Direct torque control
DTC of ac drives is based on stator voltage control; hysteresis torque and flux
controllers determine the errors which govern the selection of the required
voltage space vectors to be applied to the motor. A simple switching logic is
used to either increase or decrease the flux, and increase or decrease the
torque, or effect no changes. Move the control points A, B,
C, and D to cover the 6 sectors of the plane and observe the correcting flux
increments needed to produce these effects. Based on these observations, develop
the underlying switching table: the 4 rows represent the specified active
operating conditions and
the 6 columns denote the numbered sectors; the entries are the required basic
vectors v.
©
M.
Riaz |