Author: GOMEZ ACERO, DANIEL HERNANDO
Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
Programme: DOCTORAL DEGREE IN ELECTRICAL ENGINEERING
Department: (DEE)
Mode: Normal
Deposit date: 29/09/2022
Reading date: 01/12/2022
Reading time: 16:00
Reading place: ETSEIB_ Aula Schneider - Dept. Eng. Elèctrica. ETSEIB - Campus Sud
Thesis director: GOMIS BELLMUNT, ORIOL | CHEAH MAÑÉ, MARC
Committee:
     PRESIDENT: SAAD, HANI
     SECRETARI: PRIETO ARAUJO, EDUARDO
     VOCAL: KISH, GREGORY
Thesis abstract: High voltage direct current (HVDC) technologies have been used for bulk power transmission over long distances since the 1950s. These technologies have proven to be the most cost-efficient compared to the high voltage alternate current (HVAC) for some applications such as offshore power transmission, connecting remote loads or generation, and the interconnection of non-synchronized grids.In recent years, the study of HVDC grids has been of interest in some research projects but, its development is still uncertain. The de grid can be planned beforehand or it can use the installed lines. But, from the installed HVDC projects, it can be identified different operating voltages, used technologies, and line topologies. There are two HVDC technologies: the line commutated converter (LCC), and the voltage source converter (\/SC). Four different line topologies are identified: asymmetric monopole, symmetric monopole, bipole, and rigid bipole. Developing a de grid interconnecting isolated lines with different characteristics cannot be possible without an intermediary device: the de-de converter.This thesis studies the de-de converters interconnecting HVDC lines with different characteristics. These converters can be seen as the equivalent of ac transformers in de applications because they are capable to adapt the voltage difference between two de systems. These converters are also capable to adapt the line topology and differenttechnologies. The power electronics required for these de-de converters provide increased control flexibility used to supply additional ancillary services that the classical transformers cannot furnish.Three de-de converter topologies are modeled and simulated for the interconnection between a bipole and a symmetric monopole. The front-to-front modular multi-level converter (F2F-MMC) is chosen as the reference because it represents state­ of-the-art technology. The second converter is the de-de MMC (de-MMC) because of the topological similarityto the MMC. Then, a third converter is proposed and studied as a result of this thesis, the asymmetric de-de converter (ADCC). A set of simulations are performed for multiple operating points and faults scenarios. Then, the converters are compared quantitatively and qualitatively. The results and analysis are used to conclude and bring some perspectives for future works.

Author: JANER ANGELET, MARCEL
Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
Department: Department of Mining, Industrial and ICT Engineering (EMIT)
Mode: Normal
Deposit date: 03/10/2022
Reading date: 01/12/2022
Reading time: 12:00
Reading place: ETSEM_Sala d'Actes de l'Escola Politècnica Superior d'Enginyeria de Manresa.
Thesis director: RIERA COLOM, MARIA DOLORES
Committee:
     PRESIDENT: CASELLAS PADRO, DANIEL
     SECRETARI: FERRER REAL, INÉS
     VOCAL: LLORCA ISERN, NURIA
Thesis abstract: Ultrasonic moulding is a promising technology that could be used as a substitute for conventional injection moulding techniques. This relatively new technology has a lower energy consumption, and it could be a sustainable altemative in an industrial environment. In addition, the supply of material processed in ultrasonic moulding is delivered shot-by-shot, which makes this technology very adequate to process short batches of samples without wastage. However, up to now, ultrasonic moulding technology has not been adopted in industrials environrnents due to its lack of robustness and poor repeatability found in its results. In addition, the little knowledge about the influence of the process parameters in the polymer melt is also a handicap for the industrial operator.In this dissertation, applied research and numerical simulation was carried out to improve the ultrasonic moulding technology and to deepen the knowledge ofthe process to promote its industrialization. With this aim, this thesis presents three main areas of work.First, a study of the evolution of ultrasonic moulding machines and configurations was perforrned. This review analysed the experiments published in the literature along with the main conclusions and drawbacks found.On that basis, the developrnent and validation of a new configuration for ultrasonic moulding was done, leading to a great improvement over the performance of the method in terms of repeatability and reduction of impurities in the samples. This new configuration was applied to process polyexymethylene and cyclic olefin polymer, and the results were comparad to the conventional injection moulding. This analysis reveals that the developed rnethod is able to correctly process polymers in a repetitiva way, making ultrasonic moulding a reliable technology for the industry.Finally, research was carried out to study the viscoelastic behaviour of ultrasonic heating of polypropylene cylinders. Results obtained from the numerical simulation of the process were comparad to experimental measurements done with an infrared carnera. The analysis of the results showed an inhomogeneous temperatura distribution along the cylinder and different heating steps can be identified over time. In addition, the comparison between the nurnerical and the experimental results showed that the interaction between the sample and the rnould directly influences the temperatura distribution along the cylinder. Finally, the effect of the main parameters in ultrasonic heating was obtained, both numerically and experimentally, and comparad.As a result, the research perforrned in this dissertation improves the applicability of ultrasonic moulding technology in industrial environments by increasing its repeatability and robustness, and contributing to a better understanding of its main parameters.

