The number of electrical machines used in modern road-vehicles is continuously increasing to meet regulatory requirements regarding safety and efficiency, as well as consumer expectations in terms of comfort. For auxiliary applications, such as cooling fan or pumps, permanent-magnet synchronous machines (PMSMs) are extensively used owing to their high power density. This thesis focuses on the modelling aspects of PMSMs, with a particular focus on finite-element and reduced-order models to be used in system-level simulations. 2-D and 3-D parametric finite-element (FE) models are developed, allowing to compute irreversible demagnetization in addition to the standard quantities such as torque, back electromotive force and flux-linkages. The effects of magnet overhang on the performance of an interior PMSM is briefly discussed. Using the FE model, a reduced-order lookup-table (LUT) based electromagnetic model, having similar accuracy as FE analysis, is then developed. Coupled to a mechanical state-space representation obtained from a modal FE analysis, the final model allows to compute electromagnetic induced vibrations under pulse width modulation supply. The validation of the complete workflow is carried out on a 12slot-10pole PMSM used to drive a cooling fan. After fitting the damping coefficient in the structural state-space model, the results are in agreement with the experimental results. Due to the usage of LUTs, the simulation time is low compared to a pure FE analysis. This allows the model to be used to optimize low noise control strategies. To conclude this thesis, the parametric FE model is used in an optimization routine to minimize the cost and vibrations of the motor, whilst satisfying the working points. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Quantum sensing, a protocol that takes advantage of the extreme sensitivity of quantum systems to their environment, enables many applications of quantum systems for sensing. Inspired by direct electric field sensing using the Stark effect of a nitrogen-vacancy(NV) center, this work implements an NV-magnet hybrid way to explore the possibilities of overcoming NV’s relatively weak coupling strength to electric fields. The magnetic-noise-induced population relaxation of the NV center serves as the mechanism for sensing. Within this scheme, the magnetic noise spectrum is tuned by modulating the magnetic properties via voltage-controlled magnetic anisotropy (VCMA) or electric-field-induced magnetoelastic effect. In this way, the noise carrying the information of the electric field is taken as a signal - the shift of the noise spectrum leads to a population difference of NV energy levels, which is used for evaluating electric fields. The investigation of the relation between sensitivities and operation points reveals that lower operation frequency is desirable for better performance. The comparison between VCMA and electric-field-induced magnetoelastic effect indicates that the efficiency of converting electric field into magnetic property modulation is a critical parameter for sensitivity enhancement.

The main objective of the master`s thesis was to prove, if permanent magnet synchronous generator made by company JULI Motorenwerk s.r.o. could reach higher maximum active power with active rectifier than with six-pulse bridge rectifier. For this reason a mathematical model was made in Matlab/Simulink. The influence of the rectifiers with various kinds of loading was observed and compared by simulations on output variables, like line-to-line voltage and active power. The simulations were also compared with measurement.

This master’s thesis is focuses on the reluctance motor, especially on the design of the rotor. It shows the development of the construction of rotors of reluctance motors. Furthermore, it shows the principle of reluctance machine and its basic mathematical description and the principle of improving the machine parameters by inserting permanent magnets into the rotor. It offers an overview of patents available from 2000 to present. Also it deals with the design of the rotor with permanent magnets for stator of induction motor.

