Influence of ACSR steel core permeability on entire conductor's load parameters

摘要

Aluminum Conductor Steel Reinforced (ACSR) is usually applied for the power overhead transmission or distribution lines. Electric characteristics of applied materials, like aluminum and steel conductivity values, are always provided by the manufacturers, but not the ACSR steel core permeability. In order to investigate how important the steel core permeability is, this paper deals with the influence of this permeability on an ACSR load parameters. At basic frequency of 50 Hz and the presence of higher harmonics, inside the power line conductors, the skin and proximity effects cannot be neglected. Through those effects the steel core permeability is expecting to have significant impact on load parameters and should be taken into consideration. In order to estimate this impact several calculations were performed and the results are shown in this paper. The value of relative steel core permeability was varied from 10 to 50000 inside three different standardized ACSR conductors, at eleven different frequencies, up to 2500 Hz (50th harmonic of basic frequency). In spite of great relative permeability range, as the consequence of the big difference in the aluminum and steel conductivity values, the paper shows that the influence of steel core permeability on any ACSR conductor is much less than expected, especially at lower frequencies. All calculations were carried out numerically, applying COMSOL Multiphysics 3.5a computer program package on simplified two-dimensional model.