Dissertations / Theses: 'CHARGING AND DISCHARGING TIME'

1

Saas, Christoph [Verfasser]. "Energy Efficient Charging and Discharging of Dominant Capacitances / Christoph Saas." Aachen : Shaker, 2007. http://d-nb.info/1170528066/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Aloqaily, Osama. "Charging and Discharging Algorithms for Electric Vehicles in Smart Grid Environment." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34562.

Full text

Abstract:

Power demands will increase day-by-day because of widely adopting of Plug-in Electric Vehicles (PEVs) in the world and growing population. Finding and managing additional power resources for upcoming demands is a challenge. Renewable power is one of the alternatives. However, to manage and control renewable resources, we need suitable Energy Storage System (ESS). PEVs have a large battery pack that is used mainly to supply electric motor. Moreover, PEV battery could be used as an ESS to store power at a certain time and use it at another time. Nevertheless, it can play the same role with electric power grids, so it can store power at a time and return it at another time. This role might help the grid to meet the growing demands. In this thesis, we propose a charging and discharging coordination algorithm that effectively addresses the problem of power demand on peak time using the PEV’s batteries as a backup power storage, namely, Flexible Charging and Discharging (FCD) algorithm. The FCD algorithm aims to manage high power demands at peak times using Vehicle to Home (V2H) technologies in Smart Grid and PEV’s batteries. Intensive computer simulation is used to test FCD algorithm. The FCD algorithm shows a significant reduction in power demands and total cost, in proportion to two other algorithms, without affecting the performance of the PEV or the flexibility of PEV owner’s trip schedule.

APA, Harvard, Vancouver, ISO, and other styles

3

Fain, Daniel Ian. "A dual input bidirectional power converter for charging and discharging a PHEV battery." Connect to this title online, 2009. http://etd.lib.clemson.edu/documents/1252424759/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Wang, Dian. "Microgrid based on photovoltaic energy for charging electric vehicle stations : charging and discharging management strategies in communication with the smart grid." Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2584.

Full text

Abstract:

Le développement rapide des véhicules électriques (EVs) augmente la demande de puissance, ce qui provoque une charge supplémentaire sur le réseau public et augmente les fluctuations de la charge. Par conséquent, la forte pénétration des EVs est freinée. Un algorithme simulé en temps réel et basé sur des règles est élaboré pour les bornes de recharge des EVs alimentées par un micro-réseau DC afin de faire face aux incertitudes du comportement des utilisateurs des EVs. L'algorithme prend en considération les choix arbitraires et aléatoires proposés via l'interface homme-machine. Les résultats de simulation sont obtenus sous MATLAB / Simulink et vérifient la faisabilité de la stratégie de gestion proposée. Cette stratégie présente de bonnes performances en garantissant un contrôle précis. Par ailleurs, les algorithmes d'optimisation de délestage et de la restauration des EVs (SROA) pour la recharge de la puissance de la batterie peuvent être utilisés pour répondre aux besoins des utilisateurs. Aussi les algorithmes SROA maintiennent l'équilibre de la puissance de la station de recharge des EVs. Les algorithmes SROA prennent en compte l'intermittence de la source photovoltaïque (PV), la limitation de capacité du stockage et la limitation de puissance du réseau public. En comparant les résultats de la simulation aux algorithmes basés sur les règles, les algorithmes SROA proposés respectent le choix de l'utilisateur, réduisent le temps de charge total, augmentent le plein débit et maximisent l'utilisation de la puissance disponible. Les résultats de la simulation montrent la faisabilité et l'efficacité des algorithmes SROA. En outre, une station de charge basée sur le PV pour les EVs peut participer à la résolution de certains problèmes liés au pic de puissance. D'autre part, la technologie de véhicule à réseau (V2G) est conçue et appliquée pour fournir des services auxiliaires au réseau pendant les périodes de pointe, et V2G considère la dualité de la batterie des EVs « charge et source ». Ainsi, un algorithme de recherche dynamique des pics et de vallées est proposé pour une station de recharge des EVs afin d'atténuer l'impact sur le réseau public. Cet algorithme réduit ainsi le coût énergétique du réseau public. Les résultats de la simulation démontrent bien l'efficacité de l'algorithme de recherche des pics et des vallées. L'algorithme peut garantir l'équilibre du réseau public, satisfaire la demande de charge des utilisateurs des EVs et, surtout, réduire le coût énergétique du réseau public
The rapid development of electric vehicles (EVs) increases the power demand, which causes an extra burden on the public grid increasing the load fluctuations, therefore, hindering the high penetration of EVs. A real-time rule-based algorithm for electric vehicle (EV) charging stations empowered by a DC microgrid is proposed to deal with the uncertainties of EV users’ behaviour considering its arbitrary and random choices through the human-machine interface, meanwhile considering most of the users’ choices. The simulation results obtained under MATLAB/Simulink verify the feasibility of the proposed management strategy that presents a good performance in terms of precise control. In addition, EV shedding and restoration optimization algorithms (SROA) for battery charging power can be used to meet user needs while maintaining EV charging station power balance, taking into consideration the intermittency of the photovoltaic (PV) source, the capacity limitation of the storage, and the power limitation of the public grid. The simulation results show that compared with rule-based algorithm, the proposed SROA respect the user's choice while reducing total charging time, increasing the full rate, and maximizing the available power utilization, which shows the feasibility and effectiveness of SROA. Furthermore, a PV based charging station for EVs can participate to solve some peak power problems. On the other hand, vehicle to grid (V2G) technology is designed and applied to provide ancillary services grid during the peak periods, considering the duality of EV battery “load-source”. So, a dynamic searching peak and valley algorithm, based on energy management, is proposed for an EV charging station to mitigate the impact on the public grid, while reducing the energy cost of the public grid. Simulation results demonstrate the proposed searching peak and valley algorithm effectiveness, which can guarantee the balance of the public grid, meanwhile satisfy the charging demand of EV users, and most importantly, reduce the public grid energy cost

APA, Harvard, Vancouver, ISO, and other styles

5

Nishikawa, Kei. "Mass transfer of Li[+] ion accompanied by charging and discharging reaction of Li battery electrode." Kyoto University, 2006. http://hdl.handle.net/2433/135558.

Full text

Abstract:

Kyoto University (京都大学)
0048
新制・課程博士
博士(エネルギー科学)
甲第12623号
エネ博第141号
新制||エネ||34(附属図書館)
UT51-2006-S631
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授尾形幸生, 教授八尾健, 教授福中康博
学位規則第4条第1項該当

APA, Harvard, Vancouver, ISO, and other styles

6

Mansour, Samah. "Performance optimization of hybrid, centralized, and decentralized adaptive charging/discharging schemes for plug-in electric vehicles." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121588.

Full text

Abstract:

