The Transformation Ratio of a transformer is the voltage ratio between the high voltage side windings of the transformer and the low voltage side windings. Specifically, it represents the ratio of the rated voltage on the primary side of the transformer (usually called the high voltage side or the input side) to the rated voltage on the secondary side (usually called the low voltage side or the output side).
Mathematically, the transformer ratio (K) can be expressed as:
K = high side voltage / low voltage side rated voltage rating
Measure the voltage ratio for each tap position. Verify the results against the design data. Measure voltage ratio error % should be ≤0.5 of the specified value.
How to calculate the transformer ratio
There are several ways to calculate the transformer ratio:
1. Calculate the change by the ratio of turns of the main line
Formula: Ratio = number of turns of main coil ÷ number of turns of secondary coil
Example: If a transformer has 1000 turns in the main coil and 2000 turns in the secondary coil, the ratio is 1:2.
2. Calculate the ratio by input and output voltage
Formula: Voltage ratio = input voltage ÷ output voltage
Example: If the input voltage of the transformer is 220V and the output voltage is 110V, the ratio is 2:1.
3. Use the rated capacity of the transformer to calculate the ratio
Formula: Voltage ratio = under the root sign (rated capacity of transformer × input voltage) ÷ output voltage
Example: If the rated capacity of the transformer is 1000 watts, the input voltage is 220V, and the output voltage is 110V, the ratio is: √(1000 × 220) ÷ 110 = 2:1.
When calculating the transformer ratio, the appropriate method can be selected according to the actual known transformer parameters and scenarios.
If you know the main secondary coil number of turns, which can be directly through the number of turns than ratios calculated.
If you know the input and output voltage, can be directly through the voltage ratios calculated strain ratio.
If you know the rated capacity of the transformer and the input and output voltage, by specific formulas to calculate the strain ratio.
