near the conductor or the pipe wall, may cause severe electric field distortions, disturbing the induced charge concentrations on metal surfaces. In this paper, two types of defects, i.e. one impurity particle and two insulator cracks, are assigned in a 1000 kV AC-GIL. And the induced charge tomography (ICT) technique is developed to do defect identification and electric field reconstruction according to the induced charge distributions. Results show that the reconstructed permittivity and electric field distributions are highly consistent with the assigned cases. The ICT technique has the ability of not only identifying the outlines of insulators but also diagnosing the defects in GIL.