Skin effect calculations in pipe-type cables using a linear current subconductor technique

A new technique has been developed to accurately calculate frequency dependent underground cable parameters. The technique is based on the well-known concept of conductors' subdivision. As opposed to the traditional technique, current density is not assumed constant in the subconductors but linear with matching values at the boundaries between subconductors. This drastically reduces the number of subconductors needed for accurate calculations, especially at higher frequencies. Typical computer-time savings in a SUN SPARC workstation range from 80% to 95%, depending on the frequency at which the parameters are calculated. The application of the technique is illustrated for pipe-type cables. The results are compared with those of a finite element technique. Overall, the new technique was found to be accurate, efficient, and requires minimum user intervention. Key words: cable parameters, skin effect, resistance and inductance matrices.