Distribution of non-sinusoidal currents in parallel conductors used in three-phase four-wire networks

Optimization of Spatial Configuration of Multi-Strand Cable Lines

“…• the case of supply of a textile factory in Greece [11] Two cable groups consisting of eighteen, flat-laid, single-conductor cables laid on metallic tray in free space, each with 300 mm 2 cross-section. We assume a unit distance between the cable centers, similar distance assumed between the cables on the internal edges and the compartment The "x" coordinate of the barycenters for the case depicted in Fig.…”

“…Since 1957, the publication year of the seminal paper by Neher and McGrath [1], much attention was paid by the engineering community to the problems related to computations of current distribution in such systems [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Current distribution in multi-strand cable systems is uneven due to several factors, to mention skin and proximity effects related to strand geometry [3,5], the conditions of heat exchange with neighborhood [8,18,19], soil inhomogeneity, moisture, installation depth (if the cables are buried) harmonic spectrum of currents flowing through the cables [11], the presence of buried metal objects etc., to mention but a few. Analytical treatment of all these factors is hardly possible [20], therefore numerical methods, in particular the Finite Element and the Finite Volume methods, have found wide use for engineering purposes.…”

“…Optimal flat configuration (with neutral wires) suggested in Ref [12]. The maximal discrepancy between the gravity centers for individual phases is equal to 0.667, what, referred to the shelf width(11), is only 6.06%. The gravity center for the neutral wire may be a little distant from the other ones, because under in operation conditions (under standard assumptions concerning symmetries of supply and load) the current flowing through the neutral strands takes negligible values with respect to the phase currents.…”

Evaluation of cable and busbar system in multiconductor distribution systems in terms of current and magnetic field distributions

“…In these studies, three-phase, three and four-wire cable layouts were examined, and current imbalances of up to 119% were determined depending on the number of parallel cables per phase and cable layout. In addition, the temperature levels of cables in parallel cable systems [5], current distributions in cables in the case of loading with harmonic currents [6], phase sequence configurations for reducing magnetic fields in cable systems [7] and calculation of current distributions using finite element method [8] are investigated. In the studies carried out, it has been observed that the current imbalance between the conductors increase up to 263% depending on the number of parallel cables per phase and frequency, especially operating in harmonic current conditions.…”

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

“…The used procedure of this study does not give any view about the effects of harmonic currents or metallic layers of the cables. Distribution of parallel cables currents in four wires low-voltage system which are placed on a metallic tray is analysed by an iterative algorithm [8]. It is based on an initial guess for currents and reaching to same voltage drop in all parallel cables in each phase with ignoring of earth return path.…”