In this thesis is presented installation of Petersen coil in substation Litija, which is owned by Elektro Ljubljana, with the emphasis on response analysis of electric power system through calculations and collected data. The way of neutral point earthing of transformers has been changing constantly over the years. Installation of Petersen coil brings some changes to the system and consequently the need for replacement and upgrade of certain elements (surge arrester, overcurrent protection, automatic reclosing equipment, …).
In the first part of theoretical basis the coil is presented through classical analysis in Matlab. The basis of the first part is description of Petersen coil in substation Litija, where we discuss characteristics, tuning and operation of regulators.
In the second part are presented calculations for the transformer model which is included in Simulink for examples TR1 and TR Radanja vas. Calculation procedure is extensive, therefore the thesis doesn't include all calculations for each transformer. Further on we describe Fourier transform, which we use for representation of positive, negative and zero sequence vectors. We put emphasis on calculation of parameters of considered power line, cable and charging current. The second part of subchapters is finished with overcurrent protection, where we present algorithm for current independent delayed characteristic with time escalation, which is used in choosen network.
In the last part of the thesis we built a network model in Matlab (Simulink), where we simulated different responses of the system. We focused on voltage responses in conditions where surge arresters with higher characteristic are installed, response values of compensated ground fault current and operation of overcurrent protection, when Petersen coil is installed.
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