Reducing Power Losses by Voltage Stabilization at the DC Rolling Stock Current Collector

The invention relates to an energy-efficient method for voltage stabilization at the electric rolling stock current collector through traction substation control means which provide a nominal voltage value during the electric train movement by an interstation section. The dependence of potential distribution in the contact wire during the electric rolling stock movement by an interstation section was investigated. Also researched and developed are the new ways of voltage stabilization at the current collector of the electric rolling stock based on synchronous (the same for two adjacent traction substations) and asynchronous paths of voltage regulation at DC buses of traction substations related to one synchronous and two asynchronous ways of voltage stabilization in the contact network with obtaining the energy performance describing them. The energy performance of the investigated methods of voltage stabilization in the contact network is compared, and the energy efficiency of each of them is determined. It is proved that the use of modern types of semiconductor converters such as an active rectifier – voltage source in the power equipment of DC traction substations will enable to implement adaptive voltage stabilization systems at the rolling stock current collector, providing nominal voltage values of traction motors on the interstation section without using additional equipment on the rolling stock and, as a consequence, justification and application of these methods is suitable for upgrading the existing and designing new traction substations.

CALCULATION OF TRACTION AND ENERGY CHARACTERISTICS ELECTRIC ROLLING STOCK WITH ASYNCHRONOUS TRACTION ELECTRIC DRIVE

The issue of determining the traction and energy characteristics of electric rolling stock with asynchronous traction drive is considered. It is noted that such rolling stock can work at any point of the traction area, resulting in the need to determine the characteristics of the rolling stock for the entire traction area. The calculation of the characteristics of the traction induction motor, which are the basis for determining the traction and energy characteristics of the electric rolling stock, is considered in detail. A procedure based on the calculation of the replacement circuit of an induction motor is proposed. The calculation of power losses due to higher harmonic voltages and currents is considered. An example of calculation of traction and energy characteristics of an DC electric shunting locomotive with a traction asynchronous electric drive is given.

MANAGEMENT STRATEGIES FOR ENERGY PROCESSES IN ELECTRIC ROLLING STOCK WITH ON-BOARD ENERGY STORAGE DEVICES

The article deals with the main existing strategies for management strategy of energy exchange processes in the electric rolling stock with onboard capacitive energy storage devices. When considering strategies, it is assumed that the onboard capacitive storage has low power and capacitance. Therefore, this capacitor storage is not able to accept the full amount of regenerative braking energy of the electric rolling stock. The purpose of the paper is to consider and analyze management strategies for energy exchange processes in the electric rolling stock with onboard capacitive energy storages; to define the advantages and disadvantages of each of the existing strategies and propose a concept for the effective management of energy exchange processes in the electric rolling stock. The block diagram of electric rolling stock with the onboard capacitive energy storage which is used for the analysis of management strategies for energy exchange processes is presented. The modes of operation of electric rolling stock with onboard capacitive energy storages are described. Five main strategies for management of energy exchange processes on the electric rolling stock with onboard capacitive energy storages are determined. The advantages and disadvantages of each strategy are set out taking into account the given conditions (characteristics of the electric rolling stock, conditions of the rolling stock motion, oscillograph charts, etc.). The general advantages and shortcomings of each strategy are defined, which allowed to propose the concept of creating an adaptive strategy for managing energy exchange processes in electric rolling stock with onboard capacitive energy storages. The main concept of this management strategy is to implement efficient energy exchange between the traction equipment, the onboard capacitive energy storage, the overhead contact system, both in normal and emergency modes of traction power supply, taking into account the dynamics of energy exchange processes in the overhead contact system, which will generally allow safety and energy efficiency of the transportation process. The obtained research results will contribute to the development and implementation of effective strategies for managing energy exchange processes in the electric rolling stock.

The Use of Innovative Contact Strip for Pantographs of Electric Rolling Stock. Experience in Operational and Bench Tests

Modern high-tech composite materials are widely used in various sectors of the economy, in particular, in railway transport. Among the areas of application of such innovative materials, the manufacturing of contact strips for pantographs of electric rolling stock should be mentioned. Innovation is primarily understood as the self-lubricating property of the working surface of the linings. The linings made of such materials differ from the traditional graphite (coal) ones by the increased content of metal additives, in particular copper, which limits the possibility of their use on electric rolling stock in the countries of the European Union. Regulatory restrictions on the content of copper (35% and 40%) are associated with possible damage to the contact wire, in the case of using overlays with a content of copper (metals) greater than these restrictions. On the railways of Ukraine (countries of the former USSR), there are also restrictions on the use of linings of different types according to the degree of wear of the contact wire, no more than 40 microns is allowed per 10 thousand passes of the locomotive pantograph along the contact wire. These standards are verified during operational and bench tests. The aim of the article is to present the types of tests and compare the obtained values with similar indicators in the case of using a traditional contact strip for pantographs of electric rolling stock. The results obtained confirm the possibility of using innovative linings on iron networks, since the wear of the contact wire during testing is much lower than that of the normative and knife than for traditional types of linings. In addition, during a set of tests, the fact of improving the quality of the working surface of the contact wire was established, which positively affects the extension of the service life of the contact wire.

