City Electric Transport Research Articles

The additional consumption and savings of paid energy of traction substations when using on-board and stationary storage devices

In traction power supply systems for city electric transport without storage devices, a significant part of the recovery energy is usefully reused for the load in the process of inter-train flows along the contact network. The excess part of the recuperation is dissipated by heat in the braking resistors. The use of on-board storage devices makes it possible to redirect all recovery energy from the car's traction drive to them. The remaining amount of no more than two-thirds of the received recuperation energy is supplied back to the traction drive from the storage device, excluding internal losses, since due to ohmic resistance, the actual efficiency of any type of storage device does not exceed 64 %. The on-board storage device consumes a significant amount of paid energy from the traction substation for its transportation by car, compensation for self-discharge, etc. The total balance of recovery energy returned to traction and losses from additional energy consumption for on-board storage devices is negative. When stationary storage devices operate in the contact network, useful recuperation flows are completely preserved. The excess part of the recovery is redirected to the contact network, where one part of it powers a low-power non-traction load while charging the storage device, and the other goes to the storage device, charging it. After a short period of storage in the storage device, the remainder of the excess recovery is released into the network for the load that appears in it. A stationary storage device has no energy consumption for transportation, and the consumption of paid energy for its own needs and compensation for self-discharge is significantly less than that of an on-board storage device due to its higher load factor. The stationary storage device has a positive balance of recovery energy which allows additional savings of paid energy from the traction substation in the amount of up to 10 % relative to such consumption during useful recovery flows without the use of storage devices.

Efficiency coefficients of the energy storage device in the contact network of the city electric transport

The efficiency of stationary and on-board energy storage devices in the contact network of mountain electric transport (tram, metro) is considered. The efficiency coefficients of storage devices are derived depending on the completeness of consideration of storage systems and methods of their application. In accordance with the established formulas for calculating different types of efficiency, the operation indicators of domestic energy storage devices of various types on mountain electric transport are analyzed. It has been established that, other things being equal, stationary energy storage devices are more efficient than those of the on-board version.

SYSTEM OF CONTROL OF OPERATING MODES OF ELECTRIC TRACTION NETWORKS ON THE BASIS OF FUZZY DESCRIPTION OF THEIR CONDITION

Given the need to save energy and reduce the cost of passenger transport on urban electric transport, the greatest effect (from 5 to 15%) is achieved through the introduction of comprehensive information technologies based on rational modes of traction of electric rolling stock and traction and external power supply. The criterion for assessing the modes of operation of power supply systems of urban electric transport is the energy consumption of traction substations, which reflects most of the influencing factors, including the inseparable relationship of traction and external power supply systems. An approach to the implementation of energy-saving technologies of traction power supply of urban electric transport is proposed, which uses fuzzy models and methods of representation for analysis and selection of controls. It is proposed to implement the control of the power supply system operation modes and the selection of modes on the basis of a vague description of their states. When forming the rules, the following parameters are set: deviation of the daily number of transported passengers on the i-th interstation zone of the two-track section, for the characterization of which the values ​​of fuzzy values ​​"lag (strong, weak, absent)" and "advance (absent, weak, strong)" deviation of daily active energy losses for the substation zone and with the values ​​"strong, absent, weak"; the difference between the daily energy consumption of the i-th substation zone, for the actual mode of operation of the power supply system and the reference mode of uniform loading of the power supply system. When constructing a control model in the form of fuzzy rules, each fuzzy characteristic is approximated by N fuzzy quantities with triangular membership functions. For the fuzzy characteristic the minimum and maximum values ​​of an interval in which there are its admissible values ​​are set. Approximate quantities have a triangular degree of belonging: the vertex lies in the center, it corresponds to the degree of belonging 1, and the other two vertices - on the sides of it with degrees of belonging 0. The fuzzy conclusion is based on the rule of fuzzy Mamdani implication. The constructed base of fuzzy rules, which replaces the model of modes of the power supply system, can be used as a guide to the energy dispatcher to select control for the next time period, taking into account the conditions of uncertainty. The principles of formation of algorithms and filling of databases and knowledge of expert systems are developed and problems of maintenance of modes of energy saving in systems of traction power supply of city electric transport are solved. The proposed algorithms for creating databases of expert systems can be implemented after the modernization of power supply control systems based on new integrated systems. Expert systems must be included in the software of the automated workplace of the energy dispatcher. Their inclusion is planned after introduction of new microprocessor systems of telemechanics of regional control points.

