MV line electric field evaluation near a concrete pole

The paper presents a study of the electric field near a concrete pole supporting the three-line conductors of an MV three-phase three-wire power line. The analysis has been carried out firstly by means of two three-dimensional (3-D) numerical codes based on the finite element method (FEM) and the charge simulation method (CSM), whose results have been compared for validation purposes. Then a simple analytical model of the field distribution near the pole has been developed, whose results have been checked against the numerical data. A measurement campaign was also carried out, at the aim of a final validation of both numerical data and analytical results. A good agreement was found, as shown in the paper. The analytical model is suitable for an easy implementation in low-cost microprocessor devices to be installed on the concrete poles in order to perform the remote detection of nonsymmetric ground faults occurring at any distance along the line.