Phase shift in step-down transformer simulation

[jprg]

Hi,

I modelled a step down transformer in SPICE (LTspice IV) and noticed that if I put a parasitic resistance on the primary winding, as a real transformer would have it, there is a phase shift between the primary and the secondary voltages. The secondary voltage leads the primary by a few degrees.

Why is that?

 

[FvM]

Phase shift is also observed in real transformers. You can visualize it by sketching a phasor diagram. Besides series resistance, also leakage inductance must be considered in the real transformer equivalent circuit.