Author(s)

N. Kovač, D. Poljak, S. Kraljević, N. Božić & N. Grulović

Abstract

A procedure for the computation of the maximal value of extremely low frequency (ELF) magnetic fields from a power substation is proposed. The present technique is based on the multiquadric approximation of the magnetic field. The approximation is obtained using discrete field values calculated by the Biot-Savart law, where each energised substation conductor has been divided into a corresponding number of straight segments. The approximation sufficiently handles multidimensional multiextreme functions by interpolating their discrete values accurately. Subsequently, the maximal magnetic field value is evaluated by minimizing the negative multiquadric approximation via a stochastic optimization method – differential evolution. Therefore, the procedure provides the maximal field value assessment on the basis of the limited number of computed discrete values, thus reducing the computational cost. 1 Introduction An assessment of extremely low frequency (ELF) electromagnetic fields to which human beings are exposed has been of great interest for many years. Reason for this is the public concern regarding the possible health risk due to human exposure to such field sources. Moreover, there is a possibility of electromagnetic interference (EMI) threat concerning possible malfunction of sensitive electronic equipment. Namely, malfunction of some medical devices could seriously affect human health. Consequently, an assessment of the maximal ELF field quantities for comparison purposes with the (inter)national guidelines should be considered as a rather important task. Therefore, a particular attention should be focused to significant ELF field sources such as power substations.

Keywords