In the doctoral thesis the direct torque control of induction machine based on optimal voltage vector determination according to criterion of torque ripple reduction is proposed. The first element of the doctoral thesis original scientific contribution is the method for the determination of the voltage vectors influence on the stator flux vector and the electromagnetic torque and the second element is the modified algorithm for direct torque control of induction machine based on optimal voltage vector determination according to criterion of torque ripple reduction. Simulation and experimental results for the main propulsion drive of the low-floor tram series TMK 2200 operating in the city of Zagreb are presented in order to show the effectiveness of the proposed method. The experiments were carried out on a model of the main propulsion drive in Končar – Electronics and Informatics, Inc. test laboratory. The method for the determination of the stator flux vector module and the electromagnetic torque changes in dependence on the chosen voltage vector is based on the derived equations which describe the voltage vectors influence on the control variables. The method for the direct torque control of induction machine based on optimal voltage vector determination according to criterion of torque ripple reduction uses exact position of the stator flux vector in the complex plane sector. Depending on the operating conditions, three voltage vectors are taken into account and the predicted values of the electromagnetic torque are calculated for these voltage vectors. The voltage vector that will be applied in the next discrete time period is chosen according to the minimal value of the cost function which does not require weighting factors. Therefore, the proposed method belongs to predictive control methods but the proposed method is simpler in comparison with predictive torque control. The proposed method is also more robust because only stator variables should be calculated, and all induction machine parameters as well as the induction machine speed are not required. The obtained simulation and experimental results show that the application of the direct torque control of induction machine based on optimal voltage vector determination according to criterion of torque ripple reduction results with minimal electromagnetic torque peak to peak values and almost minimal torque ripple which can be achieved when the predictive torque control is applied.