Search Results (14)

Bidirectional electric vehicle (EV) charging represents an opportunity to leverage EVs as flexible energy assets within the power system. By enabling controlled power flow in both directions, bidirectional charging unlocks a wide range of grid services, thereby enhancing grid stability as the energy sector decarbonizes. This paper presents a comprehensive experimental evaluation of bidirectional charging systems (EVCS), focusing on response dynamics and controllability delays critical for grid services. A real ISO 15118–20–enabled EV and an EV emulator were used to conduct tests across configurations, utilizing the Watt & Well 22 kW bidirectional charging bay. The study compares CCS2 and CHAdeMO protocols under varying configuration conditions. Results show that modern chargers achieve sub-second responsiveness, with local communication delays typically below 0.4 s and ramping times around 0.5 s. However, power flow reversals introduce an additional delay of approximately 1 s. These updated controllability metrics are essential for validating bidirectional charging in time-critical applications such as primary frequency regulation. The findings highlight the influence of voltage level and modular configuration on dynamic performance, underscoring the need to integrate external control path delays for full-stack validation. This work provides a foundation for modeling and deploying bidirectional EVCS in fast-response grid services. Full article

This paper presents a thermal study of a lithium-ion traction battery with different cooling configurations during simulated city driving and high-power charging. Four liquid cooling configurations—single or triple plates with straight or U-shaped tubes—were evaluated using finite element models in the Q-Bat Toolbox for MATLAB. Simulations were conducted using the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) and a high-current charging profile based on the CHAdeMO standard (up to 400 A). The results indicate that while cooling is not strictly necessary under typical driving conditions, it significantly improves thermal stability and reduces peak temperatures. The best configuration reduced peak cell temperatures by 1.96% during driving and by 16% during fast charging. The cooling system also minimized temperature gradients within the battery, reducing the risk of degradation. Box-plot analysis confirmed that an efficient cooling system stabilizes the temperature distribution and smooths out extreme values. The results highlight the importance of thermal management for extending battery life and ensuring safe operation, particularly during fast charging conditions. Full article

To minimize the recharge time of EVs, Level 3 charging stations utilizing DC fast charging systems have become increasingly prevalent. Additionally, these systems offer bidirectional functionality, aiding in stabilizing the DC grid during peak hour. As a result, the DC–DC converters utilized in such systems must be capable of bidirectional energy transfer. Among existing typologies, DAB converters are preferred due to their simplicity and sustainability. The three-phase DAB (DAB3) is favored because the output ripple is lower compared to the single-phase structure. This characteristic assists in mitigating the negative effects on the battery caused by high-frequency current ripple. However, the input to DAB3 converters typically originates from AC–DC stages, leading to the inclusion of low harmonic frequency ripples (e.g., multiples of 360 Hz). These ripples are then transferred to the battery, increasing its temperature. To address this issue, this paper proposes a technique to mitigate negative effects by attenuating these low frequencies in the charging current. Simulations were conducted to demonstrate the effectiveness of the proposed technique. Scaled-down experiments utilizing a DAB3 prototype were conducted to corroborate the simulations. The findings demonstrated a reduction in ripple from 8.66% to below 2.67% when compared to the original controller. This reduction enabled the solution to meet the limiting current ripple criteria outlined in the CHAdeMO standard. Full article

Vehicle-to-Grid (V2G) technology is viewed as a viable solution to offer auxiliary power system services. Currently, V2G operation is only possible through DC chargers using the CHAdeMO connector with the necessary communication protocol. However, in Europe, for high-power DC charging (>50 kW), the Combined Charging Service (CCS) Type 2 is preferred over CHAdeMO. Therefore, this work presents the development of a V2G testing system with a Combo CCSType 2 charger including communication via the ISO 15118-2 protocol. The BOSCH passenger car with a 400 V battery pack is used to test and validate the technical feasibility of V2G charging via a Combo CCS Type 2 connector standard. The V2G feature is characterized in terms of efficiency, signal delay, response proportionality, magnitude accuracy and noise precision. A data driven V2G charger simulation model based on the real-time data is also developed in MATLAB/Simulink. The performance under various operating settings is presented in the outcomes, emphasizing the need for appropriate hardware calibration, and understanding while delivering standard-compliant grid control services using V2G technology. Finally, the results of the simulation model are compared with the real hardware results in terms of error, noise level and data magnitude accuracy. Full article

