What is the vector group of auto transformer?
The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. The Determination of vector group of transformers is very important before connecting two or more transformers in parallel.
Why do we need vector group in transformer?
The vector group of a transformer indicates what type of connection is made between the windings of that transformer. It also indicates what is the phase difference between the primary and secondary winding voltage of that transformer.
How did the vector group of transformer get its name?
The naming convention popularly known as Vector Group of Transformer was established by the International Electrotechnical Commission (IEC) through IEC 60076-1. This was done in order to create a notation for three-phase transformer winding configuration. Figure 1. Wye-Delta transformer winding connection.
How are coils connected in a vector group transformer?
The coil voltages can be in phase or displaced as above with the coils connected in star or delta and, in the case of a star winding, have the star point (neutral) brought out to an external terminal or not. An ac voltage applied to a coil will induce a voltage in a second coil where the two are linked by a magnetic path.
How are the phases of a transformer related?
As shown in the above figure the transformer is having 3 phases on HV Side (1U,1V,1W) and 3 Phases on LV Side (2U,2V,2W). It means the LV Side U phase Vector 2U lags the HV Side U phase Vector 1U by 30°. It is applicable to other phases also. LV Side V phase Vector 2V lags the HV Side V phase Vector 1V by 30°.
Why are phasor groups used in poly phase transformers?
Phasor or Vector groups are used to denote different connection methods for poly phase transformers. This knowledge is required for connecting the poly phase transformers in parallel. To understand the designation of these groups one has to know the assumptions. 1. In the phasor diagrams, the phasors rotate in the counter clockwise direction.