control of AC induction motor through VFD

[shami_jadoon]

thanks thanks thank you so much Camilo V Sir,

now it is clear to me but two more question sir if you can help me please.

1: what is the function of adder used after PID Controller.

2: the incremental gain that is applied for the input voltage signal amplitude (values of 0.95 and 0.25) are according to any formula are just adjusted according to example.
thanks once again

[MauraW]

Hi shami_jadoon, 

In regards to your first question the PI Controller will provide an output based on the difference between the desired speed (f0) and the "current" speed. This output is added to the "current" speed to obtain the next speed. This is part of control theory. 

As far as your second question in I will have to look into this further or suggest that you test different values for yourself and see if the results make sense 

[shami_jadoon]

thanks alot for your time Sir, as i was on EID holidays so cant reply soon. 

 one thing more than i m done ,,, here 0.95 is given as f0 or u can say desird speed, is it means that this motor speed will b 0.95*60 = 57 rpm???

[MauraW]

That looks correct to me! The units for f0 would be in Hz or rev/sec so if you wanted to go from that to rpm then multiply by 60sec/1min.