Electromobility has grown rapidly, and especially in China, Europe, and the United States. Within Europe, Germany is the largest market. Our goal in this paper is to provide a data-driven overview of the key data, including the number of vehicles sold, place of registration, battery capacity, and charging power, in Germany. The results were generated by linking car-registration data with the technical details for each car model. We identified more than 84% of the battery electric vehicles in the fleet, but the uncertainty is larger for plug-in hybrid electric vehicles. The number of sold electric vehicles doubled annually over the last two years. Simultaneously, the battery capacity and charging power per vehicle are rising. Combined, the two effects cause the cumulative battery capacity and charging power of the fleet to grow at an even faster pace. The battery energy built into electric vehicles in Germany registered on 1 August 2022 was 50.5 GWh, of which 9.5 GWh belonged to plug-in hybrids. The combined charging system became the dominant charger type for fast charging in Germany, and only 2% of the vehicle fleet used the competing CHAdeMO standard. To allow fellow researchers to work with the data, we published them free of charge on our data platform mobility charts, and we update the data monthly. Full article

This paper focuses on committee–market standards battles for the case of vehicle-to-grid technology in Europe. In this battle, standards such as CHArge de MOve (CHAdeMO) and Combined Charging System (CCS) Combo are competing. The paper identifies relevant factors with the help of a literature review and expert interviews. Furthermore, the importance weights were established for the factors. The paper ends with a discussion and conclusion in which the theoretical contributions, practical implications, limitations, and recommendations for further research are discussed. Full article

Norway is the largest Battery Electric Vehicle (BEV) market in the world per capita. The share of the passenger vehicle fleet passed 9.4% at the end of 2019, and users have access to 1500 Combined Charging System (CCS)/Chademo standard fast chargers located in more than 500 different locations. This paper analyses the usage pattern of these fast chargers using a dataset from two large operators covering most of their charging events between Q1 2016 and Q1 2018. The target of the analysis was to understand the fundamental factors that drive the demand for fast charging and influences the user experience, so that they can be taken into account when dimensioning charge facilities, and when designing vehicles. The data displays clear variations in charge power, charge time and charged energy between winter and summer, and a large spread of results due to the BEV models different technical characteristics. The charge power is clearly reduced in the winter compared to the summer, while the charge time is longer. Some charge events have a particularly low charge power which may be due to users fast charging a cold battery at a high State of Charge (SOC) in a vehicle with passive battery thermal management. Full article

Plug-in electric vehicles (PEVs) are expected to play a role as power grid ancillary service providers through vehicle-to-grid (V2G) chargers, enabling higher levels of renewable electricity penetration. However, to fully exploit the storage capacity of PEVs and fast responsiveness, it is crucial to understand their operational characteristics. This work proposes a characterization procedure for V2G systems providing grid services. It extends the existing literature on response time, AC/DC conversion and reactive power assessment. Illustrative results were obtained by implementing the procedure using a Nissan Leaf battery electric vehicle (BEV) connected to a remotely operated commercial V2G CHAdeMO charger. The V2G system was characterized as having a relative inaccuracy and variability of response inferior to 3% and 0.4%, respectively. Its average communication and ramping times are 2.37 s and 0.26 s/kW, respectively. Its conversion efficiency and power factor both showed degradation in the power values below 50% of the charger’s nominal power. Moreover, the proposed visualizations revealed that: i) the V2G system implements power requests for the DC power flow; ii) the power factor control algorithm was nonoperational; and iii) the acquired data can leverage statistical models that describe the operation of V2G systems (which is of extreme value for researchers and operators). Full article

Aggregation and control of electric vehicles (EVs) via vehicle-to-grid (V2G) technologies is seen as a valid option for providing ancillary power system services. This work presents results from V2G-ready equipment tests and modelling. The technical capabilities of an EV connected to a commercial V2G charger are investigated when controlled either locally or remotely. The charger is characterized in terms of efficiency characteristics, activation time, response granularity, ramping-up/down time, accuracy and precision. Test results show the performance for different operating conditions, highlighting the importance of a good calibration and knowledge of the employed hardware when providing standard-compliant grid regulation services via V2G technology. Ultimately, a set of simulations demonstrates that the designed EV charger model replicates accurately the operating conditions of the real hardware. Full article

