A method for continuous monitoring of the sliding contact joint during the movement of electric rolling stock

The article considers a method for continuous instantaneous control of a sliding contact joint exposed to alternating electric traction current, external factors, technical failures that cause sparking, the formation of an electric arc, and significant changes in the contact resistance that occur during the movement of electric rolling stock. The sliding electrical contact has its own characteristics in comparison with conventional electrical contacts due to the constant movement of the contact in space. During the movement of electric rolling stock by rail on different sections of the overhead contact system, violations of the normal operation of the sliding contact joint may occur separately, in different combinations, or all together, depending on the state of the contact wire, pantograph, and other structural and external factors. The essence of the method is that the electric traction current passing through the sliding contact between the pantograph and the contact wire is decomposed into a Fourier series in real time. Current harmonics associated with the normal operation of electrical equipment of electric rolling stock are subtracted from the obtained spectrum of electric traction current. The remaining harmonics of the current spectrum will characterize the instantaneous integral state of the sliding electric contact. Comparing the harmonics of the obtained spectrum with the harmonics of the reference spectrum, which characterizes the normal operation of the sliding contact, allows us to assess the defects of the pantograph and the contact wire. Continuous, almost instantaneous monitoring makes it possible to determine the contact point of the pantograph on the contact wire on the section of the electric rolling stock, provided that the operation of the spectrum analyzer is coordinated with the position of the electric rolling stock on the track section.