Читать книгу Practical Power Plant Engineering - Zark Bedalov - Страница 69

Every effort shall be made to minimize the number of transformations from the grid to the loads. Unnecessary transformers add to the voltage drops as well as to the cost of the plant in the transformers and additional associated switching and protection equipment.

For this plant, we can use two or maximum three levels of transformation, as follows:

 Grid → 230 kV–T1–13.8 kV → 13.2 kV–T2–4.16 kV → 4.0 kV Motors, or

 Grid → 230 kV–T1–13.8 kV → 13.2 kV–T2–0.48 kV → 0.46 kV Motors and feeders

 Grid → 230 kV–T1–13.8 kV → 13.2 kV–T2–4.16 kV → 4.16 kV–T3–0.48 kV → 0.46 kV Loads

 Grid → 230 kV–T1–13.8 kV → 13.2 kV–T2–0.48 kV → 0.48 kV–T3–0.48 kV → 0.48 kV Ltg. Panels¹