Knowledge of a comprehensive overview of the basic components of the electricity distribution networks and the classification of distribution panels and their operation. The electrical transformers in power stations are detailed and their classifications are clarified in terms of type, function, installation mechanism, the cooling mechanism used, number of faces, and other classifications. The types of oils used in transformers are also identified. Electrical, types of circuit breakers, busbars and tests on high, medium, and low-pressure transformers, neutral grounding of transformers, end of the periodic maintenance of transformers.