The regenerative braking is one of the most attractive ways for energy saving in electric transport. It has many advantages and its effectiveness is discussed in numerous researches, but there are no significant publications, which describe the power losses in the way of recovered current flowing. The paper describes an alternative method for estimating recovered energy losses in the elements of a DC electric transport system. In comparison with existing methods, it is based on the correlation theory of stochastic processes and takes into account the Fryze's concept for reactive power. The method is verified by the experimental researches, which are performed for the VL8, VL11M, VL11M6 locomotives, EPL2T multiple-unit train and T4D tram, which operate in DC sections, Ukraine. The losses are calculated for different elements of an electric transport system, and their theoretical and statistical distributions with basic probabilistic characteristics are shown. The results prove the validity and applicability of the method.

Losses of recovered electric energy in the elements of a DC electric transport system

The paper is dedicated to the estimation of instantaneous reactive power in a DC traction power system. Currently, the integral and frequency methods are mostly used to define reactive power and do not give high accuracy in the calculations of power balance or cannot describe the essence of physical processes. The problem is complicated in DC electric transport systems due to random impulse character of voltages and currents. As a comparison, the calculation of reactive power according to various approaches was performed for the DE1 electric locomotive. It is suggested that the instantaneous reactive power should be used for the analysis of electromagnetic exchange processes in DC power systems. The paper shows the definition and main formulas for defining the instantaneous reactive power taking into consideration the random character of voltage and current. Numerical calculations together with statistical analysis were performed for two variants of experimentally recorded voltages and currents: the first one - on the bus-bar of traction substation, which supplies the section with the Pendolino trains in Poland and the second one - on the current collector of the VL8 electric locomotive in Ukraine. They confirm the validity of the aforementioned method.

Instantaneous Reactive Power in Systems with Stochastic Electric Power Processes

Stochastic identification model for forecasting of parameters of devices of electric transport systems

O. Bondar: ORCID 0000-0003-3884-5589, O. Kurylenko: ORCID 0000-0003-2045-917X, D. Ustymenko: ORCID 0000-0003-2984-4381, O. Baliichuk: ORCID 0000-0003-0119-1446

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Experimental Investigation of Actual Stuation of using and Accounting of Recovered Energy of Regenerative Braking Mode at the DC Traction System

The statistical analysis and probability characteristics of voltage random variation on the pantograph of DC electric locomotive in the recuperation mode are presented in the article.

http://stp.diit.edu.ua/article/download/9302/8066

A. V. Nikitenko

Papers

Statistics and probability analysis of the voltage on the pantograph of dc electric locomotive in the recuperation mode