New Modulation Technique to Mitigate Common Mode Voltage Effects in Star-Connected Five-Phase AC Drives

Star-connected multiphase AC drives are being considered for electromovility applications such as electromechanical actuators (EMA), where high power density and fault tolerance is demanded. As for three-phase systems, common-mode voltage (CMV) is an issue for multiphase drives. CMV leads to shaft voltages between rotor and stator windings, generating bearing currents which accelerate bearing degradation and produce high electromagnetic interferences (EMI). CMV effects can be mitigated by using appropriate modulation techniques. Thus, this work proposes a new Hybrid PWM algorithm that effectively reduces CMV in five-phase AC electric drives, improving their reliability. All the mathematical background required to understand the proposal, i.e., vector transformations, vector sequences and calculation of analytical expressions for duty cycle determination are detailed. Additionally, practical details that simplify the implementation of the proposal in an FPGA are also included. This technique, HAZSL5M5-PWM, extends the linear range of the AZSL5M5-PWM modulation, providing a full linear range. Simulation results obtained in an accurate multiphase EMA model are provided, showing the validity of the proposed modulation approach.This work has been supported in part by the Government of the Basque Country within the fund for research groups of the Basque University system IT978-16 and in part by the Government of the Basque Country within the research program ELKARTEK as the project ENSOL (KK-2018/00040)

Control of dual three-phase IPMSM drive with cascaded DC-link capacitors for third generation EV

In this work, a dual three-phase Interior Permanent Magnet Synchronous Machine (IPMSM) drive connected to a high voltage DC/DC converter (800 V) at its input is considered for electric vehicle (EV) applications. The drive is constituted by two cascaded three-phase inverters, enabling fast charging capabilities. In this particular configuration, balancing the input voltages of the two inverters is mandatory during operation. A novel control approach that not only provides such voltage balancing but also considers the cross-coupling effects of the dual-three phase IPMSM is proposed, guaranteeing an adequate torque regulation through the whole operation range of the drive. Simulation results, generated by means of a high fidelity platform, are provided to validate the proposed approach. Additionally, preliminary experimental results are also included.This research has received funding from the European Union’s Horizon 2020 research and innovation programme under project FITGEN grant agreement No 824335. This work has been supported in part by the Government of the Basque Country within the fund for research groups of the Basque University system IT978-16 and the research program ELKARTEK (project ENSOL2-KK-2020/00077), and also by the Ministerio de Ciencia e Innovacion of Spain within the ´ project PID2020-115126RB-I00 and FEDER funds

Normalised flux weakening control technique acting on the actual speed for automotive dual three-phase IPMSMs

Comunicación presentada en 6th IEEE International Conference on Electrical Systems for Aircraft, Railway, Ship Propulsion and Road Vehicles & International Transportation Electrification Conference (ESARS-ITEC) Dates: 3/28/2023 - 3/31/2023 Venue: Arsenale di Venezia, Venice, ItalyIn this paper, a flux weakening control strategy based on a vector space decomposition (VSD) model is presented for asymmetrical dual threephase interior permanent magnet synchronous machines (IPMSMs). This strategy incorporates a voltage magnitude feedback loop, which provides robustness by adding a variation to the actual speed when enters in flux weakening mode or deviations occur in the electrical parameters of the machine. Validity of the proposal is demonstrated by simulation results carried out over standardised driving cycles, taking into account parameter mismatches.This work was supported in part by the Government of the Basque Country within the fund for research groups of the Basque University system IT1440-22 and by the MCIN/AEI/10.13039/501100011033 within the project PID2020-115126RB-I00

Full-Speed Range Control of a Symmetrical Six-Phase Automotive IPMSM Drive with a Cascaded DC-link Configuration

This work considers the utilization of a symmetrical six-phase interior permanent magnet synchronous machine drive, including a cascaded dc-link configuration, to make up an electric vehicle propulsion system. This way, fast charging capabilities are provided while avoiding the utilization of power semiconductors with high voltage ratings. In this scenario, the control algorithm must deal with the non-linearities of the machine, providing an accurate setpoint command for the whole torque and speed range of the drive. Therefore, cross-coupling effects between the winding sets must be considered, and the voltage of the cascaded dc-link capacitors must be actively monitored and balanced. In view of this, the authors propose a novel control approach that provides all these functionalities. The proposal is experimentally validated in a full-scale 70 kW electric drive prototype, tested in a laboratory set-up and in an electric vehicle under real driving cycle conditions

Estudio de factibilidad para la construcción del hangar de mantenimiento de aeronaves de la empresa FVAIR

