Diagnostics of Traction Motor Insulation by Partial Discharge Measuring Method

Monitoring the condition of traction electric motors (TEM) in locomotives involves diagnosing and predicting malfunctions. This has been a subject of a great amount of research. Accurate diagnoses and early detection of potential issues lead to timely maintenance and reduce downtime of locomotives at depots. This paper explores the use of TEM insulation diagnostics by analyzing partial discharge intensity. Methods: In recent years, a significant amount of research has been conducted to create new methods for monitoring the condition of TEM, addressing the shortcomings of traditional diagnostic techniques. Specifically, there is a shift from scheduled preventive maintenance to maintenance based on the actual operating condition of the equipment. The implementation of this approach significantly enhances the role of technical diagnostics. This paper presents an analysis of the experimental data obtained regarding changes in the partial discharge intensity during the diagnosis of the TEM insulation condition. Results: An ideal diagnostic procedure should include the essential measurements required to assess the condition of the machine. Based on the analysis of the data obtained, a diagnosis should be formed that enables an evaluation of the current state of the equipment, the timely identification of emerging failure modes in the shortest possible time. The research has shown that partial discharge currents are absent below a specific initial voltage. However, a certain degree of nonlinearity in the load gradation may still be observed even at voltage levels below this value. Practical significance: Reducing maintenance costs and preventing unplanned downtime of locomotives is a priority for manufacturers and operators. The implementation of advanced monitoring and diagnostics systems for traction electric motors will enable the development of rational proposals for improving the design of electric locomotives and enhancing their reliability during operation.