Emission levels of ELF magnetic fields from 132 kV distribution substations

Abstract

One of the leading sources of emission of ELF magnetic fields in occupational settings and residential communities is overhead power lines and electrical substations. This study aimed to investigate the emissions of ELF magnetic fields in 132 kV distribution substations within Mangaung metropolitan region, Free State, South Africa. Four 132 kV substations were randomly selected in three prominent areas of Mangaung metropolitan region. For each substation, 50 (1 m2) blocks were divided from the floor plans and a total of 200 measurements were collected using Triefield meter model XE 100. The data was analyzed using analysis ToolPak from excel programme (Microsoft 2010). ANOVA was performed to compare the mean values between four substations. The results obtained from statistical tests indicated a non-significant difference when ELF magnetic field emissions from four distribution substations were compared to one another (p< 0.39). It was also found that area one (1.26 µT) had a higher emission mean value than area two (1.15 µT) and three (1.14 µT) respectively. This study concludes that exposure levels measured in the three prominent areas of Mangaung are below the recommended ICNIRP guidelines for both workers and general public.