Urban Electric Transport Research Articles

Разработка комплексного показателя оценки состояния городского электротранспорта для органов исполнительной власти Российской Федерации

This article analyzes 115 cities on the territory of the Russian Federation in which one or more urban electric transport systems operate. It is determined that in the modern industry there is no single comprehensive indicator of the state of urban electric transport, which would allow an assessment of the state of systems not only in relation to their own indicators of previous years, but also in relation to other, similar systems. A comprehensive indicator is proposed that will allow a comprehensive assessment of the state of urban electric transport and interpret it in numerical terms for its application by state and regional authorities, allowing to quickly draw conclusions and make a decision on further adjustment of the functioning of the electric transport system, characterized by a relatively simple formula for calculation and does not require specific competencies for those conducting the analysis. The key indicators of urban electric transport are systematized, including those related to the operated energy infrastructure, linear infrastructure, park facilities, including technical buildings and structures for system maintenance, indicators related to rolling stock and its key technical characteristics, as well as the availability of urban electric transport for residents of the considered locality and passenger flows within this framework systems. The boundaries of the values of the final indicator have been determined, within which the state of urban electric transport will be assessed by state and regional authorities as satisfactory or unsatisfactory and requiring decisions on revising approaches to the development of the system within the framework of strategic transport planning documents.

Application of artificial intelligence technologies at substantiation of effective control algorithms for the electrical engineering complex of urban electric transport traction electrical equipment

Background. Studies on the current state and development trends of urban ground public electric transportation in Russia highlight the urgent need for innovative technologies. These innovations should focus on designing and operating new types of rolling stock, traction electrical equipment, and promising types of electric traction. At the same time, special attention should be paid to building autonomous control systems for electric transportation using artificial intelligence technologies. Aim. This study aims to explore the application of neural networks to develop algorithms for effectively controlling the electrical engineering complex of traction electrical equipment in urban ground rail electric transport. Materials and Methods. The research utilized data from studies on the traction electrical equipment modes of rolling stock. These studies were conducted through both computer simulations and field experiments under real operating conditions of urban electric transport using different control algorithms. By applying probability theory and mathematical statistics, the analysis identified the correlations between operational and energy parameters of rolling stock movement and the operational mode of its traction electrical equipment. Results. The identified correlation dependencies informed the design of an effective network architecture, including its size and complexity, as well as the composition of their training samples. This led to the development of an original, simplified algorithm for determining effective control parameters for the electrical complex of traction electrical equipment during the movement of a vehicle on a given section of track. Conclusion. The research concluded that using “simple” neural networks for calculating the parameters of effective control of traction electrical equipment operation modes in urban electric transport provides higher speed and sufficient accuracy compared to complex neural network models. These results are valuable for developers of intelligent control systems for streetcar transportation.

Systems of autonomous running of urban electric transport

The autonomous running system (ARS) is crucial for urban electric transport, ensuring the movement of electric rolling stock even when access to the contact network is lost owing to emergencies or repair work. Thanks to the ARS, the vehicles can maintain their set speeds, providing passengers with comfortable and safe movements. The autonomous running allows vehicles to remain mobile and accessible to passengers, even without power supply from the contact network. ARS increases the reliability and efficiency of urban electric transport, ensuring a more stable operation of the transportation system in the city. This article aims to review the transport systems of urban electric transport and assess their development potential by integrating an ARS into the rolling stock.

HOW PASSENGER TRANSPORT IS DEVELOPING IN BULGARIA IN THE CONDITIONS OF A DYNAMIC CHANGING ENVIRONMENT?

The current study seeks to establish the preferences of Bulgarians through exploring how passenger transport in Bulgaria developed from 2012 to 2022. On a theoretical level, the characteristics of this sector are described, such as types of passenger transport vehicles. The research interest is aimed at tracking the dynamics behind all the options for passenger carriage forming the supply of the transport market in Bulgaria: by rail, bus, air, water, and urban electric transport. To achieve this objective, the parameters of activity in the passenger transport segment are used as the main measures – number of passengers, passenger-kilometres and average distance travelled. During the studied period, passenger transport in Bulgaria developed at variable rates and was influenced by environmental factors. The mode of transport most affected by the pandemic in 2020–2021 was by air. A decrease in the total number of passengers and overall performance for 2022 compared to 2012 can be observed. This decline is due to a decrease in bus and rail transport indicators. The study has established that Bulgarians prefer traveling by bus to other public transport alternatives. Although the absolute number of vehicles has decreased in this segment, it has the largest relative share according to the indicators of transported passengers and performed work as part of the total transport activity in the country. In a practical respect, attention is focused on modern solutions related to information and communication technologies, as well as some opportunities to attract more public transport passengers. The author also draws attention to some EU initiatives in the field of air and maritime transport concerning Union-wide energy policy.