Application of the recurrent mathematical model for estimating the electric-traction NetWare parameters at their dynamic change

The article is devoted to the possibility of applying the methods of successive approximations in the analysis of the instantaneous scheme of the electric-traction netware. The described approach makes it possible to improve the accuracy of modeling the dynamic modes of traction power supply sections operation, and also makes it possible to significantly improve the process of modeling diagnostic and control systems for electric rolling stock at the design stage, based on a more accurate model of dynamically changing input parameters of the electric-traction netware, depending on their required level.

NORMS AND METHODS FOR DETERMINING THE ELECTROMAGNETIC COMPATIBILITY OF MODERN AUTOMATIC LOCOMOTIVE SIGNALING SYSTEMS AND ELECTRIC ROLLING STOCK WITH AN ASYNCHRONOUS TRACTION DRIVE ON THE SUBWAY

The article provides a brief overview of the development and application of automatic control systems for subway trains. Modern automatic locomotive signaling systems featuring automatic speed control with signal transmission based on double-phase-diff erence modulation are analyzed. The introduction of electric rolling stock with an asynchronous traction drive and advanced train traffi c automation and remote control systems at the St. Petersburg Metro initiates the drive to ensure their electromagnetic compatibility. For the subway train traffi c automation and remote control systems, there have been no acceptance criteria for electromagnetic interference that occur in their operating range when electric rolling stock with an asynchronous traction drive is put into operation. The article identifi es the main sources of conducted electromagnetic interference and the routes of their penetration into the receive path of automatic locomotive signaling devices with automatic speed control. A method is proposed for determining the limits of hazardous and interfering eff ects (immunity limits) for automatic train signaling systems with automatic speed regulation of the systems of the BARS automatic speed control unit with phase-diff erence modulation and the upgraded PA-M (ПА-М) train automation with phase-diff erence modulation for the St. Petersburg Metro lines. A method is given for the transition from the immunity limits of automatic locomotive signaling systems with automatic speed control to the emission limits of electric rolling stock at diff erent traction current unbalance factors. A technique for measuring traction current at high-potential points on electric rolling stock is considered. A technique for assessing the levels of conducted electromagnetic interference from electric rolling stock by calculating the eff ective value in a sliding window of a pre-fi ltered traction current signal of an electric rolling stock is presented.

MODELING THE PLAN OF THE TRANSPORTATION PROCESS DURING THE MORNING RUSH HOUR ON THE CLOSED BOLSHAYA KOLTSEVAYA LINE OF THE MOSCOW METRO

The article analyzes the characteristics of the construction of the Bolshaya Koltsevaya line (Large Circle Line) of the Moscow Metro from the point of view of the transportation process planning. The authors have studied the characteristics of all operating depots of the Moscow Metro that justify the plans for the construction of two new depots (Aminievsky and Nizhegorodsky), as well as the reconstruction of one of the existing depots (Zamoskvoretsky), located within the city limits of Moscow – inside the Moscow Automobile Ring Road (MKAD), in the vicinity of the Third Transport Ring and beyond. For the needs of modeling, the station-to-station length of the closed Bolshaya Koltsevaya line was measured, subject to the transfer of a train traffi c section from the Delovoy Tsentr station to the Khoroshevskaya station of the projected Rublyovo-Arkhangelskaya metro line. Based on the measurement fi ndings, the station-to-station travel times along the closed Bolshaya Koltsevaya line were calculated, which subsequently made it possible to determine the number of electric rolling stock units required to service the Bolshaya Koltsevaya line in the morning rush hour

The effect of air flow on an aerodynamic device for a pantograph

Objective: To evaluate the infl uence of the parameters of current collectors of high-speed and very high-speed trains on the value of aerodynamic resistance. To study the effect of airfl ow on a pantograph aerodynamic device using SolidWorks software. Methods: A comparison of the obtained values of aerodynamic air resistance with those that were produced earlier is carried out. Results: By means of aerodynamic device, it is possible to reduce the speed of the air fl ow effecting the pantograph, to reduce the values of aerodynamic resistance and energy consumption, to extend the service life of current collectors. Practical importance: The proposed design can improve the current collection, which will reduce the load on the overhead line and the pantograph slide, and reduce the energy consumption of electric rolling stock.

Simulation of the process of current distribution in a traction rail network

The article synthesizes a simulation model of a section of a traction rail network, analyzes the norms of permissible asymmetry current, at which a choke-transformer is able to function with a set quality. The simulation of the current distribution process that occurs in the traction rail network during the movement of trains of increased weight and length has been carried out. The graphs of the dependence of the asymmetry current on the traction current consumed by the electric rolling stock have been obtained, and the simulation of the dynamics of changes in the traction current in each of the rail lines has been carried out when the train was moving along a section of the traction rail network. Conclusions about the need to monitor the state of traction rail network elements, the service life of which in heavy traffic conditions is significantly reduced both due to dynamic loads and due to overheating due to the passage of increased traction currents have been made.