World Electric Vehicle Journal — Open Access Journal

Developing an efficient online predictive modeling system (PMS) is a major issue in the field of electrified vehicles as it can help reduce fuel consumption, greenhouse gasses (GHG) emission, but also the aging of power-train components, such as the battery. For this manuscript, a model predictive control (MPC) has been considered as PMS. This control design has been defined as an optimization problem that uses the projected system behaviors over a finite prediction horizon to determine the optimal control solution for the current time instant. In this manuscript, the MPC controller intents to diminish simultaneously the battery aging and the equivalent fuel consumption. The main contribution of this manuscript is to evaluate numerically the impacts of the vehicle battery model on the MPC optimal control solution when the plug hybrid electric vehicle (PHEV) is in the battery charge sustaining mode. Results show that the higher fidelity model improves the capability of accurately predicting the battery aging. Full article

As electric vehicle market penetration grows steadily and charging demand along with it, the analysis of daily usage gains in significance. We propose in this paper a simple yet powerful tool based on a Markov chain that can model the stochastic nature of day to day usage of a charging station if adequate datasets on travel patterns are available. The model is generic and therefore can be tailored to different locations with different features. Within this work, we conducted a case study with the aim to verify the algorithm. By an additional sensitivity analysis, impacts of the made assumptions are considered. With a final analysis of two charging tariff designs the model provides valuable stochastic information about electricity consumption and annual revenues at a location of interest. Full article

This study analyzed a prototype of a pouch cell containing silicon alloy anodes with the potential to significantly increase the energy density, resulting in improved autonomy for electric vehicles. An electrical characterization campaign was performed, resulting in three main observations. Firstly, measurements showed a high energy density, although a high lower cutoff voltage (3.0 V) was used due to the prototypical nature of the cells. Further optimization would allow a decrease of the lower cutoff voltage, resulting in an even higher energy density. Secondly, a large open-circuit voltage hysteresis was observed, increasing the complexity for equivalent circuit models. Thirdly, ballooning of the pouch cell was observed, most likely caused by gas formation. This leads to a loss of active surface area, significantly reducing the cell’s capacity. This third observation was more thoroughly investigated by 3D computed tomography, which showed mechanical deformation of the layers. An extensive literature review revealed that the addition of fluoroethylene carbonate (FEC) to the electrolyte enhances the cycling stability of silicon alloy batteries but leads to the production of CO${}_2$ as a side reaction. Furthermore, the usage of external pressure was proposed and validated as a methodology to reduce the production of CO${}_2$ while improving the cells’ performance. Full article

In developing the U.S. 2017–2025 Light-Duty Vehicle Greenhouse Gas Emissions Standards, the U.S. Environmental Protection Agency (EPA) modeled lithium-ion battery packs for future electrified vehicles to estimate their direct manufacturing costs through 2025. As part of the 2016 Midterm Evaluation of the standards for model years (MY) 2022 to 2025, the analysis was revised to account for developments in battery design since the 2012 rulemaking. This paper describes the methodology that was used for estimating battery capacity, power, and cost, and compares the projected cost estimates to other sources. An empirical equation is derived for specifying motor power as a function of target acceleration time, and suggested factors for converting cell-level costs to pack-level costs are developed. Full article

This paper presents a visualization methodology, in the form of a multi-dimensional techno-economic assessment diagram, to comprehensively illustrate the relationship between assumptions (sets of input parameters) and results (corresponding output variables). This methodology is applied to analyze the lifecycle costs and CO₂ emissions of hybrid vehicles (HVs) and electric vehicles (EVs). This paper then develops an eight-dimensional interactive diagram showing the relative advantages of HVs or EVs in the input space consisting of the following parameters: HV fuel efficiency; EV energy efficiency, total mileage travelled gasoline price, electricity price, battery price, gasoline CO₂ intensity, and electricity CO₂ intensity. This methodology provides a map illustrating the comprehensive relationship between the inputs and outputs in the model used, where specific scenarios (specific sets of inputs and their outputs) are represented by points plotted on the map. This methodology can be used in systematic comparisons of electric vehicles and related uncertainty analyses. Full article

