what is types of transformer connection are use in transformer? Types of transformer connection

Transformer connection

Transformer basic concept

A transformer is static (or stationary) piece of apparatus by means of which electric power in one circuit is transformed into electric power of the same frequency in another circuit. It can raise or lower the voltage in a circuit but with a corresponding decrease or increase in current. The physical basis of a transformer is mutual induction between two circuit linked by a common magnetic flux.

·        In its simplest from, it consist of two inductive coils which are electrically separated but magnetically linked through a path of low reluctance.

Transformer types

·        Single phase transformer

·        Three phase transformer

The different types of transformer are Step up and Step down Transformer, Power Transformer, Distribution Transformer, Instrument transformer comprising current and Potential Transformer, Single phase and Three phase transformer, Auto transformer, etc.

Transformer connection types

• ·        Star connection
• ·        Delta connection
• ·        Zig - zag connection

      Star connection

• In STAR connection, the starting or finishing ends (Similar ends) of three phases (coils) are connected together to form the neutral point. A common wire is taken out from the neutral point which is called Neutral. There is no such connection in Delta network. The Line voltage is root three times the phase voltage

 Usually, Star Connection is used in both transmission and distribution networks single phase supply or three – phase. Delta Connection is generally used in distribution networks. Since insulation required is less, Star Connection can be used for long distances.

Delta connection

In a standard delta–wye (or wye–delta) transformer, the positive-sequence currents and voltages on the high voltage side lead the positive-sequence currents and voltages on the low voltage side by 30°. When the high voltage phasors lag the low voltage phasors, the connection is considered to be non-standard.

Delta-star connected transformers are widely used in low power distribution with the primary windings providing a three-wire balanced load to the utility company while the secondary windings provide the required 4th-wire neutral or earth connection.

Zig-zag connection

A zigzag transformer is used to reduce harmonics on the secondary supply. A zigzag transformer is a special-purpose transformer with a zigzag or "interconnected star" winding connection, such that each output is the vector sum of two (2) phases offset by 120°.

A delta-wye transformer is a type of three-phase electric power transformer design that employs delta-connected windings on its primary and wye/star connected windings on its secondary. A neutral wire can be provided on wye output side. An equivalent term is delta-star transformer.