A SIMPLE INNOVATIVE METHOD TO REDUCE EXTREMELY LOW FREQUENCY MAGNETIC FIELD BY CONDUCTOR SPLITTING AND PHASE MIXING

Abstract

With the advent of modern day technologies, substantial increase in man-made magnetic fields was observed. At frequencies of 50 and 60 Hz, Extremely low frequency (ELF) magnetic fields are mainly from electrical energy generation, transmission, distribution and usage. One of the most commonly found source of ELF magnetic fields are electric cables as they are inevitable in a power system. Public concern on potential health problems has raised because of exposure to ELF magnetic fields. The biological effects associated with exposure to ELF magnetic fields, like leukemia, brain tumor, neurological effects and cardiovascular effects has unavoidably led to imposing legal limits. Popular methods mitigating this problem were cable twisting, active shielding, conductor splitting and phase mixing. The aim of this paper is to determine a simple, innovative and cost effective method of cable design to reduce the ELF magnetic field produced at the vicinity of single phase electric cable. The proposed method incorporates conductor splitting and phase mixing simultaneously. Conductor splitting distributes the area of a single conductor into N sub-conductors and phase mixing rearranges the conductors of N phases in specific orders. Its effectiveness was verified with theoretical calculations and computer simulation results. The cables were modeled using Finite Element Analysis (FEA) based software package Magnet, developed by Infolytica Corporation. The result from the study reveals that