PROCESSES IN URBANISM. METHODS OF RESEARCH AND DESIGN

Tasks, methodology and practical methods of research and design of processes in urban planning are revealed. The specificity of urban problems, which are complex and require consideration of the multidimensionality of solutions, creates difficulties in their study and consideration in the justification of design decisions. Based on the methodology of the systems approach, as well as the approaches that exist in the «study of operations» and which are developed in various fields of science and practice, the article considers special aspects of methodology and methods of research and design processes in urban systems. Attention is focused on problem statement, substantiation of models, their research and comprehension of analysis results. Regarding the study and design of processes in urban systems, the peculiarities of the approach are revealed in solving the problems of compaction of Lviv — a city where the population density per hectare exceeds all major cities of Ukraine, where the highest building density in the former USSR. According to the author, it is necessary to determine the formation of the urban system of Greater Lviv. The transport scheme of combination of motor transport, suburban railway connection, city electric transport, air (in particular small aviation) and subway is considered in detail. The transport framework of Lviv should consist of: - railway and automobile international transport corridors; - ring highways connected to the city by radial connections and transport interchanges at their intersections; - a new international station with a high-speed «narrow» track connected to the European railway network; - high-speed main railway lines, which will connect with the cities of the supra-regional settlement system; - subway; transport interchanges; modern bus stations. The opinion is expressed that the mechanical annexation of territories, which has already taken place by law, threatens to lead to an even greater aggravation of existing problems and the emergence of new poorly forecasted processes. The issue can be solved by developing the concept of Greater Lviv with the involvement of urban planners, specialized specialists of design and research institutions, as well as experts in this subject area.

INCREASING THE EFFICIENCY OF URBAN ELECTRIC TRANSPORT USING SADT METHODOLOGY

The issue of increasing the efficiency of urban electric transport through the introduction of CASE-technologies based on SADT-methodology is considered. The performance of the system analysis of the operation of urban electric transport is given. The system of urban electric transport is considered not as an isolated system that solves only its problems - making a profit, but in connection with the problems of the city, the population that uses transport services, enterprises that employ people who transport. The proposed methodology will allow to create a computer functional model of operation of electric vehicles in the IDEF0 format using the software package BPWin. It is shown that the operation of transport is a complex process consisting of three subsystems: operation management, commercial and technical operation. Each of these subsystems has its own functional tasks, which require appropriate resources. Therefore, to ensure resource conservation in the operation of rolling stock, the following levels of development are presented and considered: the city transport system, urban electric transport enterprises, technological processes of passenger transportation, maintenance, maintenance and repair of facilities and equipment. Also operation of city electric transport includes maintenance of vehicles in depot. This article describes the features of the impact of the rolling stock of urban electric transport on energy consumption, taking into account the influence of factors such as passenger cabin occupancy, mileage of the mobile unit when operating on the routes of large cities, operating speed. A new methodology for evaluating the work of a city electric transport company is presented, which allows to combine several different, economically independent enterprises into one functional model. It is shown that the use of the proposed model will make it possible to create a system of accounting for electricity consumption by different types of urban electric transport.