This thesis proposes a decentralized methodology for the planning and scheduling of the charging/discharging activities of plug-in electric vehicles (PEVs) within the smart grids framework. The optimization formulation is then extended to a hybrid approach that can be seen as a compromise between the centralized and decentralized solutions. The optimization objective of the different proposed coordination schemes addresses peak load reduction from the system operator's perspective. The performance of the suggested algorithms is examined by means of analysis and powerful co-simulation of both power and communications perspectives, over a converged broadband fiber-wireless communication infrastructure. A comparison of the proposed decentralized and hybrid schemes to a centralized benchmark algorithm is conducted to identify the performance trade-offs between the three methods. This comparative study examines several performance metrics, such as power demand, losses, and nodal voltage magnitudes, and from the communications perspective, the required channel bandwidth and delay. The adoption of any of the three proposed algorithms depends on many factors; however the size of the fleet seems to be the main impact factor. Centralized algorithms demonstrate optimal performance for relatively low penetration levels, Whereas decentralized schemes become a necessity with increasing PEV fleets. Hybrid schemes, on the other hand, can resolve the successive demand peaks resulting from decentralized schemes with very high penetration levels.
Cette thèse propose une méthodologie décentralisée pour la planification et la coordination des activités de charge et décharge des véhicules électriques (VEs) au sein des réseaux intelligents. La formulation d'optimisation est ensuite étendue vers une approche hybride qui peut être considérée comme un compromis entre l'approche centralisée et l'approche décentralisée. La fonction objectif des différents mécanismes de coordination proposés maximise l'écrê tage de pointe du point de vue de l'opérateur du système électrique. Les algorithmes proposés sont examinés de façon multidisciplinaire par moyen d'analyse et de co-simulation de la puissance électrique et de communication intelligente, sur une infrastructure de communications basées sur des technologies convergentes haut-débit optique et sans-fil. L'objectif principal de cette thèse est de réaliser une étude comparative entre les méthodes centralisée, décentralisée et hybride. La comparaison des méthodes proposées avec un algorithme de référence centralisé révèle le compromis de performances entre les trois approches. La comparaison tient compte de plusieurs métriques du réseau, telles que la demande de puissance, les pertes, les amplitudes de tension nodale, et, du point de vue des communications, la largeur de bande requise et le délai. L'adoption d'un algorithme parmi les trois proposés dépend de plusieurs facteurs, cependant le nombre de VEs semble être le facteur principal. Les algorithmes centralisés démontrent des performances optimales pour des taux relativement faibles de pénétration des VEs, alors que les systèmes décentralisés sont nécessaires lorsqu'il y a un nombre croissant de VEs. D'autre part, les systèmes hybrides sont capables de répondre aux pics de demandes successives résultant de systèmes décentralisés avec des taux de pénétration très élevés.

APA, Harvard, Vancouver, ISO, and other styles

7

Wu, Wenzhuo. "Charging time estimation and study of charging behavior for automotive Li-ion battery cells using a Matlab/Simulink model." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194490.

Full text

Abstract:

An accurate estimation of the charging time of an automotive traction battery is possible only with the knowledge of different parameters of the battery and the vehicle. If this information is not available to the driver, the full time needed for charging of the battery may have to be assessed only from experience. A long route planning and estimation of required service life of the vehicle are therefore only roughly possible. Furthermore, with a better knowledge of estimated charging time, better management of public charging stations and better utilization of charging equipment can be achieved. An algorithm based on Matlab/Simulink model is made in the present thesis to estimate the charging time of a Li-ion battery pack which consists of 32 cells with 40 Ah each, as well as to investigate the impact of different cell balancing methods and different charging strategies on charging process. The theoretical background of the battery and charging modelling is investigated and different battery models are compared to get the best trade-off between the model accuracy and computation complexity. In the end, an electrical equivalent circuit model from reference [1], consists of a series resistor and two ZARC elements, is chosen to represent the battery cell. The parameters of the equivalent circuit are updated according to the SOC, current and temperature changes during the charging process. The whole simulation model of the algorithm consists of a charging controller (implementing the charging strategy), cell balancing logic controller, and cell balancing hardware simulation circuit and battery cell models. Different balancing criteria: based on SOC (with PWM drive) and based on terminal voltage (with/without advance) are implemented in the cell balancing logic controller, as well as different balancing windows, to investigate their impact on charging time. As for charging strategy, traditional CCCV is investigated, further investigation is conducted into improved CCCV method. The impact of initial SOC, charging rate and aging factor on charging behavior are investigated as well. Experiment results are validated by the comparison of the results with the ones got from a Hardware-in-the-loop simulation system.
En noggrann estimering av laddtiden hos batterier avsedda för traktionsapplikationer kräver kunskap kring batteriets och dess tillhörande laddsystems parametervärden. Utan tillgång till denna information kan laddtiden endast uppskattas från fordonsägarens tidigare erfarenheter vilket försvårar t.ex. ruttplanering. En estimering av laddtiden med tillräcklig noggrannhet kan även möjliggöra bättre utnyttjade av laddutrusting inklusive nyttjandet av publika laddstationer. I detta examensarbete har en algoritm, implementerad i Matlab/Simulink, för att estimera laddtiden hos ett litiumjonbatteripack bestående av 32 celler på vardera 40 Ah tagits fram. Med hjälp av modellen har olika laddstrategier och metoder för att balansera cellerna studerats. Ett antal olika batterimodeller har jämförts i termer av noggrannhet och krav på beräkningsprestanda. En elektriskt ekvivalent krets från referens [1], bestående av en serieresistans samt två ZARC-element, valdes slutligen för att representera battericellen. Den ekvivalenta kretsens parametrar uppdateras vid förändringar i SOC, ström och temperatur. Hela simuleringsmodellen består av en laddregulator (i vilken laddstrategin är implementerad), cellbalanseringregulator och modeller för cell och cellbalanseringens hårdvara. Ett antal metoder för att balanser cellerna har jämförts med hänsyn till påverkan på den resulterande laddtiden. En traditionell samt modifierad CCCV laddstrategi har implementerats och jämförts med avseende på variationer i inledande SOC, total laddtid samt åldring. Experimentella resultat från en hardware-in-the-loop simulering har använts för att delvis kunna verifiera de framtagna resultaten.

APA, Harvard, Vancouver, ISO, and other styles

8

Huttin, Magalie [Verfasser], and M. [Akademischer Betreuer] Kamlah. "Phase-field modeling of the influence of mechanical stresses on charging and discharging processes in lithium ion batteries / Magalie Huttin. Betreuer: M. Kamlah." Karlsruhe : KIT-Bibliothek, 2014. http://d-nb.info/1049730585/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Dudley, Paul. "Optimal time-related charging in competitive markets with particular reference to electricity." Thesis, Loughborough University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297117.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Dresler, Jan. "Tester akumulátorů s modulem ESP32." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400923.

Full text

Abstract:

This thesis focuses on design of printed circuit board and programming of ESP32 module. This module communicates with discharging circuit which allows testing of battery properties. With help of voltage and current sensors it is possible to test and print results of battery on display. The testing device also allows control over web user interface thanks to ESP32.

APA, Harvard, Vancouver, ISO, and other styles

11

Jhala, Kumarsinh. "Coordinated electric vehicle charging with renewable energy sources." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/19767.

Full text

Abstract:

Master of Science
Department of Electrical and Computer Engineering
Balasubramaniam Natarajan
Anil Pahwa
Electric vehicles (EVs) are becoming increasingly popular because of their low operating costs and environmentally friendly operation. However, the anticipated increase of EV usage and increased use of renewable energy sources and smart storage devices for EV charging presents opportunities as well as challenges. Time-varying electricity pricing and day-ahead power commitment adds another dimension to this problem. This thesis, describes development of coordinated EV charging strategies for renewable energy-powered charging stations at homes and parking lots. We develop an optimal control theory-based charging strategy that minimizes power drawn from the electricity grid while utilizing maximum energy from renewable energy sources. Specifically, we derive a centralized iterative control approach in which charging rates of EVs are optimized one at a time. We also propose an algorithm that maximizes profits for parking lot operators by advantageously utilizing time-varying electricity pricing while satisfying system constraints. We propose a linear programming-based strategy for EV charging, and we specifically derive a centralized linear program that minimizes charging costs for parking lot operators while satisfying customer demand in available time. Then we model EV charging behavior of Active Consumers. We develop a real-time pricing scheme that results in favorable load profile for electric utility by influencing EV charging behavior of Active Consumers. We develop this pricing scheme as a game between electric utility and Active Consumers, in which the electric utilities decide optimal electricity prices that minimize peak-to-average load ratio and Active Consumers decide optimal charging strategy that minimizes EV charging costs for Active Consumers.

APA, Harvard, Vancouver, ISO, and other styles

12

Sadeghi, Meykola Seyedhafez. "Decreasing charging time of Lithium-Ion Battery by controlling temperature during the process." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-42265.