Analysis and development of criteria for the operational efficiency of urban electric buses

Problem. Currently, manufacturers and research specialists primarily utilize the amount of autonomous mileage and/or the specific electricity consumption of autonomous DEEs per unit of mileage to describe the general characteristics of urban electric buses. However, the structural mass and the key operational parameter, the nominal passenger capacity, are often disregarded. Therefore, comparing electric buses of the same type with identical dimensional parameters based solely on these criteria is illogical and incorrect. Goal. This study aims to establish criteria for the operational efficiency of urban low-floor electric buses of various types, considering autonomous DEE and their charging or replacement systems. These criteria should account for structural mass and nominal passenger capacity, facilitating a proper comparative assessment and the selection of the most optimal options for use in urban passenger transportation systems. Methodology. Criteria for the operational efficiency of city electric buses of various types are proposed based on an analysis of electricity consumption required for both movement and the operation of heating, ventilation, and air conditioning systems. The criteria consider the mass in the equipped state and the main parameter - nominal passenger capacity. Results. Several operational efficiency criteria for urban electric buses, incorporating mass parameters and passenger capacity, are suggested. The feasibility of their application is demonstrated through a comparison of five sketch projects of electric buses of various types with modern models. Originality. The proposed criteria for the operational efficiency of urban electric buses offer a method for adequately comparing any selected models, regardless of their types and technical specifications. Practical value. The proposed criteria for the operational efficiency of urban electric buses of various types can be beneficial for transport company specialists in selecting suitable rolling stock for specific routes. Additionally, design bureau and scientific and technical center specialists can utilize these criteria during the design process of new urban electric transport models.

THE RELEVANCE OF THE SYSTEM OF DIRECT CONTROL OF THE TORQUE OF AN ASYNCHRONOUS MOTOR

In the article, a mathematical model of the DTC (direct torque control) system of an alternating current electric drive is developed for the tasks of urban electric transport rolling stock, as an alternative to complex vector control of an asynchronous motor, taking into account its relevance, principles of operation and causes of occurrence. The research of the mathematical model of the direct control of the torque of the asynchronous motor in MATLAB was carried out, its main shortcomings, which limit the scope of its application, were revealed. The main task of the DTC system is to identify the stator flux linkage, which is solved by integration with error accumulation. The source of error accumulation is the inaccuracy of determining the active resistance of the stator and its changes during the operation of the asynchronous motor. The DTC system has a disadvantage associated with the appearance of torque ripples and rotor speed fluctuations at low loads.

Определение объемов полезной и избыточной рекуперативной энергии электроподвижного состава городского электротранспорта

Objective: consider the need to accurately determine the total amount of energy that a rolling stock generates during the conversion of mechanical braking energy into electrical energy. To show the need for the formation of measures to increase the volume of useful recovery. Methods: the use of well-known analytical expressions and the results of races obtained during the operation of electric rolling stock of urban electric transport on routes. Results: it is shown that the proposed method for determining the volumes of useful and excess regenerative energy allows us to accurately determine the energy balance in the contact network of urban electric transport. Practical importance: it is shown that the volumes of useful and excess energy recovery largely depend on seasonal changes in power and duration of non-traction load in the contact network and, consequently, on weather conditions during operation on the route. Data on the volumes of useful and excessive recovery create an opportunity for energy services of transport enterprises to develop energy saving measures.

Assessment measures developed to improve quality of route transport Polotsk and Novopolotsk

The paper considers options for reducing environmental losses in Polotsk and Novopolotsk through the development of trolleybus and tram systems – various types of urban electric transport. In order to reduce the costs of creating transport (including charging) infrastructure, as well as operating costs, the effectiveness of such systems has been determined when using not only classic types of transport, but also hybrid buses, electric buses, duo-buses. Approaches and methods have been developed to improve the quality of passenger service without deteriorating the environmental situation – this will become possible thanks to the development of tram and trolleybus traffic in Polotsk and Novopolotsk. Variants of scenarios for the use of various types of urban eclectic transport in the cities under study are presented, which will reduce investment in vehicles and the cost of creating an operational base at the expense of existing production facilities, for example, a tram fleet. The proposals outlined in the paper are aimed at improving the environmental situation in these cities by reducing the volume of emissions of harmful substances by buses, especially on the central streets

