Purpose. Investigation of the influence of sharply variable electric load on non-stationary electromagnetic phenomena and electromechanical processes in a synchronous electric drive. Methodology. Theoretical and experimental methods of research and analysis of a set of parameters of sharply varying loads of electrotechnological complexes and electromagnetic processes in electrical equipment; physical and analytical methods for obtaining dependencies of the influence of electrotechnical loads on the technical condition, the breakdown of electrical equipment, additional losses and non-stationary electromagnetic phenomena in systems and equipment. Findings. The calculations of the excess of the oscillatory processes of the synchronous electric drive shaft are performed, which are excited by sharply varying loads, relative to the norms standardized by state standards. Proceeding from the primary requirements of the electric drive and providing normalized oscillations of the motor shaft and increasing requirements to reliability, efficiency and energy consumption per unit of output, the effect of non-stationary electromagnetic processes on the electromechanical parameters of the electric drive was investigated. Originality. A mathematical technique is proposed for non-stationary electromagnetic processes in a synchronous electric drive, which allows one to investigate the effect of non-sinusoidal and unbalanced currents and voltages on electromechanical parameters. An engineering technique for estimating the oscillatory function of a shaft is given, depending on the nature of non-stationary electromagnetic processes in a synchronous motor. Practical value. An engineering technique for estimating the oscillations of a synchronous electric drive shaft is proposed for non-stationary electromagnetic processes, which lead to an increase in the parameters of normative and technical documentation.