Szabolcs Kocsis Szurke

57221944859

Publications - 29

QUANTITATIVE ANALYSIS AND OPTIMIZATION OF ENERGY EFFICIENCY IN ELECTRIC MULTIPLE UNITS

Szabolcs Fischer Mykola Sysyn Dmytro Kurhan Szabolcs Kocsis Szurke Bence Hermán

Publication Name: Facta Universitatis Series Mechanical Engineering

Publication Date: 2025-08-01

Volume: 23

Issue: 2

Page Range: 351-375

Description:

The increasing urgency for sustainable transportation solutions necessitates a thorough examination of energy efficiency within railway systems. This study investigates the energy performance of Siemens Ventus (i.e., Siemens Desiro ML type) electric multiple units on Austria's Raaberbahn network, focusing on route-specific energy consumption and the optimization of regenerative braking. Utilizing data collected from January to May 2023, the research employs a robust methodology that integrates statistical analysis, curve-fitting, and geospatial modeling to assess energy trends along routes connecting Vienna, Bratislava, and Deutschkreutz. The findings reveal that terrain, operational practices, and external environmental factors significantly contribute to energy inefficiencies. Specifically, hotspots of energy overconsumption were identified, leading to the development of tailored optimization models for each route. The analysis also produced heatmaps that illustrate critical spatial and temporal patterns, which are essential for implementing targeted interventions aimed at enhancing energy efficiency.

Open Access: Yes

DOI: 10.22190/FUME241103001F

Investigation of Convective and Radiative Heat Transfer of 21700 Lithium-Ion Battery Cells

Szabolcs Fischer Gábor Kovács Szabolcs Kocsis Szurke

Publication Name: Batteries

Publication Date: 2025-07-01

Volume: 11

Issue: 7

Page Range: Unknown

Description:

Due to their high energy density and power potential, 21700 lithium-ion battery cells are a widely used technology in hybrid and electric vehicles. Efficient thermal management is essential for maximizing the performance and capacity of Li-ion cells in both low- and high-temperature operating conditions. Optimizing thermal management systems remains critical, particularly for long-range and weight-sensitive applications. In these contexts, passive heat dissipation emerges as an ideal solution, offering effective thermal regulation with minimal additional system weight. This study aims to deepen the understanding of passive heat dissipation in 21700 battery cells and optimize their performance. Special emphasis is placed on analyzing heat transfer and the relative contributions of convective and radiative mechanisms under varying temperature and discharge conditions. Laboratory experiments were conducted under controlled environmental conditions at various discharge rates, ranging from 0.5×C to 5×C. A 3D-printed polymer casing was applied to the cell to enhance thermal dissipation, designed specifically to increase radiative heat transfer while minimizing system weight and reliance on active cooling solutions. Additionally, a numerical model was developed and optimized using experimental data. This model simulates convective and radiative heat transfer mechanisms with minimal computational demand. The optimized numerical model is intended to facilitate further investigation of the cell envelope strategy at the module and battery pack levels in future studies.

Open Access: Yes

DOI: 10.3390/batteries11070246

Analysis of the Correlation Between Electric Bus Charging Strategies and Carbon Emissions from Electricity Production

Szabolcs Kocsis Szurke Gábor Saly Roland Pál

Publication Name: World Electric Vehicle Journal

Publication Date: 2025-04-01

Volume: 16

Issue: 4

Page Range: Unknown

Description:

Reducing carbon dioxide emissions in transportation has become a priority for achieving emission targets. Transitioning to electric vehicles significantly decreases global CO2 emissions and reduces urban noise and air pollution. The selection of efficient charging strategies for electric bus fleets substantially influences their environmental impact. This study analyzes the charging strategy for electric bus fleets based on real operational data from Győr, Hungary. It evaluates the impact of different charging times and strategies on CO2 emissions, considering the energy mixes of Hungary, Poland, Germany, and Sweden. A methodology has been developed for defining sustainable and environmentally friendly charging strategies by incorporating operational conditions as well as daily, monthly, and seasonal fluctuations in emission factors. Results indicate substantial potential for emission reduction through the recommended alternative charging strategies, although further studies regarding battery lifespan and economic feasibility of infrastructure investments are recommended. The novelty of this work lies in integrating real charging data with hourly country-specific emission intensity values to assess environmental impacts dynamically. A comparative framework of four charging strategies provides quantifiable insights into emission reduction potential under diverse national energy mixes.

Open Access: Yes

DOI: 10.3390/wevj16040240

Opportunities for Pulse-Based Diagnostics in Electric and Hybrid Vehicle Batteries

Szabolcs Kocsis Szurke Illés Lorincz

Publication Name: 2025 19th International Conference on Electrical Machines Drives and Power Systems Elma 2025 Proceedings

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This study investigates pulse-based diagnostic methods for identifying faulty cells within lithium-ion battery packs in electric and hybrid vehicles. Diagnostic measurements were conducted using a fully electric Volkswagen e-Golf under both dynamic driving (WLTP) and laboratory-based Hybrid Pulse Power Characterization (HPPC) test conditions. Voltage deviations among individual battery cells were analyzed to evaluate system reliability under constant load, peak load, and regenerative braking scenarios. Results revealed that peak load conditions provided the most informative insights for fault detection due to fewer but more significant voltage deviations. In contrast, constant load and regenerative braking conditions frequently exhibited minor deviations. These findings suggest that transient, high-current events are particularly valuable for early identification of cell degradation and faults. Future studies should further investigate the long-term relationships between detected deviations and overall battery health to enhance predictive diagnostics and optimize battery management strategies.

