Determining actual magnetic field zones
In early January 2019, Witteveen+Bos was awarded the ‘Plus’ qualification by the National Institute for Public Health and the Environment (RIVM). This means that we are now qualified to calculate the width of actual magnetic field zones for every possible configuration of multiple high-voltage power lines. We have since carried out our first assignment with this qualification for a client in Haelen, Limburg.
High-voltage power lines generate magnetic fields that can be harmful to people’s health. The actual magnetic field zone is the area within which negative health effects are likely for anybody living there. The width of the zone is often a decisive factor in construction projects near high-voltage lines. Before obtaining the Plus qualification, Witteveen+Bos had held the RIVM’s ‘Basic’ qualification for a number of years. Holders of the Basic qualification are permitted to calculate actual zone widths for single high-voltage power lines (officially known as the ‘standard situation’).
With the Plus qualification, we are now permitted to make calculations in more complex scenarios – in particular, those in which several high-voltage lines are so close together that their magnetic fields influence each other significantly. To help us conduct such complex calculations, a 3D calculation model based on the RIVM’s rules was developed using MATLAB. This model takes into account a range of factors, including different phases, current directions, and conductor sag.
Thanks to this calculation model, we now have a better understanding of magnetic fields as well as a universal basis for calculating them in all manner of situations, including underground cables and transformer stations.