Prof. Abdel-Salam Hafez Abdel-Salam Hamza :: Publications:

The exposure to magnetic fields and their effects plays a major issue in the human biological study, so the need for the magnetic fields evaluation inside the electrical power system installations becomes necessary. The electrical power substations are considered the main element in any electrical power system all over world. So, there is a necessity for the evaluation of the magnetic fields and their effects on the engineering workers exist inside these power substations. In this paper, two actual and different voltage level conventional electrical power substations (500/220 kV and 220/66 kV), in Egypt, are modeled and considered. For a purpose of comparison and normalization, the magnetic field values are evaluated and depicted based on a line current equivalent to the average load in each circuit of the outgoing circuits of the two substations. In addition, the magnetic fields are evaluated based on the actual load sheets, for both substations, for different load scenarios over 24 hours of a selected day. The effects of the steel structure in the substation are neglected (considering μr =1). The transformers are considered as a blocked area. For the purpose of evaluating the interaction of the human body with power frequency (50/60 Hz) magnetic fields inside the two considered substations, a numerical human body model is developed as; multi-frustums of cones with spherical head, to represent the human body more accurately, based on the Finite Element Method (FEM). The developed human body model is exposed to the maximum obtained magnetic field values inside each electric power substation representing typical exposure cases. Based on the exposure magnetic field values with different human body electric conductivities, the induced electric fields and current densities inside the different human body parts are evaluated. The obtained results are compared with the standard values of the magnetic and electric field exposures. Keywords: Power Substation; human body modeling; electric and magnetic fields (EMF); induced currents.