Full text

Abstract:

In this report, which is written for Halmstad University and on behalf of Semcon, a mechanical design process was implemented to evaluate the possibility of executing a low-cost cooling system for one of the battery company’s products. The report started from the background of former studies to clarify the problem and finding existing solutions in the first step and following up with developing concepts based on gathered information from the literature study. The battery company provides a high-performance battery based on customer requirements because of the flexible lithium battery technology. There are two similar conditions in the operating period of the battery. One in the high performance usage of the battery and two in the charging period by adding power to the battery cells. Both of these actions generate heat which is the result of resistance of the material in the cells and the chemical reaction of the cells. The battery company wants to decrease the time of charging period in order to reach the operative condition as fast as possible by enabling fast charging. According to the battery management system (BMS), at high temperatures the efficiency of charging rate decreases and also it has a negative influence on the battery cells performance and lifetime. A cooling system is required in order to fulfil the requirement of having high performance and making fast charging possible for the battery. The goal of this thesis is to develop a cooling system based on literature study with consideration of applying to the lithium battery in order to reduce charging time by decreasing temperature in the modules during the operating period. This report contains the whole developing conceptual design process of the cooling system by starting a wide range of information gathering in the purpose of determining the main variables which have an influence on different cooling techniques. In specific, after deciding about the type of cooling method for the product, the study has been focused on the fluid dynamics and heat transfer by forced convection with airflow. The concept generation executed on the information which was gathered through the information retrieval. The final developed concept has been introduced in this thesis work which has the potential of fulfilling the requirement of designing a cooling system to decrease the temperature of the battery’s modules without making any serious changes in the product. The final concept has been developed by various changes in its components and evaluating those changes by executing simulation for each change. The final concept contains twelve similar heat sinks which have been installed over connectors to provide more surface in the purpose of exchanging heat through the airflow provided by three high-speed fans. In order to force the airflow over the heat sinks, a cover has been designed.

APA, Harvard, Vancouver, ISO, and other styles

13

Silva, F?bio Oliveira. "Sistema para controle de carga e descarga com balanceamento de carga para bateria de chumbo ?cido com c?lulas ligadas em s?rie." Universidade Estadual de Feira de Santana, 2016. http://localhost:8080/tede/handle/tede/474.

Full text

Abstract:

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2017-07-12T21:44:11Z No. of bitstreams: 1 PGCA_Dissertacao_Fabio.pdf: 17456050 bytes, checksum: 0e14f30b37a0f91b865c29f80d2ff377 (MD5)
Made available in DSpace on 2017-07-12T21:44:11Z (GMT). No. of bitstreams: 1 PGCA_Dissertacao_Fabio.pdf: 17456050 bytes, checksum: 0e14f30b37a0f91b865c29f80d2ff377 (MD5) Previous issue date: 2016-08-18
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
There are presently market a wide range of batteries. These batteries come to meet the need of electric power supply for electronic devices unable to be connected to a source of electricity for a certain period of time. For this to happen, a battery goes through a cycle involving a charge period and a discharge period. Another point to be noted is that the vast majority of applications that utilize lead acid batteries have a supply voltage above 2 volts, the voltage which is provided by a single cell. For higher voltages, it is necessary to link various cells in series. According to manufacturers of lead acid batteries, if loading and unloading are carried out in accordance with the specifications provided for the product, ensures the maximum utilization of battery life, but failure to comply with these specifications can shorten the life of a battery lead acid in more than 50%. Given the above, this paper describes the design of a system to charge control, discharge control and load balancing for lead acid batteries for better efficiency and maximum utilization of the useful life of the batteries.
Atualmente, existe no mercado uma grande gama de baterias. Estes acumuladores v?m para suprir a necessidade de fornecimento de energia el?trica para dispositivos eletroeletr?nicos impossibilitados de serem conectados a uma fonte geradora de energia el?trica por um determinado per?odo de tempo. Para que isso aconte?a, uma bateria passa por um ciclo que envolve um per?odo de carga e um per?odo de descarga. Outro ponto a ser observado ? que a grande maioria das aplica??es que utilizam baterias de chumbo ?cido possuem tens?o de alimenta??o superiores a 2 volts, que ? a tens?o fornecida por uma ?nica c?lula. Para obter tens?es maiores, faz-se necess?ria a liga??o de v?rias c?lulas em s?rie. Segundo os fabricantes das baterias de chumbo ?cido, se forem realizadas cargas e descargas em conformidade com as especifica??es fornecidas para o produto, garante-se o aproveitamento m?ximo da vida ?til da bateria, mas a inobserv?ncia destas especifica??es pode diminuir a vida ?til de uma bateria de chumbo ?cido em mais de 50%. Diante do exposto, este trabalho descreve o projeto de um sistema para controle de carga, controle de descarga e balanceamento de carga para baterias de chumbo ?cido que garanta uma melhor efici?ncia e o m?ximo aproveitamento da vida ?til destas baterias.

APA, Harvard, Vancouver, ISO, and other styles

14

Janíček, Zdeněk. "Stabilita katodového materiálu pro LI-ion akumulátory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220974.

Full text

Abstract:

This diploma thesis focuses on study of positive electrode materials for Li-Ion batteries. Our aim are intercalation materials whose are really perspective materials whose are widely used in this case. The theoretical part of my thesis focus on basic study of Li-ion batteries and their parameters. We studied charging and discharging processes. AFM and SEM were used as additional techniques for study LiCoO2 a Li0,975K0,025CoO2. We tested lifetime and stability of electrode as a perspective material for electrode for Li-ion batteries.

APA, Harvard, Vancouver, ISO, and other styles

15

Kulíková, Barbora. "Sledování vlivu teploty na vlastnosti lithium-iontové baterie." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-399541.

Full text

Abstract:

This Master’s thesis deals with a monitoring of the temperature influence on Li-ion batteries, literature search of this topic and proposal of experiments. First chapter contains the theory of evolution and fundamentals of the Li-ion batteries. Planned experiments with flow charts and block diagrams are described in the second chapter. The work station is explained along with a description of the execution of the experiments in the third chapter. The experiments are analyzed and results explained in the last chapter.

APA, Harvard, Vancouver, ISO, and other styles

16

Pisca, Marek. "Tester akumulátorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220712.

Full text

Abstract:

This master´s thesis is dealing with the theory of Li-ion accumulators and theirs charching. In this thesis has been designed accumulator tester for automatic charging and discharging of Li-ion accumulator. This tester is controlled by microprocessor.

APA, Harvard, Vancouver, ISO, and other styles

17

Sahani, Nitasha. "Optimal Charging Scheduling for Electric Vehicles Based on a Moving Horizon Approach." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/96544.

Full text

Abstract:

The rapid escalation in plug-in electric vehicles (PEVs) and their uncoordinated charging patterns pose several challenges in distribution system operation. Some of the undesirable effects include overloading of transformers, rapid voltage fluctuations, and over/under voltages. While this compromises the consumer power quality, it also puts on extra stress on the local voltage control devices. These challenges demand a well-coordinated and power network-aware charging approach for PEVs in a community. This paper formulates a realtime electric vehicle charging scheduling problem as a mixed-integer linear program (MILP). The problem is to be solved by an aggregator that provides charging services in a residential community. The proposed formulation maximizes the profit of the aggregator, enhancing the utilization of available infrastructure. With prior knowledge of load demand and hourly electricity prices, the algorithm uses a moving time horizon optimization approach, allowing an unknown number of arriving vehicles. In this realistic setting, the proposed framework ensures that power system constraints are satisfied and guarantees the desired PEV charging level within the stipulated time. Numerical tests on an IEEE 13-node feeder system demonstrate the computational and performance superiority of the proposed MILP technique.
M.S.
There is an enhanced rate of global warming due to emissions and increased usage of fossil fuels in the transportation sector. As a feasible solution, electrification of transportation has become a necessary step towards an environment-friendly future. The escalation in plug-in electric vehicles (PEVs) has increased the impact on loading and voltage fluctuations in the distribution grid due to uncoordinated charging. This puts on extra stress on the grid system and compromises the system performance. As a measure to control the vehicle charging in a residential setup, a real-time optimal charging scheduling algorithm is developed which is implemented at the neighborhood level. To increase the charging performance with the limited available resources, an aggregator is introduced. The charging profit is maximized as the PEV charging problem is solved optimally by the aggregator. This facilitates the reduction in night-time grid congestion and maximization of number of PEVs getting charged with limited dependency on communication to avoid long delays in charging control. The proposed technique guarantees the complete charging of the selected PEVs in the stipulated time while considering the power grid operational constraints. It also reduces the impact of peak load demand by flattening the base load demand curve. To demonstrate the efficiency of the proposed mixed integer linear programming optimization algorithm, numerical tests for an IEEE 13 node feeder are performed. The results are discussed to give an outlook on the balance between system and user requirements by meeting the demand of the PEV users.

