Vehicle and electronics. Innovative technologies

Double-action electrodynamic retarder system

2024-11-19T10:33:00+02:00

Problem: Issues related to increasing the performance characteristics of braking systems due to the use of car deceleration systems are considered. A structural analysis of car deceleration systems was performed according to a number of classification features: the system action mechanism; the principle of action and means of controlling the retarder; and the method of connecting the retarder brake. Ways of improving retarders based on the electrodynamic principle of construction are noted. The importance of improving the energy indicators of the pre-intermediate braking system due to the use of recuperative methods of self-sufficiency is emphasized. The Relevance of the study is determined by the increase in the number of motor vehicles involved in freight transportation in mountainous terrain. The Goal of the study is to improve the braking characteristics of the car's deceleration system under the conditions of a long descent. The research Methodology includes the improvement of the retarder design and the scheme of the braking force control system. Based on the results of the study, a classification structure of car deceleration systems was compiled; a qualitative analysis of the technical and operational characteristics of the generator-type electromagnetic retarder with axial magnetic flux was made; a technical solution for an electrodynamic retarder is proposed, which comprises two electric machines that provide a double-action braking moment, using recovered energy. The need for a quantitative assessment of the power balance of the double machine's components is identified, which allows optimization of the mass-dimensional indicators of the combined unit for the determined braking force of the deceleration system. Scientific Originality: The trend of transforming the composition of the power plant of a car with a passive electromagnetic retarder into a moderate and even full hybrid scheme is highlighted. The Practical Value of the research is demonstrated through recommendations that can be useful in the design of new systems and adaptation of existing deceleration systems of motor vehicles, which are mainly operated in mountainous terrain.

Optimized control system for a booster lithium-iron-phosphate battery

2024-10-17T13:02:55+03:00

Problem. Conventional lead-acid batteries suffer from significant limitations such as low energy density, reduced reliability over time, and inefficiency under challenging conditions like low temperatures and deep discharge. These limitations highlight the necessity of more efficient, lightweight, and durable alternatives for applications like starting internal combustion engines (ICE) and providing backup power. Methodology. This research focuses on designing and testing an optimized battery management system (BMS) for lithium-iron-phosphate (LiFePO₄) batteries. Key performance parameters, including voltage, current, and temperature, were analyzed. An advanced electronic control unit was developed to regulate charging and discharging processes, with a focus on internal resistance management and cell balancing. Experimental validation was performed under various conditions, including low temperatures and heavy loads, to ensure robust performance. Results. The developed system demonstrated superior reliability, reduced charging times, and longer lifespan compared to conventional batteries. The optimized BMS ensured stable energy output, effectively balancing the charge and managing internal resistance. This system provided consistent performance even under extreme conditions, making it more cost-effective and durable. Originality. This study introduces a novel approach to controlling LiFePO₄ battery systems using advanced BMS technology, addressing specific challenges in ICE startups and auxiliary power applications. It integrates enhanced temperature management, internal resistance monitoring, and charge balancing, providing a tailored solution for demanding environments. Practical value. The findings have practical implications for improving energy efficiency and reliability in automotive and other industries. The enhanced performance and extended lifespan of LiFePO₄ batteries make them ideal for critical applications, such as renewable energy storage and backup power systems, supporting the broader adoption of sustainable energy technologies.

The project of multi-section articulated tram cars based on an innovative layout scheme

2024-11-19T10:31:26+02:00

Problem. Tram transport refers to ecological types of passenger vehicles for public use. Therefore, it is quite widely used in many countries of the world, in particular, in 22 domestic cities. However, the current state of the fleet of its rolling stock is far from desirable because, with 2314 units as of January 2020, only 99 can be considered new, and a total of 2004 cars were in operation for less than 15 years. The total wear and tear of the fleet of tram cars has reached as much as 92.2%. Therefore, it is extremely necessary to update the rolling stock of tram transport with new competitive models in the ideal version of only domestic production as soon as possible. Goal. The purpose of the research is to develop a new innovative layout scheme and, based on its application, a sketch project of a modular-unified standard size series of two-, three- and four-section articulated tram cars, as well as an assessment of the feasibility of creating their structures for mastering production at domestic enterprises. Methodology. The development of a new layout scheme of multi-section articulated tram cars is based on the analysis of the layout schemes of modern models of such vehicles, the identification of their main types, and the determination of the main shortcomings associated with the main design and operational parameters of tram cars—dimensional parameters, mass parameters, and nominal passenger capacity, as well as the layouts of their passenger cabins. The expediency of using the proposed layout scheme for the creation of prospective models of tram cars was evaluated on the basis of the coefficients of their constructive and operational efficiency. Results. The developed project of multi-section articulated tram cars confirmed the possibility of applying the proposed innovative layout scheme to create promising and competitive models of tram cars with significantly higher indicators of operational efficiency. The use of single-axle wheeled trolleys provides the possibility of achieving faster passenger exchange at stops, and the organization of more convenient movement of passengers through passenger cabins and their access to passenger doors. Originality. A new innovative layout scheme was developed for the creation of competitive multi-section articulated tram cars. Indicators of their constructive and operational efficiency have been proposed at the stage of developing draft proposals and draft design. Practical value. The developed innovative layout scheme can serve to create new promising and competitive models of urban tram transport rolling stock. The proposed indicators of constructive and operational efficiency of tram cars can be utilized by specialists of project organizations at the stages of developing draft proposals and the stage of draft design.