Open Access: Yes

DOI: 10.1109/ELMA65795.2025.11083486

Vehicle Dynamics Measurements with a Unique Measuring System for Trams

Miklós Kuczmann Szabolcs Fischer Péter Böröcz Szabolcs Kocsis Szurke Vivien Jóvér Bence Hermán

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 24-33

Description:

One of the paramount challenges in contemporary urban transport is the efficient maintenance and operation of tramway tracks, aiming to maximize their lifespan while ensuring safe and comfortable passenger travel. Traditional methods of examining superstructure systems through observation and geometric measurements are insufficient; understanding the dynamics of vehicles adhering to their schedules is equally critical. To address this, we developed an innovative portable vehicle dynamics measurement system equipped with accelerometers and a GPS module (with GNSS system), facilitating real-time tram dynamics testing. This versatile device can be deployed at any time and on any tram, enabling continuous monitoring of track conditions. The dynamic data gathered can be systematically compared with geometric measurements, providing comprehensive insights into the railway track's condition and informing maintenance strategies. The paper consists of several examples for comparison (geometric and dynamic data series) and discusses how to develop the instrument further.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_3

Analyzing Energy Efficiency and Battery Supervision in Electric Bus Integration for Improved Urban Transport Sustainability

István Lakatos Szabolcs Kocsis Szurke Gábor Saly

Publication Name: Sustainability Switzerland

Publication Date: 2024-09-01

Volume: 16

Issue: 18

Page Range: Unknown

Description:

Addressing the critical challenge of reducing local emissions through the electrification of urban public transport, this research specifically focuses on integrating electric buses. The primary objectives are to evaluate energy efficiency and ensure battery cell supervision. Introducing electric buses plays a significant role in reducing emissions, contributing to more sustainable urban transport systems. However, this transition introduces a set of new challenges, including the complexities of electric charging logistics, the establishment of new consumption standards, and the intricate relationships between distance traveled, ambient temperature, passenger load, and battery health. Methodologically, this study collects and examines factors impacting energy consumption, including external temperatures, bus conditions, road conditions, and driver behavior. By analyzing these variables, a baseline for actual consumption can be established, allowing for the calculation of an energy balance to identify energy inefficiencies. This enables the optimization of route planning, the strategic selection of stops, and the efficient scheduling of charging times, along with ensuring the proper scaling of the bus battery system. This study found that energy consumption peaked at 116.73 kWh/100 km in the lowest temperature range of −5 °C to 0 °C. Consumption decreased significantly with rising temperatures, dropping by 25 kWh between 5 °C and 10 °C and by an additional 10 kWh between 10 °C and 15 °C. Beyond 20 °C, variations were more influenced by route and driving style than by temperature. Route and driver variability significantly influenced energy consumption, with up to threefold differences across routes due to factors such as road type and traffic volume. Additionally, there was a 31.85% difference between the most and least efficient drivers, highlighting the critical impact of driving style. Furthermore, this study explores the assessment of battery systems through cell-level diagnostics to detect potential faults. Considering that buses are equipped with significantly more batteries than typical electric vehicles, detecting and localizing faults at the cell level is crucial to avoid the substantial costs and environmental impact associated with replacing large battery systems. Utilizing the results of this research and the applied examination methods, it is possible to enhance energy efficiency and extend battery life, thereby contributing to the development of more sustainable and cost-effective urban transport solutions.

Open Access: Yes

DOI: 10.3390/su16188182

Laboratory and Numerical Investigation of Pre-Tensioned Reinforced Concrete Railway Sleepers Combined with Plastic Fiber Reinforcement

Szabolcs Fischer Mykola Sysyn Zoltán Major Sarah Khaleel Ibrahim Dmytro Kurhan Vivien Jóvér Szabolcs Szalai Hanna Csótár Klaudia Madarász András Pollák Dániel Harrach Bálint Molnár L. Gaspar Bence Hermán Szabolcs Kocsis Szurke Attila Németh I. Fekete Richárd Nagy Gusztáv Baranyai Miklós Kuczmann M. Movahedi Rad

Publication Name: Polymers

Publication Date: 2024-06-01

Volume: 16

Issue: 11

Page Range: Unknown

Description:

This research investigates the application of plastic fiber reinforcement in pre-tensioned reinforced concrete railway sleepers, conducting an in-depth examination in both experimental and computational aspects. Utilizing 3-point bending tests and the GOM ARAMIS system for Digital Image Correlation, this study meticulously evaluates the structural responses and crack development in conventional and plastic fiber-reinforced sleepers under varying bending moments. Complementing these tests, the investigation employs ABAQUS’ advanced finite element modeling to enhance the analysis, ensuring precise calibration and validation of the numerical models. This dual approach comprehensively explains the mechanical behavior differences and stresses within the examined structures. The incorporation of plastic fibers not only demonstrates a significant improvement in mechanical strength and crack resistance but paves the way for advancements in railway sleeper technology. By shedding light on the enhanced durability and performance of reinforced concrete structures, this study makes a significant contribution to civil engineering materials science, highlighting the potential for innovative material applications in the construction industry.

