The first part of the paper covers the theoretical foundations of a DC motor with independent excitation. Then, a theoretical analysis of a three-phase thyristor rectifier and its operating modes used in this paper was performed. It is important to emphasize that the output voltage from a three-phase thyristor rectifier is connected to the armature winding of a DC motor through an additional choke. Therefore, the armature voltage is controlled by the control angle of the rectifier, i.e. by decreasing or increasing the control angle, the armature current of the DC motor increases or decreases, which, with constant excitation, is proportional to the electromagnetic torque. A PI controller was used to regulate the armature current (torque). In this paper, the operation of the DC machine was analyzed only in the first quadrant, although the topology of the thyristor bridge used enables a two-quadrant operating mode. A simulation model of the control system in MATLAB - Simulink was used to analyze the electromagnetic torque regulation of a DC motor with independent excitation. Two variants of the rectifier model were used in the simulation of the control system. The simulation model is described with its basic parts and the communication windows of the model used for the simulation are explained. At the end of the work, simulations were performed and analyzed for two successive sudden changes in the torque reference of the DC motor in MATLAB - Simulink, and the influence of the inductance of the additional choke in the armature circuit on the undulation and overshoot in the torque response as regulated quantities was analyzed.