385 research outputs found

    Cloud your bus: real-time energy consumption prediction for electric city buses

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    Electric vehicle charging and routing management via multi-infrastructure data fusion

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    The introduction of Electric Vehicles (EVs) has placed a strain on the aged and already overworked electrical grid. With each EV requiring the same amount of power as 3 to 140 single family homes, depending on how fast the charge occurs, measures need to be taken in order to protect the electrical grid from serious damage. The electric grid renovations proposed by the U.S. department of energy, commonly referred to as the smart grid, could help accommodate an even greater EV penetration. The introduction of the smart grid and other cutting-edge technologies create the potential for applications which provide new consumer conveniences and aid in the preservation of the electrical grid. This thesis aims to create one such application through the production of a prototype system which takes advantage of current and in-development technologies in order to route an electric vehicle to the closest and least detrimental charge station based on current conditions. Traffic conditions are assessed based on data collected from both ITSs (Intelligent Transportation Systems) and VANETs (Vehicle Ad-hoc Networks), while grid information is gathered through the early stages of the Smart Grid. The system is hosted in a cloud environment base on the current trend of offloading Information Technology systems to the cloud ; this also allows for the advantages of a shared data space between sub-systems. As part of the thesis the prototype system was put through a stress test in a simulated environment in order to both establish system requirements and determine scalability for use with larger maps. The system requirements were compared with the technical specifications of an off-the-shelf GPS routing device. It was determined that such a device could not handle routing with such extensive underlying data, and will require hosting the prototype in a cloud environment. The system was also used to perform a case study on charging station placement in the Greater Rochester area. It was determined that the current charging stations are insufficient for a significant number of electric vehicles and that adding even six stations would provide a greater EV operational area and provide a more uniform distribution of charging station usage

    A Smart Charging Assistant for Electric Vehicles Considering Battery Degradation, Power Grid and User Constraints

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    Der Anstieg intermittierender Stromerzeugung aus erneuerbaren Energiequellen erschwert zunehmend einen effizienten und zuverlĂ€ssigen Betrieb der Versorgungsnetze. Gleichzeitig steigt die Zahl der Elektrofahrzeuge, die zum Aufladen erhebliche Mengen an elektrischer Energie benötigen, rapide an. Energie- und MobilitĂ€tssektor sind somit unweigerlich miteinander verbunden, was zur Folge hat, dass zuverlĂ€ssige ElektromobilitĂ€t von einer robusten Stromversorgung abhĂ€ngt. DarĂŒber hinaus empfinden Fahrzeugnutzer ihre individuelle MobilitĂ€t als eingeschrĂ€nkt, da Elektrofahrzeuge im Vergleich zu Fahrzeugen mit Verbrennungsmotor derzeit eine geringere Reichweite aufweisen und mehr Zeit zum Aufladen benötigen. In der vorliegenden Arbeit wird daher ein neuartiges Konzept sowie eine Softwareanwendung (Ladeassistent) vorgestellt, die den Nutzer beim Laden seines Elektrofahrzeuges unterstĂŒtzt und dabei die Interessen aller beteiligten Akteure berĂŒcksichtigt. DafĂŒr werden zunĂ€chst Gestaltungsmerkmale möglicher Softwarearchitekturen verglichen, um eine geeignete Struktur von Modulen und deren VerknĂŒpfung zu definieren. Anschließend werden anhand realer Daten sowohl Energieverbrauchs- als auch Batteriemodelle entwickelt, verbessert und validiert, welche die Fahr- und Ladeeigenschaften von Elektrofahrzeugen abbilden. Die wichtigsten BeitrĂ€ge dieser Arbeit resultieren aus der Entwicklung und Validierung der folgenden drei Kernkomponenten des Ladeassistenten. Als Erstes wird das individuelle MobilitĂ€tsverhalten der Nutzer modelliert und anhand von aufgezeichneten und halbsynthetischen Fahrdaten von Elektrofahrzeugen ausgewertet. Insbesondere wird ein neuartiger, zweistufiger Clustering-Algorithmus entwickelt, um hĂ€ufig besuchte Orte der Nutzer zu ermitteln. Anschließend werden Ensembles von Random-Forest-Modellen verwendet, um die nĂ€chsten Aufenthaltsorte und die dort typischen Parkzeiten vorherzusagen. Als Zweites wird gemischt-ganzzahlige stochastische Optimierung angewandt, um Ladestopps in einem zukĂŒnftigen Zeithorizont möglichst komfortabel und kostengĂŒnstig zu planen. Dabei wird ein graphenbasierter Algorithmus eingesetzt, um den Energiebedarf und die Eintrittswahrscheinlichkeit von MobilitĂ€tsszenarien eines Elektrofahrzeugnutzers zu quantifizieren. Zur Validierung werden zwei alternative Ladestrategien definiert und mit dem vorgeschlagenen System verglichen. Als Drittes wird ein nichtlineares Optimierungsschema entwickelt, um vorhandene Zeit- und EnergieflexibilitĂ€t in LadevorgĂ€ngen von Elektrofahrzeugen zu nutzen. Die Integration eines detaillierten Batteriemodells ermöglicht eine genaue Quantifizierung der Kosteneinsparungen aufgrund einer geringeren Batteriealterung und dynamischer Stromtarife. Anhand von Daten aus realen LadevorgĂ€ngen von Elektrofahrzeugen können EinflĂŒsse auf die RentabilitĂ€t von Vehicle-to-Grid-Anwendungen herausgearbeitet werden. Aus der Umsetzung des vorgestellten Ansatzes in einer realistischen Umgebung geht ein Architekturentwurf und ein Kommunikationskonzept fĂŒr optimierungsbasierte intelligente Ladesysteme hervor. Dabei werden weitere Herausforderungen im Zusammenhang mit standardisierter Ladekommunikation, Eingriffen der Energieversorger und Nutzerakzeptanz aufgedeckt

