Simplified pwm algorithms for multi level inverter fed direct torque controlled induction motor drives for reduced harmonic distortion and electro magnetic interference

Abstract

The Direct Torque Control (DTC) algorithm has the features of precise newlineand quick torque response and reduction of the complexity of Field Oriented newlineControl (FOC) algorithms. In DTC, the generation of inverter switching state newlineis made to restrict the stator flux and electromagnetic torque errors within newlinethe respective flux and torque hysteresis bands so as to obtain the fastest newlinetorque response and highest efficiency at every instant. Despite its simplicity, it suffers from few drawbacks such as high ripple in torque, flux and stator currents, variation in switching frequency of the inverter.