4. Power transformers

Before being transferred to the extra-high-voltage lines via the evacuation substation, the electricity generated at 24 or 20 kV must be adapted to the grid voltage (400 kV, except at Tricastin). Part of it must also supply the plant's electrical system (6.6 kV). To achieve this, each unit is equipped with three power transformers: main (TP), withdrawal (TS) and auxiliary (TA). On 900 units, the TS is located between the alternator and the main transformer; on 1,300 and N4 units, it is located after the main transformer. Only the main transformer is discussed here.