Analysis and Explanation of Resonant Phenomena Involving EHV Transformers during Power System Restoration Tests

This paper deals with the simulation and experimental confirmation of electromagnetic events that could interfere successful formation restoration path during power system procedure. The studied phenomena are more relevant for bulk systems characterized by a low short circuit as backbone. In particular, two case studies have been simulated analyzed: one related to transformer energization path, other occurred after de-energization some transmission lines autotransformer belonging path. From results, it emerged such resonant effects between supplying restored network. Such resonances negative on if they not effectively managed. order evaluate impact in real networks, measurement recordings on-field tests were compared results. It is worth noting performed analyses require knowledge several parameters always available practice. Hence, exact magnitude described was easy foresee networks. comparison confirms preliminary results highlights detailed models particularly important support management, particular planning recovery procedures.