In this paper, an advanced partitioned-stator switched-flux dual-excitation (PS-SFDE) machine, which is highly suitable for hybrid electric vehicles (HEVs), is proposed. By artfully implementing two excitation sources, namely the high-power-density permanent-magnet (PM) source and the DC-field excitation source, the proposed machine can take benefits from both sides. Unlike the existing PS-SFDE machines that sacrifice the PM materials for DC-field winding accommodation, the proposed machine instead shares the space of the armature winding with the DC-field winding. Hence, comparable power and torque levels can be potentially achieved. Full article

Today, fleet management systems with battery health monitoring capabilities are in the focus more than ever. This paper addresses the development of a novel battery health monitoring algorithm with a degradation prognosis feasibility particularly adapted for usage in fleet management systems. Moreover, the chosen degradation prognosis approach adapts itself continuously on varying environmental conditions or utilization modes by identifying the impact factors which lead to a certain degradation trend. Such findings, when accessible with a fleet management system, offer various possibilities for fleet analysis techniques e.g., to identify an imminent battery failure. Full article

Transportation accounts for more than 20% of the total Greenouse Gas (GHG) emissions in Canada. Switching from fossil fuels to more environmentally friendly energy sources and to Zero-Emission Vehicles (ZEVs) is a promising option for future transportation but well to wheel emission and charging/refuelling patterns must also be considered. This paper investigates the barriers to and opportunities for electric charging and hydrogen refueling infrastructure incentives in Ontario, Canada and estimates the number of Internal Combustion Engine Vehicles (ICEVs) that would be offset by infrastructure incentives. The paper also assesses the potential of electric and hybrid-electric powertrains to enable GHG reductions, explores the impact of the electricity supply mix for supporting zero-emission vehicles in different scenarios and studies the effect of the utility factor for PHEVs in Ontario. The authors compare the use of electric vehicle charging infrastructures and hydrogen refueling stations regarding overall GHG emission reductions for an infrastructure incentive funded by a 20-million-dollar government grant. The results suggest that this incentive can provide infrastructure that can offset around 9000 ICEVs vehicles using electricity charging infrastructure and 4000–8700 when using hydrogen refuelling stations. Having appropriate limitations and policy considerations for the potential 1.7 million electric-based vehicles that may be in use by 2024 in Ontario would result in 5–7 million tonne GHG avoidances in different scenarios, equivalent to the removal of 1–1.5 million ICEVs from the road. Full article

While an increasing number of electric bicycles are sold, the majority is still conventional, i.e., pedal powered.Electric bicycles could raise the share of people cycling in place of more inefficient modes of transportation. This paper investigates and proposes a new approach for an electric drive unit that can easily be attached and detached to a large majority of existing off-the-shelf bicycles to convert them into legal electric assisted bicycles (pedelecs). Different drive mechanisms were investigated and a design with a friction roller at the rear wheel showed the greatest potential. A good solution is achieved with a single unit that incorporates batteries, electronics, motors and sensors in a single enclosure to minimize the mounting time. With a fastening on the seat stay tube using a simple clamp mechanism it can assist the cyclist on most existing bicycles. The legally-required pedal detection is done with an integrated proximity sensor. A prototype is built to prove a simple and nonspecific installation and convenient usage. Full article

This study presents results of a survey-based analysis on user acceptance of wireless electric vehicle charging. A structural equation model is developed based on Davis’ technology acceptance model (TAM). It is expanded integrating elements of Ajzen’s theory of planned behavior (TPB). The main factors influencing acceptance of wireless electric vehicle charging are evaluated and analyzed. Empirical findings indicate that survey participants’ acceptance of wireless electric vehicle charging is mainly influenced by affective evaluations of wireless charging, subjective norms, perceived usefulness of wireless charging, and environmental awareness. The results indicate a high degree of acceptance for wireless charging. Even individuals with lower degrees of acceptance are willing to use wireless charging within car-sharing or commercial fleets. Full article

