Electronic – Synchronous Generator EMI

accurrentgeneratorphasorvoltage

In the attached image below, I don't understand the text and phasor diagram that I have highlighted in yellow.

enter image description here

Why does the induced emf on the armature winding lag the magnetic flux of the corresponding rotor pole by 90 degrees? I thought they would have been in phase.

Also how does the power factor affect this?

Best Answer

In first approximation, a synchronous generator is just a coil.

The behavior of a coil is that current and voltage have 90deg phase angle.

Flux is directly related to current I, because current I generates flux in the coil. So also flux and voltage always have 90deg phase shift.