This paper outlines the most recent developments regarding the magnetic field distribution analysis inside very high voltage substations. The study was performed in order to develop and validate a powerful computation tool able to determine and predict the magnetic field value inside any point of the substation and to check whether the exposure limits exceeds the admissible values imposed by the legislation. The study case proposed in the paper is taken from the Romanian national power grid but the conclusions outlined can be directly extended to substations belonging to other national power grids. In the first part of the paper the principles and methods proposed by the authors for the magnetic field computation in the vicinity of the power devices composing a high voltage substation are outlined. The validation of the computation module implemented was done by comparisons with detailed experimental measurements results performed inside a new rehabilitated 400 kV substation. The evaluation of the results outlines a good agreement between the computed and measured magnetic field values inside the analyzed substation. This fact motivates the usage of the computation module developed in the design of the future high voltage substations in the light of fulfilling the actual regulations regarding the human exposure to power electric and magnetic fields. In the second part of the paper results of the field values inside the studied substation are presented. The final conclusions end the paper.

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Some inverse sensing procedures combined with numerical regularization techniques are presented for identifying and reconstructing the spatial and temporal waveform of the lightning return stroke current. The novelty of the approach relies on simulation of real time acquisition of the electric and/or magnetic field generated by the discharge channel, at various locations on the ground and at various frequencies and evaluation of these field values by specific field synthesis methods.