AbstractThis paper presents a theoretical analysis of electromagnetic environments in power substations in service. A new analytical method is developed and applied to magnetic field calculations in 187‐kV and 66‐kV substations. Experimental results verify that the method offers a good prediction of the magnetic field profiles in the substations except for the areas where localized field sources exist. The analytical results show that the magnetic field strength depends to a great extent on how the load powers distribute on individual lines and buses, that the magnetic fields in substations have a three‐dimensional characteristic, and that the predominant field component depends on the position of interest. Moreover, it is suggested that objects placed in substations are exposed not only to magnetic fields of high strength in comparison to those in houses or near the distribution networks but also to fields with several percent of harmonic distortion.