Electric Field Under an MV Line Supported by Concrete Poles

This paper presents a study of the electric field under a three-phase medium voltage (MV) power line supported by concrete poles. The analyzed configuration is a pole-top-pin construction. An analytical model has been developed for the three-phase wires assuming three straight cylindrical conductors whose axes have been put parallel to each other and to the ground, and for the concrete pole a cylindrical conductor placed in a vertical position. Simple analytical formulas have been obtained for the three components of the electric field in the vertical plane containing the axis of the conductor representing the central top wire. The validity range of the model is from the ground to one quarter of the height of the concrete pole. The analytical expressions have been checked against the numerical data obtained by a 3-D numerical analysis performed by using the charge simulation method. Finally, the results have been experimentally validated. The analytical model reported here is a new easy tool for the evaluation of the electric field for the analyzed geometry.