This paper firstly examines the consolidated analytical methodologies available in literature for the calculation of the magnetic field generated by a twisted three-phase conductor arrangement carrying balanced three-phase currents. Such literature methodologies consist of an exact analytical expression of the RMS magnetic induction given in the form of complicated Bessel-function series and of an approximation of such exact expression where only the first term of the series is considered. Subsequently, a simple innovative approximated formula for the RMS magnetic induction generated by twisted three-phase power cables is obtained by means of an heuristic procedure. This formula results a good approximation of the rigorous analytical one and at the same time is much more accurate than the approximated formula found in literature, as demonstrated by the case of a twisted three-phase power cable used for power distribution at the medium voltage level.
[1]
P. Pettersson,et al.
Reduction of power system magnetic field by configuration twist
,
1997
.
[2]
Fred Haber,et al.
The Magnetic Field in the Vicinity of Parallel and Twisted Three-Wire Cable Carrying Balanced Three-Phased Current
,
1974
.
[3]
Calcolo del campo magnetico generato da cavi elicordati per la distribuzione dell'energia elettrica
,
2009
.
[4]
R. Unbehauen,et al.
On the magnetic field of an infinitely long helical line current
,
1994
.
[5]
Predicting the magnetic field from twisted three-phase arrangement
,
1997,
IEEE 1997, EMC, Austin Style. IEEE 1997 International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.97CH36113).