چكيده به لاتين
Overvoltages created in the power system caused by different factors, such as lightning and switching, cause stress on the different power system and insulation failure. Surge arresters are one of the main elements in protecting power systems against overvoltages. The widespread application of zinc oxide arresters and the importance of the dynamic behavior of this equipment in determining the proper location of the arrester and insulation coordination determine the necessity of using a precise model for simulating this dynamic behavior (frequency dependent). So far, various models have been proposed to simulate the behavior of a surge arrester against fast waves which these models did not provide the needs of specialists and designers for the transient power system studies due to reasons such as lack of information provided by the manufacturer, reduced accuracy of the model with the change of the forehead or the amplitude of the current wave. In intermediate overvoltages, the behavior of the arrester is the function of the temperature of the pills. To know the mode of operation of the arrester, in this case, is very important in order to check the thermal stability of the arrester. In this thesis, the proposed lightning and switching models for metal oxide surge arrester at simulated voltage levels of traction posts are simulated by EMTP software, and the accuracy and capability of each of the models in the face of overhead currents and switching, as well as in one the sample network has been evaluated and compared. Then, using a Cuckoo optimization algorithm to optimize the parameters of the insulation level of the transmission line, grounding resistance and energy absorption by the arrester were studied.
This study suggests that the surge arrester model should be selected according to the type of overvoltage considered in the simulation. In this case, in temporary overvoltage and normal voltage of the grid, the temperature dependent characteristic must be selected, and in each of the lightning and switching surges, a model with the least error, no need for repetition to obtain the parameters and the most suitable convergence should be selected. Also for this line, the optimal values of the insulation level of the line (22/0122 kV), grounding resistance (23/7978 Ω) and energy absorption by the arrester (9/3725 kJ / kV) were obtained
