Transformer Flux and Exciting Current

[Jin0505]

Can anyone explain in a transformer, how could a non-sinusoidal wave of exciting current produces a sinusoidal wave of flux?

 

[Hesch]

how could a non-sinusoidal wave of exciting current produces a sinusoidal wave of flux?

Say you have a triangular exciting current. If you Fourier transform this current, it will have a dominant first harmonic ( sine wave ).

It will also have a lot of higher harmonics, that are dampened due to self induction and iron losses in the transformer. Hence you will see a flux wave that is similar to a sine wave, but is not a perfect sine wave.