APA, Harvard, Vancouver, ISO, and other styles

18

Prachař, Vojtěch. "Inteligentní Li-ion akumulátor." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377066.

Full text

Abstract:

The thesis deals with lithium accumulators with electronics, which are composed to a unit called Intelligent Battery. Within this thesis, the main features of these accumulators are explained and the circuit to monitor these accumulators has been designed and manufactured, it can disconnect them when the parameters are exceeded, and it stores the history of the battery measurement in memory. It also allows reading of current and logged battery data via UART. The computer application is designed for communication, to display the information and to adjust the battery circuit parameters. The electronics secure charging when the 24V adapter is connected according to the set parameters and it also secure balancing of the individual accumulators.

APA, Harvard, Vancouver, ISO, and other styles

19

Tonar, Karel. "Zkoumání uhlíku jako aditiva záporné aktivní hmoty olověného akumulátoru pro hybridní elektrická vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218568.

Full text

Abstract:

The lead-acid bateries for hybrid-electric vehicle (HEV) working under high-rate partial-state-of-charge (HRPSoC) conditions. The negative plates of lead-acid batteries have low charge acceptance. The cycle life of the batteries is dependent on the rate accumulation of PbSO4 on the negative plates. Addition of some carbon or graphite forms to the negative paste mix improves the charge efficieny and slows down sulfation of the negative plates. The master’s thesis wants to explain the contribution of electrochemically active carbon (EAC) additives to the mechanis of the electrochemical reaction of charge of the negative plates.

APA, Harvard, Vancouver, ISO, and other styles

20

Lei, Guo. "Value of time and marginal driving costs for private car drivers with data from Stockholm congestion charging trial." Thesis, KTH, Transportvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-41550.

Full text

Abstract:

This paper uses Logit models to estimate value of time of car drivers' route choice with evidence from the Stockholm congestion charging trial. Two sets of models are estimated respectively, one is for trips whose purposes are working or running business, the other is for trips who purpose are other activities. In addition, there are two stages of model estimation. At first, the model only includes traffic characteristic variables to differentiate among trips, which includes travel time, travel distance, and congestion tolls. Thus values of time estimated are 176 SEK/h, and 184 SEK/h for working trips and other trips. Further on, socio-economic variables are also involved, along with traffic characteristic variables, in the model to differentiate among both individuals and trips. Significant socio-economic variables include household income, age, gender, access to workplace vehicles, working flexibility and so on. Results of average aggregated value of time are almost the same with the results in basic models, which is reasonable since it’s the same dataset. However, the later model shows more variation in terms of individuals.

APA, Harvard, Vancouver, ISO, and other styles

21

Přívozník, Tomáš. "Vliv přítlaku a aditiv na životnost olověného akumulátoru pro hybridní elektrická vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219748.

Full text

Abstract:

This master’s thesis deals with lead acid battery in hybrid electric vehicles which operating at mode of partial state of charge (PSoC). In this mode, there is often a negative electrode degradation mostly due to irreversible mechanism of suphation. The idea of this work is detect ideal value of mechanical pressure exerted on active mass of negative electrode in combination with additives to prevent mechanism of sulphation and lead to increased cycle life of lead acid battery.

APA, Harvard, Vancouver, ISO, and other styles

22

Vojtíšek, Miloš. "Studium vnitřního odporu článku olověného akumulátoru pro hybridní elektrická vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220111.

Full text

Abstract:

This work aims on acumulators for hybrid vehicles and deals particularly with research of inner-resistance of the lead-acid batteries. There is a brief characterization of hybrid cars in first part of the tesis. Second part is dealing with design of experimental measurement setup for measurement of lead-acid electrochemical cells. Set of experiments on several cells was performed, description of experiments and results in graphical form are present.

APA, Harvard, Vancouver, ISO, and other styles

23

Čada, Miroslav. "Vliv různých typů AGM separátorů na parametry olověných akumulátorů pro hybridní elektrická vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220075.

Full text

Abstract:

The most used type of the secondary energy sources is the lead-acid accumulator today. It is also used as a propulsion in hybrid electric vehicles. Functional principle stayed same as in foundation time, only parameters are still improving. Lifetime of lead-acid accumulator is influenced by used separator. The work deals with the description of properties of lead acid separators, methods of testing and evaluation of the suitability for use.

APA, Harvard, Vancouver, ISO, and other styles

24

Zimmerman, Nicole P. "Time-Variant Load Models of Electric Vehicle Chargers." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2297.

Full text

Abstract:

In power distribution system planning, it is essential to understand the impacts that electric vehicles (EVs), and the non-linear, time-variant loading profiles associated with their charging units, may have on power distribution networks. This research presents a design methodology for the creation of both analytical and behavioral models for EV charging units within a VHDL-AMS simulation environment. Voltage and current data collected from Electric Avenue, located on the Portland State University campus, were used to create harmonic profiles of the EV charging units at the site. From these profiles, generalized models for both single-phase (Level 2) and three-phase (Level 3) EV chargers were created. Further, these models were validated within a larger system context utilizing the IEEE 13-bus distribution test feeder system. Results from the model's validation are presented for various charger and power system configurations. Finally, an online tool that was created for use by distribution system designers is presented. This tool can aid designers in assessing the impacts that EV chargers have on electrical assets, and assist with the appropriate selection of transformers, conductor ampacities, and protection equipment & settings.

APA, Harvard, Vancouver, ISO, and other styles

25

Saifuzzaman, Mohammad. "Modelling the effects of Stockholm Congestion Charges – A comparison of the two dynamic models: Metropolis and Silvester." Thesis, KTH, Transportvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-42355.

Full text

Abstract:

Congestion charging has drawn considerable attention of transport analysts and policymakers as a mean of relieving urban traffic congestion. Proper prediction of the impacts of charging is necessary for policy makers to take right decisions. A European project named SILVERPOLIS have been introduced in this connection to describe state-of-practice in modelling effects of congestion charging and to identify features of transport models that are crucial for reliable forecasting of effects of congestion charging. This master thesis is a part of the SILVERPOLIS project, where Stockholm congestion charging scheme has been analysed using two different types of dynamic simulators: METROPOLIS and SILVESTER. The simulations are based on traffic data collected before and after the Stockholm congestion charging trial performed in spring 2006. The result of simulation suggests that METROPOLIS, which has been used for predicting effects of congestion charging in Ile-de-France, manages well to forecast the consequences of congestion charging for Stockholm. Comparison with SILVESTER model disclosed that, although calibration results of the two models differs in some respect, both models give similar results regarding impacts of congestion charging. The different modelling features and assumptions have been described for the two models. Despite the fact that the two models vary a lot in their assumptions and modelling style, both of them has proved to be good at describing the effect of congestion charging.

APA, Harvard, Vancouver, ISO, and other styles

26

Řihák, Pavel. "Zkoumání vlivu oxidu titaničitého na životnost olověných akumulátorů s aplikovaným přítlakem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220183.

Full text

Abstract:

Hybrid electric vehicles use lead acid batteries operating under partial charge. Battery life of these batteries is dependent on the speed of development of lead sulphate (PbSO4) to the negative electrodes. Different admixtures are affected battery life. This work deals with the influence of titanium dioxide on the negative active material in lead battery. Mainly devoted to the influence of the applied pressure.

APA, Harvard, Vancouver, ISO, and other styles

27

Ali, Haider Adel Ali, and Ziad Namir Abdeljawad. "THERMAL MANAGEMENT TECHNOLOGIES OF LITHIUM-ION BATTERIES APPLIED FOR STATIONARY ENERGY STORAGE SYSTEMS : Investigation on the thermal behavior of Lithium-ion batteries." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-48904.