Open Access: Yes

DOI: 10.3390/polym16111498

Self-Diagnostic Opportunities for Battery Systems in Electric and Hybrid Vehicles

István Lakatos Szabolcs Kocsis Szurke Péter Ori Gergő Sütheö

Publication Name: Machines

Publication Date: 2024-05-01

Volume: 12

Issue: 5

Page Range: Unknown

Description:

The number of battery systems is also growing significantly along with the rise in electric and hybrid car sales. Different vehicles use different types and numbers of batteries. Furthermore, the layout and operation of the control and protection electronics units may also differ. The research aims to develop an approach that can autonomously detect and localize the weakest cells. The method was validated by testing the battery systems of three different VW e-Golf electric vehicles. A wide-range discharge test was performed to examine the condition assessment and select the appropriate state of charge (SoC) for all three vehicles. On the one hand, the analysis investigated the cell voltage deviations from the average; the tests cover deviations of 0 mV, 12 mV, 60 mV, 120 mV, and 240 mV. On the other hand, the mean value calculation was used to filter out possible erroneous values. Another important aspect was examining the relationship between the state of charges (SoC) and the deviations. Therefore, the 10% step changes were tested to see which SoC level exhibited more significant voltage deviations. Based on the results, it was observed that there are differences between the cases, and the critical range is not necessarily at the lowest SoC level. Furthermore, the load rate (current) and time of its occurrence play an important role in the search for a faulty cell. An additional advantage of this approach is that the process currently being tested on the VW e-Golf can be relatively simply transferred to other types of vehicles. It can also be a very useful addition for autonomous vehicles, as it can self-test the cells in the system at low power consumption.

Open Access: Yes

DOI: 10.3390/machines12050324

Procedure for Battery Module Assessment in Hybrid Vehicles

Szabolcs Kocsis Szurke

Publication Name: 2024 23rd International Symposium on Electrical Apparatus and Technologies Siela 2024 Proceedings

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Electric and hybrid vehicles are becoming increasingly popular among environmentally conscious consumers, significantly impacting the automotive industry and the development of battery technologies. Fast diagnostic solutions are becoming critical as battery systems wear out over time and performance degrades. This study aims to investigate the battery system of a dedicated electric vehicle, the Toyota Prius, and its condition diagnostics. The test was performed by querying and saving the data using a custom Arduino-based specific measurement tool. The battery modules in the system were tested separately during the evaluation. During the condition assessment, the deviation from the average voltage of different sizes is analyzed and weighted individually depending on the size of the deviation. The analyses also cover more static and dynamic driving styles. The results show the influence of the driving style on the module voltage deviation. Furthermore, the method allows the detection and localization of weak battery modules in the system.

Open Access: Yes

DOI: 10.1109/SIELA61056.2024.10637881

Comprehensive Analysis of the Factors Affecting the Energy Efficiency of Electric Vehicles and Methods to Reduce Consumption: A Review †

Szabolcs Kocsis Szurke Gábor Saly Ferenc Szauter

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

The increasingly stricter environmental regulations and standards aim to reduce the ecological impact of vehicles and promote the sustainable use of natural resources. Improving the energy efficiency of vehicles has become a priority in recent decades. This is a key issue for vehicle development, production, and operation. Several studies and measurements have been conducted to accurately determine vehicles’ energy consumption. This research has investigated and categorized the factors according to external impacts, losses due to vehicle properties, and the effects of vehicle control and energy reduction methods. A better understanding of these factors is crucial for improving energy efficiency.

Open Access: Yes

DOI: 10.3390/engproc2024079079

Deformation Analysis of Different Lithium Battery Designs Using the DIC Technique

Szabolcs Fischer Szabolcs Szalai Szabolcs Kocsis Szurke Mátyás Szabó

Publication Name: Energies

Publication Date: 2024-01-01

Volume: 17

Issue: 2

Page Range: Unknown

Description:

The growing number of electric vehicles and devices drives the demand for lithium-ion batteries. The purpose of the batteries used in electric vehicles and applications is primarily to preserve the cells and extend their lifetime, but they will wear out over time, even under ideal conditions. Most battery system failures are caused by a few cells, but the entire system may have to be scrapped in such cases. To address this issue, the goal is to create a concept that will extend the life of batteries while reducing the industrial and chemical waste generated by batteries. Secondary use can increase battery utilization and extend battery life. However, processing a large number of used battery cells at an industrial level is a significant challenge for both manufacturers and users. The different battery sizes and compositions used by various manufacturers of electric vehicles and electronic devices make it extremely difficult to solve the processing problem at the system level. The purpose of this study is to look into non-destructive battery diagnostic options. During the tests, the condition of the cells is assessed using a new diagnostic technique, 3D surface digitalization, and the fusion of electrical parameters. In the case of surface digitalization, the digital image correlation (DIC) technique was used to estimate the cell state. The tests were conducted on various cells with widely used geometries and encapsulations. These included a lithium polymer (soft casing), 18650 standard sizes (hard casing), and prismatic cells (semi-hard). The study also included testing each battery at various charge states during charging and discharging. The findings help to clarify the changes in battery cell geometry and their localization. The findings can be applied to cell diagnostic applications such as recycling, quality assurance, and vehicle diagnostics.

Open Access: Yes

DOI: 10.3390/en17020323

Comparison of Coupled Electrochemical and Thermal Modelling Strategies of 18650 Li-Ion Batteries in Finite Element Analysis—A Review

Bence Csomós Szabolcs Kocsis Szurke Denes Fodor

Publication Name: Materials

Publication Date: 2023-12-01

Volume: 16

Issue: 24

Page Range: Unknown

Description:

The specificities of temperature-dependent electrochemical modelling strategies of 18650 Li-ion batteries were investigated in pseudo-2D, 2D and 3D domains using finite element analysis. Emphasis was placed on exploring the challenges associated with the geometric representation of the batteries in each domain, as well as analysing the performance of coupled thermal-electrochemical models. The results of the simulations were compared with real reference measurements, where temperature data were collected using temperature sensors and a thermal camera. It was highlighted that the spiral geometry provides the most realistic results in terms of the temperature distribution, as its layered structure allows for a detailed realisation of the radial heat transfer within the cell. On the other hand, the 3D-lumped thermal model is able to recover the temperature distribution in the axial direction of the cell and to reveal the influence of the cell cap and the cell wall on the thermal behaviour of the cell. The effect of cooling is an important factor that can be introduced in the models as a boundary condition by heat convection or heat flux. It has been shown that both regulated and unregulated (i.e., natural) cooling conditions can be achieved using an appropriate choice of the rate and type of cooling applied.

Open Access: Yes

DOI: 10.3390/ma16247613

DETECTION PROCESS OF ENERGY LOSS IN ELECTRIC RAILWAY VEHICLES

Szabolcs Fischer Szabolcs Kocsis Szurke

Publication Name: Facta Universitatis Series Mechanical Engineering

Publication Date: 2023-04-01

Volume: 21

Issue: 1

Page Range: 81-99

Description:

The paper deals with the detection process of energy loss in electric railway hauling vehicles. The importance of efficient energy use in railways and cost-effective rail transport tendency toward regenerative braking energy are considered. In addition, the current situation and improvement opportunities to achieve efficient energy use are examined. Seven measurement series were performed with scheduled Railjet trains between Hegyeshalom and Győr railway stations in Hungary. This railway section is related to the Hungarian State Railways' No. 1 main railway line (between Budapest-Kelenföld and Hegyeshalom state board), which is a part of the international railway line between Budapest and Vienna (capitals of Hungary and Austria, respectively). This double-track, electrified railway line with traditional ballasted superstructures and continuously welded rail tracks is important due to the international passenger and freight transport between Germany, Austria, and Hungary. The value of the regenerative braking energy can be even 20-30% of the total consumed energy. This quite enormous untapped energy can be used for several aims, e.g., for comfort energy demand (air conditioning, heating-cooling, lighting, etc.) or energy-intensive starts. The article also investigates the optimization of regenerative braking energy by seeking the energy-waste locations and the reasons for the significant consumption. The train operator's driving style and habit have been identified as one of the main reasons. Furthermore, train driver assistance systems are recommended to save energy, which is planned for future research.

Open Access: Yes

DOI: 10.22190/FUME221104046F

A Risk Assessment Technique for Energy-Efficient Drones to Support Pilots and Ensure Safe Flying

P. Földesi Szabolcs Fischer Mykola Sysyn Dmytro Kurhan Szabolcs Kocsis Szurke Norbert Perness

Publication Name: Infrastructures

Publication Date: 2023-04-01

Volume: 8

Issue: 4

Page Range: Unknown

Description:

Unmanned Aerial Vehicles, also known as UAVs, play an increasingly important part in daily life. However, the ever-increasing number of UAVs pose an ever-increasing threat to the transportation infrastructure. Despite their precision and general efficiency, infrastructural-scale Unmanned Aerial Systems (UASs) have a disadvantage regarding their capability of being implanted in the ecosystem. There are several reasons for this, but the primary bottleneck is that their systems are not transparent to society and have very complicated processes. As a result, the authors decided to investigate the functional properties of UASs and make improvements to those properties. Throughout the study, the authors’ primary focus was on analysis, which boosts productivity and ensures a significant level of safety for routine flights. The amount of power that a UAV uses depends on several variables, including the amount of power that its individual components require, the temperature of its surroundings, and the condition of the battery that it is powered by. Therefore, critical parameters and interdependencies are taken into account in the risk assessment strategy for energy-efficient Unmanned Aerial Vehicles (UAVs). In the case of UAVs, the algorithm performs a risk calculation before take-off to estimate the amount of risk that can be associated with the given flight time when using the provided battery. On the one hand, several instances of the pre-take-off state and how its parameters interact are investigated. On the other hand, they demonstrate the calculation of the risk while in flight, which is based on actual flight data.

