Electrical machine l

Welcome to our Presentation

Group-E1.Abu mohammad Fazlay rabbyId:152-33-26192.Fatema tuj zohraId:152-33-26103.Mehedi hasanId:152-33-26254.Abdur RahmanId:152-33-26925.Roudra GourabID:152-33-2693

Contents

• Fazlay Rabby ------Problem with 3-phase transformer.• Roudro---Typs of transformer• Fatema---Step up and Step down Transformer• Mehedi ----Transformer with resistance and magnetic leakage• Alamgir--Equivalent Circuit

Three phase transformer

•  3-φ supplies are used for electrical power generation, transmission, and distribution, as well as for all industrial uses

Problem with three phase transformer

• Greater cost of standby Units.• Increased cost and inconvenience of repairs.• In Single Phase transformer ( three Single Phase Transformer) failure of

one transformer, the other two, Single Phase Transformer still supply the power, while it is not possible in case of failing a Three Phase Transformer.

• Each of the 1Ø transformers weight substantially less than the corresponding 3Ø transformer. This allows a line truck to hang transformers where a 3Ø transformer might need a crane. 

Welcome to my presentation

Topic-Types of TransformerPresented by

Gourab Das-152-33-2693

THANK

YOU

ALL

Presentation on Step up & step down transformer• Fatema tuj johra• ID-152-33-2610

Step-up Transformer

• On a step-up transformer there are more turns on the secondary coil than the primary coil. The induced voltage across the secondary coil is greater than the applied voltage across the primary coil or in other words the voltage has been “stepped-up”.

Step up transformer

Step down transformer

• A step down transformer has less turns on the secondary coil that the primary coil. The induced voltage across the secondary coil is less the applied voltage across the primary coil or in other words the voltage is “stepped-down”.

Step down transformer

Generally, both primary and secondary windings of electrical power transformer are made of copper. Copper is a very good conductor of current but not a super conductor. Actually, super conductor and super conductivity both are conceptual, practically they are not available. So both windings will have some resistance. This internal resistance of both primary and secondary windings is collectively known as resistance of transformer.

Transformer’s Winding resistance

Transformer’s Winding resistance in a exact equivalent circuit

Transformer’s magnetic leakage

In a transformer it is observed that, all the flux linked with primary winding does not get linked with secondary winding. A small part of the flux completes its path through air rather than through the core and this small part of flux is called as leakage flux or magnetic leakage in transformers.

Transformer’s magnetic leakage in a exact equivalent circuit

Transformer’s impedance

As we said, both primary and secondary windings will have resistance and leakage reactance. These resistance and reactance will be in combination, is nothing but impedance of transformer. If R1 and R2 and X1 and X2 are primary and secondary resistance and leakage reactance of transformer respectively, then Z1 & Z2 impedance of primary and secondary windings are respectively,

PresentationonMagnetic Leakage in Transformer

Presented byMd. Abdur RahmanID:152-33-2692Sec:B ; Group:EDept. of EEE

Index• Magnetic Leakage• Transformer With Resistance And Leakage Reactance• Vector diagram

Magnetic Leakage in Transformer• Magnetic Leakage can be defined as the

passage of magnetic flux outside the path along which it can do useful work.

• In a transformer it is observed that, all the flux linked with primary winding does not get linked with secondary winding. A small part of the flux completes its path through air rather than through the core , and this small part of flux is called as leakage flux of transformers.

Transformer With Resistance And Leakage Reactance

 Vector diagram for different kinds of the load

( When Load is Non-Inductive) ( When Load is Inductive) ( When Load is Capacitive)