Full text

Abstract:

Batteries are promising sources of green and sustainable energy that have been widely used in various applications. Lithium-ion batteries (LIBs) have an important role in the energy storage sector due to its high specific energy and energy density relative to other rechargeable batteries. The main challenges for keeping the LIBs to work under safe conditions, and at high performance are strongly related to the battery thermal management. In this study, a critical literature review is first carried out to present the technology development status of the battery thermal management system (BTMS) based on air and liquid cooling for the application of battery energy storage systems (BESS). It was found that more attention has paid to the BTMS for electrical vehicle (EV) applications than for stationary BESS. Even though the active forced air cooling is the most commonly used method for stationary BESS, limited technical information is available. Liquid cooling has widely been used in EV applications with different system configurations and cooling patterns; nevertheless, the application for BESS is hard to find in literature.To ensure and analyze the performance of air and liquid cooling system, a battery and thermal model developed to be used for modeling of BTMS. The models are based on the car company BMW EV battery pack, which using Nickel Manganese Cobalt Oxide (NMC) prismatic lithium-ion cell. Both air and liquid cooling have been studied to evaluate the thermal performance of LIBs under the two cooling systems.According to the result, the air and liquid cooling are capable of maintaining BESS under safe operation conditions, but with considering some limits. The air-cooling is more suitable for low surrounding temperature or at low charging/discharge rate (C-rate), while liquid cooling enables BESS to operate at higher C-rates and higher surrounding temperatures. However, the requirement on the maximum temperature difference within a cell will limits the application of liquid cooling in some discharge cases at high C-rate. Finally, this work suggests that specific attention should be paid to the pack design. The design of the BMW pack is compact, which makes the air-cooling performance less efficient because of the air circulation inside the pack is low and liquid cooling is more suitable for this type of compact battery pack.

APA, Harvard, Vancouver, ISO, and other styles

28

Kubizňák, Jan. "Bezobslužná nabíjecí stanice pro elektromobily." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218357.

Full text

Abstract:

The subject of this diploma thesis is a creation of SW for the self-service charging station of ELNICO Ltd. company. The work consists of two main parts. The first part contains an overview of general charging stations for electro cars at current market. After this the prototype of the ELNICO system is described. It's main components and the control system realized by the development kit DK-LM3S9B96 are characterized here. The real-time operating system FreeRTOS, that is used by the kit, is also specified. The second part of the document deals with the SW design and realization. The thesis describes the structure and the main modules of the program. The functionality is then demonstrated by photos of running application.

APA, Harvard, Vancouver, ISO, and other styles

29

Karlén, Albin, and Sebastian Genas. "Marginaler för morgondagen : En kvantitativ analys av flexibiliteten hos aggregerade laddande elbilar." Thesis, Linköpings universitet, Energisystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177967.

Full text

Abstract:

Elektrifieringen av bilflottan sker i rasande takt. Även andra samhällssektorers efterfrågan på el väntas öka drastiskt under kommande decennier, vilket i kombination med en växande andel intermittenta energikällor trappar upp påfrestningarna på elnätet och ställer krav på anpassningar. En föreslagen dellösning till kraftsystemets kommande utmaningar är att utnyttja efterfrågeflexibiliteten i laddande elbilar genom att en aggregator styr ett stort antal elbilsladdare och säljer den sammanlagda kapaciteten på till exempel Svenska kraftnäts stödtjänstmarknader. För att avgöra hur mycket flexibilitet som elbilsladdning kan bidra med behöver aggregatorn upprätta prognoser över hur mycket effekt som mest sannolikt finns tillgänglig vid en viss tidpunkt – en punktprognos – men också en uppskattning av vilken effektnivå man kan vara nästan säker på att utfallet överstiger – en kvantilprognos. I den här studien har en undersökning gjorts av hur prognosfelet förändras om gruppen av aggregerade elbilsladdare ökas, och hur mycket en aggregator på så sätt kan sänka sina marginaler vid försäljning av efterfrågeflexibiliteten för att med säkerhet kunna uppfylla sitt bud. Det gjordes genom att kvantifiera flexibiliteten för 1 000 destinationsladdare belägna vid huvudsakligen arbetsplatser, och genom att skala upp och ner datamängden genom slumpmässiga urval. För dessa grupper gjordes sedan probabilistiska prognoser av flexibiliteten med en rullande medelvärdes- och en ARIMA-modell. Utifrån prognoserna simulerades slutligen potentiella intäkter om aggregatorn skulle använda den flexibla kapaciteten för uppreglering till stödtjänsten FCR-D upp, vilket är en frekvensreserv som aktiveras vid störningar av nätfrekvensen. Resultaten visar att en tiodubbling av antalet aggregerade elbilsladdare mer än halverar det relativa prognosfelet. De båda prognosmodellerna visade sig ha jämförbar precision, vilket talar för att använda sig av den rullande medelvärdesmetoden på grund av dess lägre komplexitet. Den ökade säkerheten i prognosen resulterade dessutom i högre intäkter per laddare. De genomsnittliga intäkterna av att leverera flexibilitet från 1 000 aggregerade elbilsladdare till FCR-D uppgick till 6 900 kr per månad, eller 0,8 kr per session – siffror som troligen hade varit högre utan coronapandemins ökade hemarbete. En 99-procentig konfidensgrad för kvantilprognosen resulterade i en säkerhetsmarginal med varierande storlek, som i genomsnitt var runt 90 procent för 100 laddpunkter, 60 procent för 1 000 laddpunkter samt 30 procent för 10 000 laddpunkter. Mest flexibilitet fanns tillgänglig under vardagsförmiddagar då ungefär 600 kW fanns tillgängligt som mest för 1 000 laddpunkter. Att döma av tio års nätfrekvensdata är den sammanlagda sannolikheten för att över 50 procent aktivering av FCR-D-budet skulle sammanfalla med att utfallet för den tillgängliga kapaciteten är en-på-hundra-låg i princip obefintlig – en gång på drygt 511 år. Att aggregatorn lägger sina bud utifrån en 99-procentig konfidensgrad kan alltså anses säkert.
The electrification of the car fleet is taking place at a frenetic pace. Additionally, demand for electricity from other sectors of the Swedish society is expected to grow considerably in the coming decades, which in combination with an increasing proportion of intermittent energy sources puts increasing pressure on the electrical grid and prompts a need to adapt to these changes. A proposed solution to part of the power system's upcoming challenges is to utilize the flexibility available from charging electric vehicles (EVs) by letting an aggregator control a large number of EV chargers and sell the extra capacity to, for example, Svenska kraftnät's balancing markets. To quantify how much flexibility charging EVs can contribute with, the aggregator needs to make forecasts of how much power that is most likely available at a given time – a point forecast – but also an estimate of what power level the aggregator almost certainly will exceed – a quantile forecast. In this study, an investigation has been made of how the forecast error changes if the amount of aggregated EV chargers is increased, and how much an aggregator can lower their margins when selling the flexibility to be able to deliver according to the bid with certainty. This was done by quantifying the flexibility of 1000 EV chargers located at mainly workplaces, and by scaling up and down the data through random sampling. For these groups, probabilistic forecasts of the flexibility were then made with a moving average forecast as well as an ARIMA model. Based on the forecasts, potential revenues were finally simulated for the case where the aggregator uses the available flexibility for up-regulation to the balancing market FCR-D up, which is a frequency containment reserve that is activated in the event of disturbances. The results show that a tenfold increase in the number of aggregated EV chargers more than halves the forecast error. The two forecast models proved to have comparable precision, which suggests that the moving average forecast is recommended due to its lower complexity compared to the ARIMA model. The increased precision in the forecasts also resulted in higher revenues per charger. The average income from delivering flexibility from 1000 aggregated electric car chargers to FCR-D amounted to SEK 6900 per month, or SEK 0.8 per session – figures that would probably have been higher without the corona pandemic's increased share of work done from home. A 99 percent confidence level for the quantile forecast resulted in a safety margin of varying size, which on average was around 90 percent for 100 chargers, 60 percent for 1000 chargers and 30 percent for 10,000 chargers. Most flexibility was shown to be available on weekday mornings when approximately 600 kW was available at most for 1000 chargers. By examining frequency data for the Nordic power grid from the past ten years, the joint probability that a more than 50 percent activation of the FCR-D bid would coincide with the outcome for the available capacity being one-in-a-hundred-low, was concluded to be nearly non-existent – likely only once in about 511 years. For the aggregator to place bids based on a 99 percent confidence level can thus be considered safe.

APA, Harvard, Vancouver, ISO, and other styles

30

Pospíchal, Martin. "Vliv přítlaku na životnost olověných akumulátorů u hybridních elektrických vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219878.

Full text

Abstract:

The lead-acid batteries used in hybrid electronic vehicles HEV operate in high-rate mode in a state of partial charge PSoC. It occurs when the degradation mechanisms related to irreversible sulphation and negative electrodes are a limiting factor in the life of lead-acid batteries. The electrode system was applied to experimental pressure cells of different sizes. Exp. cells were subjected to measurement and evaluation of potential negative electrode, a negative active mass resistance, contact resistance of transition collector - the active mass with the evaluation and measurement of pressure fluctuations within four PSoC runs.

APA, Harvard, Vancouver, ISO, and other styles

31

Alghamdi, Turki. "Interactions of Connected Electric Vehicles with Modern Power Grids in Smart Cities." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42513.

Full text

Abstract:

In a smart city, it is vital to provide a clean and green environment by curbing air pollution and greenhouse gas emissions (GHGs) from transportation. As a recent action from many governments aiming to minimize transportation’s pollution upon the climate, new plans have been announced to ban cars with gas engines throughout the world. Therefore, it is anticipated that the presence of electric vehicles (EVs) will grow very fast globally. Consequently, the necessity to establish electric vehicle supply equipment (EVSE) in the smart city through public charging stations is growing incrementally year by year. However, the EV charging process via EVSE which is primarily connected to the power grid will put high pressure upon the centralized power grid, especially during peak demand periods. Increasing the power production of power grid will increase the environmental impact. Therefore, it is fundamental for the smart city to be equipped with a modern power grid to cope with the traditional power grid’s drawbacks. In this thesis, we conduct an in-depth analysis of the problem of EVs’ interaction with the modern power grid in a smart city to manage and control EV charging and discharging processes. We also present various approaches and mechanisms toward identifying and investigating these challenges and requirements to manage the power demand. We propose novel solutions, namely Decentralized-EVSE (D-EVSE), for EVs’ charging and discharging processes based on Renewable Energy Sources (RESs) and an energy storage system. We present two algorithms to manage the interaction between EVs and D-EVSE while maximizing EV drivers’ satisfaction in terms of reducing the waiting time for charging or discharging services and minimizing the stress placed on D-EVSE. We propose an optimization model based on Game Theory (GT) to manage the interaction between EVs and D-EVSE. We name this the decentralized-GT (D-GT) model. This model aims to ﬁnd the optimal solution for EVs and D-EVSE based on the concept of win-win. We design a decentralized proﬁt maximization algorithm to help D-EVSE take proﬁt from the electricity price variation during the day when selling or buying electricity respectively to EVs or from the grid or EVs as discharging processes. We implement different scenarios to these models and show through analytical and simulation results that our proposed models help to minimize the D-EVSE stress level, increase the D-EVSE sustainability, maximize the D-EVSE proﬁt, as well as maximize EV drivers’ satisfaction and reduce EVs’ waiting time.

APA, Harvard, Vancouver, ISO, and other styles

32

Konečný, Zdeněk. "Vliv oxidu titaničitého na vlastnosti olověných akumulátorů pracujících v režimu hybridních vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219871.

Full text

Abstract:

This work deals with lead-acid batteries operating in hybrid electric vehicles mode, i.e. in a partial state of charge. The adverse effects such as premature capacity loss and large internal resistance can markedly affect the life of a lead battery. The experiment described in this work aims to clarify the influence of the titanium dioxide in the active mass of negative electrodes especially in the life of lead acid batteries.

APA, Harvard, Vancouver, ISO, and other styles

33

Cirkovský, Jaroslav. "Vliv iontů manganu ve struktuře hydroxidu nikelnatého na vlastnosti elektrod." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218706.

Full text

Abstract:

The aim of my diploma thesis was to explore the influence of manganese ions put into nickel nitrate structure. The attention was focused mainly on the stabilization of nickel nitrate a modification, which could not change into b modification. The theoretical part of my thesis focused on applied materials, kinds of acumulators, basic parameters of acumulators and the description of chosen methods of measurement employed. It contained the electrodeposition, the impedance spectroscopy and the cyclic voltammetry. The task of the experimental part was to measure the effect of manganese ions put into potassium hydroxide structure. Proportions of Ni (nickel nitrate) : Mn (manganese nitrate) 10:0, 7:3, 5:5, 6:1 and 6:4 were blended for the measurement. By means of the electrodeposition, there was a thin layer of nickel hydroxide with an admixture of manganese ions from nickel nitrate and manganese nitrate dilution put on the nickel plate. After the spread of the thin layer on the nickel plate, the measurement by the method of cyclic voltammetry followed. The next task consisted in trying to add KOH (potassium hydroxide) anionic and cationic surfactant into the dilution.

APA, Harvard, Vancouver, ISO, and other styles

34

Georgescu, Ionut. "Rare-gas clusters in intense VUV laser fields." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1226316004337-66645.

Full text

Abstract:

A hybrid quantum-classical approach to the interaction of atomic clusters with intense laser fields in the vacuum ultra-violet (VUV) has been developed. Much emphasis is put on localized electrons, those quasi-free electrons which localize about the ions and screen them. These electrons set a time scale, which is used to interpolate between the quantum, rate based description of photon absorption by bound electrons and the classical, deterministic description of the cluster nano-plasma. Typical observables such as total energy absorption, electron and ion spectra are in very good agreement with the experimental findings. A scheme to probe the multi-electron motion in clusters with attosecond laser pulses is introduced. Conventional final state measurements in the energy domain cannot provide information about earlier states of the system due to the incoherent nature of the dynamics. Time-delayed attosecond pulses in the extreme ultra-violet (XUV) are used to probe the transient charging of the cluster ions during the interaction with the laser by measuring the kinetic energy of the electrons detached by the probe pulse. This information is otherwise lost at later times due to recombination. Knowledge about the transient charging would also shed more light on the still controversial subject of the energy absorption mechanisms in the VUV regime. Moving to shorter duration of the excitation, the characteristic time-scales for ionization and plasma equilibration are inversed. An attosecond laser pulse in the VUV regime creates a dense, warm nano-plasma far from equilibrium. Time-delayed attosecond pulses in the XUV probe then both the creation and the relaxation. The latter shows the breakup of the Bogoliubov hierarchy of characteristic times, indicating strongly-coupled plasma dynamics and drawing parallels to the relaxation of extended ultra-cold neutral plasmas with millions of particles.

APA, Harvard, Vancouver, ISO, and other styles

35

Georgescu, Ionut. "Rare-gas clusters in intense VUV laser fields." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A24072.

Full text

Abstract:

A hybrid quantum-classical approach to the interaction of atomic clusters with intense laser fields in the vacuum ultra-violet (VUV) has been developed. Much emphasis is put on localized electrons, those quasi-free electrons which localize about the ions and screen them. These electrons set a time scale, which is used to interpolate between the quantum, rate based description of photon absorption by bound electrons and the classical, deterministic description of the cluster nano-plasma. Typical observables such as total energy absorption, electron and ion spectra are in very good agreement with the experimental findings. A scheme to probe the multi-electron motion in clusters with attosecond laser pulses is introduced. Conventional final state measurements in the energy domain cannot provide information about earlier states of the system due to the incoherent nature of the dynamics. Time-delayed attosecond pulses in the extreme ultra-violet (XUV) are used to probe the transient charging of the cluster ions during the interaction with the laser by measuring the kinetic energy of the electrons detached by the probe pulse. This information is otherwise lost at later times due to recombination. Knowledge about the transient charging would also shed more light on the still controversial subject of the energy absorption mechanisms in the VUV regime. Moving to shorter duration of the excitation, the characteristic time-scales for ionization and plasma equilibration are inversed. An attosecond laser pulse in the VUV regime creates a dense, warm nano-plasma far from equilibrium. Time-delayed attosecond pulses in the XUV probe then both the creation and the relaxation. The latter shows the breakup of the Bogoliubov hierarchy of characteristic times, indicating strongly-coupled plasma dynamics and drawing parallels to the relaxation of extended ultra-cold neutral plasmas with millions of particles.

