What are the four main connection of 3-phase transformer?

We now know that there are four different ways in which three single-phase transformers may be connected together between their primary and secondary three-phase circuits. These four standard configurations are given as: Delta-Delta (Dd), Star-Star (Yy), Star-Delta (Yd), and Delta-Star (Dy).

How does a 3-phase transformers work?

Working Principle of Three-Phase Transformer The primary winding of the three phase transformer is energized from a three phase supply. Then, the flux is produced in the core by the primary currents in the three windings. The core has three limbs, where any two limbs act as return path for the flux in the third limb.

What is H1 H2 H3 on a transformer?

There are usually three high-voltage leads marked H1-H2-H3. The secondary leads would be marked X1-X2-X3. In three-phase transformers the phase rotation or phase sequence, is critical between the primary and the secondary. Each of the phase windings within the transformer normally have the same relative polarity.

What is Star and delta connection?

In STAR Connection, the starting or finishing ends (similar ends) of three coils are connected together to form the neutral point. A common wire is taken out from the neutral point which is called Neutral. In DELTA Connection, the opposite ends of three coils are connected together.

What does a 3-phase transformer look like?

A three-phase transformer is made of three sets of primary and secondary windings, each set wound around one leg of an iron core assembly. Essentially it looks like three single-phase transformers sharing a joined core as in Figure below. Three phase transformer core has three sets of windings.

What is X1 and X2 on a transformer?

For small control transformers, there will be X1 and X2 terminals only where X1 is the power side and X2 the grounding and a side of the low voltage.

What is X1 X2 X3 X4 in transformer?

Terminations, include; H1, H2, H3, and H4, which signifies the high voltage side if transformer and X1, X2, X3, and X4, which means low voltage side of a transformer.