Electric vehicles (EVs) with vehicle-integrated photovoltaics (VIPV) and vehicle-to-grid (V2G) technology can help address power grid challenges arising from the energy transition. While VIPV and V2G offer widespread benefits, their impact on EV battery life affects their economic viability. Many existing studies examining the impact of VIPV and V2G on EV battery life do not fully capture the complexity of real-world battery usage, often relying on less detailed battery data. This work models and combines detailed and validated EV battery data with validated battery ageing models to determine the impact of VIPV and V2G on EV battery life. First, a validated EV battery simulation model is used to generate realistic, per-second battery data for an EV operating in The Netherlands and Spain. Following this, VIPV power profiles, V2G day-ahead energy trading power profiles, and V2G automatic frequency restoration reserve power profiles are integrated with the battery data. Subsequently, battery datasets for different scenarios are implemented in both NMC and LFP-based semi-empirical ageing models to quantify calendar and cycling ageing capacity loss. The results show that gradual VIPV charging decreases the required annual grid charging frequency by 23% in The Netherlands and 44% in Spain, leading to lower SoC ranges, which can reduce NMC and LFP calendar ageing capacity loss by 9% in both countries. Additional cycling due to V2G day-ahead energy trading can shorten battery life by up to 12.5 years for NMC and up to 3.9 years for LFP. Moreover, the research indicates that ageing models based on tests with regular power profiles may not accurately estimate cycling ageing in power profiles with increased irregularity caused by VIPV and V2G.@en

Quasi-resonant boundary-conduction mode (QR-BCM) and triangular current mode (TCM) have found widespread use in the literature and industry due to their good performance at relatively low complexity. However, additional control challenges occur when these modulations are applied to the four-switch buck-boost (FSBB) converter, due to a discontinuity in switching frequency in multimode operation. This article presents the first closed-loop operation of a variable-frequency, multimode, quasi-resonant BCM control scheme including smooth mode transitions. The proposed control utilizes feed-forward mode transition techniques, based on software interrupt handlers integrated into the digital control scheme. In contrast to most soft-switching schemes in the literature, the proposed digital control does not imperatively rely on high-frequency current measurements but uses dc measurements and high-frequency voltage measurements instead. A 10 kW prototype is developed with which the proposed modulation is compared with three other soft-switching modulation schemes. Our results indicate that the losses of FSBB converter can be reduced by up to 60% using the proposed modulation. Especially at partial powers and high voltages, significant efficiency gains can be achieved.

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Lithium-ion batteries (LIB) are widely used in various applications. The LIB degradation curve and, most significantly, the knee-point and End-of-life (EoL) point identification are critical factors for the selection of the appropriate application, such as electric vehicles and stationary energy storage systems, due to their effect on performance and lifespan, safety, and environmental footprint. Linear degradation models can be inaccurate in capturing the highly nonlinear behavior of LIB degradation caused by multiple simultaneous degradation mechanisms. Hence, this work first analyzes the main different mechanisms, their causes, and their interrelations. Secondly, the various single- and multi-mechanism physics-based (PB) and data-driven (DD) models for LIB degradation and knee-point identification are summarized and compared regarding their prediction performance on degradation and transition from stabilized to saturated aging. While single-mechanism PB models can be effective in the LIB first-life prediction, they can seriously undermine the knee-point and saturated aging. Moreover, the modeling of the different aging mechanisms can significantly increase the complexity of the multi-mechanism PB models. Finally, while DD models for LIB degradation have been developed, a DD model focused on knee-point identification and LIB second-life is still missing from the literature.

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To tackle the potential grid overloading issue induced by excessive Electric Vehicles (EV) charging demand, a Low Voltage (LV) grid congestion management algorithm with three centralised EV charging management schemes is proposed in this study. The developed algorithm integrates grid information and aims at tackling the foreseen congestion issues by operating on the EV charging processes. This is done through linear programming (LP) or iterative calculations. While the first charging scheme aims at managing the congestion by only affecting the elements with the greatest influence on the congestion, the other two aim at ensuring impartiality towards all users and the overall energy transfer to the EVs, respectively. The simulated results are compared in terms of performance criteria such as grid impact, user satisfaction and fulfilment of charging energy demand. Overall, this study shows that the first scheme brings the best results from a grid perspective. On the other hand, the last scheme leads to competitive results from a grid point of view and the best overall results from a user perspective.@en

