Proximity-Aware Calculation of Cable Series Impedance for Systems of Solid and Hollow Conductors

TL;DR

This paper extends a surface current method to accurately and efficiently compute the frequency-dependent series impedance of cables with tubular conductors, including proximity and ground effects, for electromagnetic transient modeling.

Contribution

It introduces a novel approach for modeling tubular conductors and ground effects, improving accuracy and efficiency over finite element methods.

Findings

Accurately predicts proximity effects in complex cable configurations.

Computes 120 frequency samples in only six seconds of CPU time.

Extends existing models to include tubular conductors and lossy ground effects.

Abstract

Wide-band cable models for the prediction of electromagnetic transients in power systems require the accurate calculation of the cable series impedance as function of frequency. A surface current approach was recently proposed for systems of round solid conductors, with inclusion of skin and proximity effects. In this paper we extend the approach to include tubular conductors, allowing to model realistic cables with tubular sheaths, armors and pipes. We also include the effect of a lossy ground. A noteworthy feature of the proposed technique is the accurate prediction of proximity effects, which can be of major importance in three-phase, pipe type, and closely-packed single-core cables. The new approach is highly efficient compared to finite elements. In the case of a cross-bonded cable system featuring three phase conductors and three screens, the proposed technique computes the required 120 frequency samples in only six seconds of CPU time.