Open Access: Yes

DOI: 10.3390/infrastructures8040067

Numerical Investigation of Pre-Stressed Reinforced Concrete Railway Sleeper for High-Speed Application

Szabolcs Fischer Zoltán Major Szabolcs Szalai Mykola Sysyn Attila Németh Dmytro Kurhan Dóra Harangozó M. Movahedi Rad Sarah Khaleel Ibrahim Dániel Harrach Szabolcs Kocsis Szurke Gusztáv Baranyai Géza Herczeg L. Gaspar

Publication Name: Infrastructures

Publication Date: 2023-03-01

Volume: 8

Issue: 3

Page Range: Unknown

Description:

The current paper deals with the numerical investigation of a unique designed pre-stressed reinforced concrete railway sleeper for the design speed of 300 km/h, as well as an axle load of 180 kN. The authors applied different methodologies in their research: traditional hand-made calculations and two types of finite element software. The latter were AxisVM and ABAQUS, respectively. During the calculations, the prestressing loss was not considered. The results from the three methods were compared with each other. The hand-made calculations and the finite element modeling executed by AxisVM software are adequate for determining the mechanical inner forces of the sleeper; however, ABAQUS is appropriate for consideration of enhanced and sophisticated material models, as well as the stress-state of the elements, i.e., concrete, pre-stressed tendons, etc. The authors certified the applicability of these methodologies for performing the dimensioning and design of reinforced concrete railway sleepers with pre-stressing technology. The research team would like to continue their research in an improved manner, taking into consideration real laboratory tests and validating the results from FE modeling, special material models that allow calculation of crackings and their effects in the concrete, and so that the real pattern of the crackings can be measured by GOM Digital Image Correlation (DIC) technology, etc.

Open Access: Yes

DOI: 10.3390/infrastructures8030041

Vibration Diagnostic Methods of Automatic Transmission Service Requirement Prediction

Szabolcs Fischer István Lakatos Mykola Sysyn Dmytro Kurhan Szabolcs Kocsis Szurke Péter Ori

Publication Name: Infrastructures

Publication Date: 2023-02-01

Volume: 8

Issue: 2

Page Range: Unknown

Description:

Automatic transmission is a key factor for autonomous driving. The transmission condition is highly affected by the quality and quantity of transmission oil in the system. However, the oil condition is not monitored in the system, and the oil change interval and method are still a subject of discussion. This paper analyzes the effects of oil changes in automatic transmissions. The measurements were carried out before and after the oil change with the same external conditions. With the vibration measurement method, data can be collected without disassembling the parts and during operational conditions. Furthermore, time- and frequency-based analyses were conducted to compare different transmissions’ operations. The results have shown that the effect of oil degradation is measurable on the amplitude of the signals and, therefore, predictable with vibration diagnostics. During the evaluation, the maximum values were compared on measurements with at least a 2-s length.

Open Access: Yes

DOI: 10.3390/infrastructures8020031

Sustainability in Railways – A Review

Szabolcs Fischer Szabolcs Szalai Szabolcs Kocsis Szurke András Brautigam Laszlo Ezsias

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 7-12

Description:

This paper examines the sustainability of railways. A comprehensive international literature review was conducted on railway vehicles, traction, and railway permanent way. The main goal was to find the factors and parameters that affect railway sustainability the most. CO2 emissions from transportation, mining, raw material production, manufacturing, use, operation and maintenance, and demolition and restoration must be significantly reduced. Naturally, the attention will be on the considerable energy and financial savings. This article's main topics are sustainability, affordable and clean energy, industry, innovation, infrastructure, sustainable cities and communities, responsible consumption and production, climate action, and life on land. Building materials come from quarries and gravel pits, but availability is decreasing. Future pavement construction and maintenance require recycling demolition and industrial waste. Engineers must choose materials and technology that extend track lifetimes to ensure reliability, availability, maintainability, safety, sustainability, and economy in permanent railroad ways. Life-cycle costs can be reduced, e.g., by Building Information Modeling. Electric machinery is preferred for construction equipment, materials, and management. Sustainability, like grassed tracks and recyclable plastics, has improved urban life. Sheet metal forming using recycled materials and sustainability shows how important environmental protection is in car and train design. Electric road and rail propulsion are driven by environmental concerns, while supercapacitors and batteries are studied. In conclusion, by preferring rail for freight and passenger transport, both for private and public transport, energy savings and CO2 emissions can be up to 2-10 times higher than for other modes of transport.

