In this paper, the stationary characteristics of a voltage-controlled squirrel-cage induction motor without a neutral conductor are analyzed, with special emphasis on the calculation of losses and determination of the degree of efficiency. In order to analyze the stationary characteristics of the drive with a.m. and tir.pr. voltages, a mathematical model of the thyristor circuit-asynchronous motor system was developed. Thyristor voltage converters are mainly used to adjust the supply voltage of an a.m. motor. In order to determine the current-voltage conditions that occur in an ohmic-inductive circuit with thyristors turned on, we considered a simple scheme of a single-phase voltage converter. The presented relations for an ohmic-inductive load are also valid for an asynchronous motor. In voltage regulation of a.m., a connection of antiparallel-connected thyristors in each phase is most often used, where the stator winding is connected without a neutral conductor. The structure of the electric motor drive is formed by two connected systems: a thyristor circuit and an asynchronous motor. The mathematical description of a thyristor in the conducting and blocking states is represented by a thyristor circuit model. Interruption of thyristor conduction in individual phases is a typical example of asymmetry, which is caused by the inclusion of a sufficiently large resistance in series with the winding of one of the phases. In this paper, we used the mathematical model a. m. written in the coordinate system, where the axes are attached to the stator and are at rest. Model of three-phase a.m. without the influence of current suppression in the rotor is shown in the picture. When feeding a.m. from a non-sinusoidal power source, eddy currents in the rotor have a significant influence on its static and dynamic characteristics. This influence is covered by mat.mod. which is derived based on the replacement of the rotor rod with a finite number of R, L loops. To justify the choice of mat. mod. engine based on the replacement of the rotor rod with an equivalent double cage, we performed the calculation for the error in the real and imaginary part of the impedance eq. on a specific example. double cage. So, checkmate. mod. a.m. obtained by replacing the rotor rod with eq. two. with selected parameters for more accurate calculation of 1, 5 and 7 harmonics was chosen as suitable for calculation and analysis in the mode of power supply from a non-sinusoidal source. In order to verify the mat. mod. and the program for simulation of drives with voltage-controlled a.m., the waveforms of voltage and current obtained by simulation of stationary states were compared with the results of measurements on a laboratory model. Before starting to record the waveforms of voltage and current in characteristic operating points in a stationary state, the waveforms of current and voltage a.m. were recorded when the motor was powered directly from the network. We notice certain distortions in the voltage curve that originate from higher harmonic terms in the network voltage. On a laboratory model, recordings of waveforms of voltage and current in char. operating points in a stationary state were carried out and these results were compared with the waveforms obtained by simulation on a mat. model. Due to the complexity of the loss analysis and the usefulness of voltage-controlled a.m., we had to combine the procedures of measurement and calculation of individual losses. In order to analyze the influence of individual harmonics in current and voltage, the program for calculating harmonic components uses simulation results and the FFT algorithm, which takes 2N points during the period as input values. We made a harmonic analysis of up to 13 harmonics and in order to compare the results, we carried out the measurement in the lab. models with the use of a wave analyzer. In order to be able to calculate the power, losses and utility of a.m. powered from a non-sinusoidal power source, when the voltage and current are not sinusoidal, we had to start from the basic terms for the specified quantities. According to the described procedure, we started the calculation of losses and usefulness of a.m. power 2.2 kW for different loads and steering angles in a stationary state. - losses in the stator copper: with increasing load, they increase due to the increase in the basic and higher harmonics of the stator current. - losses in the stator iron: for the same loads, the losses are lower at larger steering angles because increasing the steering angle reduces the basic harmonic voltage, i.e. induction in the air gap. By increasing the load at a constant steering angle, the current and the voltage drop on the stator impedance increase, which causes a reduction in the induction in the gap and a reduction in iron losses. - losses in the rotor copper: for the same load at reduced voltage, the losses are greater than the losses in the case when the motor is supplied with full voltage, and the main reason for this is that by reducing the voltage, the slip increases and the rotor current increases. - losses in the iron of the rotor: these losses are small and their share in the total losses is negligible. - losses in rotor copper with calculated suppression: losses increase due to current suppression. It is to be expected that with motors of higher power, the suppression effect would be more pronounced, i.e. due to current suppression, the losses in the rotor would increase significantly. - efficiency at lower loads: increases with increasing steering angle due to reduced iron losses at higher angles, due to reduced first harmonic of stator voltage. - efficiency at higher loads: