Power factor for Induction Generator

The power factor for induction generator is lagging as it need vars for magnetising the stator so they need capacitors to compensate.

Are you working in wind farm?

Yes, i am.

But the point is induction generator supplies active power to grid and consumes reactive power from grid. In which quadrant, the resultant current vector is?

2nd quadrant since power is generated to the grid.

Induction generator operation would mean that it is drawing its excitation power from the grid. This is taken in the form of stator drawing current which should have magnetizing armature reaction. (Armature reaction is demagnetizing when stator current is of lagging power factor, cross magnetizing at unity power factor and magnetizing at leading power factor). So for the purpose of analysis, stator would carry two currents. First the load current, power factor of which is decided by the nature of load and second magnetizing current which would be of zero leading power factor. Net power factor will be decided by vectorial sum of the two currents.

Just google -

Self Excited Induction generator

Capacitor Excited Induction generator

or

Induction generator Excitation

and you will find a lot of good papers and articles (and quite a few are for the Wind Energy)

A few are from the theoritical aspect also from different universities and also the theory of AC circuits link

If a generator is a permanent magnet, then the power factor is lagging. However, if it is a synchronous generator, the level of excitation would determine whether power factor is leading or lagging. If it is over-excited, then power factor would be leading, and if under-excited, then power factor would be lagging. Generally, power factors of large machines are adjustable. Possibly, part of the reason wind turbine manufacturers use large capacitor banks is to cancel out the reactive L.