Induction motors, often referred to as the workhorse of the industry, play an important role in production today. Therefore, it's important to diagnose any faulty induction motor prior to failure to avoid costly and time consuming production stops.This thesis compares methods for diagnosing induction motors in operation, MCSA, Park's vector approach and the standard method used by Swedish industries today. By simulating broken rotor bars and short-circuit in one of the windings, each method is tested and the results are compared using matlab.The results need further verification due to uncertainties of the condition of the test motor, even though the experiment gives a hint of the different advantages of each method. A combination of the methods should be able to tell if the motor needs further examination.

Στην παρούσα διπλωματική εργασία ασχοληθήκαμε με το θέμα της μελέτης και διάγνωσης σφαλμάτων λόγω δυναμικής εκκεντρότητας σε Ασύγχρονη Μηχανή. Μοντελοποιήθηκε και αναλύθηκε η λειτουργία ενός τριφασικού ασύγχρονου τετραπολικού κινητήρα κλωβού, ισχύος 4 kW με 36 αυλακώσεις στο στάτη και 28 αυλακώσεις στο δρομέα, τόσο σε υγιή κατάσταση όσο και υπό συνθήκες σφάλματος. Πιο συγκεκριμένα, με χρήση της μεθόδου των Πεπερασμένων Στοιχείων σε δύο διαστάσεις μέσω του προγράμματος Opera, προσομοιώθηκε η λειτουργία του κινητήρα μας υπό δύο διαφορετικά ποσοστά σφάλματος, για 20% και για 40% και εφαρμόστηκε η μέθοδος της “Motor Current Signature Analysis - MCSA” για τη διάγνωση του σφάλματος αυτού υπό διαφορετικά επίπεδα φορτίου. / In this paper we addressed the issue of diagnostic research due to dynamic eccentricity related faults in Induction Machines. We modeled and analyzed the function of a three-phase quadrupole induction motor with a cage rotor with 36 stator slots and 28 rotor slots, both in healthy condition and under fault conditions. More specifically, using the finite element method in two dimensions through the "Opera" software, we simulated our motor operation under our two different error rates for 20% and 40% and subsequently we used the "Motor Current Signature Analysis - MCSA" diagnostic method for the diagnosis of this error under different load levels.

This thesis is concerned with condition monitoring and quantitative analysis of synchronous motors. Constantly rising requirements on the reliability of motors develop new methods of predictive diagnostics, which can identify failure conditions in the initial stage. Created mechatronic systems with the implemented failure from pre-prepared PMSM model are tested by unconventional condition monitoring methods. Software solutions of diagnostics and model designs of the mechatronic systems are implemented in MATLAB & Simulink. Part of this work is also a short introduction to the issue with necessary theoretical fundamentals and research of some selected methods of predictive diagnostics.

Dans une machine à induction, le diagnostic de défauts par analyse du signal du courant électrique nécessite la connaissance du comportement dynamique de la machine. En plus des sources externes d'excitation, le comportement du moteur est gouverné par un ensemble de phénomènes périodiques liés sa géométrie angulairement périodique et couplés par leur caractère multiphysique. En présence d’un défaut de roulement, les grandeurs mesurables présenteront des composantes à sa fréquence caractéristique combinée aux fréquences caractéristiques du moteur. La compréhension des interactions, en particulier de modulation, passe par la mise en place de modèles numériques qui représentent les manifestations des phénomènes couplés. Ce travail de thèse propose donc un modèle électro-magnéto-mécanique d'une machine à induction à cage d'écureuil couplé à un modèle de palier à roulement à billes dans un cadre original d'écriture appelé "Approches Angulaires". En conservant dans la modélisation la relation "Angle-Temps" il est possible d'étendre aisèment la modélisation aux conditions de fonctionnement non-stationnaires et d'introduire un couplage fort entre les modèles mécanique et électromagnétique. Ainsi, on montre que la vitesse angulaire instantanée est la grandeur qui assure la transmission du défaut mécanique localisé aux grandeurs électriques. Le modèle proposé offre ainsi un décryptage des phénomènes de modulation présents sur la voie de transfert et décrits par les couplages de comportements dynamiques cycliques (réseau de perméances, chargement des éléments roulants,...) et/ou périodiques (résonances de structure, résonance électriques, ...). Ces travaux ouvrent la voie à une meilleure compréhension du comportement couplé multiphysique d'une machine électrique pour mieux spécifier les outils de surveillance à mettre en œuvre. Les futurs développements peuvent maintenant s'orienter ver une complexification des modèles ou l'exploitation de comportements dynamiques fins en régime non-stationnaire. / In an induction machine, the diagnosis of defects by analysis of the electrical current signal requires knowledge of the dynamic behavior of the machine. In addition to external excitation sources, the behavior of the motor is governed by a set of periodic phenomena related to its angularly periodic geometry and coupled by their multiphysical character. In the presence of a bearing defect, measurable quantities will have components at its characteristic frequency combined with the characteristic frequencies of the engine. The understanding of interactions, in particular modulation, requires the implementation of numerical models that represent the manifestations of coupled phenomena. This thesis work proposes an electro-magneto-mechanical model of a squirrel-cage induction machine coupled to a rolling bearing model in an original writing frame called "Angular Approaches". By keeping the "Angle-Time" relation in modeling, it is possible to easily extend the modeling to non-stationary operating conditions and to introduce a strong coupling between the mechanical and electromagnetic models. Thus, it is shown that the instantaneous angular speed is the quantity which ensures the transmission of the localized mechanical defect to the electrical quantities. The proposed model thus offers a decryption of the modulation phenomena present on the transfer path and described by the couplings of cyclic dynamic behaviors (permeance network, loading of the rolling elements, etc.) and / or periodic (structural resonances, electrical resonance, etc.). This work opens the way for a better understanding of the multiphysical coupled behaviors of an electrical machine to better specify the monitoring tools to be used. Further developments can now be directed to a complexity of models or to the exploitation of fine dynamic behaviors in a non-steady operating conditions.

