Abstract
Ensuring reliability is one of the most important issues in the creation and operation of any technical system. This is especially important for complex systems, such as power supply systems with internal and external connections consisting of many elements. The task of ensuring the reliability of power supply systems includes a whole set of technical, economic and organizational measures aimed at reducing damage caused by violations of the normal mode of operation of electricity consumers. To obtain information about the reliability of elements of power supply systems, it is necessary to study a fairly large number of identical elements over a long period of time. In the real conditions of an industrial enterprise, this creates certain difficulties, so it is possible to conduct an accelerated reliability test using mathematical modeling [3]. The article discusses some ways to solve the main problem of reliability theory - building a mathematical model and obtaining criteria for selecting optimal options for power supply systems. In this paper, the main materials for calculating the reliability of power supply systems using the mathematical apparatus of probability theory are presented.