Transformer with Resistance and Leakage Reactance Calculation

Transformer with Resistance and Leakage Reactance

What do you mean by the Transformer Resistance and Leakage Rcctance?

The Transformer resistance means the resistance of the primary and secondary winding of the transformer. 

Transformer Leakage Reactance means there is some magnetic leaking in both of the primary and secondary windings that should be equal to inductive coils connected in both primary & secondary windings.

In the figure above, the primary and secondary windings of a transformer with reactances taken out of the windings are shown. 

The primary impedance is given by
Z₁ = sqr(R₁²+X₁²)

Similarly, secondary impedance is given by
Z₂ = sqr(R₂²+X₂²)

The resistance and leakage reactance of each winding are responsible for some voltage drop in each winding. 

In the primary, the leakage reactance drop is I₁X₁(usually 1 or 2% of V₁).

Hence,
V₁= E₁+ I₁(R₁+jX₁) =E₁+I₁Z₁

Similarly, there are I₂R₂ and I₂X₂ drops in secondary which combine with V₂ to give E₂.

E2 = V2 + I₂(R2+jX2) =V₂+ I₂Z₂

It may be noted that leakage reactances can also be transferred from one winding to the other in the same way as resistance.