АНАЛІЗ СТАНУ ТА ПЕРСПЕКТИВИ РОЗВИТКУ МІСЬКОГО ГРОМАДСЬКОГО ТРАНСПОРТУ УКРАЇНИ

The production, distribution and consumption of goods is impossible without the participation of transport, in particular urban public transport, which is in a deep economic crisis, which only deepens with the passage of time. In addition, the city's public transport and its infrastructure suffered huge losses during the period of full-scale military aggression, but are gradually being restored thanks to the efforts of the city councils and the help of partner countries. Therefore, we consider it important to analyze the current state and prospects for the development of urban public transport in our country. The article identified, researched and analyzed the main performance indicators of enterprises that are part of the Corporation of Urban Electric Transport Enterprises of Ukraine "Ukrelektrotrans", namely: volumes of transport work, volumes of passenger transportation, own expenses and revenues for 2022-2023. The analysis of the dynamics of all technical and economic indicators without exception showed that in the country as a whole in 2022 they significantly decreased compared to the indicators of 2021, but in 2023 the opposite trend was observed - an increase in the volume of transport work, passenger transportation, income and expenses at almost all enterprises of the country. Regarding the analysis and comparison of the indicator of cost coverage of enterprises at the expense of their own income from the main type of activity (income from the sale of travel tickets) and the indicator of cost coverage at the expense of all available items of income, the first indicator remains at an extremely low level, like all previous ones years of existence of city public transport. But the financing of enterprises at the expense of external sources made record figures for the industry, which determined the sufficient level of the indicator of cost coverage at the expense of all available income items. So, the lack of financing, which is so often talked about by the managers of transport companies, has been overcome. Therefore, the results of 2023 inspire hope for the revival of the industry. It is necessary to maintain this trend in 2024 and in all the post-war years, when the industry will be in high demand.

ОБЗОР ПРОБЛЕМЫ ИСПОЛЬЗОВАНИЯ ГАЗОТУРБИННОЙ УСТАНОВКИ ДЛЯ ЗАРЯДКИ АККУМУЛЯТОРНЫХ СИСТЕМ ГРАЖДАНСКОГО ЭЛЕКТРОТРАНСПОРТА

The issues of energy saving are considered on the example of the operation of urban electric transport. The review of various chargers, stations for electric transport is carried out, various comparative characteristics of microturbine and gas piston installations are presented. The technical features of electric vehicles of various manufacturers are analyzed, the classification of electric vehicle power plants is given, the results of using prototypes of urban electrical engineering are indicated, and a review of microturbine technologies on the Russian market is given.

Analysis of the state and energy efficiency of electric traction networks of urban electric transport

Analysis of the state and energy efficiency of electric traction networks of urban electric transport

Determination of the Reliability of Urban Electric Transport Running Autonomously through Diagnostic Parameters

The urban transport network involves complex processes, operating 24 h a day and 365 days a year. The sustainable development of the urban transport network using electric buses and trolleybuses that run autonomously is an urgent task since the transport network performs integral social functions and is the transport artery of any urban center. The social and economic life of a city as a whole depends on the reliability of the transportation network. A theory is proposed for the technical and economic evaluation of reliability improvement in electric buses and trolleybuses running autonomously, which enables the determination of the reliability parameters of electric buses and forecasts for the future from the point of view of optimal economic costs for the operation of electric equipment in electric buses. As a result of the application of the proposed theory, it was found that increasing the reliability of the transportation fleet can lead to a decrease in both specific operating costs and capital investments in the development of the fleet. This is achieved as a result of increasing the annual productivity of vehicles by reducing the time they are out of service to eliminate the consequences of failures and carry out maintenance and repair. The conducted experiments confirmed that the theory and methodology of optimal reliability level selection not only enable the rational use of the material resources of the urban transport network but also the release of funds for its scientific and technical development by reducing the number of failures in the electrical equipment of transport systems by 14%.

