Sometimes may wonder what this transformer vector group means and how it is used in the electrical engineering field. The winding of the three-phase transformer connects in different ways according to its connection. So we need to identify the phase shift of the transformer. The vector group is an indication of determining the phase difference between the transformer’s primary and secondary.
Where can you find the vector group of the transformer?
You can find the Transformer Vector Groups by checking the nameplate of that transformer.
There are a symbol and specific file the vector group, and by this, you can understand it very easily.
For example, when the symbol shows the Yy0.
This means that the primary winding is Star.
Secondary Winding is Delta
Vector Group is 0
How to Decode Vector Group and Identify
Now you can understand that a vector group is a number, and from this number, you can decode it to phase shift of primary and secondary.
Following are the representation of Digit to the phase-shifted.
- Vector Number 0 =0° ( Phase Shift of 0° Angle)
- Vector Number 1 =30° ( Phase Shift of 30° Angle)
- Vector Number t 11 =330° ( Phase Shift of 330° Angle)
- Vector Number 6 = 180° ( Phase Shift of 180° Angle)
In some transformer, the grouped divide further as follows.
Group I (0 o’clock, 0°)
Group II (6 o’clock, 180°)
Group III (1 o’clock, -30°)
Group IV (11 o’clock, +30°)
So By group number, you can also identify the phase shift of each transformer.You can easily understand it by this clock number
Some Examples of Transfer Vector Groups
So in transformed, there are different vector representations, and you can decode the vector group and identify the config run very easily.
Following are the type 0f Vector Groupd you can find in transformer nameplate.
Yy0 – HV Winding Star, LV Vinding Star, and Phase Shift 0°
Dd0 – HV Winding Delta, LV Vinding Delta, and Phase Shift 0°
Yd1- HV Winding Star, LV Vinding Delta, and Phase Shift 30°
Dy1- HV Winding Delta, LV Vinding Star, and Phase Shift 30°
Yy6 -HV Winding Star, LV Vinding Star, and Phase Shift 180°
Dd6 – HV Winding Delta, LV Vinding Delta, and Phase Shift 180°
Yd11- HV Winding Star, LV Vinding Delta, and Phase Shift -30°
Dy11- HV Winding Delta, LV Vinding Stara, and Phase Shift -30°
Why is the transformer vector group important?
This is one of the important factors when parreral several transformers together.
Differnt combination of transformer winging create differnt phase angles then the voltage level of such transformers is different.
When you connect two different transformer vector group parral, then the phase differnt of each transformed gets higher. It will flow a large circulating current between that transformer, which is extremely dangerous.