Purpose. The study provides the methods and models development of reducing damages of traction energy systems (TES) at electrified railways of Ukraine. Definition the indicator of preventing damage evaluation TES at electrified railways is necessary. Paper is aimed to search the modern methods and approaches to improve the system of TES monitoring, diagnosis and maintenance. Methodology. To achieve this purpose a study of foreign experience and publications that focus on problem-solving quality of TES using a linguistic approach based on the theory of fuzzy multiple numbers and linguistic variable were done. Findings. In result of research an algorithm to reduce TPS damages which operates under uncertainty was developed. It is found that the solution of this problem is possible by timely detection of actual technical condition of equipment in terms of quality maintenance, diagnostics and update resource of electrical equipment traction substations (TS) power supply TES. The study examined the fuzzy inference scheme, which is based on the use of mechanisms to minimize the area of decision-making. It contributes not only to structural identification in the process of developing a database, but also can significantly improve the efficiency of finding the parameters of fuzzy model, which in turn reduces the efforts that are necessary for the analysis and the design of effective control systems maintenance and repair (M and R) TES. Originality. For the first time the algorithm of reduction the damage of traction energy system of electrified railways of Ukraine was offered. The mathematical model of reduction the damage calculation of TES from TP power equipment failures by improving system maintenance (M and P) was developed. Firstly evaluation index was proposed to prevent the damage of traction energy system. Practical value. The article describes the fuzzy inference scheme, which is based on the use of the mechanism to minimize the area of decision-making and contributes not only to structural identification in the process of developing a database, but also can significantly improve the performance of determining the parameters of fuzzy model. Implementation of this approach comes to the determination of the main stages, features and optimal justification of quantitative and qualitative requirements for system M and R of TS. It will be done with allowable costs for improvements to reduce TPS damage and address the equipment of traction substations in working condition in terms of growth rates and volumes aging (compared to the current speed and volume of updates).