let's refer to the following (vector) control schemes:
Qd0 is the synchronous reference frame, with d alligned to the pm magnetic field. the system is balanced and symmetric (so no 0 component).
the motor is an internal mounted permanent magnet ac motor.
for what I understood the main advantage is having vq and vd DC instead of va,vb,vc AC.
this means that at steady state I have a zero error (PI doesn't zero the error for AC? I'm not so sure about it). Qd0 scheme is more expensive due to the computational cost associated with the trasformation matrices.
Now I have this sentence on my book: ''Qd0 control is more performant since the current bandwidth does not depend on the speed''.
Why is that? I don't see why the current bandwidth is affected by the speed in the a,b,c reference frame, so I don't know wwhy this is not the case for q,d,0.
Is it because the speed (in a synchronous) pm machine is linked with the frequency of va,vb,vc (and so ia,ib,ic frequencies) ? I miss the actual connection to the bandwidth tho.
any advantage in using a,b,c? for now there doesn't seem any.