Aujourd'hui, il est impératif de réduire les émissions de CO2 des véhicules routiers en raison des changements climatiques. L’une des stratégies les plus prometteuses consiste à utiliser les véhicules électriques (VÉ) et hybrides électriques (VÉH). Les VÉ et VÉH ont besoin de machines électriques pour réaliser la conversion d’énergie électromécanique. Les machines électriques à aimant permanent semblent être les meilleurs candidats pour les applications VÉ et VÉH en termes de performances exceptionnelles. L’aimant permanent des terres rares le plus puissant est le type de Néodyme-Fer-Bore (Nd2Fe14B) ou simplement appelés NdFeB. Généralement, une petite quantité d’éléments terres rares lourds, comme le Dysprosium (Dy) ou le Terbium (Tb) est ajoutée à l’alliage de NdFeB afin d'améliorer les performances. Cependant, cette forte demande en terres rares implique de sérieux problèmes d’approvisionnement. Dans ce cas, l'une des solutions possibles pour que l'Europe lutter contre les risques d'approvisionnement en terres rares consiste au recyclage des aimants terres rares. DEMETER est l’acronyme anglais pour le groupe européen de formation universitaire pour la conception et le recyclage de moteurs et de générateurs électriques à aimants permanents terres rares pour les véhicules tout-électriques et hybrides électriques. Son objectif était étudier les trois voies possible pour le recyclage des aimants permanents à base de terres rares présents dans les moteurs électriques : la réutilisation directe, le recyclage direct et le recyclage indirect. Valeo et G2Elab sont les principaux partenaires de ce projet. Ils se concentrent principalement sur la réutilisation directe des aimants permanents. La thèse est supervisée par Valeo et G2Elab et se concentre principalement sur les machines électriques à flux radial à aimants permanents qui sont les machines électriques les plus utilisées de nos jours. Les applications visées sont les véhicules hybrides électriques à niveau d’hybridation douce ou les petits VÉ. Le dimensionnement de ce moteur innovant doit non seulement être recyclable du point de vue des aimants permanents mais doit également répondre à tous les critères exigeants du cahier des charges.Des études bibliographiques approfondies, l’optimisation FEM et l’analyse thermique / mécanique ont révélé qu’une machine synchrone à aimants permanent insérés (MSAPI) peut largement satisfaire à toutes les exigences et à toutes les contraintes. Ensuite, nous avons utilisé un aimant lié pour à la MSAPI pour réutilisés. L'assemblage de la machine avec des aimants liés est plus facile que l'assemblage avec des aimants frittés, comme l'aimant lié est directement assemblé au fer rotorique par moulage par injection. Le démontage des aimants est également plus facile. Dans le contexte d’un procédé de recyclage des rotors à aimants liés, ces derniers pourraient être chauffés afin de faire fondre les aimants liés et les extraire ensuite facilement. Ils peuvent être mélangés à des aimants recyclés avec un certain pourcentage de composé d’aimants vierges pour fabriquer de nouveaux aimants liés sans modification notable des performances magnétiques de l’aimant. De nombreux essais de référence ont été à réalisés évaluer les performances de cette machine, puis comparés aux résultats de la simulation. Dans cette thèse, en plus des propositions de dimensionnements innovants, l’objectif est d'évaluer les machines électriques du point de vue de leur recyclabilité. La recyclabilité est quantifiée par deux indices. Ces derniers peuvent être regroupés sous le terme WIRE (Weighted Index of Recycling and Energy – index Pondéré de recyclage et de consommation énergétique). En utilisant WIRE, la recyclabilité entre différentes machines peut être comparable, même avec des dimensions ou des performances différentes. La méthode de réutilisation et de recyclage des aimants permet d’obtenir des avantages environnementaux sans pertes économiques. / Nowadays it is imperative to reduce the CO2 emission of automotives due to the climate changes. One of the essential strategies is to use new energy vehicles, such as Hybrid and pure Electrical Vehicles ((H)EVs). However, no matter what the energy storage devices (H)EVs have, they always need electrical machines to transfer electrical energy into mechanical energy. Permanent Magnet (PM) electrical machines seem to be the best candidates for (H)EV applications in terms of their outstanding performances. However, the supply and cost of PMs are essential for PM machines. The strongest rare earth PM is Neodymium-Iron-Boron (Nd2Fe14B) type magnet, or simply written as NdFeB. Commonly, in order to improve the temperature stability as well as resistant demagnetization of magnets, small portion of heavy rare earth element, Dysprosium (Dy) or Terbium (Tb), is added to the alloy. However, with a high demand of high grade NdFeB magnets, the supplies of these rare earth elements, including Neodymium (Nd), face serious challenge, especially for Europe. In this case, one of the possible solutions for Europe to tackle the rare earth supply risks is to recycle rare earth magnets. Demeter -European Training Network for the Design and Recycling of Rare-Earth Permanent Magnet Motors and Generators in Hybrid and Full Electric Vehicles, is an Europe Union registered project. DEMETER envisaged three routes for the recovery of rare earth PM from these devices, which are so called direct re-use, direct recycling and indirect recycling. Valeo and G2Elab are the principal partners in this project, and they mainly focus on the route of PM direct re-use. This doctor thesis is supervised by Valeo and G2Elab, and mainly focuses on radial flux type PM electrical machines, which are the most widely used type of electrical machines nowadays. The applications include Mild Hybrid Electric Vehicles (MHEV) or small Electric Vehicles (EV). The new motor design not only needs to be recycle friendly for PMs, but also needs to meet all the strict requirements for the applications.With thorough literature studies, FEM optimization and thermal/mechanical analysis, it was found that an IPMSM design can fairly fulfill all the requirements and constraints. Then new magnet materials and assembly methods were implemented for the magnet recycling - a kind of bonded magnet was used for the IPMSM. This bonded magnet was made from a Hydrogen Decrepitation Deabsorbation Recombination (HDDR) anisotropic NdFeB magnet powder, with Sulfide (PPS) binder. It has the possibility to directly assemble the magnet into the rotor by injection molding. Thus the assembly of the magnets would not be constraint by their shapes. The disassembly of the magnets became easy as well – it is possible to heated up the rotors so that the bonded magnets can be melted down for extraction. Then they can be mixed with a certain percent of virgin magnets compound to make new bonded magnets without remarkable changes on performances. In summary, the entire recycling process is relatively easy and ecologically sustainable. Thus, based on this new concept, an IPMSM with bonded NdFeB magnets were fabricated. Series benchmark tests were carried out, for instance measurements of back-EMF, torque, efficiency, short circuit current and stator temperatures. In this thesis, apart from new design ideas of electrical machines, another goal is to evaluate e-machines with respect to the recyclability. The recyclability is quantified by two indexes, together they can be named Weighted Index of Recycling and Energy (WIRE). By using WIRE, the recyclability between different machines can be comparable, even with different dimension or performances. It was found that by using WIRE to evaluate the new designed PM machine, promising results can be obtained. The magnet reuse and recycling approach can gain environment benefit without economic losses.

