Electronic – leakage inductance on three winding transformer

testingtransformer

I have a toroidal 3 winding transformer. It's a step up, lets say 1:10 ratio, the secondaries are identical. If I measure the leakage inductance, shorting 1 secondary at a time, I get about the same leakage for both secondaries. If I short both, I get about 10% smaller than the individual leakage. Anyone know the reason or have an idea of what the equivalent circuit would look like?

Best Answer

You have two parallel leakage inductance paths so obviously with both other coils shorted , it will be less than just one shorted.