This paper proposes a new method of calculating currents in three-phase overhead medium and high voltage networks by measuring the magnetic fields generated in the close vicinity of the power line conductors. A mathematical model for magnetic fields is presented in the form of second order partial differential equations that are derived from Maxwell's equation. The analysis of the magnetic field surrounding overhead conductors is performed using Finite Element Method. The least squares method is used for the formulation of equations for estimating currents from the measured magnetic fields for each phase. A computational program for detail analysis is developed in MATLAB. A plan for measurement points is developed for triangular arrangement of conductors. Field measurement with increased number of measuring points gives better results than those with the single points.
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