It is evident from equation 12 that the rotor current i^e_dr will decay to zero and stay at zero regardless of other transients that may be taking place. Hence, the torque (from equation 2 ) is given by

(13)     (14)   (15)   (16)   (17)   (18)

Together, equation 19 and equation 21 suggest the generic rotor flux oriented control shown in Figure 2 .