
24-16 Power Electronics and Motor Drives
Since in a Syn-Rel there is no excitation on rotor, excitation ux must be provided from the stator side
and this is the principal dierence, when compared to the PMSM drives. Here again a question arises as to
how to subdivide the available stator current into corresponding d–q axis current references. e same idea
of MTPA control is used as with IPMSMs. Using (24.19), electromagnetic torque (24.23) can be written as
T P L L i
e d q s
= −
0 5 2
2
. sin δ
(24.24)
By dierentiating (24.24) with respect to angle δ, one gets this time a straightforward solution δ = 45°
as the MTPA condition. is means that ...