Modeling of Electrified Transportation Systems Featuring Multiple Vehicles and Complex Power Supply Layout

The paper proposes a novel approach to modeling electrified transportation systems. The proposed solution reflects the mechanical dynamics of vehicles as well as the distribution and losses of electric supply. Moreover, energy conversion losses between the mechanical and electrical subsystems and their bilateral influences are included. Such a complete model makes it possible to replicate, e.g., the impact of voltage drops on vehicle acceleration or the necessity of partial disposal of regenerative braking energy due to temporary lack of power transmission capability. The modeling methodology uses a flexible twin data-bus structure, which poses no limitation on the number of vehicles and enables modeling complex traction power supply structures. The proposed solution is suitable for various electrified transportation systems including suburban and urban systems. The modeling methodology is applicable i.a. to Matlab/Simulink, which makes it broadly available and customizable, and provides short computation time. The applicability and accuracy of the method were verified by comparing simulation and measurement results on an exemplary trolleybus system operating in Pilsen, Czech Republic. Simulation of daily operation of an area including four supply sections and maximal simultaneous number of nine vehicles showed a good conformance with the measured data, with the difference in the total consumed energy not exceeding 5%.

Energy efficiency of power electronics converters in traction power supply networks at voltage increase

The main features of the procedure for predicting electrical losses in power semiconductor converters of AC-DC and DC-AC systems of high voltage DC traction are presented. The procedure is based on simulation of multi-cycle switching of IGBT modules in combination with simulation of static and dynamic switching losses in traction converter circuits. The models take into account the switching frequency, physical processes in the formation of voltage and current diagrams at transition processes and in the static state of the switch elements. The model of loss assessment using particular types of IGBT modules is the basis for calculating the energy efficiency characteristics of traction converters for advanced high-voltage direct current traction systems.

Subway Traction Power Supply System Based on PWM Rectifier

At present, PWM rectifier is widely used in various high power and high voltage situations because of its high energy, low harmonic content, constant voltage and bidirectional energy. The energy supply system of subway traction power supply system based on PWM rectifier shows the topology of a dual transformer with three winding transformers and four PWM rectifiers in parallel, which is superior to the modular model. Finally, the correctness of the control strategy is verified by Matlab/Initial simulation.

Application of Traction Power Supply for Metro Rail Transit Based on Electromagnetic Sensing Technology

With the gradual acceleration of modernization, metro projects have been opened for the development and construction of urban areas. How to ensure the smooth operation of subway project in public service has become the focus of urban public safety service research. In view of this content, this paper studies the subway field of urban rail transit operation and improves the public safety of urban rail transit operation. Firstly, the factors affecting the track traction power supply are analyzed, the anti-interference technology of ring array electromagnetic sensor is added, and the research scheme is formulated according to the track potential research standard to ensure the operation of the power supply system. Then, the electromagnetic sensor traction algorithm is used to detect the subway track power supply signal, and the working characteristics and advantages of single electromagnetic induction and double electromagnetic induction are analyzed. The experimental results show that compared with the traditional electromagnetic sensor power supply signal detection algorithm, the content of this paper can judge whether the power supply is normal according to electromagnetic induction, detect whether the subway traffic deviates from the track traction coordinates, and understand the size of the deviation from the track. It improves the efficiency of traction power supply detection, stabilizes the running track of subway traffic, and is conducive to the protection and development of urban public safety.

Analysis of compensating devices efficiency in ac traction power supply systems

The article describes the main methods of reactive power compensation used in 27.5 kV AC traction power supply systems on the railways of the Russian Federation. The cases of installation of the longitudinal and transverse capacitive compensation devices at traction substation and sectiolizing post are considered in this paper. Based on experimental data their effectiveness has been analysed by comparing the main parameters of the traction power supply system before and after the installation of the compensating devices. The main effect in terms of power consumption reduction is achieved through application of reactive power cross-compensation devices. The results of the analysis show that the total electricity consumption in the researched area decreased by 23 % and the proportion of higher harmonic elements of voltage decreased by 15 %.

Model of the traction and external power supply system joint operation

The paper presents a description of mathematical model designed to study the joint operation of 25 kV alternating current traction power supply systems and 110 - 750 kV power supply systemsThe design concept of three-phase and single-phase PU-generators on the basis of the EMF source behind inductive resistance as well as three-phase and single-phase loads is considered. Based on the above mathematical expressions, a computer model has been developed to analyze the joint operation of three-phase networks of external power supply and single-phase traction networks. The model is implemented in the software package MATLAB -Simulink. Using this computer model the influence of power overflows in the 110 - 330 kV network of PJSC “Karelenergo” and PJSC “FGC UES” on the equalizing currents in the traction network of the Knyazhaya-Idel’ section of the October railroad was analyzed. Brief analysis of modeling results is presented.

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.

Selection of electricity storage devices for mobile DC traction substations

The aim of the study is to review the sources covering the problems of accumulating electricity on the railways and to find new solutions to reduce the use of electricity in traction power supply system. The article analyses some existing types of electric energy storage devices (capacitive, inertial, superconducting inductive, electrochemical, fuel cells and pumped storage power plants), their common installation locations, advantages, and disadvantages. The possibility of using them in railway traction power supply systems, in particular in mobile traction substations, is also assessed. In addition, the article lists the parameters on the basis of which the optimum type of storage device can be selected for the given conditions. The study concludes that the use of some types of energy storage devices in mobile traction substations is acceptable when regenerative braking can be used at the site, and this method of energy saving can be recommended in the engineering of new or reconstruction of existing traction substations. It has been found that capacitive and inertial (flywheel) electrical energy storage units are the most suitable in terms of parameters for installation of traction power supply systems.

ANALYSIS OF THE PROCESSES OF OCCURRENCE OF SUBHARMONIC COMPONENTS IN CONTACT POWER SUPPLY NETWORKS WITH NONLINEAR LOADS

The article considers the calculation of the modes of occurrence of subharmonic components in traction power supply networks of railway transport, containing traction converters, controlled and uncontrolled rectifiers. The processes of the appearance of harmonic components during the operation of electric locomotives with zone-phase and pulse control using a four-quadrant 4q-S converter in power circuits are considered. Harmonics related to the fundamental and subharmonic components are determined by the harmonic balance method.