Study of the influence of electric transmission parameters on the efficiency of freight rolling stock of direct current

The negative impact of non-uniformity of current distribution in the power circuit of a freight direct current rolling stock on its operation efficiency was experimentally established. In contrast to existing approaches, the presented study reveals the entire range of factors that together affect non-uniformity of current distribution. The method of calculation of comprehensive influence of structural, technological and operational factors on current distribution was developed. It made it possible to determine conditions of elimination of the difference of currents and to increase traction properties of locomotives when controlling freight trains. The proposed coefficients allow analyzing the effect of various factors on current distribution and relationship between parameters of motors, connected in parallel. They visually show that deviation of currents at interaction of a locomotive with freight wagons affect not only particular parameters of wheel-motor units, but also their connection. The merit of this approach is the possibility of evaluation of non-uniformity of current distribution depending on the structure of electric machines and connection of structural parameters of a wheel-motor unit. Results of the study can be used during repairs of freight direct current rolling stock and in designing automatic control systems.