The research for electric vehicles has been growing during last years and the development of electric drive trains can be considered a main challenge. This thesis presents the electric drive train of the research concept vehicle (RCV) 2013, with particular focus on electric machines, motor controllers, and the communication system. In the first part of this thesis, the electric drive train configuration and components are described. In-wheel motors are proposed which is a permanent magnet synchronous machine (PMSM). This technology allows the use of autonomous corner modules (ACM) increasing the quality and safety of the system. Each of the four in-wheel motors has a controller enabling the use of torque or speed control mode. Furthermore, a dSPACE unit provides the total control of the system by CAN bus. Additionally, the dSPACE ControlDesk interface used to control the drive system is presented. In the second part, the heat sink of the AC Drive is investigated by measurements and analytical calculations. Furthermore, the motor temperature at different loads is also presented and discussed. Finally, the efficiency of an in-wheel motor (PRA 230) is studied. Also the efficiency of the motor controller is estimated and discussed.

This report aims to draw a comparison between two commercial mobile forensics and recovery tools, Magnet AXIOM and MOBILedit. A thorough look at previously done studies was helpful to know what aspects of the data extractions must be compared and which areas are the most important ones to focus upon. This work focuses on how the data extracted from one tool compares with another and provides comprehensive extraction based on different scenarios, circumstances, and aspects. Performances of both tools are compared based on various benchmarks and criteria. This study has helped establish that MOBILedit has been able to outperform Magnet AXIOM on more data extraction and recovery aspects. It is a comparatively better tool to get your hands on.

Summary: The aim of thi disertation was to enlighten the term magnet hospital. Introduction of this thesis describes personnel situation in health care systém in the Czech republic and globaly. It also shows predictions of the future critical nurse staff shortage on labour market all around the world and it's possible impact on quality of care. Magnet hospitals as the kind of organization that creates work enviroment which increases nurses work satisfaction, quality of care and patients outcomes, sees the author as one of the possible solution of nursing shortage in the Czech republic. Second part of this theses, rpresents the results of the qualitative and quantitative research, participant were 16 nurses at the management positions (structured intewies) and 250 nurses (questionare NWI-R autor's own translation). Results: It was obvious that still prevails the traditional hierarchy and medical model of care delivery. Also there is streotypical view of the role and position of the nurses in health care teams, nurses do not feel like they are involved in management of the hospital. According to the findings we cannot describe those organizations as magnet hospital. It's also clear that the nursing care managers play the key role in creating the good work environment. We should pay more attention to their...