Author: BANDERAS BRAGA, MARCELO
Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
Programme: DOCTORAL DEGREE IN ARCHITECTURAL DESIGN
Department: Department of Architectural Design (PA)
Mode: Normal
Deposit date: 06/09/2022
Reading date: 02/12/2022
Reading time: 11:00
Reading place: ETSAB_ meet.google.com/axr-wqzh-wtu
Thesis director: LINARES SOLER, ALFREDO
Committee:
     PRESIDENT: FERRER FORES, JAIME JOSE
     SECRETARI: ESCODA PASTOR, MARIA CARMEN
     VOCAL NO PRESENCIAL: ESTEBAN MALUENDA, ANA MARIA
     VOCAL NO PRESENCIAL: FREDIANI I SARFATI, ARTURO
     VOCAL NO PRESENCIAL: LLORACH HERRERO, ENRIC
Thesis abstract: Modern architecture arrived in Quito through a complex process of assimilation of the lessons and values that emerged in Western Europe and the United States in the early 20th and late 19th centuries.The location of Quito on the Andes mountains required an appropriate way of introducing an architecture that, as Colin Rowe has indicated, focused its attention on the exploration of space as a mainly horizontal condition, beyond any vertical freedom that it had enjoyed for over two thousand years. In response to these challenges a group of architects between 1960 and 1985 designed a series of modern houses that managed to respond to the physical, environmental, technological, and cultural conditions of a city that until the first decades of the 20th century was isolated from more technological developed countries. The location of these houses on the mountainous hills of the city, pushes us to evaluate and question the dependence on the plan as the primary graphic tool used in the analysis or these projects, which today are seen as fundamental for local modern architecture. By shifting the emphasis from the horizontal cut of the plan to the vertical cut of the section, a tectonic dimension is introduced into the design and analytical process, connecting space and form to conditions of load, materiality and sensory perception. In this investigation we will see how the vertical cut, due to its capacity to make evident the material assemblies used in the different elements that come into contact with the ground, as well as those that rise more lightly toward the sky, tend to reveal architectural intentions which are usually hidden behind the finished surface of a project. In these the tectonic objectives used to give character or perceptual value to the different spaces, introducing notions of techné as the ontological essence of architecture.This led to the creation of an architecture that implicitly or explicitly incorporated the horizontal fluidity typical of early 20th century modern space with the vertical openness of the courtyard house. This typological cross between pavilion and courtyard, more than a nostalgic crossbreeding between past and present, arose from an objective response to the external topographic, environmental and phenomenological forces to which the young architects of this period responded. Therefore, the vertical cut of the house, and its placement on one or more platforms located on different levels, altered the idea of the architectural object as an isolated pavilion, where the exterior garden, more than an open and continuous space becomes a series of courtyards with clear physical and dimensional limits, resulting from the displacement of the bearing walls of the tradicional house to the perimeter of the site, generating an ambiguous reading between what is inside and outside.In this sense, the irregular topography of the sloping sites on which the modern houses were built between 1960 and 1985, can be seen not only as a constructive challenge, but as a catalyst that led to spatial, morphological and material solutions of great value. For this reason, independent of the particular strategy of vertical cut used, we find in the section and the horizontal and vertical displacement of certain elements such as slab, wall or roof, an ideal design tool for the investigation of architectural form, materiality, space and sensory perception.In conclusion, despite the fact that the modern movement assigned to the plan or horizontal cut the role of primary design tool, this investigation proposes that the section, rather than a drawing that only emphasizes the technical and material aspects of a building, is one that allows the architect to think of space as directly related to place, where space is intertwined with the sensory conditions of perception and the world as experience by the human body.

Author: BERMEO AYERBE, MIGUEL ANGEL
Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
Programme: DOCTORAL DEGREE IN AUTOMATIC CONTROL, ROBOTICS AND VISION
Department: Institute of Robotics and Industrial Informatics (IRI)
Mode: Temporary seizure
Deposit date: 30/09/2022
Reading date: 02/12/2022
Reading time: 11:00
Reading place: fme_ ala de Juntes, Facultat de Matemàtiques i Estadística (FME), Campus Diagonal Sud, Carrer de Pau Gargallo, 14, 08028 Barcelona.