Multi-type fast charging stations are being deployed over Europe as electric vehicle adoption becomes more popular. The growth of an electrical charging infrastructure in different countries poses different challenges related to its installation. One of these challenges is related to weather conditions that are extremely heterogeneous due to different latitudes, in which fast charging stations are located and whose impact on the charging performance is often neglected or unknown. The present study focused on the evaluation of the electric vehicle (EV) charging process with fast charging devices (up to 50 kW) at ambient (25 °C) and at extreme temperatures (−25 °C, −15 °C, +40 °C). A sample of seven fast chargers and two electric vehicles (CCS (combined charging system) and CHAdeMO (CHArge de Move)) available on the commercial market was considered in the study. Three phase voltages and currents at the wall socket, where the charger was connected, as well as voltage and current at the plug connection between the charger and vehicle have been recorded. According to SAE (Society of Automotive Engineers) J2894/1, the power conversion efficiency during the charging process has been calculated as the ratio between the instantaneous DC power delivered to the vehicle and the instantaneous AC power supplied from the grid in order to test the performance of the charger. The inverse of the efficiency of the charging process, i.e., a kind of energy return ratio (ERR), has been calculated as the ratio between the AC energy supplied by the grid to the electric vehicle supply equipment (EVSE) and the energy delivered to the vehicle’s battery. The evaluation has shown a varied scenario, confirming the efficiency values declared by the manufacturers at ambient temperature and reporting lower energy efficiencies at extreme temperatures, due to lower requested and, thus, delivered power levels. The lowest and highest power conversion efficiencies of 39% and 93% were observed at −25 °C and ambient temperature (+25 °C), respectively. Full article

Paper deals with an extensive experimental activity carried out in Italy by ENEA Research Lab on Low impact vehicles and by the Energy engineering group of the University of L'Aquila about the energy efficiency of quick vehicle battery charging using a DC CHAdeMO compliant recharging 50 kW infrastructure. Both the charger and the vehicle (a Nissan Leaf) battery were fully monitored to gather detailed information about their behaviour at different power loads. The performances of the battery pack equipping the vehicle have also been monitored and evaluated through an extensive campaign, both on typical urban and extra-urban uses, and on vehicle rolling test bench. Full article

Electric Vehicle is widely used in passenger service gradually. It is a critical successful factor to have a sufficient electric energy supply. In order to solve the constraint of economical issue, the fast charging method can decrease the charging time such that the service time can be extended without dramatically increasing the battery numbers. This research develops a fast charging system which follows international regulation. The fast charging system includes a charging station simulation system, a battery loading simulation system, and a charging controller mounted on a fast charging vehicle. This system has completed connection tests with charging stations of ABB from Europe and Delta in Taiwan and also finished system verification with Japan HASETEC, which is a major company involving in CHAdeMO association affair. The developing charging controller undergoes several charging/discharging experiments for marine high capacity lithium ion battery module. The cells of the battery module still maintain reasonable balance status after charging process, which proves the developed charging controller of this research can safely and efficiently fast charge a lithium battery module via high voltage direct current. It is the goal for this research that promote adopting electric boat in touring water field for carbon emission reduction and water resource protection can be realized all at once. Full article

At present, low-output 1 to 2 kW AC electric vehicle chargers are the norm for the charging infrastructure installed in residential areas and business offices. In order to shorten the charging times, there is a belief that it would be best to implement changes that would increase the kW output. However, an objective look at the conditions surrounding the charging process shows such modifications are not necessary. There is a sufficient amount of charging time available and the upgrading of the distribution power grid would require the installation of additional high-power electrical equipment that would ultimately burden users.
Nevertheless, in some cases, fast charging is necessary. Hence, in order to fulfill this need, the installation of a moderate number of quick chargers would be more effective than increasing the output of the individual AC chargers in a halfway manner. The role of this quick-charging infrastructure would primarily be supplementary and in order to achieve a substantial reduction in the charging time, the output would have to be boosted up to around 50kW. Such upgrades would increase the risks associated with high voltage electricity such as electric shocks, burn injuries and fires.
Therefore, after taking these risks into consideration, the CHAdeMO quick charger was designed so that general users will not be exposed to any unnecessary danger when charging their EVs. A report of the CHAdeMO quick charger design features is as follows. Full article

In the transportation sector, electric vehicles (EV) are expected to play an instrumental role in reducing carbon dioxide emissions due to their eco-friendly and high-energy efficiency features. Further, in light of recent plans that have been announced globally to introduce the EV, it is believed that the spread of this new technology will be inevitable.
Although EVs were on track to become widespread many times in the past, they never did take off and the underlying reason(s) why must be investigated so as to not repeat the same mistakes that had prevented the past dissemination of this revolutionary new technology.
The major factor impeding the spread of EVs is the limited capacity of the lithium ion battery stored inside the vehicle. Although, there have been price and performance improvements allowing for widespread application to cell phones and computers etcetera, the exorbitant costs make substantial onboard battery enhancements prohibitive. Although the present infrastructure is unable to support electric vehicles, it is believed that with sufficient upgrades such facilities can be made useful and help pave the way for reduced battery capacity. In developing the design of the CHAdeMO standard quick charger, the following past infrastructure challenges were addressed. Full article