The Vehicle-2-grid (V2G) technology enabling bidirectional charging between electric vehicles and the energy grid system for frequency regulation and load balancing has the potential of significantly improving the financial viability of electric mobility. This paper has identified that the introduction of V2G offers a plethora of potentially beneficial business models, which primarily focus on providing stability services to the energy grid and optimizing the economic benefits of owning an EV. Within these overarching categories, it is likely that several niche business models will emerge, as the current V2G concepts include the integration of intermittent renewable energy into the grid, reduction of peak load, charging optimization, and regulation of participating capacity. Most important is the balancing of the five market factors in order to create a profitable business case, as this is what makes V2G move from a potential revenue generator to a profitable business. Full article

Lithium sulfur batteries have a promisingly high theoretical specific energy density of about 2600 Wh/kg and an expected practical specific energy density of about 500–600 Wh/kg. Therefore, it is a highly promising future energy storage technology for electric vehicles. Beside these advantages, this technology shows a low cell capacity at high discharge currents. Due to the capacity recovery effect, up to $20\%$ of the total cell capacity becomes available again with some rest time. This study shows a newly-developed capacity recovery model for lithium sulfur batteries. Due to the long rest periods of electric vehicles, this effect has an important influence on the usable cell capacity and depth of discharge in lithium sulfur batteries. Full article

Heavy-duty trucks are one of the main contributors to greenhouse gas emissions in German traffic. Drivetrain electrification is an option to reduce tailpipe emissions by increasing energy conversion efficiency. To evaluate the vehicle’s environmental impacts, it is necessary to consider the entire life cycle. In addition to the daily use, it is also necessary to include the impact of production and disposal. This study presents the comparative life cycle analysis of a parallel hybrid and a conventional heavy-duty truck in long-haul operation. Assuming a uniform vehicle glider, only the differing parts of both drivetrains are taken into account to calculate the environmental burdens of the production. The use phase is modeled by a backward simulation in MATLAB/Simulink considering a characteristic driving cycle. A break-even analysis is conducted to show at what mileage the larger CO_2eq emissions due to the production of the electric drivetrain are compensated. The effect of parameter variation on the break-even mileage is investigated by a sensitivity analysis. The results of this analysis show the difference in CO_2eq/t km is negative, indicating that the hybrid vehicle releases 4.34 g CO_2eq/t km over a lifetime fewer emissions compared to the diesel truck. The break-even analysis also emphasizes the advantages of the electrified drivetrain, compensating the larger emissions generated during production after already a distance of 15,800 km (approx. 1.5 months of operation time). The intersection coordinates, distance, and CO_2eq, strongly depend on fuel, emissions for battery production and the driving profile, which lead to nearly all parameter variations showing an increase in break-even distance. Full article

To fill in mobility gaps, volunteer-based flexible transit solutions have been successfully implemented in Germany since early 1980s. These concepts have evolved to address a diverse array of needs and situations, and to incorporate new solutions and technologies. Such is the case of electrical vehicles (EVs), which have found an application in these systems through state-run initiatives seeking to promote sustainable mobility. This article presents two electric-car volunteer-based rural demand-responsive services, namely, a Buerger(ruf)auto (Dial-a-ride or “Citizen-operated-car”) and a Buergerbus (“Citizen-operated-bus”). The article outlines specific aspects of the EVs that are used, which need to be addressed to in order to achieve an operational efficiency that is comparable to an equivalent service using internal combustion vehicles. Specific challenges are identified, namely in relation to the technological limitations, and the size and characteristic of the vehicles required. In addition, specific challenges include the need for the vehicle components that allow data gathering directly from the car’s electric motor in order to analyze the car’s performance under different operational conditions. The article mentions the issues explicitly and specifies what would be required of electrical vehicles to become an asset in the provision of demand-responsive systems in rural settings. Full article

The paper presents the results of experimental testing of the exhaust emission and energy consumption of two gasoline plug-in hybrid vehicles in an emission testing laboratory with different drive cycles and drive modes and at summer and winter temperatures. One was a compact vehicle with a type approval electric mode range of 50 km, the other a mid-sized vehicle with an electric mode range of 31 km. Additionally, an online survey of 2065 private plug-in hybrid vehicles (PHEV) owners investigated the usage pattern of the vehicles. Combining the laboratory tests with the user survey results provided an estimate for the reduction of CO₂-emission of PHEVs in use in Norway. The main conclusion is that the PHEV is a vehicle type that needs to match well with the use pattern to produce low CO₂- and local emissions. The achievable CO₂-emission reduction was proportional to the range in electric drive-mode (E-mode), i.e., 50 km range resulted in about 50% reduction. Full article

In Europe, a heterogeneous range of national vehicle taxation systems exists in parallel, so that a simple comparison of electric vehicle (xEV) tax advantages is not straightforward. In this contribution, various European vehicle taxation systems are examined and a methodology is introduced which allows a comprehensible comparison and overview by calculating CO₂ based taxation step curves. This methodology provides a powerful tool for benchmarking xEV technologies and analyzing consumer acceptance of xEVs and enables furthermore the discussion about possible future taxation and incentive schemes. Full article

The next generation of the Volt vehicle with the new “Voltec” extended-range propulsion system was introduced into the market in 2016. The second-generation Volt’s powertrain architecture provides five modes of operation, including two electric vehicle operations and three extended-range operations. Vehicle testing was performed on a chassis dynamometer set within a thermal chamber at the Advanced Powertrain Research Facility at Argonne National Laboratory. The study first focused on assessing the improvement of the new Voltec system by comparing the system efficiency with the previous system. Second, control behavior and performance were analyzed under normal ambient temperature to understand the supervisory control strategy on the Voltec system based on the test data. The analysis focused on the engine on/off strategy, powertrain operation mode, energy management, and engine operating conditions. Third, test data from the control analysis were used to summarize the vehicle control logic. Full article

The present paper is focused on the evaluation of the economic influence of a battery lifetime model upon the optimal sizing and energy management strategy of a dual energy storage system (ESS) composed of Lithium-ion batteries and supercapacitors. The operation of a Hybrid Bus is taken as a case study in order to evaluate the effects of battery lifetime models’ accuracy on ESS sizing and operation in a heavy-duty application. For this purpose, two different lifetime models (a Wöhler-curve-based model and a semi-empirical model) were applied in the multi-objective optimisation of a hybrid electric urban bus. Differences up to ca. 8% on the daily operation costs and ca. 25% on the dual ESS costs were estimated depending on the lifetime model considered for the optimisation. Full article

E-mobility services are important enablers for the success of electric vehicles. In contrast to conventional mobility, where an ecosystem consisting of the vehicle and complementary services has been built up and has improved over decades, the ecosystem for e-mobility is far less advanced and still in its infancy. In order to get on the sustainable path to success in the steadily growing e-mobility market, innovative ideas are necessary which are not covered by existing service offerings. This paper therefore describes a study that explored opportunities for innovative e-mobility service business models through a systematic analysis. Furthermore, each e-mobility service depends on information technology (IT) support. Therefore, IT standardization is an important issue to consider in order to build up more complex services on top of basic services and further advance the e-mobility ecosystem. Consequently, this paper presents results from a survey conducted with 27 e-mobility experts from Germany to help identify necessary standardization gaps in the context of e-mobility services. The paper contributes to the existing body of knowledge by proposing a structured, repeatable method for identifying innovative business models and by offering insights into study results. In addition, gaps in the standardization of IT infrastructure that are important for the provision of existing e-mobility services are illustrated. Full article