Ways to improve operation reliability of traction electric motors of the rolling stock of electric transport

Abstract

We found that the electrical equipment has a dynamics of failure rate growth according to the results of the processing of the statistical information of electric transport enterprises and analysis of the operating conditions of rolling stock systems and aggregates. We established that traction electric motor failures make up 20 % of all failures of electrical equipment. We analyzed the conditions of operation of traction electric motors and estimated the reliability. The study of probabilistic and statistical characteristics of the functions of the distribution density of traction electric motors failure shows that some failures are approximated by an asymmetric distribution. In this regard, it is advisable to use a truncated normal distribution function N N{t; T; }, which will make possible tp increase the adequacy of models. We established that the number of failures in the interval 0-t1 decreases significantly for large probability Q. We can consider the flow of failures in this interval as stationary for certain values. We proposed a mathematical model for reliability evaluation (14), which, unlike existing models, is based on the system analysis of the probabilities of failure of subsystems, which are subjected to diagnosis (brush-holding unit, stator, anchor, collector), on a base of structural and functional diagrams of traction electric motor elements. It makes possible to determine parameters of various elements of traction electric motors during operation. The model differs qualitatively from the existing ones by taking into account structural and electromagnetic characteristics and gibes possibility to optimize parameters of different units in relation to the requirements of the system of planned and preventive repair, when traction motors developed a given resource and continue to operate. Thus, it is possible to estimate reliability parameters a traction electric motor of any type according to the results of the studies and the above calculations.