Bakgrund Forskning visar att utebliven omvårdnad är ett faktum på sjukhus i stora delar av världen. Detta medför en risk för vårdskador, onödigt lidande för patienter samt en ökad kostnad för samhället. Det kan även bidra till att sjuksköterskor upplever en sämre arbetsmiljö vilket kan leda till uppsägningar och brist på sjuksköterskor. Syfte Syftet är att beskriva faktorer som kan leda till utebliven omvårdnad på sjukhus. Metod Detta examensarbete är en strukturerad litteraturöversikt med inslag av den metodologi som används vid systematiska översikter. Femton vetenskapliga studier ligger till grund för resultatet och dessa har sökts fram från databaserna CINAHL och PubMed, studierna är publicerade mellan åren 2012 - 2022. Resultat Litteraturöversiktens resultat visar att såväl mänskliga/demografiska som organisatoriska faktorer bidrar till utebliven omvårdnad. Resultatet visar att otillräcklig bemanning, brist på materiella resurser, arbetsmiljöproblem och bristande kommunikation är faktorer som kan leda till utebliven omvårdnad. Förekomsten av utebliven omvårdnad har även visat sig variera beroende på personalens yrkeskategori. Slutsats Otillräcklig bemanning är den mest betydande faktorn i relation till utebliven omvårdnad under kategorin organisatoriska faktorer, brist på materiella resurser och negativa upplevelser av arbetsmiljön bidrar till fall av utebliven omvårdnad. / Background Research shows that missed nursing care is a fact in hospitals in large parts of the world. This entails a risk of healthcare injuries and unnecessary suffering for patients as well as an increased cost to society. This can contribute to nurses experiencing a poorer working environment, which can lead to redundancies and a shortage of nurses. Aim The aim is to describe factors that can lead to missed nursing care in hospitals. Method This thesis is a structured literature review with elements of the methodology used in systematic reviews. Fifteen scientific articles are the basis for the results, and these have been retrieved from the database CINAHL and PubMed, the articles are published between the years 2012-2022 Results The results of this study show that both human/demographic and organizational factors that contributes to missed nursing care. The results show that insufficient staffing, lack of material resources, work environment problems and lack of communication are factors that can lead to missed nursing care. The incidence of missed nursing care has also been shown to vary depending on the occupational category of the staff. Conclusions Insufficient staffing is the most significant factor in relation to missed nursing care under the category of organizational factors, but also lack of material resources and a negative experience of the work environment contribute to cases of missed nursing care.

Many U.S. hospitals have historically failed to recognize nursing as essential to quality of care. Given the relationship between the patients' experiences, measured by the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS), and government reimbursement, stakeholders now value the role of nurses in the care experience. Some hospitals have pursued Magnet designation, which is a rigorous and costly process, in order to promote patient satisfaction through nurse autonomy and retention. The purpose of this study was to understand whether non-Magnet hospitals received similar HCAHPS scores. Expectancy disconfirmation theory provides a framework to understand the components of patient satisfaction within the context of organizational structures and norms addressed by the Bourdieu theory of cultural health capital. A quantitative study was conducted using secondary data from a stratified random sample of 317 non-Magnet hospitals and a purposive sample of 317 Magnet hospitals. Chi-square tests of independence were performed; Magnet designation was significantly related to nurse communication, pain management, timely responsiveness of care, explanation of medication, and willingness to recommend. Magnet designation consistently had a higher proportion of 3-star and 4-star ratings compared to the tendency of non-Magnet hospitals to be more normally distributed across all five ratings. Study results, combined with the climate of patient consumerism, provide the social impetus for healthcare improvement specialists to promote social change through Magnet-like culture and protocols using an evidence-based practice outcome approach to champion better care experiences through empowerment of both patients and nurses to match expected care with delivered care.