Open Access: Yes

DOI: 10.3303/CET23107002

Numerical Optimization of Battery Heat Management of Electric Vehicles

Szabolcs Fischer Mykola Sysyn Gábor Kovács Jianxing Liu Szabolcs Kocsis Szurke

Publication Name: Journal of Applied and Computational Mechanics

Publication Date: 2023-01-01

Volume: 9

Issue: 4

Page Range: 1076-1092

Description:

Lithium-ion battery technology in the modern automotive industry utilizes highly temperature-sensitive batteries. Here, air cooling strategies will be the most applicable for the chosen example based on strategies for temperature control. Simulations have been utilized to evaluate the different thermal management strategies. A battery model was developed using the solutions offered by Computational Fluid Dynamics (CFD) simulation technology. It utilizes the heat produced by the discharge of the battery cells. Due to the simulation's limited computational capacity, the energy transfer model was implemented with a simplified but sufficiently complex physical mesh. Ten actual measurements were conducted in the laboratory to investigate the heating of the cell during the charging and discharging of 18650-type batteries. The results were applied to validate the simulation model. The simulation outcomes and thermal camera readings were compared. The cell-level numerical model was then extended to examine the temperature variation at the system level. The primary design objective is to achieve the highest energy density possible, which necessitates that the cells be constructed as closely as possible; however, increasing the distance between the cells can provide superior cooling from a thermal management perspective. The effect of varying the distance between individual cells on the system's heating was analyzed. Greater distance resulted in a more efficient heat transfer. It was also discovered that, in some instances, a small distance between cells produces inferior results compared to when constructed adjacently. A critical distance range has been established based on these simulations, which facilitates the placement of the cells.

Open Access: Yes

DOI: 10.22055/jacm.2023.43703.4119

Cell Fault Identification and Localization Procedure for Lithium-Ion Battery System of Electric Vehicles Based on Real Measurement Data

Szabolcs Fischer István Lakatos Szabolcs Kocsis Szurke Antal Apagyi Gergő Sütheö

Publication Name: Algorithms

Publication Date: 2022-12-01

Volume: 15

Issue: 12

Page Range: Unknown

Description:

Vehicle safety risk can be decreased by diagnosing the lithium-ion battery system of electric road vehicles. Real-time cell diagnostics can avoid unexpected occurrences. However, lithium-ion batteries in electric vehicles can significantly differ in design, capacity, and chemical composition. In addition, the battery monitoring systems of the various vehicles are also diverse, so communication across the board is not available or can only be achieved with significant difficulty. Hence, unique type-dependent data queries and filtering are necessary in most cases. In this paper, a Volkswagen e-Golf electric vehicle is investigated; communication with the vehicle was implemented via an onboard diagnostic port (so-called OBD), and the data stream was recorded. The goal of the research is principally to filter out, identify, and localize defective/weak battery cells. Numerous test cycles (constant and dynamic measurements) were carried out to identify cell abnormalities (so-called deviations). A query and data filtering process was designed to detect defective battery cells. The fault detection procedure is based on several cell voltage interruptions at various loading levels. The methodology demonstrated in this article uses a fault diagnosis technique based on voltage abnormalities. In addition, it employs a hybrid algorithm that executes calculations on measurement and recorded data. In the evaluation, a status line comprising three different categories was obtained by parametrizing and prioritizing (weighting) the individual measured values. It allows the cells to be divided into the categories green (adequate region), yellow (to be monitored), and red (possible error). In addition, several querying strategies were developed accordingly to clarify and validate the measurement results. The several strategies were examined individually and analyzed for their strengths and weaknesses. Based on the results, a data collection, processing, and evaluation strategy for an electric vehicle battery system have been developed. The advantage of the developed algorithm is that the method can be adapted to any electric or hybrid vehicle battery.

Open Access: Yes

DOI: 10.3390/a15120467

Hierarchical Diagnostics and Risk Assessment for Energy Supply in Military Vehicles

P. Földesi Szabolcs Kocsis Szurke Dániel Csikor Ferenc Szauter L. T. Koczy

Publication Name: Energies

Publication Date: 2022-07-01

Volume: 15

Issue: 13

Page Range: Unknown

Description:

Hybrid vehicles are gaining increasing global prominence, especially in the military, where unexpected breakdowns or even power deficits are not only associated with greater expense but can also cost the lives of military personnel. In some cases, it is extremely important that all battery cells and modules deliver the specified amount of capacity. Therefore, it is recommended to introduce a new measurement line of rapid diagnostics before deployment, in addition to the usual procedures. Using the results of rapid testing, we recommend the introduction of a hierarchical three-step diagnostics and assessment procedure. In this procedure, the key factor is the building up of a hierarchical tree-structured fuzzy signature that expresses the partial interdependence or redundancy of the uncertain descriptors obtained from the rapid tests. The fuzzy signature structure has two main important components: the tree structure itself, and the aggregations assigned to the internal nodes. The fuzzy signatures that are thus determined synthesize the results from the regular maintenance data, as well as the effects of the previous operating conditions and the actual state of the battery under examination; a signature that is established this way can be evaluated by “executing the instructions” coded into the aggregations. Based on the single fuzzy membership degree calculated for the root of the signature, an overall decision can be made concerning the general condition of the batteries.

