# What is mean by vector group of transformer ?

The vector group of a transformer refers to the arrangement of windings and their connections in relation to the phase shift between the primary and secondary windings. It specifies how the windings are connected and the angular displacement between them. Each vector group designation represents a specific phasing arrangement that affects the transformer’s performance, particularly in terms of voltage regulation and phase relationships.

In transformer terminology, the vector group denotes the relationship between the primary and secondary winding voltages and currents. It is crucial for ensuring correct operation and phase synchronization in multi-winding transformers or those used in three-phase systems. The vector group designation provides information about the phase displacement and connection configuration of the transformer windings, helping in proper installation and synchronization with the electrical system.

The DYN11 vector group is a specific designation indicating the transformer’s configuration and phase relationships. In DYN11, “D” signifies that the primary winding delta (Δ) is connected, “Y” denotes that the secondary winding is star (Y) connected, and “N” indicates that the secondary winding is neutrally grounded. The numbers following DYN indicate the phase shift between the primary and secondary windings. In DYN11, the phase shift between the primary and secondary windings is 150 degrees.

The vector diagram of a transformer illustrates the relationship between the primary and secondary voltages and currents. It depicts the magnitude and phase angle differences between these quantities, typically shown in a vector format where arrows represent voltage or current vectors. The diagram helps in understanding the transformer’s performance characteristics, including voltage regulation, phase displacement, and impedance matching.

DYN5 and DYN11 are different vector group designations used for transformers. The key difference lies in the phase shift between the primary and secondary windings. DYN5 has a phase shift of 30 degrees (positive sequence) between the primary and secondary windings. In contrast, DYN11 has a phase shift of 150 degrees (negative sequence). This difference affects how the transformer interacts with the electrical system, influencing factors such as voltage stability, fault currents, and harmonic distortion. The choice between DYN5 and DYN11 depends on specific application requirements and compatibility with the existing power system configuration.