The main problem of DTC control system is to set
the reference point of the controller. As discussed above,
the dry–wet temperature difference is related to the
dryer load and, consequently, to the motor intensity
(restricted to 160 A). However, the relationship between
DT and intensity is not univocal as can be seen in Fig. 8,
where this relation is shown for two different periods of
time. Thus, the dryer operator should be somewhat conservative
when fitting the set point to avoid overloading
the motor.