No abstract

The paper presents a numerical model that allows the calculation of the magnetic flux produced by current through the wires of a multiple conductor, helically wrapped over the steel core, the size of wires which compose the conductor being provided. The numerical model is implemented in finite element software package Vector Fields Opera. The numerical results were compared with those experimentally determined. Also, the paper calculates the internal inductance of a multiple conductor.

Phase conductors of overhead power lines are made of wires, which contain an aluminum conductive area and an area of steel to ensure strength. The aluminum wires are wrapped helically over the area of cylindrical steel. The paper shows the calculation of magnetic field intensity in any point inside the helical coil. Calculations were performed considering homogeneous medium with permeability μ 0 and the conductor filamentary wires are located on the axis of the real wires.

Phase conductors of overhead power lines are made of wires, which contain an aluminum conductive area and an area of steel to ensure strength. The aluminum wires are wrapped helically over the area of cylindrical steel. The paper shows the calculation of total induction of conductor. Calculations were performed considering homogeneous medium with permeability μ0 and the cable filamentary conductors are located on the axis of the real conductors.

Detecting defects in transmission and distribution networks of electricity needs to be analyzed solving transient regimes. The complexity of electrical circuits associated to power grids requires the use of numerical methods for transient analysis. This paper uses PSpice program for analyzing transient faults caused by three phase short-circuits. Because a three-phase short circuit is symmetrical, the power line parameters that occur in the transient analysis are the ones of positive and negative sequence. The paper analyzes 14 different cases, considering some lengths of the line until the fault point (5 km, 10 km, 20 km) and several initial phases of the tension of the R phase, at the time when the short-circuit is produced. The paper presents a virtual electric power subsystem, designed and developed by the authors, which allows numerical analysis of transients regimes caused by faults.