Purpose. Conduct a study of commutation processes and develop a methodology for determining the switching frequency of semiconductor elements in the converter for high-voltage electromechanical systems to minimize electrical losses during their operation with fan loads. Methodology. Methods of multi-criteria and single-criteria optimization for finding the optimal values of electrical losses in an electromechanical system, methods for solving first-order differential equation systems, and analytical methods. Findings. To improve the energy efficiency of a high-voltage electromechanical system for stationary industrial fan installations without modifying their structural design, the level of total losses has been assessed. A target function has been constructed to represent the dependence of total losses in the electric drive on the switching frequency of power switches and the harmonic distortion coefficients of the stator and rotor currents in a high-voltage wound-rotor asynchronous motor. Through approximation, a generating dependence of the switching frequency of the converter’s power switches on the harmonic distortion coefficient of the stator and rotor currents of the asynchronous motor has been established. The target function, initially dependent on three variables, has been transformed into a function of a single variable. Simulation modeling of electromagnetic and energy processes in the high-voltage electromechanical system has been conducted to evaluate total loss levels. A comparative analysis has been performed, confirming the adequacy of the obtained analytical expression for determining the optimal switching frequency of the converter’s power elements under the condition of minimizing losses in the high-voltage electromechanical system, with results validated through simulation. Originality. A study of commutation processes in the power elements of the converter, which is part of the high-voltage electromechanical system, has been conducted. More precise analytical dependencies have been obtained, allowing for the determination of the main and commutation losses in the power elements of the converter for the high-voltage electromechanical system. Practical value. A methodology for determining the optimal switching frequency of the semiconductor elements in the converter, which is part of the high-voltage electromechanical system, has been proposed. The calculation error of the optimal switching frequency of the semiconductor elements, obtained analytically, does not exceed 3.5% compared to the results obtained through simulation. The proposed methodology can be applied to minimizing losses in high-voltage electromechanical drive systems for both AC and DC applications used in various industrial mechanisms.