The thesis Diagnostics of rotating electric machines deals with the theory of diagnostics of rotating machines, focusing especially on the diagnosis of asynchronous motors of high power. Due to the importance of maintaining the trouble-free condition of these machines with regard to serviceability, the importance of their diagnosis is growing. Due to inappropriate working conditions or for many other reasons, different types of malfunctions may occur in the machine. The list and the way of occurrence of possible failures are included and explained in this thesis. With the growing age of the machine, it is important to check the insulation status through insulation testing. These tests are performed in the practical part of the thesis and the results are presented. In the case of asynchronous machines, each anomaly leaves a signature in the form of an electrical, magnetic or vibrational signal. These signals are analyzed and evaluated using a specific measuring equipment with the intention of deciding on the current state of the machine. Motor current signature analysis (MCSA) is considered to be the main diagnostic method of asynchronous machines in this thesis. This method is described in detail in this paper and is being applied in electrical engineering.

[pt] Esta dissertação pretendeu compreender de que forma a sociedade civil participou na formulação de estratégias e de controle da execução da política de Assistência Social na cidade do Rio de Janeiro. Sobretudo, compreender as formas e os mecanismos pelos quais os conselheiros eleitos, representantes da sociedade civil para a gestão 2013-2015, inscreveram seus projetos políticos no seio do aparelho de Estado através da representação das suas entidades, entendidas neste estudo como aparelhos privados de hegemonia. Neste contexto, buscou-se: a) identificar quais temas e situações foram analisados na gestão 2013- 2015 do CMAS/RJ; b) conhecer as formas e os mecanismos pelos quais os conselheiros civis inscreveram seus projetos através da representação das suas entidades; c) entender como os consensos foram construídos e d) até que ponto os projetos dos conselheiros civis estavam alinhados com as diretrizes do Sistema Único de Assistência Social (SUAS). Para o desenvolvimento do estudo foram utilizados conceitos gramscianos, tais como sociedade civil, intelectuais orgânicos, entre outros Os procedimentos metodológicos adotados incluíram, além da realização da pesquisa bibliográfica que forneceu informações aproximativas sobre o recorte da temática em questão, a análise documental, realizada a partir dos documentos coletados no campo, isto é, de 41 atas, 175 resoluções e 4 relatórios elaborados na gestão analisada, os quais foram posteriormente examinados a partir do seu conteúdo temático. Também foram realizadas 12 entrevistas semiestruturadas, as quais permitiram um contato mais íntimo com os sujeitos da pesquisa. Essa etapa proporcionou uma melhor compreensão não só sobre o material coletado, mas, em especial, sobre a reconstituição da criação do CMAS/RJ, pois alguns desses entrevistados já estavam nesse espaço há bastante tempo. Os dados obtidos e as análises empreendidas levam à constatação de que o CMAS/RJ se encontra numa posição periférica em relação aos processos que envolvem decisões propositivas para a política de assistência social em decorrência do caráter extremamente autorreferenciado e cartorial. Pode-se também identificar uma tendência conscienciosa e colaborativa entre os conselheiros titulares e suplentes civis e governamentais, além de identificada uma dinâmica boca-a-boca para a reprodução e perpetuação do establishment realizada pelos conselheiros que, em sua grande maioria, mais de 90 por cento, são assistentes socais. O que está em disputa na agenda do Conselho é a interdependência entre o público e o privado na prestação dos serviços socioassistenciais. Dessa maneira, o estudo revela o quanto a Política Nacional de Assistência Social (PNAS) não rompeu e nem superou a relação público-privado, mas a resinificou na história da assistência social no Brasil. O grande desafio esteve em pensar o CMAS/RJ tendo em conta suas tensões, contradições, limites e possibilidades sem, contudo, reiterar um discurso fatalista que configura este local como o da barganha, da cooptação e da luta por interesses corporativos ou tomando como o único espaço possível para a materialização da democracia e de exclusivo meio para avaliação e proposição das políticas de assistência social no município. / [en] It was intended to understand how civil society participated in the formulation of strategies and control of the implementation of Social Assistance policy in the municipality of Rio de Janeiro and, above all, to understand the forms and mechanisms by which elected councilors, representatives of civil society in the 2013-2015 administration inscribed their political projects within the State apparatus through the representation