A Long-Life Predictive Guidance with Homogeneous Competence Promotion for University Teaching Design

Even though planning the educational action to optimize student performance is a very complex task, teachers typically face this challenging issue with no external assistance. Previous experience is, in most cases, the main driving force in curriculum design. This procedure commonly overlooks the students’ perception and weakly integrates the students’ feedback by using a non-systematic approach. Furthermore, transverse competences are, unfortunately, typically omitted in this procedure. This work suggests the use of a predictive tool that determines the optimal application time of different methodological instruments. The suggested method can be used for an infinite number of scenarios of promoted competences. The results can be regarded as a guide to modify the course structure, but, more importantly, it offers valuable information to understand better what is occurring in the teaching-learning process and detect anomalies in the subject and avoid the students’ exclusion. The predictive scheme simultaneously considers the teacher’s perspective, the student’s feedback, and the previous scores in a systematic manner. Therefore, results provide a broader picture of the educational process. The proposal is assessed in a course of Electrical Machines at the University of Malaga during the academic year 2021–2022.This research was funded in part by the Spanish Government under the Plan Estatal with the reference PID2021-127131OB-I00, in part by the Junta de Andalucia under the grant UMA20-FEDERJA-039 and in part by the Ministry of Science, Innovation and Universities under the Juan de la Cierva grant IJC2020-042700-I. Partial funding for open access charge: Universidad de Málag

Estudio comparativo de estrategia de control post-falta en accionamientos eléctricos multifásicos

Falta palabras clavesLas máquinas multifásicas son un tema ampliamente estudiado en los últimos años. La literatura referida a este tipo de máquinas señala las diferentes ventajas que éstas presentan sobre las máquinas trifásicas convencionales, tal vez la más importante sea su capacidad de proporcionar tolerancia al fallo sin la necesidad de hardware adicional. Esta característica es especialmente apreciada en las aplicaciones donde la seguridad resulta crítica, como la aeroespacial o la naval. En tales casos, la redundancia inherente que ofrecen estos sistemas multifásicos permite el funcionamiento post-falta del sistema sin necesidad de hardware adicional. Sin embargo, el funcionamiento post-falta no siempre resulta imprescindible, a pesar de ello puede ser muy apreciado en aquellas aplicaciones donde el funcionamiento continuo del sistema se traduce en beneficios económicos. Un ejemplo de esta situación se puede encontrar en la industria de la energía eólica en el mar, donde las tareas de mantenimiento no siempre son posibles. Independientemente de la aplicación, es necesario implementar topologías y sistemas de control post-falta adecuados a este modo de funcionamiento especial. Esta Tesis Doctoral presenta el estado del arte en el área de máquinas multifásicas, con especial atención en la situación post-falta. Se describen diferentes topologías y esquemas de control para este modo de funcionamiento especial. Con el fin de contribuir al desarrollo del conocimiento en el campo, se presentan las siguientes contribuciones: La primera contribución presenta un estudio sobre la tolerancia al fallo de las máquinas de inducción de seis fases alimentadas por conjuntos de convertidores en paralelo con dc-links independientes. La topología propuesta es descrita, ésta incluye dos conjuntos de convertidores conectados en paralelo que alimentan a cada conjunto de devanados trifásicos. Debido a la redundancia proporcionada por los convertidores en paralelo, una falta de fase abierta en cualquiera de los convertidores no implica una fase abierta en la máquina. Este hecho permite minimizar la reducción de potencia del sistema cuando se produce el fallo, si una estrategia de control post-falta adecuada es implementada. Con el fin de reducir al mínimo la reducción de potencia del sistema, se presenta un nuevo esquema de control que permite repartir la corriente de forma desigual entre ambos devanados. Para optimizar el funcionamiento el desequilibrio es mantenido al mínimo posible usando un controlador que regula la distribución de corriente entre el devanado sano y el dañado. Este modo de funcionamiento desequilibrado se consigue gracias a la inyección de corrientes. Las referencias de estas corrientes se obtienen de las restricciones debidas a la falta, y el control se lleva a cabo en un sistema de referencia anti-síncrono que permite el uso de controladores proporcionales-integrales (PI) con un buen rendimiento. La segunda contribución en la que apoya esta Tesis Doctoral considera la misma topología de convertidores paralelos y dc-link de la primera de las contribuciones. Sin embargo, el rendimiento del sistema se mejora incluyendo un control eficiente. Ya que el funcionamiento post-falta implica valores de par/potencia por debajo de los valores nominales, el mantenimiento del valor nominal del flujo de magnetización no es una solución óptima. Con el objetivo de mejorar el rendimiento del sistema, el flujo es optimizado para cada punto de funcionamiento utilizando una técnica Loss Control Model (LMC). Este método offline permite calcular el flujo óptimo a partir del modelo de la máquina y de las restricciones debidas a la falta. Como resultado de su implementación, las pérdidas de la máquina se reducen consiguiendo además un rendimiento dinámico satisfactorio Aunque, el objetivo principal de esta estrategia de control es reducir las pérdidas en la máquina, su implementación también permite lograr un mayor par/potencia post-falta y reducir el grado de desequilibrio en el reparto de las corrientes de los dos conjuntos de devanados trifásicos. La tercera aportación también analiza la tolerancia al fallo proporcionada por un sistema multifásico con convertidores en paralelo para aplicaciones renovables de alta potencia y baja tensión. En este caso los convertidores que alimentan a cada conjunto trifásicos están conectados en paralelo con un dc-link común. Las corrientes en el conjunto dañado no se limitan por igual, lo que permite aumentar la producción de par/potencia después del fallo. Este trabajo explora diferentes escenarios de falta, el método de control post-falta implementado utiliza diferentes corrientes de referencia en función del tipo de falta y de la configuración de la máquina empleada. El esquema de control también es modificado para encontrar un sistema de referencia donde las corrientes en el plano sean constantes. De lo contrario, se deberán usar controladores resonantes que proporcionen un rendimiento satisfactorio. En este estudio la máquina multifásica es configurada con uno o dos neutros aislados. Los resultados obtenidos muestran que si se utiliza un único neutro aislado es posible obtener un mayor par post-falta, si se asume un esquema de control más complejo

Assessment of a Universal Reconfiguration-less Control Approach in Open-Phase Fault Operation for Multiphase Drives

Multiphase drives have been important in particular industry applications where reliability is a desired goal. The main reason for this is their inherent fault tolerance. Di erent nonlinear controllers that do not include modulation stages, like direct torque control (DTC) or model-based predictive control (MPC), have been used in recent times to govern these complex systems, including mandatory control reconfiguration to guarantee the fault tolerance characteristic. A new reconfiguration-less approach based on virtual voltage vectors (VVs) was recently proposed for MPC, providing a natural healthy and faulty closed-loop regulation of a particular asymmetrical six-phase drive. This work validates the interest in the reconfiguration-less approach for direct controllers and multiphase drives

Spatial Interpolation contribution to noise maps uncertainty

Noise maps results are usually presented as contour graphs or isophone curves, which describe the sound levels as functions of spatial location. These maps are added to Geographic Information Systems (GIS), allowing sound level evaluation as a function of the continuous coordinates x and y, for a given height above ground. Although the outcome of the system is a continuous variable, the calculations that allow its evaluation are obtained in discrete points that form a calculation grid, which is created by the application of spatial sampling techniques. Using spatial interpolation tools, values are assigned to the locations in which measures or calculations have not been performed. The application of sampling and interpolation techniques (the type of grid, its density, the interpolation algorithms…) contributes to the uncertainty of the results. This paper describes a calculation method to quantify the uncertainty associated to the spatial sampling and interpolation process. We also propose a revision of the classical meaning of noise mapping uncertainty, taking into account the final application of the results

Symmetrical six-phase induction machines: a solution for multiphase direct control strategies

Six-phase induction machines are considered an interesting multiphase option because they can benefit from the well-known three-phase converter technology. These multiphase machines can be classified according to the spatial distribution of their windings into two main groups: asymmetrical and symmetrical six-phase machines. In the case of symmetrical sixphase machines, some sets of voltage vectors show an important advantage from the point of view of the - current mitigation. They provide an active production in the - plane with a completely null injection of - components. This fact is a desired feature for direct control strategies, such as standard model predictive control (MPC), where a single switching state is applied during the entire sampling period. Based on these statements, this work proposes an MPC strategy for symmetrical six-phase induction machines using voltage vectors with null - voltage production in order to obtain the flux/torque generation with minimum - currents. Simulated results have been included to validate the goodness of the developed control scheme.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Current Imbalance Detection Method based on Vector Space Decomposition Approach for Five-Phase Induction Motor Drives

