MEASUREMENTS OF ELF ELECTROMAGNETIC EXPOSURE OF THE GENERAL PUBLIC FROM BELGIAN POWER DISTRIBUTION SUBSTATIONS

Abstract

In this paper, the exposure of the general public due to distribution substations of 11/0.22-0.4 kV is investigated. The substations are categorized according to their location (substations in buildings, detached substations, substations between two houses, and underground substations in the pavement), and eight relevant substations are selected to perform measurements of the electromagnetic fields. The purpose of this paper is to determine the "minimum distances" for the general public--defined as the distances outside which the field levels do not exceed a certain field value--of these substations. In total, 637 field measurements were performed: 358 measurements of the magnetic field and 279 measurements of the electric field in different locations. Measured momentary magnetic field values are within the range of 0.025 to 47.39 microT. Electric fields are within the range 0.1 to 536 V m(-1). Also, magnetic field measurements as a function of the height above the ground were performed. The maximal magnetic (values over one day) and electric fields for all the investigated substations were below 100 microT and 5 kV m(-1), respectively. For exposure over a year, all substations except one delivered values below 100 microT. For the substation producing a magnetic field above 100 microT, a minimum distance of about 0.5 m was obtained. When comparing the average exposure with the value of 0.4 microT, minimum distances of maximally 5.4 m (average day) and 7.2 m (average year) were obtained.