En la compañía FVAir se ha identificado una oportunidad de mejora en el área de mantenimiento de las aeronaves que actualmente posee la compañía; debido a que es de vital importancia para la operación, contar con un buen mantenimiento especializado que se ajuste con los itinerarios de las aeronaves y se pueda cumplir con la disponibilidad para prestar el servicio, sin generar pérdida de credibilidad ante el cliente final debido a retrasos o cancelaciones por mantenimiento. Actualmente la compañía contrata los servicios de mantenimiento con talleres de la competencia y dada la baja oferta de estos servicios en el país se genera que los costos sean elevados, ocasionando un aumento en el presupuesto de mantenimiento anual para los aviones; estos altos costos de operación impactan el modelo económico de la organización conocido como “low cost”, modelo que hace referencia a que el cliente paga solo por los servicios que necesita. El proyecto desarrollado a continuación presentará la factibilidad para la construcción de un hangar de mantenimiento especializado propio para la compañía. Es por ello por lo que partiendo de la apropiación de los mantenimientos se planea presentar una alternativa para reducir los costos por concepto de gastos de sostenimiento de las aeronaves. De esta manera se logrará que el negocio aumente su rentabilidad y que la compañía tenga mayor control en la programación y cumplimiento de los planes de mantenimiento preventivo de las aeronaves, sin afectar la disponibilidad para servicio y garantizando el modelo ¨low cost”, logrando así aumentar su participación en el mercado de las aerolíneas, con un mejor manejo y promoción de la oferta.FVAir has identified an improvement in the aircraft maintenance area currently owned by the company; because it is very important for the operation to have a good specialized maintenance that is in line with the itineraries of the aircraft and it can fulfil the availability to provide the service without generating loss of credibility to the end customer due to maintenance delays or cancellations. Currently the company get maintenance services with competing workshops and given the low supply of these services in the country generates an increase in costs, causing an increase in the annual maintenance budget for aircraft; these high operating costs impact the economic model of the organization known as "low cost", a model that refers to the customer paying only for the services they need. The next project will give the feasibility for the construction of a dedicated maintenance hangar for the company. That is why since the appropriation of the maintenance plans to present an alternative to reduce the costs of sustaining the aircraft. In this way, the business will increase its profitability and the company will have more control in the programming and compliance with the preventive maintenance plans of the aircraft, without affecting the availability for service and guaranteeing the low-cost model", getting to increase their participation in the airline market, with better management and promotion of the offer

Análisis del modelo de Evaluación y desempeño, de la empresa Manpower, Seccional Cesar, para el segundo semestre del año 2020

En el mundo laboral de hoy al Talento Humano se le considera como una de las variables más importantes en las que las organizaciones deben centrar gran parte de su atención y de sus recursos, de esta manera el presente trabajo de investigación desde el punto de vista conceptual de la Evaluación de Desempeño su importancia no radica únicamente en detectar los errores, sino reflejarse en la realimentación y en las acciones diseñadas de forma estratégica para buscar la mejora continua, tal como se ha evidenciado en la organización Manpower Seccional cesar, identificando las falencias en el modelo de evaluación y desempeño de la Empresa Manpower Seccional cesar e identificando las necesidades de los aliados estratégicos y diseñando estrategias organizacionales. Se realizó una investigación cuantitativa, en donde a través de una encuesta se evidencio que actualmente no existe una comunicación asertiva con los clientes de la marca y NPS desenfocado para el cumplimiento de los objetivos organizacionales de las marcas aliadas. Teniendo en cuenta lo anterior, la evaluación de desempeño es primordial dentro de la organización Manpower para su desarrollo y crecimiento, esto le permite tener una ventaja competitiva dentro de sus competidores, es por eso por lo que como resultado determinaremos una serie de cambios de forma en cuento al objetivos y determinación de enfoque en la evaluación al momento de la aplicación y de fondo en cuento al marco legal y teórico que la abriga para cada organización aliada Se concluyo que como organización siempre se debe trabajar para la mejora continua, basado en la innovación, reinvención y cambios informáticos de vanguardia, eso obliga a que toda organización aplique cambios continuos en sus proceso y equipo de Talento Humano de cada organización como una marca Manpower se vea encaminado al fortalecimiento del proceso de la evaluación de desempeño.In today's world of work, Human Talent is considered one of the most important variables on which organizations should focus a large part of their attention and resources, in this way the present research work from the conceptual point of view of Performance Evaluation, its importance does not lie solely in detecting errors, but is reflected in the feedback and actions strategically designed to seek continuous improvement, as has been evidenced in the Manpower Sectional organization cease, identifying the shortcomings in the evaluation and performance model of the Company Manpower and identifying the needs of strategic allies and designing organizational strategies. A quantitative investigation was carried out, where through a survey it was evidenced that currently there is no assertive communication with the brand's clients and the NPS is out of focus for the fulfillment of the organizational objectives of the allied brands. Considering the above, the performance evaluation is essential within the Manpower organization for its development and growth, this allows it to have a competitive advantage within its competitors, that is why as a result we will determine a series of changes accordingly to the objectives and determination of focus in the evaluation at the time of the application and in the background regarding the legal and theoretical framework that shelters it for each partner organization It can be concluded that as an organization you should always work for continuous improvement, based on innovation, reinvention and cutting-edge computer changes, this means that every organization applies continuous changes in its process and in the Human Talent team of each organization as a brand Manpower refers to the strengthening of the performance evaluation process

Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at √s=8 TeV

The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Una mirada a las diferentes perspectivas de los negocios internacionales: estrategias, principios y casos de internacionalización

Este libro consolida resultados de investigación que permiten mirar los negocios internacionales a partir de diferentes perspectivas, proporcionando un aporte sistémico para la academia y el mercado. A partir de discusiones del punto de vista de relaciones internacionales, comercio exterior, logística, estrategias de internacionalización y negociación, esta obra discute aspectos actuales aplicables y relacionados a la actuación de las empresas colombianas en el mercado internacional, sus oportunidades y potencialidades competitivas. A lo largo de sus siete capítulos e introducción, el libro “Una mirada a las diferentes perspectivas de los Negocios Internacionales: Estrategias, principios y casos de internacionalización” presenta diferentes metodologías, herramientas, fundamentos y casos de referencia que pueden apoyar profesionales en el estudio y en la práctica de los negocios internacionales

Search for pair-produced resonances decaying to jet pairs in proton-proton collisions at √s=8 TeV

Results are reported of a general search for pair production of heavy resonances decaying to pairs of hadronic jets in events with at least four jets. The study is based on up to 19.4 fb(-1) of integrated luminosity from proton-proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The first assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV