The objective of the thesis is to analyze the electromagnetic pollution generated by High Voltage electrical substations - specifically EHV/HV (Extra High Voltage/High Voltage) substations - with a focus on current regulations regarding the protection of people from exposure to electromagnetic fields. The research activity was centered on the development of a numerical code in MATLAB capable of accurately and effectively modeling the main components of substations. The resulting tool allows, starting from a limited number of input parameters, the complete description of the source geometry. It proves useful both in the preliminary design phase and for the analysis of existing installations.