Modeling critical overloading in 6–10/0.4 kV, 250–630 kVA power, oil-immersed transformers

This study was motivated by its critical importance to the current problem of electricity supplies in Armenia. The time duration for oil-immersed power transformers in both operating (heating process) and standby (cooling process) regimes is determined for a given overloading degree. This process is compared with experimental results on TM-(630,400,250)/10-0.4 kV transformers, and overloading times and cycle durations for each power transformer type are determined. The information may be used to determine the overloading degree of transformers and the permissible duration of their usage in overload regimes.