The inherent fault-tolerant capability against open-phase faults (OPFs) of multiphase machines is an appreciated advantage in applications where high-reliability is a main concern. This desirable feature has usually required fault localization and post-fault control reconfiguration to provide a suitable performance in this anomaly situation. However, recent model predictive control (MPC) based on virtual voltage vectors (VVs) has validated the multiphase machine fault-tolerant capability without post-fault control reconfiguration. This fact allows to relax some of the OPF detection methods requirements. On the other hand, incipient faults or damaged connections can generate resistance dissymmetry (RD) situations that produces overheating and control degradation. Although the origin of OPFs and RDs can be of a different nature, the symptoms of both anomalies are common: a current imbalance that generates non-null x-y currents appears. Focusing on this approach, this work suggests new settings for an OPF detection method based on the vector space decomposition (VSD) in order to make it universally valid both in OPF and RD situations. The proposed current imbalance detection (CID) method is implemented together with a natural fault-tolerant direct torque control (DTC) for five-phase induction motor drives. Experimental results are employed to verify the goodness of the proposed method.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

La fisión mediada por DRP1 tiene un papel importante en las enfermedades de Alzheimer y Parkinson

Our objectives were to perform a bibliometric analysis with which to highlight the role of Drp1 in the pathogenesis of AD and PD as a fundamental regulator of mitochondrial fusion and fission homeostasis, in addition to highlighting Drp1 as a possible therapeutic target in AD and PD.Nuestros objetivos son realizar un análisis bibliométrico con el que destacar la relevancia de Drp1 en la patogénesis de la EA y la EP como regulador fundamental de la homeostasis de la fusión y fisión mitocondrial, además de destacar a Drp1 como posible diana terapéutica en la EA y la EP.Ciencias Experimentale

Field Oriented Control of Multiphase Drives with Passive Fault-Tolerance

Multiphase machines provide continuous operation of the drive with no additional hardware in the event of one or more open-phase faults. This faulttolerant capability is highly appreciated by industry for security and economic reasons. However, the steadystate post-fault operation has only been feasible in previous works after the fault localization and control reconfiguration. Even though this is done at the software stage, the obligation to identify the faulty phases and store the modifications for every fault scenario adds further complexity. This work reveals that this software reconfiguration can be avoided if the field-oriented control (FOC) strategy is designed to satisfactorily handle pre- and post-fault situations. Experimental results confirm the capability to obtain suitable postfault operation without fault localization and control reconfiguration, thus achieving a passive/natural fault tolerance.Ministerio de Ciencia, Innovación y Universidades RTI2018-096151-B-I0

Impact of post-fault flux adaptation on six-phase induction motor drives with parallel converters

The redundancy of multiphase drives provides an inherent fault-tolerant capability that is appreciated in applications with a complicated corrective maintenance or safety-critical requirements. Fault restrictions however force the system to be reconfigured to operate in a smooth and efficient manner. Previous works have been focused on the optimization of current waveforms to generate an undisturbed operation but still maintaining the pre-fault rated flux settings. This work shows that efficient controllers can improve the post-fault performance in six-phase induction machines supplied by parallel- connected converters if offline optimization is used to obtain a variable reference flux. Theoretical and experimental results confirm that the proposed flux adaptation method provides higher torque/power capability, lower degree of imbalance in the current sharing between windings and efficiency improvementMinisterio de Ciencia e Innovación ENE2014-52536-C2-1-R DPI2013- 44278-RJunta de Andalucía P11-TEP-755

Environment mapping using a 3D laser scanner for unmanned ground vehicles

This is the author’s version of a work that was accepted for publication in Microprocessors and Microsystems. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Microprocessors and Microsystems, Vol 39, Issue 8, (2015) DOI 10.1016/j.micpro.2015.10.003Unmanned ground vehicles need accurate sensors to detect obstacles and map their surroundings. Laser-based distance sensors offers precise results, but 3D off-the-shelf sensors may be too expensive. This paper presents a 3D sensing system using a 2D laser sensor with a rotation system. Point cloud density analyses are presented in order to achieve the optimal rotation speed depending on the vehicle speed, distance to obstacles, etc. The proposed system is able to generate real-time point clouds, detect obstacles and produce maps, with high accuracy and a reasonable price (less than 5, 000 USD).This work has been done with an INNPACTO program support, in the frame of ARGOS project IPT - 2012 - 0308 - 390000 (Union Europea, Fondos FEDER). It is a joint project between Robomotion and the HCTLab, Human Computer Technology Laboratory, of Universidad Aut onoma de Madrid, Spain