3,438 research outputs found
Aggregated Impact of EV Charger Type and EV Penetration level in Improving PV Integration in Distribution Grids
No full textMass deployment of Electric Vehicles (EVs) can improve the loading characteristics of low voltage distribution grids with high Photovoltaic (PV) penetration. This impact is investigated in the paper from two point of views, namely, the EV charger type and the EV penetration level. Based on the measured usage data for home, public and semi-public EV chargers, it is highlighted that the ratio of the number of these charger types can influence the grid level impact of PV penetration. Using Monte-Carlo method with aggregated power balance model, it is suggested that the increase in percentage of public and semi-public chargers relative to home chargers can improve self-consumption of PV energy in the grid, thereby reducing the power mismatch due to excess local generation. A PowerFactory based simulation with real measurement based data on real German distribution grids reveals that the grids have no risk of congestion at all with 80% EV penetration, allowing for a possibility even higher EV penetration in the future. Furthermore, with the considered uncontrolled EV charging, it is observed that the grids experience reverse power flows due to excess PV generation. This excess PV energy reduces by about 5% with high EV penetration, indicating a future potential for targeted smart charging application for improving these benchmarked results.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
TMD diagnosis–What should general dentists and orthodontists know?
No full text\ua9 2024 The Author(s)Diagnosis is the cornerstone of care for temporomandibular disorders (TMD) in order to provide crucial forward momentum in terms of patient engagement and education alongside provision of appropriate management. Despite its importance diagnostic confidence for TMD is reported as low in the primary care settings. This article will consider potential reasons for this and outline the importance of diagnosis for both individuals living with the condition and clinicians. We will suggest utilisation of a pragmatic, evidence based, broad group diagnosis using simplified examination procedures and diagnostic aids to support the TMD diagnostic process for clinicians
Differentially expressed genes selected on spline (EV) or VSN transformed data
No full text<p><b>Copyright information:</b></p><p>Taken from "An adaptation of the LMS method to determine expression variations in profiling data"</p><p></p><p>Nucleic Acids Research 2007;35(9):e71-e71.</p><p>Published online 25 Apr 2007</p><p>PMCID:PMC1888829.</p><p>© 2007 The Author(s)</p> The same dataset represented in was used to select differentially expressed genes on spline (EV) or VSN-transformed data. MA plots of scaled log-transformed signals for probe sets from two experimental conditions of the B6.1 cells. Color codes are as in . Up-regulated genes are shown as green bold dots, down-regulated as red bold dots. () Distribution of 555 genes (-value = 0.05) selected upon a spline fit. () Distribution of 555 genes (FC = 1.63) on VSN-transformed data. () Distribution of genes selected by both approaches. () Distribution of genes selected by EV (spline fit) alone. () genes selected by VSN (arcsinh transformation) alone
Frequency Regulation Reserves Provision in EV Smart-Charging
No full textSmart-Charging of Electric Vehicles (EVs) is able to provide frequency regulation capacity services to the System Operator (SO) upon an automation generation control (AGC) signal. While the amount of available regulation capacity is of-fered in the Day-Ahead Market (DAM), there is high uncertainty on the actual amount of reserves that will be called in the Real-Time Market (RTM). This work focuses on aiding EV smart-charging to offer a consistent and reasonable amount of regulation capacity, taking into account the impact of potential future instantaneous called regulation reserves while also maintaining simplicity. The work also analyzes the results of different charger types with different characteristics and shows that they play an important role on the regulation provision. Finally, it has been shown that even though the regulation income is inevitably reduced (up to 66%), the Energy Management System (EMS) can still successfully charge the EV s and simultaneously provide regulation reserves with remuneration.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Optimal System Design for a Solar Powered EV Charging Station
No full textCharging electric vehicles (EV) from photovoltaic (PV) panels provides a sustainable mode of transportation. In order to reduce the net costs of charging EV from PV and the grid, the PV generation and/or the EV charging can be controlled based on the energy prices in the grid. The traditional approach to designing the solar system for EV charging is to maximize the energy yield. In this paper, an alternate approach to PV system design is proposed by which the PV panels are orientated so as to maximize the PV revenue. This technique is compared with that of reducing the net costs by smart charging of the EV based on energy prices. Two case studies for Netherlands and Texas are done to compare the PV energy generated and the net cost of EV charging from PV based on the two techniques.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
End-of-Life Comparison of Full-Bridge and Half-Bridge DC/DC Converter Switches Used for EV Charging
No full textEV fast chargers are essential in addressing the concern of limited driving range for E-mobility applications. However, the load profile of a converter for fast charging involves a high-current pulse that can last for a few minutes to efficiently replenish the EV battery, which is followed by a cooldown period after the charging process is finished. This results in thermal cycles that can lead to thermo-mechanical fatigue and degradation of power electronic components, thereby impacting device lifetime. This paper presents a comparative study on the reliability of power devices in isolated half-bridge and full-bridge DC-DC converters in EV fast chargers. The study focuses on the differences in thermal stresses that Si switches experience in each converter during charging cycles and how it impacts the end-of-life of each device. This study provides valuable insights for selecting reliable power converters for EV fast charging applications.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Using dedicated EV charging areas to resolve grid violations caused by renewable energy generation
No full textEV Charging is expected to be a significant load on the grid in the future. But they can also be a part of the solution to grid violations. As the amount of renewable energy generation increases, there is a large amount of power flowing in the reverse direction in the distribution network, which is undesirable. To reduce this, EVs can charge at strategically located “Grid Management Parking Lots”. Here the EV charging power level varies in accordance with the amount of capacity available in the grid. This is a win-win situation for both parties, the grid operator and the EV owner, as the grid operator reduces the amount of violations in the grid and the EV owner has his/her vehicle charged sooner.Accepted Author ManuscriptDC systems, Energy conversion & Storag
Submodeling Method-Based Thermal Investigation of the Battery Energy Storage System Integrated in a 450 kW EV Charger
No full textThe electric vehicle (EV) market is expanding rapidly. However, the main barriers to EV adoption are high vehicle costs, range issues, and charging infrastructure. Meanwhile, energy storage systems (ESS) appear as a promising solution to preventing grid overload during charging and reducing infrastructure costs. In this paper, the integration of the battery energy storage system (BESS) in a 450 kW EV charger is designed and investigated via modeling and simulation mainly from the perspective of thermal management. To explore the heat dissipation and the temperature distribution across the pack, the thermal model based on the sub-modeling technique is developed via COMSOL, and a preliminary layout and cooling strategy are determined.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Access barriers to antiretroviral therapy (ART) in Zimbabwe: a case study of Chivhu Hospital
No full textIncludes abstract.Includes bibliographical references.Access to healthcare is one of the basic social goods which ensures that individuals lead healthy and long lives. There is an increased need towards ensuring access to health care for all, which has led to the question of how access is defined. Access in this study is defined as the degree of fit between the health care system and patients. It involves an interaction between the system and patients in a way which removes access barriers to care. A comprehensive framework was used to measure access in this study. The framework allows for a systematic approach to the concept of access and measures access in three dimensions namely affordability, availability and acceptability. Using this framework, the study looked into the factors affecting access to antiretroviral therapy (ART) by patients at Chivhu Hospital in Zimbabwe. Chivhu was chosen because it has a mixed population of urban and rural patients which represents the typical Zimbabwean population. A cross sectional study design was adopted for this study
Optimized Scheduling of EV Charging in Solar Parking Lots for Local Peak Reduction under EV Demand Uncertainty
No full textScheduled charging offers the potential for electric vehicles (EVs) to use renewable energy more efficiently, lowering costs and improving the stability of the electricity grid. Many studies related to EV charge scheduling found in the literature assume perfect or highly accurate knowledge of energy demand for EVs expected to arrive after the scheduling is performed. However, in practice, there is always a degree of uncertainty related to future EV charging demands. In this work, a Model Predictive Control (MPC) based smart charging strategy is developed, which takes this uncertainty into account, both in terms of the timing of the EV arrival as well as the magnitude of energy demand. The objective of the strategy is to reduce the peak electricity demand at an EV parking lot with PVarrays. The developed strategy is compared with both conventional EV charging as well as smart charging with an assumption of perfect knowledge of uncertain future events. The comparison reveals that the inclusion of a 24 h forecast of EV demand has a considerable effect on the improvement of the performance of the system. Further, strategies that are able to robustly consider uncertainty across many possible forecasts can reduce the peak electricity demand by as much as 39% at an office parking space. The reduction of peak electricity demand can lead to increased flexibility for system design, planning for EV charging facilities, deferral or avoidance of the upgrade of grid capacity as well as its better utilizationEnergy TechnologyEnergie and Industri
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