Resource-saving technologies of operation of a contact network on the state for city electric transport

The work is devoted to solving an urgent task - to develop a complex of scientifically-based proposals of conditions and measures that provide technologies for the operation of electricity traction networks based on energy and resource conservation. The article deals with theoretical and practical issues of technology development and repair of the contact network (CN) on state to ensure the process of passenger transportation. The technical criteria for the status of CN are determined and the technologies of maintenance are offered as monotonically changing parameter control. The set of diagnostic and reliable indicators is offered. Generalized structural diagrams of the system of assessment of the condition of the CN and the ranking of repair work taking into account the possible impact of defects. It is proposed to rank them by three characteristic features: first-class failures in which the CM as a system completely loses its capacity; type 2 failures (partial) in which the effectiveness of the functioning of the CM decreases; failures of the 3rd kind - are noted in the elements of KM for the time of work on the current composition and repair. It is shown that the use of maintenance system according to the state with parameter control is possible if: operating conditions of the CM conditions do not allow the work to failure; KM devices have high functional value with insufficient degree of reserve; there is a high level of operational adaptability and repairability. The basic criteria of the condition of the CM and the quality of current flow are summarized. Technologies based on the synthesis of probabilistic methods of parameter estimation, real diagnostics and simulation modeling of the CM state are proposed. The basic criteria of the condition of KM, which allow to estimate the resource saving during maintenance and repair, are defined.

Methodology for the assessment of the operation reliability of pulling electric machines of city electric transport

One of the most commonly used means of the city’s electric traffic system is trolleybus that has a lot of advantages in comparison with fixed-route taxis, buses and trams. During trolleybuses operation, the most electric and mechanical load has an effect on the traction electric engines, on which the further effective operation of a trolleybus on a transfer line depends. Statistic data concerning the trolleybuses operations in Ukraine prove that reliability of traction electric engines has been reduced for subjective and objective reasons over the past 10-15 years. New developments and the use of technologies are therefore needed for more effective use of the known technical equipment, its modernization, reliability improvement and extending the service life. To determine the effectiveness of trolleybus operation on the route, the modern methods of reliability assessment of the traction electric engines are used, which allow to get adequate characteristics of the structure, functional links of parts and units. But some methods don’t meet the necessary requirements to ensure the reliability of traction electric engines operation. So the subject and the tasks of the research work are still relevant today. New solutions of characterization the reliability of traction electric engines guarantee reducing energy and resource consumption during operation, repair and production. A methodology is presented that allows assessing the operational reliability of electrical machines from the point of view of system analysis. Uncertainty of information data arising during the operation of electrical machines is considered. The decomposition of the goal for the efficient operation and maintenance of electrical machines has been carried out, which is reflected in the form of a "goal tree". The results obtained can be used as initial data for the formulation and solution of a number of problems of control over the operational reliability of electrical machines.

Evaluating energy indicators of electric vehicle compressor electric drive

Problem. Solving the problem of resource conservation in Ukraine requires increasing the energy efficiency of all electricity consumers. This is especially true for electric drives, which consume more than 60% of electricity produced in the world. Since electric transport requires significant consumption of electricity, the issues of its rational use are quite relevant. Goal. Research of operation modes of city electric transport compressors electric drives and estimation of their energy efficiency is the aim of the work. Methods of experimental research of energy characteristics of the electric drive of the trolleybus compressor are used. Results. The article presents the results of the study and proposals for improving the energy efficiency of electric drives of electric vehicle compressors based on the measurement of operating parameters of the electric motor and compressor. The study of the trolleybus compressor traction drive shows the following: the average ratio of the maximum value of the compressor motor starting current to a constant value; the average ratio of the maximum value of the engine starting current to the nominal; the average duration of the transient - the power of the compressor engine at the start, the average amount of the electric power consumed by pneumatic system during a working change of a rolling stock on the route. Originality. The results of experiments proving the irrational use of electric drives of trolleybus rolling stock are obtained, and the ways of solving the problem are indicated. Practical value. The expediency of solving resource saving issues when choosing auxiliary electric drives of electric transport rolling stock is shown.Key words: electric transport, compressor, electric drive, energy efficiency, catenary, power.

Description of a complex technical system of urban electric transport from the standpoint of synergistic methodology

City electric transport is considered from the standpoint of a synergistic methodology in order to search for modern approaches to solving the actual problem of increasing its efficiency. The properties of the urban electric transport system are identified in their unity and interdependence in terms of synergetics. Methodological interpretations of these properties from the standpoint of an actually existing system of urban electric transport will allow determining its theoretical synergetic model.

