Reliability and Overload Capacity of Power Transformers

The article describes the reliability of transformers, the failure rate and uptime to the first failure, the durability and maintainability of transformers and their service life, the allowable temperature rises and the dependence of steady-state overheating on the load factor of the transformer. An assessment of the effect of ambient temperature on the rated power of the transformer is shown. Dependences of heating on the changing load of transformers are given. The heating time constant is calculated depending on the power and cooling system of the transformer. The winding heating temperature is considered for real daily load schedules of a 33/11 kV transformer, the maximum actual overheats are compared when loaded with full power with allowable overheats. These studies can be used in transformers 33/11 kV and others with subsequent interpolation of values.