Vector Group or Transformer DYn11

 

Vector groups of transformer

Description: Vector group of the transformer states the phase difference between the primary and secondary windings of transformer. Transformer vector group shows the physical arrangements of windings of power transformer.There are several ways to connect three phase windings of a transformer for a three phase transformer. Vector group of a power transformer describes the winding connections as well as the phase difference between the primary and secondary of the power transformer.

Dyn11 transformer vector group

Three phase power transformers are divided in 4 vector groups with respect to the primary high tension and secondary low tension. Vector group of transformer states the connection detail as well as the phase difference between primary and secondary windings. Phase difference is the angle of lag by which the secondary power to the primary power. The vector group is measured in in the units of 30 degrees in the direction of clock or in clockwise direction.

• Group No. 1 No phase displacement
• Group No. 2 180 Degree phase displacement
• Group No. 3 -30 Degree phase displacement
• Group No. 4 30 Degree phase displacement

DY11 is a delta to start transformer in which high voltage primary winding is delta connected and the low voltage secondary winding is connected in star or Y. Where as the number 11 shows that there is a phase lag of 30 degrees from primary to secondary side. Meaning to say that the secondary or low voltage side is 30 degree lag behind the high voltage primary side. Or the primary side is 30 degree advance the secondary side. The number 11 shows the hour hand of the clock which indicates -30 degree phase shift. There are 0, 1,6 and 11 are common numbers shown in the group to indicate the phase shift for different transformers.

Information about the vector group is important as with the help of this information we know if a transformer can be connected in parallel with another transformer or not. The same group transformers can be connected in parallel. Like YY transformer can be connected to YY same way DD transformer can be connected to DD but can't be connected to DY transformer.