The study presents Electric Vehicle (EV) Point-of-View (POV) Vehicle to Grid (V2G) optimisation, where the system knows the trips and energy demand of the EV. This allows it to be less conservative in the departure State of Charge (SoC) of the EV battery. The peak and cost reduction of Vehicle POV optimisation are compared with state-of-the-art Location Point-of-View optimisation, this is, the car can do V2G but it has to depart each location with at least 80% SoC as the next trip energy demand is unknown. A Mix Integer Linear Programming (MILP) V2G optimisation approach is presented to reduce peak demand and total system cost of a fleet of EVs travelling between several residential locations and one common workplace. Simulations were conducted with 26 EVs unevenly distributed between five residential locations and commuters to a common workplace. The results indicate little differences in the reduction of peak demand between both POVs of V2G optimisation. However, the system cost can be further reduced with Vehicle Point-of-View optimization, saving an additional 200 euros annually per household by transporting cheaper energy from workplaces to residential locations.@en

The development of lithium-ion batteries has experienced massive progress in recent years. Battery aging models are employed in advanced battery management systems (BMSs) to optimize the use of the battery and prolong its lifetime. However, Li-ion battery cells often experience fluctuations in battery capacity and performance during cycling, which makes capacity prediction more difficult. Moreover, the reason for the capacity regeneration phenomenon occurring after resting periods is not clear yet, as well as the influence of cycling conditions on capacity regeneration. A relationship between this phenomenon to cycling state of charge (SoC) ranges and current rates was investigated in this article on a battery cell with lithium nickel manganese cobalt (NMC) oxide positive electrode. Experimental results show that the capacity increase is a consequence of decreased internal impedance after the resting period. The experiments also showed that a significant power drop and subsequent power regeneration after a resting period occurs only for specific SoC ranges, and applying a resting period after battery cycling can mitigate this power fading process. The semi-empirical model of battery degradation including capacity regeneration is proposed in this article based on physical processes inside of the cell retaining low computational requirements. The acquired results can be utilized in BMSs for more accurate state of health (SoH) estimation and to prolong battery lifetime.

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Distributed generation, such as photovoltaics (PVs), and electrification of heating and transportation with heat pumps (HPs) and electric vehicles (EVs) will play a major role in the energy transition. However, these low-carbon technologies (LCTs) do not come without side effects such as voltage violations, power loss increase, component overloading, higher energy consumption, power peaks, and power quality issues, e.g., harmonics and phase unbalance. This work constitutes a review analysis and summary of all the important findings concerning the various grid impact issues that can appear due to the grid integration of these 3 LCTs. The work also encapsulates various research characteristics such as grid topology, seasons, simultaneous operation under various LCT combinations, penetration levels, etc. Moreover, it incorporates a qualitative analysis of the impact level of the most investigated grid issues and quantitative comparisons between the different grid types and LCTs. It has been shown that the combined integration of PVs-EVs and PVs-HPs can result in mitigation effects without extra solutions. Moreover, voltage deviations and unbalance affect more the rural grids while component overloading is more hazardous for suburban grids. Finally, proposed mitigation solutions, such as energy storage, smart charging, etc., are correlated with their respective grid impact issues.

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Power control of flexible loads will play a significant role in energy transition. This work has developed a mixed-integer linear power control (MILP) model that manages electric vehicle (EV) chargers, heat pumps (HPs), and PV rooftops. The power control was tested with and without vehicle-to-grid (V2G) capabilities in different grid types, namely residential, commercial, and mixed grids. Moreover, the effect of different seasons and charger efficiencies was investigated. It was shown that grid characteristics such as EV parking times and building occupations can affect significantly the power control, e.g. the amount of imported and V2G power. Moreover, while V2G power is rarely used due to current V2G round-trip efficiency, future efficiency improvement can lead to a significant increase in V2G use. Finally, the seasonal effect had also a significant impact with Summer being characterized by higher exported and lower imported energy due to the high and prolonged PV power availability.

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This paper compares the indirect cooling method using a heatpipe and air-cooled circular fins with conventional cooling methods like forced air convection and forced water convection for cooling power electronics placed underground. A two-module dual active bridge power converter with reconfigurable outputs for electric vehicle charging is used for the thermal analysis. The comparison is based on specific constraints imposed by semiconductor switch surface area requirements and the maximum junction temperature limit. A detailed analysis is presented, and performance parameters like convective resistance, pressure drop, and mechanical pumping power of the cooling systems as the function of volume flow of working fluid are obtained. Commercially available cooling components like extruded fin heatsinks, cold plate, and heat exchanger are used for conventional cooling methods analysis. Whereas indirect cooling using heatpipes and air-cooled circular fins is designed by performing individual analysis on a heatpipe sizing, air-cooled circular fin design, and heatpipe integrated base plate. This work also highlights the equivalent thermal resistance model for each cooling system.

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The transportation industry is a significant source of greenhouse gas emissions, with freight transport emerging as one of the main contributors owing to its extensive mileage and substantial weight. As a result, electrification of road transportation has become a vital step in reducing direct CO₂ emissions. While the adoption of passenger electric vehicles has gained notable traction, the landscape for Heavy-Duty Electric Vehicles (HDEVs) is still in its early stages of development. Accelerating the advancement and adoption of HDEVs hinges on prioritizing the installation of their charging infrastructure. This requires a deep understanding of HDEVs' energy and power requirements while also considering grid limitations. Meeting the high demand for charging necessitates exploring on-site renewable energy generation and stationary batteries as viable solutions. Recognizing this imperative, a multiobjective sizing model has been developed, tailored specifically to address the requirements of HDEV charging stations. These objectives include minimizing investment costs, penalizing undercharged or rejected HDEVs' charging demand, reducing idle charger time, and managing expenditures within a charging station. The key outcomes of the model encompass various critical factors essential for designing and implementing charging infrastructure for HDEVs. These factors include determining the optimal number of PV panels and wind turbines to harness renewable energy, specifying the capacity of the battery energy storage system, and identifying the necessary number and rated power of chargers in alignment with the grid contract limit.

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In this chapter, various electric vehicle (EV) charging technologies are reviewed, including onboard charging, offboard charging, and contactless charging. The focus is on charging power control as well as its converter topology. Because EV charging significantly influences the grid, the power quality of EV charging is thoroughly reviewed in terms of modeling, analysis, and mitigation measures. EV charging, especially overnight, gives a lot of flexibility to instant charging power, which can be used to improve the load flow in the electric grid. Smart charging describes those approaches, which are also reviewed.

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The aviation industry, responsible for over 2% of energy-related CO₂ emissions in 2022, aims for Net Zero Emissions by 2050. Despite electric aircraft's environmental benefits and improved operational efficiency, the current battery technology limits their range and size. Based on the optimal system voltage and power profile of the reference all-electric aircraft, this paper presents the design of a hybrid reconfigurable battery pack. The design incorporates a combination of high-specific-energy (263 W h kg^-1 at cell level) and high-specific-power (1800 W kg^-1 at cell level) battery types and its performance is compared with that of a fixed configuration battery pack comprising a single battery type. Simulation results suggest a potential 900 kg (18% lighter than fixed configuration) weight savings with reconfigurable pack, translating into enhanced payload, energy savings, or range extension for 9 PAX Eviation Alice electric aircraft at just 0.4% more energy capacity loss in 500 cycles.

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This paper proposes a shared multi-stakeholder PV system for traction substations and nearby residential loads to reduce the need for storage, AC grid exchange, and curtailment. The residential stakeholders offer both the base electrical load and the solar panels installation space needed by the traction stakeholder, who brings the peak load and investments to the former. Two case studies were conducted for one year in the city of Arnhem, The cy=Netherlands, using comprehensive and verified simulation models: A high-traffic and a low-traffic substation. The results showed a positive, synergetic benefit in reducing the PV system's excess energy and size requirement for any type of traction substations connected to any number of households. In one detailed example, the multi-stakeholder system suggested in this paper is shown to reduce curtailment by up to 80% in moments of zero-traction load. Generally, the direct load coverage of a PV system is increased by as much as 7 absolute percentage points to the single-stakeholder system when looking at energy-neutral system sizes. This multi-stakeholders system offers then an increase in the techno-economic feasibility of PV system integration in urban loads.

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Electric aircraft is a promising alternative to conventional fuel-based aircraft, offering reduced greenhouse gas emissions and enhanced operational efficiency. To ensure seamless operations and optimize energy management, accurate electric aircraft charging demand prediction becomes imperative. This paper presents a study on forecasting the charging demand for future small, short-range electric aircraft. First, battery sizes are determined for various types of small all-electric aircraft and electric vertical takeoff and landing aircraft. Utilizing the electrical circuit model for lithium-ion batteries, this study derives the charging power curve of electric aircraft under the constant current constant voltage charging strategy. Subsequently, charging demand prediction is conducted using the flight schedule of a selected airport, allowing for a realistic assessment of the power requirements for charging electric aircraft. Finally, case studies exploring charging demand under different scenarios are conducted. The results highlight the substantial power demand associated with the charging process, emphasizing the essential infrastructure needs and potential approaches for managing charging power in electric flight.

