Many different types of electric vehicle (EV) charging technologies are described in literature and implemented in practical applications. This paper presents an overview of the existing and proposed ...EV charging technologies in terms of converter topologies, power levels, power flow directions and charging control strategies. An overview of the main charging methods is presented as well, particularly the goal is to highlight an effective and fast charging technique for lithium ions batteries concerning prolonging cell cycle life and retaining high charging efficiency. Once presented the main important aspects of charging technologies and strategies, in the last part of this paper, through the use of genetic algorithm, the optimal size of the charging systems is estimated and, on the base of a sensitive analysis, the possible future trends in this field are finally valued.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Road transport electrification is essential for meeting the European Union's goals of decarbonization and climate change. In this context, an Ultra-Fast Charging (UFC) system is deemed necessary to ...facilitate the massive penetration of Electric Vehicles (EVs) on the market; particularly as medium-long distance travels are concerned. Anyway, an ultra-fast charging infrastructure represents the most critical point as regards hardware technology, grid-related issues, and financial sustainability. Thus far, this paper presents an impact analysis of a fast-charging station on the grid in terms of power consumption, obtained by the Monte Carlo simulation. Simulation results show that it is not economical convenient size the assumed ultra-fast charging station for the maximum possible power also considering its high impact on the grid. In view of the results obtained from the impact analysis, the last part of the paper focuses on finding a method to reduce the power installed for the DC/DC stage while keeping the possibility for the electric vehicle to charge at their maximum power. To achieve this goal a modular approach is proposed. Finally, two different modular architectures are presented and compared. In both the solutions, the probability of having EVs charging at limited power is less than 5%.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The present paper proposes a new methodology to aid the electrification process of local public transport (LPT). In more detail, real drive cycles of traditional buses currently in use are evaluated ...together with other data to simulate the consumption of equivalent e-buses (electric buses) with similar characteristics. The results are then used in order to design the best charging infrastructure. The proposed methodology is applied to the case study of Algeciras Bay, where a specific line of LPT is considered. Real measurements are used as data for the simulation model, and the average consumption of an equivalent e-bus is obtained for different operating conditions. Based on these results, different sizes and locations for fast-charging infrastructure are proposed, and the size of the depot charging system is defined trying to maintain the current buses timetable. Finally, some future developments of the present work are presented by considering other bus lines that may benefit from the introduction of the defined charging systems.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The installation of ultra-fast charging stations (UFCSs) is essential to push the adoption of electric vehicles (EVs). Given the high amount of power required by this charging technology, the ...integration of renewable energy sources (RESs) and energy storage systems (ESSs) in the design of the station represents a valuable option to decrease its impact on the grid and the environment. Therefore, this paper proposes a multi-objective optimization problem for the optimal sizing of photovoltaic (PV) system and battery ESS (BESS) in a UFCS of EVs. The proposed multi-objective function aims to minimize, on one side, the annualized cost of the station, and on the other side, the produced pollutant emissions. The decision variables are the number of PV panels and the capacity of the ESS to be installed. The optimization problem is reduced to a single-objective problem by applying the linear scalarization method. Then the equivalent single-objective function is optimized through a genetic algorithm (GA). The proposed optimization framework is applied to a study case and the results prove that PV and ESS could lead to a significant reduction of both the annualized cost and the pollutant emissions. Finally, a sensitivity analysis is also presented to validate the effectiveness of the proposed solution.
