many thanks, i will correct in futures videos!

No! To properly control the motor (speed/torque), you only need to feedback Ia, Ib & Ic plus information on the rotor position (which can be given by a position sensor - encoder, resolver, etc. or even can be derived from the back emf of the motor). The stator voltages are actually what the inverter is outputting to the machine, since Va = ma*VDC and ma (the modulation index at phase a) is the control output of the feedback loop - given currents Ia, Ib, Ic and rotor position, your controllers calculate what the modulation index should be at each phase to achieve the desired speed/torque (R & L are actually encapsulated in the dynamic model of the machine for control purposes).

There is not any flux made by the rotor, if it's angle shoudn't change regarded to the stators flux .Therefore "slip" (beetwen two axes ) must being present in assyncronous mode operation.

i did most of them. some of them were made by a fellow professor (the phasor diagrams).

and some (such as the motor spining at the beggining) are from wikipedia

@@PedroAlmeida0 Hi Almeida, what software do you use to make animations? It looks so great !

their vector sum is not zero. you are doing the sums of their modules (amplitudes). their vector sum equals the space vector v, which has the same direction at this instant as phase va, because theta=0. this means that at instant theta=0, the space vector is aligned with phase a.

i_s=ia+ib * e^(j120)+ ic * e^(j240) , if you make a definition like this, their vector sum is not zero, of course. But, there does not such a voltage or current exist at the stator. What really exists is 0=ia+ib+ic.Stop the video at 5:08,check the graph on the right, you can see their sum is zero. The sum of vectors on the left is not zero. So,the graph on the left is not same the graph on the right. I think, we are trying to create this i_s current at the stator, to control the torque(quadrature part of i_s) and flux(diret part of i_s).

@@agemennon so why math does not fit with the real world? The rotor is rotating, we know that so ther emust be a V vector. why on the time scale sum of all phases are giving zero not V?

I think you may be confused with a space vector. It is very different from just adding the three vectors' amplitudes together.