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The report examines the role of Standalone Microgrids (SMs) in electrification and emissions reduction, focusing on the comparison of HOMER Pro and iHOGA PRO+ software. It assesses these tools using 22 criteria and three case studies, highlighting differences in optimization results and the importance of selecting software based on specific requirements. Despite minor discrepancies in sizing, the comparison underscores each software’s strengths and weaknesses in designing efficient and cost-effective SMs. The main authors have identified the following 3 Key Takeaways from the report: HOMER PRO and iHOGA PRO+ are publicly available software tools for the microgrid optimization process during the microgrid pre-design phase. Task 18 has defined 22 criteria (quantitative and qualitative) to help software users evaluate which software tool fits better their needs. Based on the quantitative criteria, Task 18 has found that the simulation results from both software tools are equivalent, both when simulating an existing microgrid with real measurement data and when simulating a new microgrid from scratch. However, based on the qualitative criteria, both software tools have some uniqueness in terms of their features.@en

The large Electric Vehicle (EV) fleet penetrations can provoke several grid impact issues if no EV smart-charging is implemented. However, many EV smart-charging works assume an accurate prediction of input data, such as the EV driving patterns, which are highly uncertain. This paper addresses the impact and potential management of several uncertainties related to EV smart charging, such as photovoltaic (PV) generation, load demand, arrival state-of-charge (SOC), requested energy, and arrival and departure time of the EVs. The application of different levels of uncertainty budgets is proposed to account for the gradual impact of every uncertainty on smart charging performance. Moreover, potential uncertainty management is investigated with the use of robust optimization (RO) in predictive receding-horizon EV smart charging under the worst-case uncertainty level, and the ''price of robustness"is calculated. The results show that the EV driving uncertainties are more hazardous for the provided charging energy. In contrast, PV generation and load demand uncertainties have a significant impact mostly on the charging cost. Moreover, the price of robustness is very low for EV charging under every uncertainty case.

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Electric aircraft technology has gained considerable attention and is rapidly developing to mitigate the environmental impact of air transportation and move toward more sustainable modes. Nevertheless, the unique characteristics of electric aircraft pose significant challenges for the charging infrastructure, which must be effectively addressed to facilitate the growth of electric aircraft. This article provides a comprehensive review of the latest developments and future trends in electric aviation, which covers electric aircraft, battery technology, and electric aircraft charging systems. This article also surveys the possible charging system architectures that can be employed for electric aircraft charging. Various power electronic converter topologies that are suitable for future electric aircraft dc fast chargers are presented. This article concludes by identifying future challenges in the path toward charging electric aircraft and discusses potential solutions to these challenges.

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In the presence of a catenary infrastructure, the transition from fossil fuel-based bus fleets to electric-powered ones can be facilitated through conventional trolleybuses or In-Motion-Charging trolleybuses, offering environmentally friendly and cost-effective solutions. However, grid congestion at traction substations (TSs) can limit this transition as the grid operator is incapable or unwilling to provide more capacity. As grid connection contracts are typically tallied and billed in periods of 15 minutes, stationary energy storage devices can prove useful in short-term buffering of the power demand. Consequently, more electrification projects can be rolled out under the same, or minimally extended grid contract. In this aim, this paper looks at validating energy storage as a means of enabling bus fleet electrification. It presents a power management strategy that controls the power exchange between the energy storage system (ESS) within the TS, specifically to manage the 15-minute average power. This strategy also serves as a tool for sizing the ESS with the minimum capacity required for the application. A case study for the city of Bologna, Italy, has been considered to validate the proposed approach. The findings indicate that billing contract power can be reduced by up to 41.7% when a storage device actuates in high-energy-demand substations. Furthermore, different types of Lithium-ion cells, including their second-life versions, are compared to determine the most beneficial options under limited cost and volume constraints. Recommendations are drawn on the exact scenarios where each type of cell is most beneficial.

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The rising demand for electric vehicles (EVs) in the face of limited grid capacity encourages the development and implementation of smart charging (SC) algorithms. Experimental validation plays a pivotal role in advancing this field. This article formulates a hierarchical mixed integer programming EV SC algorithm designed for low voltage (LV) distribution grid applications. A flexible receding horizon scheme is introduced in response to system uncertainties. It also considers the practical constraints in protocols, such as IEC/ISO 15118 and IEC 61851-1. The proposed algorithm is verified and assessed in a power hardware-in-the-loop testbed that incorporates models of real LV distribution grids. Furthermore, the algorithm's capabilities are examined through eight scenarios, out of which four focus on the uncertainties of the input data and two address the engagement of extra grid capacity restrictions. The results demonstrate that the SC algorithm adequately lowers the EV charging cost while fulfilling the charging demand, and substantially reduces the peak power as well as the overloading duration, even when faced with input data uncertainty. The additional grid restrictions in place are proven to improve peak demand reduction and overloading mitigation further. Finally, the limitations and potentials of the developed algorithm are scrutinized.

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