Related Topics

  Protection of Transformer  Equivalent Circuit diagram of single phase Transformer   Core type Transformer and Shell type Transformer  Transformer with winding Resistance and Magnetic Leakage  Transformer with winding Resistance but No Magnetic Leakage  Equivalent Resistance of single phase Transformer  Magnetic leakage of Single Phase Transformer  Oil Flow Indicator of the pump of Power Transformer  Silica Gel Breather of Transformer  Oil Pump of Transformer   Radiator of Transformer and working of Radiator  PRD of Transformer  MOG ( magnetic oil gauge ) of Transformer  Bushing of Transformer ( for H.V side and L.V side )  WTI and OTI of Transformer  Buchholz Relay of Transformer and Working of Buchholz Relay  Conservator tank of Transformer  What is a Power Transformer ?  Short Circuit Test or Full load Cu loss of Transformer   Open circuit test or No load Test of Transformer   Parallel operation of 3-phase Transformer  Earthing or Neutral Grounding Transformer   Transformer on On load Condition   What is a Transformer ?  E.m.f Equation of Transformer   Transformer on No load Condition


SymbolsTransformerRelayPower-SystemBasic-electricalACSR-ConductorCircuit-BreakerInterview-questions-of-Basic-ElectricityInterview-questions-of-transformerInsulatorCurrent-TransformerMCQMCQ-powersystemThermal-power-stationInterview-questions-of-Power-SystemPower-ElectronicsInterview-questions-of-Underground-CableInterview-questions-of-IlluminationIlluminationMCQ-of-ElectronicsMCQ-of-Basic-ElectricalMCQ-of-Transformers MCQ-of-D.C-motor MCQ-of-D.C-generators

Magnetic leakage of Single Phase Transformer

The magnetic Leakage flux:

When the a.c power supply is applied to the primary winding of a transformer, the primary winding produces magnetic flux φ which flows through the Iron core of the transformer and the magnetic flux cuts the secondary winding of the transformer. But, all flux of primary winding does not cut the secondary winding, some part of flux i.e φL1 completes its magnetic circuit by passing through the air rather than around the core which is shown in fig. This leakage flux is produced due to the primary-amp turn ( m.m.f ) existing between point a and b. This leakage flux φL1 completes the magnetic circuit in the portion ( a-b ) .Hence, this flux is known as primary leakage flux and is proportional to the primary ampere-turns. This flux φL1 is in time phase with primary current I1 and induces an e.m.f eL1 in primary winding only.

Similarly, due to secondary ampere-turns ( m.m.f) across points c and d , leakage flux is produced φL2 which is linked with secondary winding only,( not linked with primary winding ). This φL2is in time phase with I2 and produces a self-induced e.m.f eL2 in the secondary winding. The both leakage flux at primary and secondary fully depends on the load of the transformer. If load of transformer increase, leakage flux will simultaneously increase.

The leakage flux linking with each winding , produce a self induced e.m.f in the winding . and this e.m.f is equivalent to a small choker or inductive coil in series with each winding. And the voltage drop in each series coil is equal to that produced by leakage flux. A transformer with to an ideal transformer is equivalent to an ideal transformer with the inductive coil connected in both primary and secondary circuit as shown in the figure.

Let,X1 is primary leakage reactance and X2 is secondary leakage reactance of a transformer.
Therefore, X1 = eL1 / I1 ( where I1 is Primary current and eL1 is self-induce e.m.f in primary winding )
X2= eL2 / I2 ( where I2 is Secondary current and eL2 is self induce e.m.f in Secondary winding )
Due to leakage reactance, the reactive drop should be added with the resistive drop at both windings.Therefore, The reactive drop in primary winding = I1X1 and the rective drop in secondary winding = I2X2.

Please note that the leakage fluxes of the transformer can be minimized by sectionalizing and interleaving the primary and secondary windings which is shown in the figure below.

<< Previous Next >> More details go to:-
  • Related topics :

    Recent Post

    Multiple Choice Question (MCQ) of Electronics page-17:
    241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor.
    b) The saturation voltage VCE for germanium transistor is more than silicon transistor.
    c) The saturation voltage VCE for silicon transistor is same as that for germanium.
    d) The saturation voltage VCE for silicon transistor is lower than germanium transistor.


    Multiple Choice Question (MCQ) of Electronics page-16:
    226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor.
    b) Bound electrons are always present in the semiconductor.
    c) Free electrons are always present in the semiconductor.
    d) Inner and bound electrons are always present in the semiconductor.


    Multiple Choice Question (MCQ) of Electronics page-15:
    211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors
    b) Conductors
    c) Insulators
    d) Alloys


    Multiple Choice Question (MCQ) of Electronics page-14:
    196. In which of the following device the base resistors are not added in the package but added externally? a) UJT
    b) CUJT
    c) PUT
    d) None of the above


    Multiple Choice Question (MCQ) of Electronics page-13:
    181. The conduction in JEFT is always by the a) Majority carriers
    b) Minority carriers
    c) Holes
    d) Electrons
    e) Holes and electrons simultaneously


    Name :