Organizational aspects of operational management of the city electric transport complex

Organizational aspects of operational management of the city electric transport complex

Organization of responsibility accounting of city electric transport enterprises’ activity

The problems of organization of responsibility accounting of the city electric transport (CET) enterprises' activity are considered. The industry specifics of the activity of tram and trolleybus enterprises are determined. It is substantiated that the organizational and methodical structure of accounting of the CET enterprises’ activity is influenced by factors of the internal and external environment. These include state regulation of the industry, peculiarities in relations with customers, the specific nature of the products and technological peculiarities of structural units. The mathematical model of quality of service of transport enterprise customers on the basis of the verified resource efficiency indicator is developed. Such a step will allow linking the rating efficiency of transport routes with the problems of structural optimization when choosing the priorities in the maintenance of vehicles. In addition, the developed model allows evaluating the fulfillment of the route schedule, which will increase the confidence of passengers in city transport and increase passenger traffic. Thus, the proposed solution allows increasing the efficiency of passenger transport by improving the quality of service within the existing budget.

Energy efficient motion control of the electric bus on route

At present, the urgent problem is the reduction of energy costs of urban motor transport. The article proposes a method of solving this problem by developing an energy-efficient law governing the movement of an electric bus along a city route. To solve this problem, an algorithm is developed based on the dynamic programming method. The proposed method allows you to take into account the constraints imposed on the phase coordinates, control action, as well as on the time of the route. In the course of solving the problem, the model of rectilinear motion of an electric bus on a horizontal reference surface is considered, taking into account the assumptions that allow it to be adapted for the implementation of the method. For the formation of a control action in the equations of motion dynamics, an algorithm for changing the traction / braking torque on the wheels of an electric bus is considered, depending on the magnitude of the control parameter and the speed of motion. An optimal phase trajectory was obtained on a selected section of the road for the prototype of an electric bus. The article presents the comparison of simulation results obtained with the optimal energy efficient control law with the results obtained by a test driver. The comparison proved feasibility of the energy efficient control law for the automobile city electric transport.

City electric transport preferences and motives of the Russian students

The share of electric transport in Russia is very small. Many cities refuse operation of urban electric passenger transportation. Basic reasons of it are high cost value and expensive operation. In Moscow the emphasis is placed on development of rail electric transport. It provides fast movement and pollutes the city environment less. The Moscow students understand that for an urban transportation ecological compatibility and safety are important but they choose buses and individual cars with the internal combustion engine for daily use. The main criteria of the choice are the speed and comfort. Ecological compatibility of the individual transport costs on one of the last places.

Passenger Transport System of a Trestle Type for City Electric Transport

<p>During the years of evolvement traditional modes of transport actually have depleted reserves intended for their further development. However, the growing population in major cities, massive migration, economic and social processes bring forward absolutely new passenger transportation requirements, which can’t be satisfied to the fullest extent nowadays, and in the nearest future they will serve as a powerful factor in its development. Fundamentally new technical solutions, which would tackle the whole complex of problems (security, a distance range, travel time, cost of transport; one-time investment, etc) more efficiently, are required. The use of separate track structures solves these problems most effectively.<br />Having analyzed various options of passenger transport complexes with separate track structures, the authors concluded that the track structure in the form of the elevated trestle of a pipeline type is the most rational for urban conditions.</p>

ОцінкИ пошкодженнЯ пластичниХ матеріаліВ нА рУхомомУ складІ міськОгО електротранспортУ

The various deformations of plastic materials under the dynamic loads to study the effect on the kinematics and the accumulation of damage and material fracture durability with a further static tension on the rolling stock of the city electric transport have been shown

PROBLEMS AND PROSPECTS OF DEVELOPMENT OF URBAN ELECTRIC TRANSPORT

General tendencies, actual problems and perspective trends of the development of enterprises of city electric transport are determined in the article. The complex of arrangements directed to stabilization of the work of the enterprises of the field is proposed.