Power-frequency magnetic field calculation around an indoor transformer substation

The authors propose a full three-dimensional (3D) calculation model based on a multipole technique able to predict the magnetic field pollution outside of indoor medium voltage/low voltage (MV/LV) transformer substations. The authors demonstrate that the proposed model may be advantageously used in all problems related to the characterization of the electromagnetic environment around a MV/LV transformer substation. They also show how the model may be used to support the optimised design of the cabin layout when this solution is sufficient to assure the reduction (below the exposure limits fixed by law) of the magnetic flux density in target volumes within civil buildings. In particular, the proposed algorithm has been applied to evaluate the magnetic flux density levels in the neighbourhood of a typical indoor MV/LV cabin placed at ground zero of a civil building (and therefore bordering on houses and/or offices). In addition, in order to mitigate the magnetic field outside the transformer substation, using the proposed calculation code an attempt was made to design the layout of the cabin by rearranging the position of the LV distribution switchboard (i.e., the power center, PC).