This article describes a vibration model connected by individual nodes of a DC motor. The purpose of the article is a mathematical model allowing to predict the work of machines with a depreciation resource and search for ways to increase the information content of assessing the functioning of the rolling stock condition without dismantling them. Currently, the operational reliability of the DC motor is reduced after the development of the service life. Study and evaluation of the vibration effect on the brush-collector node. The main components of the DC motor (bearings, electrical brushes) are unrecoverable. Therefore, any interference with their normal operation leads to premature wear of the entire DC motor. Existing methods for life-extending maintain the operational reliability of a DC motor equal or close to the passport data for several years. This model allows vibration diagnostics without dismantling the DC motor and stopping the rolling stock. The mathematical model describes the oscillations of each node of the DC motor in the direction of movement of the rolling stock, showing the excess of the permissible value. After mathematical processing of the results, a machine reliability model under study is obtained (usually in the form of polynomials) as a function of the needed parametersthe influencing factors. Due to this model, pre-detected defects can save on repairs and maintenance in the future. This model is the basis of software for online diagnostics. The proposed model allows providing an objective use of repair and restoration compositions depending on the current technical condition, which will lead to an increase in the service life of the mechanism and savings in operating costs. On the one hand, extending the operating life of a DC motor should produce an economic effect, and on the other hand, technical measures to maintain operational reliability cause an increase in material costs.

Discussed here is a technique for testing digital devices based on the calculation and control of two or more characteristics of a binary electric signal at a reference point. Signals coming from a healthy and failed digital device that are indistinguishable by the value of one of the characteristics may differ in value of the other characteristic. The combination of test methods can significantly reduce the potential of not detecting the failure of digital device. The technique is aimed at increasing the information content of the healthy state monitoring results and the possibility of localizing failures in digital instruments and devices of power systems.

Modern methods for analyzing and assessing the reliability of complex technical systems consider only its individual elements. The specifics of structural-functional interactions and integration into subsystems of different hierarchical levels are not taken into account. Studies show that analyzing the reliability of urban electric transport, also focus on individual components: the reliability of electric traction rolling stock, the reliability of the power supply system, the reliability of the track infrastructure, etc. The authors propose an approach that allows to consider urban electric transport as a complex technical system consisting of several levels that are hierarchically subordinate. Each level combines the components directly involved in the transmission and transformation of electric power into mechanical operation of the rolling stock under the influence of the external environment by means of traction electrical equipment. This approach will allow to develop the theoretical foundations of methods for analyzing the impact of the reliability of individual components of a complex technical system of urban electric transport on the effectiveness of the electric traction implementation.

A technique is proposed for optimization the composition of diagnostic parameters based on a combination of heuristic algorithms with the method of linear integer programming. The solution obtained using the heuristic algorithm with relatively small consumption of computational resources is taken as an initial one for optimization or checking the optimality of the composition of parameters using the linear integer programming method. The combination of a heuristic algorithm with the method of linear integer programming saves significant computational resources when searching for the optimal solution. The technique is aimed at minimizing costs when creating diagnostic support for monitoring performance and failure detection when considering the serviced and reconstructed electronic devices and equipment of power systems.

Research shows that the existing theory and methods for calculating rational operating modes of traction electrical equipment do not provide a sufficient level of adequacy under real operating conditions of urban electric transport, which is due to the high complexity of the processes and the lack of a sufficiently developed methodology for their interpretation in industry theory. The purpose of the study was researching the process of electric traction as a result of transformation electrical energy in purposeful mechanical movement of electric rolling stock with the implementation of all technological conditions of production and technical system of urban electric transport. The scientific hypothesis that the modes of operation of electric traction equipment as part of an automated electric drive of the rolling stock of urban electric transport are formed under the influence of a complexly organized technological process of electric traction and are the topological basis of its structure is theoretically substantiated. The main result of the research is the formulated theoretical system which allows us to present the process of electric traction as a system consisting of five levels that are in hierarchical relations and solve each specific problem of building the movement of electric transport. Such an approach will contribute to the development of theory and methods for calculating rational operating modes of traction electrical equipment of urban electric transport, the improvement of the energy efficiency of which is the actual scientific problem.