Tap changer
Transformer tap changer
\[ Kp = \frac{U_{1}}{U_{2}} = \frac{U_{1N}+(3-p)·ΔU}{U_{2}} \]· Kp: Transformer ratio
· U1: High voltage side voltage, V
· U2: Low voltage side voltage, V
· U1N: Nominal high voltage (p = 3), V
· p: Tap changer position
· ΔU: Voltage interval between tabs
· 3: Nominal position (intermediate) according to nameplate
Transformer conditions, p = x
\[ K_{p=x} = \frac{U_{1N}+(3-x)·ΔU}{U_{x}} \] \[ U_{y} = \frac{U_{1}}{K_{p-y}} = \frac{K_{p=x}·{U_{x}}}{K_{p=y}} \] \[ U_{y} = U_{x} · \frac{U_{1N}+(3-x)·ΔU}{U_{1N}+(3-y)·ΔU} \]· U: Current voltage in low voltage, V
· Uy: Low voltage side voltage (p = y), V
· Ux: Current voltage in low voltage (p = x), V