of their entities, understood in this study as private hegemony devices. In this context, we was sought to: a) identify which themes and situations were analyzed in the 2013-2015 administration of the CMAS / RJ; b) know the forms and the mechanisms by which the civil councilors inscribed their projects through the representation of their entities; c) to understand how consensus was built; and d) to know the extent to which the civil counselors projects were aligned with the guidelines of the Single Social Assistance System (SUAS). For the development of the study Gramscian concepts such as civil society, organic intellectuals, among others, were used besides the accomplishment of bibliographical research that provided approximate information on the cut of the subject in question. The research also had documentary analysis collected in the field, that is, of 41 minutes, 175 resolutions and 4 reports elaborated in the analyzed management, which were later examined from the thematic content. There were also 12 semi-structured interviews, which allowed a more intimate contact with the research subjects. This step provided a better understanding not only of the material collected, but especially about the reconstitution of the creation of CMAS/RJ, since some of those interviewees had been in this space for a long time. The data obtained and the analyzes undertaken lead to the realization that the CMAS/RJ is in a peripheral position in relation to the processes involving propositive decisions for social assistance policy due to the extremely self-referential and cartorial character. It is also possible to identify a conscientious and collaborative trend among the civil and government board members and deputies, as well as to identify a dynamic word of mouth for the reproduction and perpetuation of the establishment by the councilors, who more of 90 percent, are social workers. What is in dispute on the Council s agenda is the interdependence between the public and the private in the provision of social assistance services. In this way, the study reveals how the National Social Assistance Policy (PNAS) did not break and did not overcome the public-private relationship, but it has resignified it in the history of social assistance in Brazil. The main challenge was to think about CMAS/RJ, taking into account its tensions, contradictions, limits and possibilities, without reiterating a fatalistic discourse that configures this place as that of bargaining, cooptation and the struggle for corporate interests or taking as the the only possible space for the materialization of democracy and the exclusive means for evaluating and proposing social assistance policies in the municipality.

Las máquinas eléctricas de inducción están presentes en la mayoría de los procesos productivos (suponen alrededor de un 90% del total de máquinas eléctricas existentes en el mercado), gracias a su simplicidad constructiva y a su fiabilidad. Por motivos de producción y sobre todo económicos se hace necesario poder diagnosticas y detectar los posibles fallos que puedan surgir, incluso de modo incipiente, para evitar paradas no programadas con las consecuencias negativas que esto supone. De ahí que en las últimas décadas se hayan realizado inversiones tanto económicas como humanas para investigar y desarrollar técnicas no invasivas que sean capaces de detectar y diagnosticar los fallos o averías que puedan surgir. Además es muy recomendable que estas técnicas puedan ser aplicadas en línea, sin necesidad de parar la máquina eléctrica y bajo cualquier régimen de funcionamiento. Tradicionalmente, la detección y diagnosis de fallos en las máquinas eléctricas se ha realizado en régimen permanente. Inicialmente, se utilizó la medida de las vibraciones de la máquina. Desde hace unos años se está investigando y experimentando con la medida de la corriente estatórica, basándose principlamente en el análisis frecuencial mediante la transformada de Fourier. Recientemente, se están aplicando nuevas técnicas avanzadas de análisis de señal para sustituir a la transformada de Fourier, ya que esta presenta problemas indeseados, como por ejemplo el efecto de dispersión de la señal o comúnmente denominado como efecto "leakage". También se ha comenzado a utilizar señales capturadas en régimen transitorio, principlameante la corriente de la máquina eléctrica consumida en el aarranque, para su posterior análisis mediante la transformada wavelets y a través de esta transformada diagnosticar y detectar las posibles averías. Esta es una de las líneas principales de desarrollo del grupo de investigación al que pertenezco. En la presente tesis se desarrollan cuatro nuevos métodos basados en dif / Puche Panadero, R. (2008). Nuevos métodos de diagnosis de excentricidad y otras asimetrías rotóricas en máquinas eléctricas de inducción a través del análisis de la corriente estatórica [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/3543

