Mining enterprises are examples of energy-intensive enterprises. At the same time, in the total volume of electric energy consumption, they consume about 80% such as: a crushing and sorting factory, a main drainage system, skip hoisting installations and main ventilation installations. In particular, ventilation plants consume approximately 30% of the total electricity consumption, this fact is due to the fact that according to the technology of underground mining, the iron ore mines are aired around the clock, and the electrical capacities of these plants reach 2 MW.Electromechanical complexes of fan installations, in turn, are equipped with synchronous drive electric motors. In order to regulate the performance of the main ventilation unit, inefficient measures are used: turning fan blades, and opening and turning working flaps. Meanwhile, with an increase in the depth of production of iron ore below 1500 m, the effectiveness of the existing ventilation process of underground workings is complicated, and these measures become even more ineffective.The process of the necessary improvement of ventilation systems in iron ore mines and the development of appropriate energy efficient systems to control the rotational speed of the synchronous drive motor of the main ventilation unit must be carried out in a plane of reach to reduce the electrical energy consumption of these units, in turn, will lead to the desired reduction of electrical energy consumption by iron ore mines at all. One of the real directions to achieve this goal is the creation of high-voltage converters, which will increase the energy efficiency of the electric drive of the main fan systems as a whole. In this study, based on the analysis, the possibility of using a power converter based on a multi-level cascade voltage inverter is considered. The proposed method of controlling and shaping the high-voltage supply voltage of the converter will increase the efficiency of the electromechanical system as a whole, as well as reduce the weight and volume of transistor modules and filter components, in the final form will achieve the desired level of performance of electromechanical complexes and all main fan systems as a whole.The prospect of introducing a controlled electric drive for main ventilation installations in underground mining enterprises is a priori economically viable measure that will significantly reduce power consumption by main ventilation systems, facilitate the start-up of synchronous motors and reduce starting currents. In addition, an adjustable electric drive increases the static efficiency and the range of technological use of the main ventilation systems, and, thereby, further reduces power consumption. Meanwhile, to achieve the desired level of electrical energy efficiency of electrical systems, as the entire complex of the main ventilation systems, it is necessary to develop sufficiently efficient circuits of voltage converters.Ref. 12, fig. 5, tabl. 2