To enhance the current Public Transport (PT) service in the northern Italian region of Lombardy, this work tries to plan fully a new electric Skibus line connecting the cities of Santa Caterina and ...Livigno. As a first try outside the city environment, the electrification study is set on a limited mountain zone hence featured by steep grades and cold temperatures. In the first part of the paper, the energy consumed by an electric bus working in such a context is assessed, and from the learned outcomes, proper charging infrastructure is proposed. From the found results, the introduction of a new electric bus line in the chosen region seems feasible. Finally, in the last part of the work the performances of an electric bus fleet are compared with that of a diesel one, in terms of fuel costs and Well-to-Wheel (WTW) emissions. The results prove that an electric fleet would be more convenient for both the economic and the environmental aspects.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The installation of Ultra-Fast Charging stations (UFCS) is of vital importance to enhance and support the global shift to electric mobility. However, since UFCSs require a huge amount of energy in ...short period of time, their integration with the energy transmission and distribution grids will lead to a considerable number of technical challenges. To mitigate these negative aspects the incorporation of a Photovoltaic (PV) power plant and a Battery Energy Storage System (BESS) in the station systems seems crucial. In this paper an optimization study to find the size of these additional components is carried out. The final aim is to find their optimal dimensions to make the integration the most convenient as possible from an economic point of view. To achieve such a purpose, a single-objective optimization problem is simulated. The objective function aims to maximize the Net Present Value (NPV) of the overall charging station. The single-objective function is optimized through a genetic algorithm (GA) and the optimization toolbox embedded in the MATLAB software has been used to run the proposed optimization. The results highlight how the configuration complemented with the PV plant and the BESS is better from a technical-economic perspective. As a matter of fact, the profitability of such UFCS will be 7.5 % higher than the solution without additional components.
•Simulation of EVs charging demand in an UFCS with probabilistic approach•Optimal size of a UFCS integrated with PV and BESS by maximizing the NPV.•Identifying the impacts of different EMS on the optimal results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
An ever-increasing penetration of electric vehicles (EVs) on the roads inevitably leads to an ever-stringent need for an adequate charging infrastructure. The emerging ultra-fast charging (UFC) ...technology has the potential to provide a refueling experience similar to that of gasoline vehicles; hence, it has a key role in enabling the adoption of EVs for medium-long distance travels. From the perspective of the UFC station, the differences existing in the EVs currently on the market make the sizing problem more challenging. A suitably conceived charging strategy can help to address these concerns. In this paper, we present a smart charging station concept that, through a modular DC/DC stage design, allows the split of the output power among the different charging ports. We model the issue of finding the optimal charging station as a single-objective optimization problem, where the goal is to find the number of modular shared DC/DC converters, and where the power rate of each module ensures the minimum charging time and charging cost. Simulation results show that the proposed solution could significantly reduce the required installed power. In particular, they prove that with an installed power of 800 kW it is possible to satisfy the needs of a UFC station composed of 10 charging spots.
In the city of Milan, an ever-increasing spread of the use of electric scooters, especially among young people, is taking place. The main motivations behind this trend are related to the fact that ...these vehicles guarantee reduced travel times and ease in finding parking, compared to cars. For this reason, the focus of this paper is to analyze the performances of an electric scooter as means of transport to connect the two Politecnico di Milano's Campus. The analysis aims to carry out the energy consumption and then the emissions produced to complete the trip. In particular, two different scenarios in terms of driving style are simulated, and the related produced emissions are compared with those of a conventional scooter. The results show that 90% of CO 2 emissions can be saved with an electric scooter. Finally, a preliminary cost analysis is performed.
Public and Micro-Mobility Transportation Modes Comparison Leone, Carola; Longo, Michela; Foiadelli, Federica
2021 Sixteenth International Conference on Ecological Vehicles and Renewable Energies (EVER),
2021-May-5
Conference Proceeding
Public transport and electric vehicles, two-wheeled especially, are expected to constitute a major part of future sustainable transport systems in smart cities. The focus of this paper is to analyze ...different paradigms of mobility on a fixed route in the center of Milan. The chosen path connects Milan Central station to Milano Bovisa station, a very traffic way. The first part of the paper is based on the analysis of the two most common means of urban transport in Milan: the train and the trolley bus. The comparison is performed in terms of energy consumption, emissions, and costs. In the second part, instead, the focus has been shifted to other means of transport: electric light micro-mobility. Given the increased interest these days in both electric scooters and electric bikes, a preliminary analysis of these two means of transport is carried out. From the results, it is possible to conclude that these types of vehicles represent a sustainable alternative for getting around the city.
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