Diagnosis of material wear on the running track bearing of a synchronous permanent magnet electric motor

This study addresses the issue of creating methods for diagnosing the condition of bearing assemblies using an onboard diagnostic complex of an urban electric bus. The purpose of the study is to identify types of rolling bearing failures in the composition of the traction electric drive of urban route transport and to develop methods for their diagnosis using analysis of phase currents in the windings of the electric motor. As a result of the study, a new mathematical model of resistance torque was developed, and the diagnostic feature value of defect development was established. Thus, this study has practical significance for ensuring the reliability and safety of urban transport, especially under conditions of intensive operation and high loads on the electric drive. Keywords: urban electric transport, diagnostics, bearing assemblies, onboard diagnostic complex, analysis of phase currents, mathematical model, defect

Methods for increasing the potential of integration of EV chargers into the DC catenary of electric transport grids: A trolleygrid case study

The traction substations of urban electric transport grids are oversized and underutilized in terms of their capacity. While their over-sizing is an unfortunate waste, their under-utilization creates the major hurdle for the integration of renewables into these grids due to the lack of a base load. Therefore, integrating smart grid loads such as EV chargers is not only an opportunity but a necessity for the sustainable transport grid of the future.This paper examines six methods for increasing the potential of EV chargers in three case studies of a trolleygrid, namely a higher substation no-load voltage, a higher substation power capacity, a smart charging method, adding a third overheard parallel line, adding a bilateral connection, and installing a multi-port converter between two substations. From the case studies, the most promising and cost-effective method seems to be introducing a bilateral connection, bringing a charging capacity for up to 175 electric cars per day. Meanwhile, other costly and complex methods, such as smart charging with grid state sensors and communication, can offer charging room for over 200 electric cars per day. Furthermore, using solar PV systems to power the grid showed a more than doubling of the directly utilized energy by installing a 150kW charger, from 19% to 41%. This reduces the power mismatch between the trolleygrid and the PV system from 81% to 59% and thereby reduces the severe economic need for storage, AC grid power exchange, or PV power curtailment while allowing a high penetration of renewables.

Comparison of the Flywheel Energy Storage Performance in the Tram Overhead Contact System in the Cold and Warm Transport Operation Seasons

The article discusses the results of statistical and field studies of the energy consumption modes by the traction and non-traction loads in the overhead contact system (OCS) of the on-ground urban electric transport vehicles in the warm and hot seasons and the associated changes in the operation modes of an NKE-3GT stationary buffer energy storage. It is shown that the reduction of non-traction load, which takes place mainly in the warm season, entails a redistribution in the amounts of surplus and useful energy of electric rolling stock regenerative braking toward surplus energy and, hence, a growth in the surplus regeneration energy flows through the buffer energy storage.

ПРОБЛЕМИ ЕНЕРГОЗАБЕЗПЕЧЕННЯ СУЧАСНОГО ТА МАЙБУТНЬОГО ГРОМАДСЬКОГО ЕЛЕКТРОТРАНСПОРТУ УКРАЇНИ

This article discusses the common issues of energy supply faced by most municipal enterprises of urban electric transport in Ukraine, which have been affected to some extent by military aggression, impacting their primary function of passenger transportation. The energy supply situation in Ukraine is a matter of global concern, making the topic of this article highly relevant. The article analyzes the structure of electricity generation in the unified power system of Ukraine, revealing that the cheapest electricity is produced by nuclear and hydroelectric power plants in the country, while the most expensive, known as "green" electricity, is generated by solar and wind power plants. Additionally, the article presents a diagram illustrating the changes in funding that occurred in 2023 among the ministries and departments of Ukraine compared to the budget of the previous year. An analysis is provided regarding the prospects of increasing funding for the energy sector of Ukraine during this period. Moreover, the article offers recommendations to municipal enterprises and city councils on post-war procurement of energy-efficient rolling stock for the country's public transport enterprises. These recommendations are based on the analysis of energy consumption indicators for various types of electric passenger transport, including traditional and modern hybrid urban electric transport capable of covering a certain portion of the route without being connected to power wires, thanks to battery packs. Such vehicles can be electric buses or trolleybuses with autonomous operation. The ecological aspect of these hybrid electric transport types is also considered. Hybrid electric transport models are expected to replace city transport powered by internal combustion engines. The article also separately examines the project for renewing the rolling stock of electric transport in the city of Kharkiv, which is the authors' hometown, and explores the possibilities for municipal transport enterprises in this city to increase their entrepreneurial activity by providing charging services to other electric vehicles owned by citizens under private ownership rights. The authors have developed a scheme for the development of charging infrastructure for electric cars, electric bicycles, and other similar vehicles.

Условия труда производственного персонала трамваев в городах Челябинской области в 1930-е гг.

