Sadeghi Larijani - Power Electronic and Protection Laboratory (PEP Lab.), Faculty of Electrical and Computer Engineering Tarbiat Modares University
Shahparasti - Power Electronic and Protection Laboratory (PEP Lab.), Faculty of Electrical and Computer Engineering Tarbiat Modares University
Fatemi - Power Electronic and Protection Laboratory (PEP Lab.), Faculty of Electrical and Computer Engineering Tarbiat Modares University
Amiri - Power Electronic and Protection Laboratory (PEP Lab.), Faculty of Electrical and Computer Engineering Tarbiat Modares University

This paper investigates the switching-table based direct torque control (ST-DTC) drive of induction motors using a three-level neutral-point clamped inverter. A novel optimized switching table for ST-DTC is proposed regarding the effects of motor speed and load on torque changes. Furthermore, for deviation of neutral point voltage in three-level NPC inverter, an innovative closed loop control method is introduced that is not only straightforward in implementation, but is also capable of restricting voltage fluctuations in the specified limit. Simulation results are provided to confirm the performance of proposed strategies.

Induction motor, direct torque control, neutral point voltage, optimized switching table, three-level NPC inverters