Direct Torque Control (DTC) is known to produce quick and robust torque response for AC drives. However, during steady state operation, the DTC produces high level of torque ripple and variable switching frequency. Development of DTC for overcoming the drawbacks of ltr" Keywords: Direct Torque Control, Induction Motor, Loss Minimization, Space Vector Modulation, Torque Ripple Introduction Direct torque control (DTC) of induction motor drives offers high performance in terms of simplicity in control and fast torque response. Principle of the classical DTC is decoupled control of flux and torque using hysteresis control of flux and torque error and flux position. In this method, switching look-up table is included for selection of voltage vectors feeding the induction motor [1]. However, during steady state operation, the DTC produces high level of torque ripple and variable switching frequency of inverter. Development of DTC for overcoming the drawbacks of classical DTC is voltage modulation application replacing look-up table of the voltage vector selection. The voltage modulation is based on space vector modulation (SVM) with constant switching frequency. The SVM strategy is based on space vector representation of the converter AC side voltage and has become very popular because of its simplicity. Contrary to conventional Pulse Width Modulation (PWM) method, in the SVM method there is no separate modulators for each phase. Alternatively, SVM method is incorporated with direct torque control (so-called DTC-SVM) for induction motor drives to provide a constant inverter switching frequency. Several methods with DTC-SVM are presented in the literature. The first method is based on deadbeat control derived from the torque and stator flux errors [2]. It offers good steady state and dynamic performance .However, this technique has a limitation since it is computationally intensive. Another method is based on fuzzy logic and artificial neural network for decoupled stator flux and torque control [3]. Good steady state and dynamic response are achieved. Another method uses two PI controllers instead of hysteresis controllers for generating direct and quadrature components of the voltage from stator flux and torque errors, respectively [4], [5]. This method provides good transient performance, robustness and reduced torque ripple. Choosing the level of flux in the induction motor remains an open problem for the perspective of maximizing motor efficiency and many researchers continue to work on this problem. Numerous operation schemes have been proposed by many researchers concerning the optimal choice of flux level for a given operating point. In low-frequency operation, core loss (hysteresis and eddy current losses) is rather low compared with copper loss. As the speed goes up, the contribution of the eddy current loss increases and finally becomes dominant. The technique allowing efficiency improvement can be divided into two categories. The first category is the loss-model-based approach [6], which consists of computing losses by using the machine model and selecting a flux level that minimizes the losses. The second category is the search controller [7], in which, the flux is decreased until the input power settles down to the lowest value for a given torque and speed. Important drawbacks of the search controller are the slow convergence and high torque ripples. The loss-model-based approach is fast and does not produce torque ripple. However, the accuracy depends on the accurate modeling of the motor and the losses. Different loss models for loss minimization in induction motor can be found in the literature. In model-based loss minimization algorithms, the leakage inductance of stator and rotor are usually neglected to simplify the loss model and minimization algorithm. However, with these simplified models, the exact loss minimization cannot be achieved, especially in high-speed operation of the motor, since a large voltage drop across the leakage inductance is neglected. In this thesis, a simplified loss model without neglecting the inductance, which presented in [8], is used. The main contribution of this thesis is torque ripple minimization along with efficiency optimization of induction motor which is based on the analytical determination of torque ripple in DTC-SVM. Torque ripple minimization is achieved by optimum selection of switching pattern in SVM and efficiency optimization is achieved by optimum selection of stator flux level in DTC.