Med övergången från Industri 3.0 till Industri 4.0 kommer stora krav på utvecklingen av Prediktiva Underhållsmetoder (PU) för att skona både miljö och ekonomi från påfrestande haverier. I detta projekt utfördes en installation av ett iba datainsamlingssystem, som är ett bra exempel på utvecklingen mot Industri 4.0. Vidare togs en prediktiv modell som skattar återstående livslängd med metoden Motor Current Signature Analysis (MCSA), som baseras på linjeströmsmätning, fram i projektet. Metoden analyserade strömmen från två olika induktionsmotorer för kylvattenpumpar där det var en ny pump och en sliten pump. Induktionsmotorer används inte enbart i kylvattentillämpningar utan integreras frekvent i kommersiellt tillgänglig utrustning, så den prediktiva modellen har ett expanderbart användningsområde. Två tillvägagångssätt testades för att hitta signaturer i linjeströmmen. Först testades spektrum-analys med 10Hz och 1000Hz som samplingsfrekvenser med slutsatsen att högre samplingsfrekvens troligen behövs för ett trovärdigt resultat. Sedan testades Analys av signalegenskaper med ANOVA som gav en klar signatur för toppvärden i ström med slutsatsen att skillnaden i ström mellan ny och sliten pump var tydlig men kunde vara av installationstekniska skäl. En förenklad skattning av Remaining Useful Life (RUL) med tillhörande rekommendation av underhållsinsats togs fram för att visualisera resultatet. Rekommenderat fortsatt arbete med modellen var klassificeringsalgoritmer, anpassad datainsamlingsutrustning och förlängd datainsamlingsperiod. / With the transition from Industry 3.0 to Industry 4.0 follows great demands on the development of predictive maintenance (PU) in order to spare both the economy and the climate from costly breakdowns. An installation of a iba data acquisition system was applied in this project, which is a good example on the advances made through Industry 4.0. The project shows the development of a predictive model, which estimates the remaining life with the method motor current signature analysis (MCSA) that is based on phase current. Data was collected on two different induction motors for cooling water pumps, one new and one worn out pump. Induction motors are not only used in cooling water applications but are frequently applied in commercially available equipment, thus the method has a expandable use. Two methods were tested for finding signatures in the phase current. First, spectrum analysis with 10 and 1000Hz as sampling frequencies with the conclusion that a higher sampling frequency likely is needed for a reliable result. Secondly an analysis of signal properties with ANOVA was preformed. This gave a clear signature for peak values in the current with the conclusion that the difference between new and worn out pump was clear but could be the result of installation related issues. A simplified version of remaining useful life (RUL) with related maintenance procedure was developed to visualize the result. For continued work with this model it is recommended to develop classification algorithms, improve the data acquisition equipment and prolong the data acquisition period.

This qualitatively oriented Practical Theology research project was based on a narrative inquiry into the spiritualities of six gay women who are related to Northfield Methodist Church, which is situated in Benoni, Gauteng. These conversations occurred within a small group context, and were aimed at co-authoring preferred ways of being both gay and Christian. Toward the end of the research journey, I asked each participant to prepare a written text that would summarise their experience of being simultaneously gay and Christian, so that by hearing their own stories of their journey, they would be able to find a voice. As these women are usually marginalised in the Methodist Church, I invited various groups to audience their stories. This research report records the beginning of my journey into working towards the complete acceptance of gay and lesbian Christians into the Methodist Church of Southern Africa. / Practical Theology / M. Th. (Pastoral Therapy)

This qualitatively oriented Practical Theology research project was based on a narrative inquiry into the spiritualities of six gay women who are related to Northfield Methodist Church, which is situated in Benoni, Gauteng. These conversations occurred within a small group context, and were aimed at co-authoring preferred ways of being both gay and Christian. Toward the end of the research journey, I asked each participant to prepare a written text that would summarise their experience of being simultaneously gay and Christian, so that by hearing their own stories of their journey, they would be able to find a voice. As these women are usually marginalised in the Methodist Church, I invited various groups to audience their stories. This research report records the beginning of my journey into working towards the complete acceptance of gay and lesbian Christians into the Methodist Church of Southern Africa. / Philosophy, Practical and Systematic Theology / M. Th. (Pastoral Therapy)