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Arresters are widely used in power systems to protect other equipment against overvoltages. However, in some conditions, they can’t operate successfully. One of the disturbances leading to the failure of the riser pole arresters is the ferroresonance overvoltages. In this paper, at first the influence of different transformer simulation models of ATP software on the occurrence of ferroresonance is studied and then the effect of ferroresonance on the riser pole arrester has been scrutinized through the thermal and electrical performance of the arrester in an underground distribution system. The results show that the arrester temperature rises due to energy dissipation in a ferroresonance circumstance, which indeed may result into the explosion of the arrester. Also, applying different models of the transformer in the ATP software and comparing the results, it is shown that the available models do not show the same effect on the arrester.

Summary: Despite power system operators' efforts, blackouts occur; therefore, power systems should be restored. To attain this, power system restoration is done applying different strategies after a complete blackout. The most famous one is the bottom‐up strategy. Determining the islands is of extreme importance in this strategy. Hence, this paper proposes a new version of multi‐objective populated simulated annealing considering the cohesiveness and the quality of islands as objective functions. The proposed method takes into account miscellaneous constraints such as black‐start availability in each island, load‐generation balance, power flow establishment equations, and the availability of synchronization devices. Simulation results for the IEEE 39 and 118‐bus test systems confirm the effectiveness of the proposed method in determining the islands. [ABSTRACT FROM AUTHOR]