Open Access: Yes

DOI: 10.3390/en15134791

Investigation of deformations of a lithium polymer cell using the Digital Image Correlation Method (DICM)

Szabolcs Fischer Szabolcs Szalai Dóra Harangozó Szabolcs Kocsis Szurke

Publication Name: Reports in Mechanical Engineering

Publication Date: 2022-01-01

Volume: 3

Issue: 1

Page Range: 116-134

Description:

This research aims to investigate the adaptability of a measurement system or a process in determining the parameters of batteries. Methods are suggested for different applications, and properties gained by these measurements are specified. Deformations of lithium polymer batteries measured by various methodologies are also analyzed in detail. Changes in the geometry of worn-out batteries and the localization of the changes can be better understood by applying the results. The GOM ATOS and the GOM ARAMIS systems were applied to characterize lithium polymer batteries. Discontinuous tests were performed and the battery was discharged to 0 V and then fully charged for both methods. The advantages and disadvantages and the applicability of the two measurement systems were analyzed in this topic.

Open Access: Yes

DOI: 10.31181/rme20008022022s

Testing and Modeling Procedure of the 18650 Lithium Battery at Different Temperatures

Adrienn Dineva István Lakatos Szabolcs Kocsis Szurke

Publication Name: 2022 22nd International Symposium on Electrical Apparatus and Technologies Siela 2022 Proceedings

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In this paper a two-time constant (TTC) electrical model is investigated to simulate the operation of 18650 batteries at different temperatures. To determine the parameters of the model, a new test procedure is developed, which can be used to obtain a wide range of information on the behavior of the tested batteries after 10 measurements. After performing the tests, detailed information on the constant, transient, and dynamic behavior of the battery over a wide temperature range is available. After, a statistics-based Ordered Weighted Averaging (OWA) aggregation operator is applied to evaluate the results. The general model is developed based on standardized parameters. Worldwide Harmonized Light Vehicle Test Procedure (WLTP) tests are performed to validate the simulation results. The operation of the model has been tested at 4 different temperatures: -15 °C, 0 °C, 25 °C, 60 °C. The simulation results are compared and evaluated with real measurement data.

Open Access: Yes

DOI: 10.1109/SIELA54794.2022.9845767

Determination of critical deformation regions of a lithium polymer battery by dic measurement and wowa filter

Adrienn Dineva István Lakatos Szabolcs Szalai Szabolcs Kocsis Szurke

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2022-01-01

Volume: 19

Issue: 2

Page Range: 113-134

Description:

This paper considers the determination method of deformation location of lithium polymer batteries. Measurements are performed using the Digital Image Correlation (DIC) technique and the obtained results are sorted into a database as a function of the charge level. A statistically based algorithm is used to eliminate measurement errors and outliers. This paper adopts the Weighted Ordered Weighted Averaging (WOWA) operator-based 2D filtering method with the purpose of determining the critical regions of the cell. During the tests, several lithium polymer batteries of the same type but in different states are compared. Measurements on completely new and also on worn-out batteries are performed. The results support that the regions where greater deformation is expected during charging and discharging can be predicted. Results of investigations validate that the proposed approach is suitable for determining the critical deformation regions with high accuracy.

Open Access: Yes

DOI: DOI not available

Application of Machine Learning to Automatic Gear Shift Schedule Design of Alternative Drive Systems

Adrienn Dineva Szabolcs Kocsis Szurke Adam Zsuga

Publication Name: 2022 22nd International Symposium on Electrical Apparatus and Technologies Siela 2022 Proceedings

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Intelligent automatic transmission shift schedule design has been well established in the last decade. However, due to the paradigm change is currently taking place in mobility sector, which resulted in a rapid progress of Electric Vehicles and Autonomous Vehicles, intelligent automatic gear shift strategies are still in the focus of much research. In addition, the proper transmission shift schedule generation is especially important from the viewpoint of energy efficiency optimizing algorithms, which is affected by the driving style, power losses, etc. Fundamentally, conventional shift schedule design relies on lookup tables obtained from test-bench measurements and real-world driving measurements. During real time test data collection, the measurement of some variables may be impractical and/or patterns of important driving conditions may be unavailable during short-distance routes neglecting the comprehensive effects of the transient operation. Machine Learning methods in combination with model-based data generation is a promising alternative, which allows a significant reduction in development time and a more precise calibration by using rich historical data rich. Such models can be easily fitted to alternative drive systems also, which may raise more specific requirements regarding gear shift scheduling issues coupled with efficiency. In this paper the performances of Machine Learning models are investigated in automatic gear shift schedule generation based on simulated driving cycle test data. Results of simulation investigations validate the applicability and efficiency of the proposed approach.

