At present, the designing of a power supply system for mine sections is performed in accordance with obsolete regulatory documents made in the early 90s of the 20th century. This slows down the implementation of the ‘digital mining operation’ concept and prevents the full potential for energy savings from being realized. At the same time, development of digital technologies makes the issues of computer simulation of the power supply system of the coal mine sections urgent. Simulating computer modelling is required to develop measures for increasing the efficiency of the power supply system of operating coal mines as well as for designing new coal mines. The article offers the methodology of forming simulation computer models for evaluation of the energy efficiency of the power supply system for a coal mine section. To ensure the correct development of active and reactive power consumption profiles, it is proposed to use scenario approach to modelling dynamic processes. As an example of using the proposed approach, one of the scenarios for the operation of power supply system of a mine section at one of the coal mines of Kuzbass is reviewed here. The proposed approach to scenario modelling of operating modes of a mine section ensures the correct modelling of dynamic processes for the subsequent assessment of the effectiveness of the use of intelligent devices for controlling the flows of active and reactive power, which will make it possible to accurately assess the effect of FACTS devices on the level of active power losses, as well as the quality indicators of the electrical energy. The proposed methodology can be used in the development of computer-aided design systems for the design of energy-efficient power supply systems for extraction areas.