Comparison of DTC-CLASSIC and DTC-SVPWM methods for controlling induction motors applying two-level and three-level inverters

Direct torque control (DTC) is one of the most effective methods for controlling the induction motor. In direct torque control, motor flux and torque are considered as reference quantities, and are controlled by optimal selection of inverter switching vectors. Using the direct torque control method, you can reduce the field oriented control (FOC) constraints and complexities. The direct torque control has a very fast torque response and is resistant to sudden load variations. In this paper, a complete comparison was made between two methods of classic direct torque control (DTC-CLASSIC) and direct torque control based on space vector pulse width modulation (DTC-SVPWM) using two-level and three-level diode clamp inverters (NPC). Comparison of these methods was carried out using simulation results in MATLAB software. The results of the simulation show that, with respect to the limitation constraint of maximum switching frequency, the DTC-SVPWM applying three-level inverter has less flux and torque ripple and less THD of stator current than the other three.