Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
Development of computer model for calculating quantitative assessment of traction electric motor trolleybus reliability
Abstract
The authors have analyzed the failures of 47 trolleybuses at the Tomsk tram-trolley department and have revealed that 69,7 % of failures are operational. More than half of them relates to the failure of the electrical equipment, the most important part of which is the traction electric motor trolley. The urgency of the discussed issue is caused by frequent failures of trolley traction motors and the need to develop a set of measures to ensure the required level of reliability. The main aim of the study is to develop a mathematical model for statistical definition of quantitative assessment of operational reliability for traction electric motor trolley. The methods used in the study: statistical methods for determining the quantitative assessment of operational reliability, the laws of distribution functions. The results: The paper introduces the algorithm for determining the parameters of the mathematical model of operational reliability of trolley traction electric motor. The quantitative reliability indices of traction motor trolley, histogram and probability function of uptime normal, log-normal distribution law, and the law of the Weibull distribution were obtained by the proposed mathematical model. Conclusions: For the first time the authors developed the computer model to calculate quantitative indicators of operational reliability of trolley traction electric motor, allowing estimating the electric motor as a whole, and the rotor, stator and bearings separately. The introduced and described computer model of quantitative assessment of operational reliability, using the methods of statistical analysis for three laws of distribution: normal, lognormal, and Weibull distribution law, is highly accurate. The algorithm is implemented in Mathcad and it can facilitate and expedite the reliability indicator identification and analysis of electric traction motor reliability. The authors obtained the distribution laws of operational reliability of trolleybus traction electric motors, quantitative estimation of time to failure, failure rate. The data given were used to develop the software and computing complex for quantitative assessment of trolleybus traction electric motor reliability.