Thesis director: OCAMPO MARTINEZ, CARLOS AUGUSTO | DÍAZ ROZO, JAVIER
Committee:
     PRESIDENT: SALVO ROSSI, PIERLUIGI
     SECRETARI: TORNIL SIN, SEBASTIAN
     VOCAL: SCHOU, CASPER
Thesis abstract: Concern about energy efficiency has increased in the industry, mainly motivated by rising energy prices and government policies to raise awareness of environmental impact. For this reason, this thesis is dedicated to developing energy efficiency improvements in the industry, optimizing the use of electrical resources, and providing methodologies for proper equipment maintenance. Take into account that energy efficiency is not only maximized with proper management, but also is achieved by enhancing equipment efficiency with early maintenance under a predictive maintenance scheme. The proposed methodologies have been validated in realistic industrial scenarios, using testbeds based on industrial equipment and processes. A case study has been carried out at Bilbao airport to prove the effectiveness of one of the proposed methods.A nonlinear dynamic modeling approach is proposed to create accurate models based on electrical consumption measurements of an industrial machine, whose model structure is widely used in control theory. Using this modeling methodology, an adaptive mechanism is developed that can be defined as a digital twin of a manufacturing machine, being able to update the model when the system undergoes a new behavior. The adaptive digital twin can track the degradation trend of the actual system. The digital twin can be easily integrated into innovative infrastructures such as the energy cloud. The data-driven modeling methodology is used to design a model predictive control approach to improve energy efficiency in a manufacturing machine, without affecting productivity. This control strategy manages the peripheral devices of the machine, guaranteeing the proper operation of the auxiliary tasks while maximizing the energy efficiency of the machine. The adaptive mechanism is integrated with the controller, giving robustness to the control to deal with industrial environments. Towards an energy improvement of the industry through proper maintenance, this dissertation presents condition monitoring approaches for early detection and prognosis of electromechanical system failures, exclusively using electrical measurements. The proposed approaches characterize and monitor the torque oscillations transmitted in the motor stator current. Mechanical and electrical anomalies that can lead to failures are detected early, simply by installing a non-intrusive sensor on the motor. A healthy index is designed to track the degradation trend of the system without the need to specify a particular failure. For industrial cases where the information on possible faults may be limited or null, this healthy index is proposed to deal with those situations, extracting a general condition of an electromechanical system. The health index measures how the behavior of the current spectrum fits into a healthy representation by an average spectrum and its distribution. This methodology provides early warnings to schedule maintenance interventions as soon as possible, where a comprehensive diagnosis can be made. A prognosis methodology is proposed to anticipate failures with enough time to schedule proper maintenance. This is designed to monitor the most critical components that are sensitive to failure. A new health index is presented that characterizes the fundamental failure frequencies. This indicator has a monotonically increasing trend, which has been modeled with exponential regressions. By computing the online multiple exponential regression, a non-parametric distribution of time-to-failure is updated, describing the remaining time to reach an established failure threshold. The most likely time-to-failure is revealed over time, being used to estimate the remaining useful life of the components with confidence limits. With this novel and reliable methodologies, the maintenance process in the industry can be improved, avoiding falls in inefficiencies for a long time that causes energy waste.

Author: CASTILLO FUENTEALBA, CARLOS IGNACIO
Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
Programme: DOCTORAL DEGREE IN ARCHITECTURAL DESIGN
Department: Department of Architectural Design (PA)
Mode: Normal
Deposit date: 04/11/2022
Reading date: pending
Reading time: pending
Reading place: pending
Thesis director: SOLAGUREN-BEASCOA DE CORRAL, FELIX
Committee:
     PRESIDENT: FERRER FORES, JAIME JOSE
     SECRETARI: GASTON GUIRAO, CRISTINA
     VOCAL: LABARTA AIZPUN, CARLOS
     VOCAL: FERNANDEZ ELORZA, HECTOR DANIEL
     VOCAL: PALOMARES FIGUERES, MAITE
Thesis abstract: The purpose of the doctoral thesis is to study interior spaces - built in the old tradition of closed and contrasted architecture ¿ relativized in their interior condition. In the classical opacity and the difference between the inside and the outside, we find a different relationship to the so-called "fluid space" of modernity, between the interior and the exterior condition. The first part approaches a conceptual definition of the topic, understanding the interior-exterior as the construction of an interior and, simultaneously, an exterior experience, of opposite tendency in the intimacy of confinement. Reviewing from the intemperie, that manufactures the intrusion of atmospheric phenomena in the enclosed space, to a more unprejudiced and heterogeneous way of understanding the interior as exterior.The body of the thesis is divided into three maps (or parts) that grasp the interior-exterior from an independent point of view, studying the treatment of its limits, but with the constraint of always beginning the story in Mediterranean interiors, to continue in Germany, and culminate mainly in the architecture of Nordic neoclassicism in Sweden and Denmark. Together, they make up the observatory proposed by the Thesis, overlapping in a single cartography that follows the reverse orientation left by the displacements of Northern European architects to the classical world.Within each map, the interiors are ordered according to two simultaneous criteria: firstly, a thematic perspective. And, secondly, a geographical disposition with a northerly direction. The interiors are progressively linked to explain the proposed argument and each interior space presupposes the explanation of the previous one. Moreover, the three maps follow a sequential order, although each one has enough individual nature for non-linear reading.The first map revisits the maximum exteriority that defines the symbol of contained universal space and the vertical tendency of the enclosure, finding its revelation in the infinite staircase. The second map traces the dome and the tent in the romantic garden, both suspended within traditional roofs, hidden among trees of picturesque outdoor promenades. Finally, the third map explores inductively the things, inventorying elements that, placed inside, relativize the interior and approach the ambiguity of an internal landscape.The winter climate conditions the architecture of Northern Europe and the need for covering establishes a dialectical relationship with the exterior experience and also with the repetition and interpretation of the admired classical interiors, increasing, by contrast, the exterior condition of its interiors.