The Impact of Cooling Medium Temperatures on the Nominal Power Selection at Substation Transformers (Kabun-1, Syria)

Monitoring the condition of power transformers is of great importance when considering issues of reliability and safety in the power system. Thermal stress is the main factor that needs to be controlled. Sharp fluctuations in the temperature of the transformer winding, oil, insulating medium, etc. affect the operating conditions, service life and safety of transformers. The purpose of the study is to determine the type of approximation functions for the dependence of the temperature of the windings and oil of power transformers on their load, then build a graph of the value of the equivalent average winding heating temperature (t
w.av.f
), depending on the load factor of the 33/11 kV transformers at the substation "Kabun-1" in Syria, taking into account: the duration of the load value in the interval (t=1h); the heating time constant (T
0
=2.5h); the value of overheating of the transformer structural for t=0 (θ
0
=30°C); the value of the equivalent annual temperature for the Syrian climate (θ
eq
= 22°С).