Nauka ta progres transportu (Feb 2013)
Theoretical aspects and methods of parameters identification of the electric traction system devices. method of cyclic current-voltage characteristics
Abstract
Purpose. To define the characteristics of numerical calculations of mathematical model with one or more cyclic current voltage characteristics (CVC). This is an urgent problem, since any electric traction system device and electrified track in general, like non-linear passive or active two-terminal network in the present operating mode is described by current-voltage characteristic (CVC), which is based on the given input voltage and input current. Me-thodology. The electromagnetic process calculation in the power circuits of traction electric energy supply is the probabilistic task with solving nonlinear stochastic differential equations requiring for the development of special methods. Given the calculation difficulty, it is reasonable to perform them either by real CVC graph bypass or initially by applying its equivalent replacement with, for example, an ellipse. Findings. Numerical calculations of the mathematical model with one or more cyclic CVC can be performed by “real” CVC bypass or by "idealization" i. e. approximate replacement of real cyclic CVC. Originality. This paper presents the dynamic CVC of the DS3 and 2ES5K electric locomotives at different currents of electric locomotives. Practical value. Cyclic CVC normally and definitely can be applied in the system of electromagnetic state equations while transient state calculating in the traction system. Therefore while calculating the experimentally obtained CVC for the most “difficult and complex” (or/and the “easiest”) mode is applied.
