# reluctance of the transformer windings

are the reluctance of both the transformer winding same? if that's so ? how ? because reluctance = effective length of wire/ (permeability X area ) , so is this ratio in both the sides always the same?

• Transformer performance is largely affected by "Leakage Reactance" than winding reactance, which one you meant? What you see in equivalent circuit is leakage reactance and has to do with leakage flux. – Deep Feb 12 '18 at 13:17

I've altered this answer because it was getting down voted and the only reason I can summize is that the embedded picture was too small to read so I've taken the main points and re-written them below.

Windings don't have reluctance - the magnetic core that a transformer (or inductor) is made from has magnetic reluctance. It's a bit like ohms law but for magnetics.

• Ohms law is resistance = volts/amp whereas for a magnetic core,
• Reluctance = ampere-turn/weber

So if you have 1 amp passing through ten turns producing 1 weber of magnetic flux you have a reluctance of 10 turns per henry. Yes ampere-turns per weber reduce to turns per henry.

because reluctance = effective length of wire/ (permeability X area )

Reluctance is also the length of the core divided by magnetic permeability and area of the core. The only consideration of wire length comes when you make turns

• OK who is this phantom down voter? – Andy aka Feb 8 '18 at 10:21
• Oh another down vote. Can anyone explain why? – Andy aka Feb 11 '18 at 10:21
• +1. Your answer is correct (of course). Helping null the down votes. – Marla Feb 11 '18 at 16:58

It seems that you are talking about "Leakage Reactance" as referred to primary and secondary windings of a transformer.

That reactance is actually a fictious reactance and it's formula has "not so easily measurable" parameters cause it deals with leakage flux paths, instead usual practice is to calculate overall reactance of transformer by short circuit test.

And no, leakage reactance as referred to primary and that referred to secondary need not to be equal.