| Abstract |
This paper presents a new strategy of Direct Torque Control (DTC) of an induction motor fed by a
three phase multi-cell voltage-source inverter (VSI). This strategy is generalized regarding the
inverter number of cells (levels), and allows operation of the inverter under quasi-constant switching
frequency, independently on shaft speed and load torque. The control algorithm is divided into three
hierarchical units (space vector selection; reference phase levels selection; switching cell selection),
each one exploiting a particular type of degrees of freedom. Simulation results are presented for
comparison of both DiCoIF strategy with three-cell (four levels) VSI, and the classical DTC strategy
with two-levels VSI, regarding frequency deviation, torque ripple magnitude and transient torque
response. |
