BASIC PRINCIPLE: "_ and "+”signals are delivered to two
hysteresis comparators. The corresponding digitized output
variables: change of magnetic flux _, of mechanical torque _+
and the stator flux position sector Sn created a digital word,
which selects the appropriate voltage vector from the
switching table[4]. The selection table generates pulses Sa, Sb,
Sc to control the power switches in the inverter. Three level
torque and two level flux hysteresis controllers are used
according to the outputs of the torque controller and the sector
information (S_ ) of _s , appropriate voltage vectors for both
the inverters are selected from a switching table as it is shown
in Table1.