Effects of non‐sinusoidal current on current division, ampacity and magnetic field of parallel power cables

Abstract

The current distribution, ampacity and magnetic field of parallel power cables are calculated. The calculations are performed in both sinusoidal and harmonic current profiles. The simulations are conducted on the underground medium voltage cables with metallic sheaths. The effects of single‐point bonding and solid bonding of sheaths grounding system are evaluated. In this study, cables are installed in flat formation with three cables in each phase and the effect of different distances between cables on the parallel cables parameters is studied. Computations are conducted for all possible arrangements of parallel cables and the worst and the best arrangements from the point of balancing current division, maximum ampacity and minimum magnetic field are presented. Furthermore, the effects of placing parallel cables in one row or two rows above each other are investigated. Calculations of current distribution and magnetic field are performed using the sub‐conductors method that considers the skin and proximity effects. Finite element method thermal simulations are excited to determine the power cable ampacity in different configurations. Experimental tests on parallel cables in both single‐point bonding and solid bonding systems are carried out and the results verify the accuracy of simulations.