Open Access: Yes

DOI: 10.1109/SIELA54794.2022.9845718

Statistical approach for designing generic 18650 battery model

Adrienn Dineva István Lakatos Krisztian Horvath Szabolcs Kocsis Szurke

Publication Name: 2021 17th Conference on Electrical Machines Drives and Power Systems Elma 2021 Proceedings

Publication Date: 2021-07-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Most battery models are designed by estimating its parameters of one or two different cells. During simulations, these models perform satisfactorily and produce results very close to reality. The problem occurs when measurements are conducted with cells from different manufacturers and large variations are observed during the dynamic loads. The purpose of this paper is to design a general model for 18650 designed batteries, which provides as little deviation as possible when using different cell types. To establish the general model, constant load, transient, and dynamic load tests on 8 different cells are performed. An Ordered Weighted Averaging operator is used to standardize the measurement results and determine the model parameters. Outliers are filtered out using the weight parameter. To create the battery model a two-time-constant circuit model is used in MATLAB Simulink. Worldwide Harmonized Light Vehicle Test Procedure (WLTP) tests are used to validate the results.

Open Access: Yes

DOI: 10.1109/ELMA52514.2021.9503034

Investigation of the performance of direct forecasting strategy using machine learning in State-of-Charge prediction of Li-ion batteries exposed to dynamic loads

Adrienn Dineva Bence Csomós Szabolcs Kocsis Szurke Istvan Vajda

Publication Name: Journal of Energy Storage

Publication Date: 2021-04-01

Volume: 36

Issue: Unknown

Page Range: Unknown

Description:

On account of intense technological advances regarding Electric Vehicles, the state evaluation and prediction issues of Li-ion cells have become increasingly important for ensuring the competitiveness in terms of feasible performance and range. Albeit the wide investigation of various standard modelling and estimation techniques, only limited researches focus on their precision and applicability under heavy transient working conditions. This paper is concerned with Li-ion battery terminal voltage and State-of-Charge (SoC) prediction for two types of dynamic loads. Attention is focused on the investigation of the applicability of direct multi-step forecasting strategy in combination with Machine Learning. Beside that, a feature bank is composed of discharge profiles obtained at different C-rates. The set of discharge curves is proposed to complement the feature extraction, i.e. the additional historical data is considered for model building. Special care is devoted for the design of appropriate training data. Hence, a battery cell model is built for simulating intensive dynamic load scenarios in addition to the experimental setup. The cell model is validated by using measurement data. Results have demonstrated, that in case of WLTP-type discharge load of 0.3C-rate the forecasting performance is highly efficient on measurement data. Under dynamic loads of 1C-rate, or when small historical data is available, the application of feature bank improves the performance. We have obtained comprehensive results proving that the application of direct multi-step forecasting strategy using XGBoost represents a viable alternative to capture real-time the cell dynamics and predict the terminal voltage and SoC of Li-ion batteries exposed to dynamic loads.

Open Access: Yes

DOI: 10.1016/j.est.2021.102351

Battery deformation measurement with DIC technique

István Lakatos Szabolcs Szalai Szabolcs Kocsis Szurke

Publication Name: 2020 21st International Symposium on Electrical Apparatus and Technologies Siela 2020 Proceedings

Publication Date: 2020-06-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In this paper the deformation of lithium polymer batteries during charging and discharging is measured using a GOM Atos system. The aim of the study is to evaluate the deformation of the cell surface. During the tests, the battery cell is re-digitized after 10% energy input and output. Trend results are recorded and analysed for deformation as a function of charge level. We also determine open circuit voltage and average deformation point relationship. Our study supports that there is a correlation between the deformation data and the charge level.

Open Access: Yes

DOI: 10.1109/SIELA49118.2020.9167109

Data-driven terminal voltage prediction of li-ion batteries under dynamic loads

Adrienn Dineva Szabolcs Kocsis Szurke Istvan Vajda

Publication Name: 2020 21st International Symposium on Electrical Apparatus and Technologies Siela 2020 Proceedings

Publication Date: 2020-06-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Extensive investigation and prediction of the effects of dynamic battery loading is key to on-board Battery Management Systems (BMS) of Electric Vehicles (EVs) in order to ensure reliable operation and efficient energy management. In this paper, measurements of WLTP discharge tests at different temperatures are conducted on a Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) cell. Terminal voltage, discharge rate and temperatures at four points are taken into consideration. After, historical measurement data is used to build ensemble of boosted tree models and then predict cell voltage outcome sequence into the future. The efficiency of the performance is compared in case of various measurement sets. The results support the efficiency and applicability of direct multi-step-ahead forecasting strategy with standard Machine Learning techniques in battery SoC prediction.

Open Access: Yes

DOI: 10.1109/SIELA49118.2020.9167039

The lithium polymer battery swelling test with high-precision displacement sensors

István Lakatos Szabolcs Kocsis Szurke

Publication Name: 2018 20th International Symposium on Electrical Apparatus and Technologies Siela 2018 Proceedings

Publication Date: 2018-08-24

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The inappropriate charge-discharge of lithium polymer batteries or the high number of cycles (degradation) can lead to volume expansion. The principal motivation is to precisely determine the beginning and the causes of this expansion. During the research one of the objectives is to create a measurement system which can sample the deformation occurring in the course of charge and discharge. The other main aim is to process the measured results and to detect the conditions which critically influence the lifespan of the battery.

Open Access: Yes

DOI: 10.1109/SIELA.2018.8447119