TIDUFE5 July 2025
The next step in system design is to modify a 2-phase orthogonal system (α, β) in the (d, q) rotating reference frame. Consider the d axis aligned with the rotor flux, Figure 3-8 shows the relationship for the current vector from the two-reference frame.
The flux and torque components of the current vector are determined by Equation 26.
where
These components depend on the current vector (α, β) components and on the rotor flux position; if the right rotor flux position is known, then, by this projection the d,q component becomes a constant. Two phase currents now turn into dc quantity (time-invariant). At this point the torque control becomes easier where the constant isd (flux component) and the isq (torque component) current components are controlled independently.