At the 110 kV step-down substation, two-winding transformers are installed. The number of transformers is n=2. The catalogued data are following: nominal power Snom=16 MV A; nominal voltage of primary winding Vpr nom=115 kV; nominal voltage of secondary winding Vs nom=11 kV; adjustment range of voltage ±9x1.78%.

Voltage deviations at the 110 kV busses are V1=-5.63% during on-peak regime and V2=-0.18% during off-peak regime.

The total voltage drop in transformer ∆VT1=4.5% during on-peak regime and ∆VT2=1.54% during off-peak regime.

to calculate transformer turns ratio for on-peak and off-peak regimes if voltage control is provided at the 10 kV busses.