DIRECT TORQUE CONTROL OF INDUCTION MOTOR

Abstract

Induction motors with variable frequency AC inverters are commonly utilized in industrial applications because they provide good dynamic steady-state performance over a wide range of speeds. Scalar control has always been incorrect and provides poor dynamic performance due to variable coupling.. In a wide range of application vector control by rotor flux, orientation drive offers good dynamic performance analogs to DC machines. The vector control is still very complex to implement. An improvised scalar method known as Direct Torque Control (DTC) was established be grateful to the tireless efforts of different research engineers. This technology significantly reduces the computational load on the control platform while providing performance comparable to a vector-controlled drive. The optimal selection of inverter switching vectors allows the DTC technique using a Voltage Source Inverter (VSI) to directly regulate the stator flux linkage and electromagnetic torque. The flux and torque errors are limited within the respective flux and torque hysteresis bands by the inverter switching vector. This results in quick torque response, low inverter switching frequency, and minimal harmonic losses. The modeling and simulation of an induction motor drive using DTC are carried out in this thesis, and the results are presented.