Torque dynamic behavior of induction machine DTC in 4 quadrant operation

In the frame work of Direct Torque Control for induction machines, our paper deals with the dynamic behavior of the torque in all Pour quadrants of operation, A formal development of the expression of the dynamical machine torque is given, This theoretical derivation is based on a small variation model valid for a short sampling times, It allows to understand and predict the electromagnetic behavior of the machine in both motor operation acid particularly in generator mode, Hence, the "empirical approach", usually used to choose the inverter voltage states (voltage vector), is replaced by an analytical approach, This allows to develop a look up table accurately specifying the inverter states that lead to a four-quadrant D.T.C strategy. Simulation results are presented demonstrating the control performance as mdf as the validity of the expression of the torque derivative. The main objective of this work aims at a better understanding of the torque behavior, particularly for generator operation, This allows to design a Direct: Torque Control strategy based an a formal analysis of the induction machine electromagnetic state.