What is a Transformer Connection?

What is a Transformer Connection?

Three-phase Transformer Connections Definition

A three-phase transformer connects its primary and secondary windings in star or delta configurations for various electrical applications.

Star Connection

In star connection, three windings connect at one end to form a neutral point, used for creating a neutral terminal.

In star connection, a line-to-line current is the same as a line-to-neutral current.

we can find that the line-to-line voltage is √3 times line-to-neutral voltage.

Delta Connection

In delta connection, windings form a closed loop, creating a triangle-like shape, providing a path for the supply to the junction points.

we can find that the line-to-line current is √3 times line-to-neutral current.

line-to-line voltage is the same as line-to-neutral voltage.

Types of Connections

Delta-Delta

The line current is √3 times phase current under balance condition. When magnetizing current is neglected, the current ratios is;

Star-Star

 Delta-Star

Star-Delta

Open Delta Connection

This connection operates with two transformers, maintaining three-phase power with a lower load capacity when one transformer is out of service.