    Evaluating system architectures for driving range estimation and charge planning for electric vehicles

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    Due to sparse charging infrastructure and short driving ranges, drivers of battery electric vehicles (BEVs) can experience range anxiety, which is the fear of stranding with an empty battery. To help eliminate range anxiety and make BEVs more attractive for customers, accurate range estimation methods need to be developed. In recent years, many publications have suggested machine learning algorithms as a fitting method to achieve accurate range estimations. However, these algorithms use a large amount of data and have high computational requirements. A traditional placement of the software within a vehicle\u27s electronic control unit could lead to high latencies and thus detrimental to user experience. But since modern vehicles are connected to a backend, where software modules can be implemented, high latencies can be prevented with intelligent distribution of the algorithm parts. On the other hand, communication between vehicle and backend can be slow or expensive. In this article, an intelligent deployment of a range estimation software based on ML is analyzed. We model hardware and software to enable performance evaluation in early stages of the development process. Based on simulations, different system architectures and module placements are then analyzed in terms of latency, network usage, energy usage, and cost. We show that a distributed system with cloud‐based module placement reduces the end‐to‐end latency significantly, when compared with a traditional vehicle‐based placement. Furthermore, we show that network usage is significantly reduced. This intelligent system enables the application of complex, but accurate range estimation with low latencies, resulting in an improved user experience, which enhances the practicality and acceptance of BEVs

    Advancing state of charge management in electric vehicles with machine learning : a technological review

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    As the share of electric vehicles increases, electric vehicles are exposed to broader of driving conditions (e.g., extreme weather), which reduce the performance and driving ranges of electric vehicles below their nameplate rating. To ensure customer confidence and support steady growth in electric vehicle adoption rates, accurate estimation of battery state of charge and maintaining battery state of health through optimal charge/discharge decisions are critical. Recently, vehicle manufacturers have begun to employ machine learning techniques to improve state-of-charge management to better inform drivers about both the short-term (state of charge) and long-term (state of health) performance of their vehicles. This comprehensive review article explores the intersection of machine learning and state of charge management in electric vehicles. Recognizing the critical importance of the state of charge in optimizing electric vehicle performance, the article starts by evaluating traditional state of charge estimation methods. Subsequently, it delves into the transformative impact of machine learning techniques and associated algorithms on state of charge management. Through the lens of various case studies, this article demonstrates how machine learning-based state of charge estimation empowers electric vehicles to make informed and dynamic energy usage decisions, enhancing efficiency and extending battery life. The challenges of data availability, model interpretability, and real-time processing constraints are acknowledged as impediments to the widespread adoption of machine learning techniques. Despite these challenges, the future outlook for machine learning in the state of charge management appears promising, with emerging trends such as deep learning and reinforcement learning poised to refine the state of charge estimation accuracy. Moreover, this study sheds light on the transformative potential of machine learning in enhancing the state of charge management efficiency and effectiveness for electric vehicles, offering critical insights. Machine learning emerges as a game-changing force in state of charge management for electric vehicles, paving the way for intelligent and adaptive vehicles that are both environmentally friendly and efficient. This evolving field invites further research and development, making it a vital and exciting area within the automotive industry

    Energy Uncertainty Analysis of Electric Buses

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    Uncertainty in operation factors, such as the weather and driving behavior, makes it difficult to accurately predict the energy consumption of electric buses. As the consumption varies, the dimensioning of the battery capacity and charging systems is challenging and requires a dedicated decision-making process. To investigate the impact of uncertainty, six electric buses were measured in three routes with an Internet of Things (IoT) system from February 2016 to December 2017 in southern Finland in real operation conditions. The measurement results were thoroughly analyzed and the operation factors that caused variation in the energy consumption and internal resistance of the battery were studied in detail. The average energy consumption was 0.78 kWh/km and the consumption varied by more than 1 kWh/km between trips. Furthermore, consumption was 15% lower on a suburban route than on city routes. The energy consumption was mostly influenced by the ambient temperature, driving behavior, and route characteristics. The internal resistance varied mainly as a result of changes in the battery temperature and charging current. The energy consumption was predicted with above 75% accuracy with a linear model. The operation factors were correlated and a novel second-order normalization method was introduced to improve the interpretation of the results. The presented models and analyses can be integrated to powertrain and charging system design, as well as schedule planning.Peer reviewe
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