An important characteristic of the level of development of society is the material conditions of the life and work of its people. The relevance of the study is due to the ability to identify the conditions which primarily determined the efficient operation of urban electric transport based on analysis of historical sources. The purpose of the study is to identify the main factors which influenced tram workers in their daily work in Chelyabinsk, Zlatoust, Magnitogorsk in the 1930s. On the basis of materials from Federal and Regional archives and journalistic press, the paper presents the main production characteristics of the tram economy of the RSFSR. It analyzes the operational characteristics of the rolling stock, working conditions in the depot and on the traffic lines, and the influence of the human factor in the 1930s on the working of the trams. Historical sources were analyzed through the prism of the history of everyday life. The methodology was based on case-studies. The author shows that the cumulative effect of the harsh natural and climatic conditions, the lack of equipped work places, tools, and materials led to excessively long working shifts, and constant personnel turnover. The circumstances of working conditions were dictated by the general level of technical equipment of the time and the level of development of the industry. The factors identified in the course of the study which influenced the working conditions in the tram facilities of the cities of the Chelyabinsk region enabled the general situation in the 1930s in the field of trams in the cities of the RSFSR to be characterised (with the exception of Moscow and Leningrad).

Двенадцатипульсовые выпрямители в системе электроснабжения городского электрического транспорта

The introduction of twelve-pulse rectifiers instead of six-pulse ones at traction substations of urban electric transport leads to an increase in technical and economic indicators, energy savings, a decrease in leakage current. These result in electrical safety of passengers, a trolleybus driver and depot maintenance personnel. Twelve-pulse rectifiers can have a serial or parallel connection of sixpulse bridges. With a parallel circuit, it is necessary to have an equalizing reactor. The implementation of a twelvepulse serial type rectification scheme can be carried out by industrial development by manufacturers of new dry converter transformers with different typical power and new rectifiers (blocks). As part of the new rectifiers, it is necessary to have tablet avalanche valves with coolers based on heat pipes due to their advantages over nonavalanche valves.

МЕТОДИКА ИЗМЕРЕНИЯ УСТОЙЧИВОГО РАЗВИТИЯ ГОРОДОВ РОССИИ: ESG-ИНДЕКС ВЭБ.РФ

The article presents a methodology for analyzing the ESG efficiency of Russian cities. According to the authors, ESG assessment of cities is advisable not only when making management decisions, but also when choosing priority projects to improve the quality of life of residents. The purpose of the article is to test the methodology for determining priority projects needed for implementation in Russian cities, taking into account the ESG criterion, as well as to demonstrate a system for ranking cities according to ESG efficiency criteria. The article focuses on the comparison of existing ESG analysis tools of cities. The authors use the methodology of the ESG Index of the VEB.RF as the main tool. The advantage of this Index is determined by its focus on Russian cities. Open database also combines objective and subjective indicators. The article examines the ESG indicators of Yekaterinburg, Pskov and Taganrog. The authors demonstrate that programs for modernization and creation of urban electric transport systems and programs for the construction of social facilities most effectively stimulate the improvement of urban ESG environment and contribute to the sustainable development of Yekaterinburg, Pskov and Taganrog. The ESG rating of Russian cities is presented in the article.

МУЛЬТИМОДАЛЬНИЙ ГРОМАДСЬКИЙ ТРАНСПОРТ УКРАЇНИ: ПЕРСПЕКТИВИ РОЗВИТКУ

The article discusses some common problems faced by most municipal urban electric transport enterprises that existed in the pre-war period and provides a forecast for the post-war recovery of the industry. It emphasizes that the urban public transport in Ukraine should develop based on the principle of multimodality, where schedules of different types of urban public transport are coordinated and tickets are valid for a certain period of time, allowing passengers to transfer between a certain number of transport modes. Specific measures are proposed to improve the functioning of urban public transport in Ukraine on the path to multimodality. The article also provides a brief overview of the application of multimodal transport by public transport in a number of developed countries around the world. According to the forecasts made in the article, in the coming years, public transport will become not only more technological and environmentally friendly, but also more economical due to the introduction of advanced types of public transport, various convenient forms of payment for passenger services based on contactless electronic media, the development of other transport technologies and electronic transport applications. All this, combined with modernized dispatching of urban passenger transport, route rationalization, and the optimization of coordinated schedules, will inevitably lead to the creation of a highly automated multimodal public transport system in our cities, which will make urban public transport a better choice compared to private vehicles in the future. The article provides interesting illustrative material showing how equal-sized groups of people, who are public transport passengers, use micro-mobility vehicles (bicycles) and are owners and passengers of cars in the urban space. The presented material vividly demonstrates the advantages of public transport in terms of relieving congested roads in the majority of Ukrainian cities. Multimodality of urban public transport is the decisive word in the post-war recovery and further sustainable development of our country's urban public transport.