Simulation modeling of the LTC4020 charging controller for lithium-ion batteries

2024-11-21T10:34:12+02:00

Problem. Modern lithium-ion batteries are widely used in electric vehicles, medical devices, photovoltaic systems, and other fields due to their high energy density and efficiency. However, they require complex charging management to ensure safety, prevent degradation, and extend lifespan. Existing charging devices often have limitations in supporting a wide range of voltages and currents, as well as versatility in working with different types of batteries. Goal. To analyze and simulate the operation of the combined LTC4020 controller to optimize the charging process for lithium-ion batteries while ensuring high efficiency and safety. Methodology. The research utilized LTSpice software for the simulation of the LTC4020 controller. A lithium-ion battery model based on the Thevenin equivalent circuit was developed to balance accuracy and model complexity. The study focused on the controller’s operation in the constant current-constant voltage (CC-CV) charging mode. Results. Simulations confirmed the effectiveness of the LTC4020 controller in providing precise regulation of current and voltage. The device demonstrated efficient charging of lithium-ion batteries across a wide range of input voltages (4.5 V–55 V), achieving energy efficiency of 90–97%. It was shown that maintaining the voltage range of 2.8–4.2 V is critical to preventing battery degradation. Originality. The study proposed an optimized charging process based on the simulation of the LTC4020 controller using the Thevenin model for lithium-ion batteries. This research highlights the impact of charging device parameters on battery performance and durability, which has not been thoroughly addressed in previous studies. Practical value. The obtained results can be applied to the development of modern charging devices that provide high efficiency, versatility, and safety. This will promote the adoption of energy-efficient technologies in electric transportation, renewable energy, and portable electronics sectors.

Analysis of Public Transport Accessibility for Mining Districts of Kryvyi Rih

2024-11-11T15:38:45+02:00

Problem. Mining and processing plants, along with a metallurgical plant, serve as the primary destinations and origins for work trips in Kryvyi Rih. The transport and pedestrian accessibility of public transport (PT) and its stops in these industrial areas are crucial, particularly given the city's linear planning structure characterized by scattered mining districts and economic activities concentrated along the main transport axis. Despite the extensive body of literature focused on PT accessibility, there has yet to be a study specifically examining the accessibility of PT for mining districts within a city that features a linear and dispersed planning structure. Goal. The aim of this study is to perform a comprehensive analysis of public transport accessibility (PTA) as an indicator of transport supply for the mining districts (zones) within the city’s linearly dispersed urban structure. Methodology. The methodology for this comprehensive analysis of PTA relies on transport modeling using PTV Visum software, along with the collection of baseline data to evaluate shifts in transport demand in Kryvyi Rih from 2021 to 2024. Five zones with the highest job concentrations, as defined by Ukrainian Classification of Economic Activities B, were identified. PTA indicators were calculated for both the zones and their serving stops, with travel time set as the primary accessibility criterion, analysed through a comparison of accessibility isochrones. Given the large spatial extent of the mining zones, pedestrian accessibility to these stops is proposed to be evaluated based on the length of PT connectors and the area of each zone within the model. Originality. The study introduces, for the first time, the "limited accessibility of stops" indicator, defined as the ratio of the length of PT connectors to the area of the corresponding zones within the model. This indicator aims to account for the pedestrian accessibility of mining district's stops. Practical value. Proposed practical measures aim to enhance PT efficiency in terms of accessibility within a city characterized by a linearly dispersed planning structure.

Management of quality for planning of city passenger transportation systems

2024-11-21T10:52:13+02:00

Problem. The article addresses the critical issue of enhancing the quality of urban passenger transport systems (UPTS) at the planning stage. Achieving this goal requires the creation of a comprehensive quantitative mathematical model capable of optimizing the system's quality based on predefined objectives. This optimization involves the development of quantitative indicators for the entire system and its components, which serve as a foundation for decision-making. Goal. The study aims to improve UPTS functioning by focusing on key priority attributes, such as flexibility, ensuring the ability to swiftly reorganize traffic routes and redistribute passenger flows; reliability, providing confidence in delivering passengers with minimal deviations from schedules; ergonomics and safety, emphasizing passenger comfort and protection; and economic properties, addressing cost-efficiency and operational sustainability. Methodology. The research utilizes theoretical-analytical methods to create a structured framework for planning UPTS. Mathematical modeling forms the core of the methodology, enabling detailed evaluation and optimization of critical system attributes. Results. The study provides insights into the optimization of UPTS functioning, demonstrating improved performance through targeted planning and adjustment of quantitative quality indicators. The integration of mathematical modeling into planning allows identifying inefficiencies and addressing them systematically. Originality. The novelty of the research lies in its integrated and systematic approach to defining and quantifying quality indicators for UPTS. Unlike traditional evaluations that often emphasize comfort, this study introduces a comprehensive model encompassing various attributes, including flexibility, reliability, and economic feasibility. Practical value. The proposed model allows practitioners to use empirical data and technical specifications of system components to calculate key performance indicators. This approach supports more informed decision-making and targeted improvements in urban transport planning.