APA, Harvard, Vancouver, ISO, and other styles

36

Papaix, Claire. "Mise en œuvre des instruments de politique publique allant dans le sens d’une mobilité bas carbone des personnes en milieu urbain." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST0059.

Full text

Abstract:

Cette thèse s'intéresse à la réconciliation entre le défi mondial du changement climatique et les solutions locales et sectorielles qu'il convient de bien articuler pour contribuer, efficacement, équitablement et de la manière la plus acceptable, à la réduction des émissions de CO2. Plus précisément, nous étudions les conditions pour une mise en place réussie de la politique climatique à l'échelle de la mobilité urbaine des personnes
This PhD thesis deals with the reconciliation of the global challenge that is climate change and the local and sectoral solutions that need to be accurately designed to remedy to it the most efficiently, equitably and acceptably possible. More specifically, we investigate the conditions for a successful implementation of climate policy at the scale of the urban mobility of passengers

APA, Harvard, Vancouver, ISO, and other styles

37

Leitman, Valentín. "Koncept nabíjecí stanice s možností off-grid provozu pro elektrokola." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-319544.

Full text

Abstract:

This thesis deals with charging stations for electric bicycles powered by renewable energy. The aim of this work is to make a proposal for the hybrid charging stations for electric bicycles, which will work independently and, if necessary, will be backed up by a network. In this thesis is entered theoretical information on the issue of electric bicycles, the batteries, charging stations, the connectors of chargers, and photovoltaic systems. The practical part of this thesis is the basic design of the charging station and its design of the mathematical model of the individual parts in Simulink program, which are linked to the actual design of the charging station. In conclusion, this thesis deals with energy and economic analysis of the proposed system, therein included various methods of assessing investment recommendations of appropriate processing methods and overall assessment of the subject.

APA, Harvard, Vancouver, ISO, and other styles

38

KUMAR, NITIN. "PERFORMANCE ANALYSIS OF LATENT HEAT THERMAL ENERGY STORAGE SYSTEM USING FINS." Thesis, 2023. http://dspace.dtu.ac.in:8080/jspui/handle/repository/19964.

Full text

Abstract:

The Purpose of the current work is to examine the performance of a PCM i.e. phase change material within a Trapezoidal shape unit to store heat energy. The Numerical simulation is done using ANSYS 22 software to simulate and analyze the results, focusing on temperature and time contours throughout melting part and solidification part of PCM. Storage unit features a square shape tube in which fins are attached to the tube to study the HTR. One main challenge encountered in PCM melting is the collection of solid material at the lowermost in a process of charging and LF rests at the uppermost during the process of discharging. The numerical simulation explains the temperature distribution across various ranges during the melting and solidification phases. The system's effectiveness and performance are enhanced by using this setup. The simulation's results show that throughout the melting process, the liquid percentage rapidly grows, reaching 78% during the first 250 minutes. This is because heat is transferred through convection and conduction. However, after then, heat is transferred primarily through conduction, which results in a decline in the rate of liquid fraction and a total melting time of 2390 minutes for the PCM. In a similar manner, following the first 250 minutes of discharge, the solid percentage increases more slowly, solidifying to about 34%. However, it takes 1660 minutes for the PCM to fully solidify. The study's finding show that using a trapezoidal form geometry and including fins may enhance the melting and solidification part for a TESs.

APA, Harvard, Vancouver, ISO, and other styles

39

Huang, You-chun, and 黃宥鈞. "Charging/discharging circuit for battery test system." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/66d77h.

Full text

Abstract:

碩士
國立中山大學
電機工程學系研究所
106
In the conventional battery test system, charging and discharging currents go through several stages of AC-to-DC and DC-to-DC power converters causing power conversion losses during formatting and grading processes. An H-bridge converter is interleaved between two tested batteries, which are paired up to counterbalance the charging and discharging powers by properly arranging the manufacturing schedule. To cope with the designated formatting and grading profiles, each battery is attached by a bidirectional flyback converter to complement the insufficient current into or remove the excessive current from the tested battery. A great amount of energy can be saved in battery production for a battery test system with fewer power conversion stages and less power transfer between the tested batteries and the DC-bus. Experiments on two pair-up batteries with the proposed charging/discharging circuit are conducted to accomplish the profiles of constant-current discharging and constant-current constant-voltage charging. Experimental results demonstrate that the power losses can be effectively reduced by 50 % during the grading process as compared with that of the conventional battery test system.

APA, Harvard, Vancouver, ISO, and other styles

40

Syu, Kai-Chen, and 徐愷辰. "SPICE Model of Battery Charging and Discharging." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/fyk7f9.

Full text

Abstract:

碩士
國立交通大學
機械工程系所
107
Battery is the most widely used electrical energy storage device nowadays. From electronics such as notebook computers, mobile phones and remote controls to high-power devices such as uninterruptible power systems, airplanes and electric vehicles, battery applications can be seen. The capacitor of a battery is the most concerned information about the use of batteries. In the past, battery models often obtained the relationship between the capacity and the battery terminal voltage through experimental measurements and used polynomial or table lookup. The disadvantage is that the correlation between the battery model and the physical world is lacking. In this study a new battery model base on different combination structure of capacitors is used to analogous to the relationship between battery voltage and the capacity. Batteries are charged/discharge by the electronically load. Record the terminal voltage and current to obtain the charging/discharging curve of the battery. Analysis the relationship between the voltage and experimental result and finds the of the battery variable capacitance equivalent circuit model of the battery under test.

APA, Harvard, Vancouver, ISO, and other styles

41

Liu, Feng-Chi, and 劉峰其. "Nonlinear Lithium Battery Modelsfor Battery Charging and Discharging." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/89841116009443647499.

Full text

Abstract:

碩士
國立中央大學
電機工程研究所
98
Nowadays, lithium battery circuit models, some are too simple, can not simulate the cycle time and temperature effects. One with fully functioning model can only simulate discharging behavior, not charging. In addition, at this stage, circuit models are only for specific manufacturer, not an universal solution. This paper presents the circuit model for both battery charging and discharging. Based on the manufacturer’s data sheet, the model parameters are extracted to derive the coefficients of the expressions of the major components in the circuit model. This experiment used Lithium iron phosphate ion battery for a comparison. Results show that, at the battery discharging and charging conditions, the errors between the measurement results and the simulated results. In discharging condition, when the battery voltage reaches cut-off voltage 2.5V, the time is 6480 seconds, the error is 3.12%. And the maximum error voltage is 16mV, in 0.501%. In charging condition, when the battery voltage reaches a predetermined nomial voltage 3.65V, the time is 2880 seconds, the error is 0.712%. And the maximum error voltage is 37mV, in 1.072%. Thus, the proposed circuit model can be used for battery simulation. It not only diminishes the risk of experimental safety but also decreases the cost from battery manufacturer.

APA, Harvard, Vancouver, ISO, and other styles

42

Wan-YiHorng and 洪琬宜. "Balance Charging/Discharging Method for Series-Connected Batteries." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/29600486172482592417.

Full text

Abstract:

碩士
國立成功大學
電機工程學系碩博士班
101
A novel balancing method for series connected batteries is proposed in this thesis. A balancing circuit applying this method is activated when the voltage of the corresponding cell reaches rated charge or discharge voltage. Based on the cell voltage, this method does not suffer the problem, occurring in conventional methods, of overcharge or overdischarge due to estimation errors of state-of-charge (SOC). In addition, the control circuit and designing process is simple without current feedback. The operating principles and energy transferring patterns for series connected batteries system and battery module system are analyzed. A flyback converter with the leakage inductance recycling mechanism is adopted as balancing circuit to realize the proposed method. Finally, a battery module composed of four series 3.3-V 15-Ah lithium iron phosphate (LiFePO4) batteries, balancing circuits for each battery, and a bidirectional converter is implemented to demonstrate the feasibility of the proposed balancing method.

