Analysis method of steady-state random processes in power carrier chains of electric stock

Abstract

The half of main and suburban, all open-cut transport and also urban electric transport use direct current. Theoretically it is considered that locomotives, electric trains, motorized railcars of subways, trams and trolley buses use direct current with nominal value from 500 to 3000 V. Nevertheless, in practice it does not occur , as real-life, continuous and random changes of supply voltage and traction current are not taken into consideration. In other words the systems of electric transport (nominally) of direct current are the systems of alternating current and they need appropriate analysis of their processes. On the other hand theoretical electric engineering does not have analysis methods of electric circuits with random voltages and currents, so the development of special analysis methods of electromagnetic processes in probability interpretation is necessary. In the paper based on adaptation to the theory of random Duhamel integral processes, the analysis method of steady-state random process in power carrier chains of electric stock(ES)is developed and proved with numerical calculations. In the capacity of operator (ES) as investigating system, transition function is chosen. The method is based on the correlation theory of random processes and so that it is intended the definition of probabilistic characteristics of investigating process. In the paper calculations of mathematical expectations, correlation function, dispersion, mean-square deviation, traction current of locomotive VL8 are done, while its using with goods trains on Prydneprovsk railway.