The relevance of the research is determined by the need to develop and consistently implement effective methods of the monitoring of the current technical condition of power transformer substations within the railway system of the Republic of Kazakhstan. The methodological approach in this research is based on combination of methods of system analysis of currently existing approaches to monitoring the current technical condition of power transformers using acoustic diagnostic methods with an analytical study of the fundamental possibilities of carrying out these operations within the railway system of the Republic of Kazakhstan.During the experimental part of the study, acoustic sensors of partial discharges showed high efficiency in detecting partial discharges on the surface of the insulating layer of equipment of power transformer substations. This equipment, when using the acoustic emission testing method, demonstrated high performance. Good results were also shown by the acoustic control method, since the promptitude of control and the possibility of taking readings without interrupting power voltage supply make it possible to reduce time of the experiment while obtaining high-precision results, to determine the causes of faults on the surface of the insulating layer of power transformers and to localise areas of occurrence of such defect most accurately.Several proposals have been made on the role that the acoustic control method could play in the overall system for organising the inspection of the technical condition, operation, and repair of the electrical power equipment.The results obtained indicate availability of various options for using acoustic emission testing methods and also confirm the need for their further improvement to achieve high quality of control of technical condition and functioning of railway power transformer substations.