APA, Harvard, Vancouver, ISO, and other styles

43

Yi-YuanChung and 鍾義元. "Voltage Clamping Balance for Charging/Discharging Battery Module." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/5kyae4.

Full text

Abstract:

碩士
國立成功大學
電機工程學系
102
Battery power module (BPM) plays an important role in the applications of rechargeable batteries for its great flexibility and high reliability. Moreover, the unbalance phenomenon between batteries in different BPMs can be eliminated by controlling the power flow though BPMs. In conventional BPM balancing method, the output current between BPMs is distributed according to the state of charge (SOC) of each BPM. However, the accurate SOC is difficult to evaluate and the control scheme for battery balance is very complex. In order to solve these problems, this thesis proposes a battery system composed of several BPMs and a central control circuit with a novel battery balancing method. The control circuit of the battery system manages the input current/output voltage by adjusting the input/output power of battery modules. There are many advantages in the proposed method, including large total discharging capacity, simple control scheme, highly reliable and can be achieved without evaluating SOC. The BPM in this thesis is composed of four LiFePO4 batteries and a bidirectional converter. The central control circuit in the BPM is realized by using an analog IC to regulate the output voltage of the system or achieve the charging function of BPMs. Finally, the experimental results of the battery charging/discharging verify the feasibility of the proposed battery balancing method and high system reliability.

APA, Harvard, Vancouver, ISO, and other styles

44

Lin, Yi-quan, and 林憶全. "Experiment of Charging and Discharging Strategies forRe-used Battery." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/p227wp.

Full text

Abstract:

碩士
國立中山大學
電機工程學系研究所
107
Energy storage systems are considered important in the integration of large scale renewables in the power system. However, due to their high initial cost, the deployment of batteries in large renewable power plants to smooth the intermittent outputs are less popular. Due to the adoption of electrified transportation, large amount of used electrical vehicle batteries with state-of-health (SOH) that is good enough for backup power applications are becoming available. In this thesis, a DC-DC converter considering various levels of SOH and state-of-charge (SOC) of used batteries, a charging and discharging strategy is proposed to fully utilize the second life of the batteries. The control algorithm adopted is to seek for the equality of the SOC during the charging and discharging process such that the left capacity of the batteries could be fully utilized. Study results indicate that using the proposed strategies, it can reduce the initial cost of storage system to satisfy the load requirement and increase value of the batteries.

APA, Harvard, Vancouver, ISO, and other styles

45

Wu, Huai-De, and 吳懷德. "STUDY OF CHARGING/DISCHARGING CONTROL SYSTEMS FOR LEAD-ACID BATTERYZENG." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/97383621864833301370.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Chen, Cheng-Ping, and 陳正平. "Dynamics Analysis and Controller Design for Battery Charging and Discharging." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/5s4q2j.

Full text

Abstract:

碩士
國立臺北科技大學
電機工程系研究所
100
This paper uses half bridge converter structure and PWM signal to control DC / DC converter high side and low side MOSFET switches. The proposed technique can achieve bi-direction energy transmission where the battery is charged when an outer source is attached, whereas the battery can also provide stable voltage when a load is attached. In order to ensure both charge and discharge modes can work well, we start from the state equations, derive the error equations, and find controller parameters. Then we can implement battery charge and discharge controller using the same state feedback gains. We use simulation software to verify feasibility and apply the obtained controller parameters on actual circuit to achieve both charge and discharge purpose. This structure is with advantages of simplifying circuit structure and cost reducing.

APA, Harvard, Vancouver, ISO, and other styles

47

Yeh, Ing-Jye, and 葉英杰. "Contactless Bidirectional Charging and Discharging System for Complex Apartment Parking Lot." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/80524863341916671928.

Full text

Abstract:

碩士
國立中興大學
電機工程學系所
101
Contactless bidirectional charge and discharge technologies are promising technologies to be used in the vehicles which could be used to extend the usage of energy stored in the vehicle battery. As daily life of the vehicle battery is charged by the combustion engine, battery energy is mostly stayed in the saturated status. Since most energy requirement is provided by the alternator, energy stored in the battery is not fully used which causes a waste of energy. The purpose of this thesis is to develop a contactless charging and discharging system for the vehicle which is able to send the excessive battery energy to the energy storage system in the complex apartment parking lot and is able to be rechanged from the energy storage system. The idea "Many a little makes a mickle" to accumulate all vehicles’ excessive battery energy to boost the use of battery energy. To verify applicability of this energy conversion system, the simulation study has been conducted using the Protel Altium Designer 10 Software, which is used to select the components and determine related parameter values. Hardware implementation is also presented. Keywords: contactless bidirectional charging and discharging device, magnetic energy conversion, the resonant circuit

APA, Harvard, Vancouver, ISO, and other styles

48

Cheng, Hung-Wei, and 鄭弘偉. "Optimal Charging and Discharging Control for Electric Vehicles in Parking Lot." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/hrjm85.

Full text

Abstract:

碩士
國立臺北科技大學
自動化科技研究所
102
Recently, there are a lot of issues regarding energy demand. For example, Some issers related to the nuclear and electricity, etc, is it an important to effectively use energy. Electric cars are the best representatives of environmental protection and the effective of energy. In this paper, we use the latest V2G(vehicle-to-grid) technology. So that the energy can contribute to the grid , and the solution will satisfy the power companies, car industry, and users .We use fuzzy inference system (Fuzzy Inference System) to calculate weighting factors and linear programming (linear programming) to find the optimal solution, It is different with other papers. In this paper, we design fuzzy theory to solve the problem of electric vehicle charging and discharging in a real-time systems, and we can reasonably explain that electric vehicles charging priorities or discharging priorities, and the solution satisfy the power companies, car industry, and the users.

APA, Harvard, Vancouver, ISO, and other styles

49

Hsieh, Jia-Da, and 謝佳達. "Battery Charging/Discharging Test and Control System with Energy Saving Features." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/15252270095035061998.

Full text

Abstract:

碩士
國立中正大學
電機工程所
97
This thesis presents development of battery charging/discharging test and control system with Energy-Saving features. This system is composed of an AC/DC bidirectional inverter with Power Factor Correction, a DC/DC bidirectional converter, a buck charger, a boost discharger and a LabVIEW human-machine interface. This system allows batteries to be charging and discharging at the same time. The discharged energy of the batteries can be recycled to charge batteries, and the excess discharged energy can be recycled with grid-connection, greatly reducing power consumption in the battery charging and discharging test process. The charging and discharging Current and Voltage waveforms can be recorded by the LabVIEW software package. In this study, we develop three chargers, three dischargers and a LabVIEW human-machine interface to verify the energy-recycle function. Comparing this system with the conventional one reveals that this system can save energy up to 73 %.

APA, Harvard, Vancouver, ISO, and other styles

50

Chen, Jai-Bin, and 陳嘉斌. "Study of Charging and Discharging Characteristics of Battery for Electric Vehicle." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/35295884701402166991.

Full text

Abstract:

碩士
國立彰化師範大學
工業教育學系
87
The purpose of this thesis is to study the charging and discharging characteristics of the battery usded in an electric vehicle. The electric vehicles are not yet widely accepted for replacement with conventional internal combustion engine cars, due to some unsolved technical problems. The main problem is long battery charging time. In the thesis, different charging techniques were analyzed to find out the charging techniques with shortest charging time and the highest charging efficiency. Another difficult problem associated with the development of electric vehicles is battery residual capacity prediction. A new approach to develop a battery state of charge indictor used in an electric vehicle is discribed and studied. This approach determines the state of charge by combining the open voltage and coulombmetric measurement technique. After elongated testing, the optimum prediction parameters were obtained and summarized.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'CHARGING AND DISCHARGING TIME'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles