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Dissertations / Theses on the topic 'Motor Current Signature Analysis'
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1
Štěpanovský, Libor. "Vyhodnocení provozního stavu asynchronních motorů jaderné elektrárny Dukovany metodou frekvenční analýzy statorového proudu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442548.
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The masters thesis is concerned with the setting of limits and criteria, the design of database environment and the evaluation of the current state of motors of the important machines related to own consumption of the Nuclear power plant Dukovany. The first part of the thesis is a short description of induction motors, the evaluation method and the inventory of the observed motors related to own consumption of Nuclear power plant Dukovany. The second part of the thesis concerns the design of limits and criteria for evaluating the current state of these important motors. Finally, the thesis shows a short description of the electro monitoring system together with the description of the database environment created. In the supplementary materials of the thesis, there is a design of a protocol template for evaluation of the current state of the motor and a technical report template for regular evaluation in monitored areas MCSA (Motor Current Signature Analysis) of the state of the induction motors.
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Davari, Ardakani Hossein. "Prognostics and Health Management of Engineering Systems Using Minimal Sensing Techniques." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1467987980.
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Doan, Donald Scott. "Using Motor Electrical Signature Analysis to Determine the Mechanical Condition of Vane-Axial Fans." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3256/.
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The purpose of this research was a proof of concept using a fan motor stator as transducer to monitor motor rotor and attached axial fan for mechanical motion. The proof was to determine whether bearing faults and fan imbalances could be detected in vane-axial fans using Motor Electrical Signature Analysis (MESA). The data was statistically analyzed to determine if the MESA systems could distinguish between baseline conditions and discrete fault frequencies for the three test conditions: bearing inner race defect, bearing outer race defect, and fan imbalance. The statistical conclusions for these proofs of concept were that MESA could identify all three faulted conditions.
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Guldemir, Hanifi. "Prediction of induction motor line current spectra from design data." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287180.
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Lippi, Silvio. "Analysis of rotor eddy-current losses in synchronous motors." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022.
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La stima delle perdite rotoriche per correnti parassite (Eddy currents) è cruciale nella progettazione dei moderni motori SPM. Poichè le loro prestazioni dipendono fortemente da esse. I motori devo essere progettati in modo da prevenire eccessive perdite rotoriche, le quali possono portare alla demagnetizzazione dei magneti e ad un deterioramento delle performance generali della macchina. Nel capitolo 1 sono illustati i principi fisici che descrivono il comportamento dei motori elettrici e delle perdite rotoriche per correnti parassite. Sono poi discusse le proprietà dei materiali impiegati nell'ambito della costruzione di macchine elettriche ed infine sono presentate le tecniche al momento più diffuse per la stima delle correnti parassite. Dopo di che nel capitolo 2 è analizzato un modello semplificato di un SPM, in cui il rotore è sostituito con un cilindro solido. In particolare è stata investigata la dipendenza dalla resistività del materiale impiegato per il rotore. Una tecnica basata sul current sheet per la stima delle perdite rotoriche è presentata in dettaglio e implementata. Infine è riportata la validazione della procedura basata sul current sheet. Nel capitolo 3 l'analisi è estesa a un reale motore SPM, in particolare sono investigate le perdite nei magneti. Sono quindi illustrate le criticità di tale analisi e i limiti del modello. Per finire nel capitolo 4 sono riportati i risultati dei test effettuati, e sono discussi possibili futuri sviluppi del metodo illustrato.
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Gan, Jinyun, and 干金云. "Design, analysis and control of multiphase flux regulated permanent magnet brushless DC motor drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31245304.
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Whittaker, Lucy M. T. "Modelling and analysis of current and concept vehicles for the purpose of enhancing vehicle handling : executive summary." Thesis, University of Warwick, 2001. http://wrap.warwick.ac.uk/2902/.
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In this document, research into the modelling and analysis of current and concept vehicles for the purpose of enhancing vehicle handling is summarised. This work is recounted in detail in a portfolio of reports that has been submitted for the degree of Doctor of Engineering. The portfolio includes fifteen submissions, eleven of which are concerned with the analysis and simulation of drivers' steering behaviour. Two relate to a novel suspension concept. One addresses a current problem caused by suspension variability and one introduces a process for selecting between new suspension concepts. Each of these fifteen submissions is summarised in this document. In addition, the order in which it is recommended that these submissions be read is listed. In section 4, a project summary of the research into the analysis and simulation of drivers' steering behaviour is presented. Existing models of drivers' steering behaviour are reviewed. Vehicle tests that illustrate the different steering styles used by different drivers are recounted. A driver model that simulates the steering behaviour exhibited in these tests is formulated . Then, this driver model is used to develop a switching strategy for variable dampers. It is demonstrated that the switching strategy enhances vehicle handling and reduces the roll experienced by drivers during a handling manoeuvre. Finally, it is verified that this research complies with the requirement of the degree of Doctor of Engineering to demonstrate innovation in the application of knowledge to the engineering business environment. This is achieved by specifying eight examples of where new ideas and methods have been applied to address current issues within the automotive industry.
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Wu, Long. "Separating Load Torque Oscillation and Rotor Faults in Stator Current Based-Induction Motor Condition Monitoring." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14545.
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Stator current spectral analysis techniques are usually used to detect rotor faults in induction machines. Magnetic field anomalies in the airgap due to the rotor faults result in characteristic side-band harmonic components in the stator current spectrum, which can be measured as rotor fault signatures. A position-varying load torque oscillation at multiples of the rotational speed, however, has exactly the same effect. Stator current harmonics due to a load torque oscillation often obscure and even overwhelm rotor eccentricity fault detection since the magnitude of load oscillation induced harmonics is usually much larger.
Although previous research has suggested some methods to differentiate between these two effects, most of them rely heavily on the accurate estimation of motor parameters. The objective of this research is to develop a far more practical and computationally efficient method to detect rotor faults effectively in the presence of a load torque oscillation. A significant advantage of the proposed scheme is that it does not need any knowledge of motor parameters. The normalized negative sequence information induced by a mixed rotor eccentricity in the stator current or terminal voltage space vector spectra, serves as a reliable rotor fault indicator to eliminate load oscillation effects.
Detailed airgap magnetic field analysis for an eccentric motor is performed and all machine inductance matrices as well as their derivatives are reformulated accordingly. Careful observation of these inductance matrices provides a fundamental understanding of motor operation characteristics under a fault condition. Simulation results based on both induction motor dynamic model and Maxwell 2D Finite Element Model demonstrate clearly the existence of the predicted rotor fault indicator. Extensive experimental results also validate the effectiveness and feasibility of the proposed detection scheme.
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Blödt, Martin. "Condition Monitoring of Mechanical Faults in Variable Speed Induction Motor Drives. Application of Stator Current Time-Frequency Analysis and Parameter Estimation." Phd thesis, Toulouse, INPT, 2006. http://oatao.univ-toulouse.fr/7468/1/blodt.pdf.
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This Ph.D. thesis deals with condition monitoring of mechanical failures in variable speed induction motor drives by stator current analysis. Two effects of a mechanical fault are considered: load torque oscillations and airgap eccentricity. The analytical modelling using the magnetomotive force and permeance wave approach leads to two stator current models. The fault provokes amplitude or phase modulation of the fundamental current component. Suitable detection methods are spectral analysis and parameter estimation in steady state whereas time-frequency analysis is required during transients. Instantaneous frequency estimation, the Wigner Distribution and the spectrogram are studied. Simulation and experimental results validate the theoretical approach. Automatic extraction of fault indicators is proposed for an unsupervised monitoring system. Moreover, load torque oscillations and dynamic eccentricity can be discriminated with the proposed methods. The feasibility of an on-line monitoring system is demonstrated by a DSP implementation of the time-frequency analysis including indicator extraction.
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Rabbi, Ata-E. "Detection of stator interturn fault of synchronous machine by rotor current analysis : A SIMULATION APPROACH." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187654.
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One of the major electrical faults of synchronous machines is an interturn short circuit in the stator winding, due to winding insulation failure. A synchronous machine is designed to have electrical and mechanical symmetry in the stator and rotor. An interturn fault in a synchronous machine damages the symmetrical property, thereby inducing abnormal symptoms like varying torque, mechanical vibration, and deviation of stator and rotor terminal currents from their usual waveform. This last symptom is what is studied in this thesis, as an indicator of the presence of an interturn fault. An interturn fault during machine operation can lead to a catastrophic machine failure and consequent long outage, unless it is rapidly detected and the machine shut down. Prevention of such outages is an important concern for machine owners and power system operators. That is why early detection of interturn faults is desirable to prevent such machine failure. Several external sensors can be implemented to detect such interturn fault, which is costly. That is why it is desirable if the interturn fault can be detected by analyzing the measured currents that already are available to a protective relay. In this thesis a simulation approach is presented to observe the pattern and frequency spectrum of rotor field current in presence of a stator inter turn fault. All simulations have been performed using Matlab-based programs written during this thesis work in the Electromagnetic department (ETK) in KTH. The outcome of the thesis is that in the presence of an interturn fault in the stator, several even harmonic components are found in the frequency spectrum of the rotor field current. The presence of these harmonics is not a definitive sign of an interturn fault, as almost the same even harmonics are found in the rotor field current if the stator winding asymmetry is taken into account.En av de största elektriska felen i synkronmaskiner är en kortslutning mellan varv i statorlindningen, på grund av skadad lindningsisolering. En synkronmaskins konstruktion ger elektrisk och mekanisk symmetri i statorn och rotorn vilket ger en hög effektivitet. Ett varvfel i statorn skadar symmetrin och inducerar onormalt stora strömmarvilket leder till ett tidsvarierande vridmoment, mekanisk vibration, och onormala vågformer av strömmarna vid statorns och rotorns poler. Varvfel under maskinens drift kan snabbt orsaka stora skador, med följd av långa avbrottstider. Förebyggande av sådana avbrott är viktig hos maskinägare och systemansvariga. Därför är snabb detektering av sådana fel, och urdrifttagning av maskinen önskvärd för att minska skadan. Däremot ska detekteringen ha låg sannolikhet att lösa ut i onödan, av annat skäl. Externa sensorer kan användas för att upptäcka sådana fel, men det är tydligt önskvärt om detekteringen kan göras genom att analysera strömmarna som redan mäts av skyddsreläer för synkronmaskiner. I denna avhandling presenteras en metod för att simulera och observera mönster och frekvensspektrum av rotors magnetiseringsström i fall där statorn har varvfel, samt i andra fall som måste kunna skiljas från varvfel. Alla simuleringar har utförts med Matlab hos avdelningen för Elektroteknisk teori och konstruktion (ETK) i Skolan för Elektro- och systemteknik (EES) på KTH.
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Lim, Jung Youl. "A distributed multi-level current modeling method for design analysis and optimization of permanent magnet electromechanical actuators." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53990.
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This thesis has been motivated by the growing needs for multi-degree of freedom (M-DOF) electromagnetic actuators capable of smooth and accurate multi-dimensional driving motions. Because high coercive rare-earth permanent-magnets (PMs) are widely available at low cost, their uses for developing compact, energy-efficient M-DOF actuators have been widely researched. To facilitate design analysis and optimization, this thesis research seeks to develop a general method based on distributed source models to characterize M-DOF PM-based actuators and optimize their designs to achieve high torque-to-weight performance with compact structures
To achieve the above stated objective, a new method that is referred to here as distributed multi-level current (DMC) utilizes geometrically defined point sources has been developed to model electromagnetic components and phenomena, which include PMs, electromagnets (EMs), iron paths and induced eddy current. Unlike existing numerical methods (such as FEM, FDM, or MLM) which solve for the magnetic fields from Maxwell’s equations and boundary conditions, the DMC-based method develops closed-form solutions to the magnetic field and force problems on the basis of electromagnetic point currents in a multi-level structure while allowing trade-off between computational speed and accuracy. Since the multi-level currents can be directly defined at the geometrically decomposed volumes and surfaces of the components (such as electric conductors and magnetic materials) that make up of the electromagnetic system, the DMC model has been effectively incorporated in topology optimization to maximize the torque-to-weight ratio of an electromechanical actuator. To demonstrate the above advantages, the DMC optimization has been employed to optimize the several designs ranging from conventional single-axis actuators, 2-DOF linear-rotary motors to 3-DOF spherical motors.
The DMC modeling method has been experimentally validated and compared against published data. While the DMC model offers an efficient means for the design analysis and optimization of electromechanical systems with improved computational accuracy and speed, it can be extended to a broad spectrum of emerging and creative applications involving electromagnetic systems.
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Hromek, Lukáš. "Posouzení a vyhodnocení bezpečnosti u el. strojů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242123.
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This thesis is focused on the security and improving of electrical rotating machines service life, especially asynchronous motors. Work includes a description of the most common disorders, short description of the asynchronous motor cage casting, analysis of provided decommissioned motors with photo documentation. The last part of this thesis is focused to vibrodiagnostic of asynchronous motor with simulated imbalance and motor emplacement by laser.
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Běloušek, Radim. "Náhradní zapojení asynchronních strojů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219367.
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Although induction motors are the simplest and most working reliability machines, is the identification of the parameters of their substituting circuit very difficult. There is solved the identification of the parameters of the substituting circuit in the T-network and ? –network in this work. The work also includes the proposal of magnetic circuit of the induction motor, the calculation of magnetizing and leakage inductances and resistances of the machine. The conclusion of the work is devoted to the sensitivity analysis of current and torque characteristics of induction motor upon the change of the single parameters of the substituting circuit.
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Oliveira, Venicio Soares de. "AplicaÃÃo do MÃtodo dos Elementos Finitos 3D na CaracterizaÃÃo EletromagnÃtica EstÃtica de Motores de RelutÃncia VariÃvel com ValidaÃÃo Experimental." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9299.
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nÃo hÃNeste trabalho à apresentado um estudo sobre as caracterÃsticas de magnetizaÃÃo estÃtica de um MRRV â Motor Rotativo de RelutÃncia VariÃvel â de 1 cv, com base na simulaÃÃo do projeto da mÃquina utilizando AnÃlise por Elementos Finitos (AEF) 3D com malhas tetraÃdricas e hexaÃdricas, com vistas a investigar a que mais adequava-se a esse estudo. TrÃs mÃtodos experimentais foram utilizados para a validaÃÃo do projeto via Elementos Finitos: mÃtodo de determinaÃÃo da impedÃncia com tensÃo CA, mÃtodo do tempo de subida de corrente DC de fase e mÃtodo do tempo de descida de corrente DC de fase. Um estudo comparativo foi realizado como forma de efetivar a validaÃÃo. Todas as tarefas de simulaÃÃo e de mediÃÃo foram realizadas utilizando um microcomputador. Para a realizaÃÃo da simulaÃÃo do projeto foi utilizado um software de simulaÃÃo numÃrica com anÃlise dos Elementos Finitos (CST STUDIO SUITE TM 2010Â) em trÃs dimensÃes, utilizando para tanto, malhas tetraÃdricas e hexaÃdricas. Para as tarefas de mediÃÃo, foi utilizada tambÃm uma placa de aquisiÃÃo de dados (DAQ) integrada a duas interfaces: do LabView e Signal Express ambos desenvolvidos pelo o mesmo fabricante da placa de aquisiÃÃo (National Instruments) com o objetivo de determinar a indutÃncia por fase do MRRV. A partir dos valores obtidos de indutÃncias por fase, foi calculado o fluxo concatenado por fase. GrÃficos de fluxo concatenado por corrente e perfis de indutÃncias para sete posiÃÃes sÃo apresentados e entÃo comparados com a simulaÃÃo por AEF. Tabelas evidenciando as diferenÃas de alguns valores entre os mÃtodos em termo de porcentagem sÃo apresentadas e discutidas. Uma avaliaÃÃo sobre todos os mÃtodos foi feita, evidenciando aspectos positivos, negativos, limitaÃÃes e sugestÃes de melhoria dos mesmos. A mÃquina estudada foi um Motor Rotativo de relutÃncia VariÃvel 6/4 (6 pÃlos no estator e 4 pÃlos no rotor), trifÃsico, de 1 cv de potÃncia, corrente nominal de 10A e velocidade de 2.000 rpm, projetado pelo Grupo de Pesquisa em AutomaÃÃo e RobÃtica do Departamento de Engenharia ElÃtrica da Universidade Federal do CearÃ.
This paper presents a study on the characteristics of a static magnetization VRRM - Variable Reluctance Rotating Motor â 1 hp, based on the simulation of machine design using Finite Element Analysis (FEA) with 3D tetrahedral and hexahedral meshes intending to investigate which meshes is the most suited to this study. Three experimental methods to validate the design via Finite Elements were used: method for determining the impedance with AC voltage, the rising time method of DC current phase and falling time of DC current phase method. All tasks of simulation and measurement were performed using a personal computer. To perform the design simulation a numeric simulation software was used with finite element analysis (CST STUDIO SUITE TM 2010Â) in three dimensions, using both, tetrahedral and hexahedral meshes. For measurement tasks also a data acquisition board (DAQ) integrated with two interfaces was used: the LabView and Signal Express both developed by the same manufacturer of the acquisition board (National Instruments) aiming to determine the inductance per phase of the VRRM. From the values obtained of inductance per phase the flux linkage per phase was calculated. Graphs of flux linkage with current and inductance profiles for seven positions are shown and compared with the simulation FEA. Tables showing the values of some differences between the methods in terms of percentage are presented and discussed. An evaluation of all methods was done, showing positives and negatives aspects, limitations and suggestions to improve them. The machine was a studied Variable Reluctance Rotating Motor 6/4 (6 stator poles and 4 poles on the rotor), three-phase, 1 hp, rated current of 10A and speed of 2.000 rpm, designed by the Research Group on Automation and Robotics, Department of Electrical Engineering, Federal University of CearÃ.
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Kroupa, Martin. "Analýza změny zátěže asynchronního motoru z měření statorových proudů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221189.
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This thesis is focused on the evaluation of rotor dynamics of the induction machine, which can be used as a basis for online diagnosis of driven load in the future. It describes the problem of time varying loading torque at its impact to electromagnetic variables in induction machine. Followed by the possible ways of monitoring and diagnostic of loading torque using Fourier analysis on supply current.
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Fabricio, Marcos Aurelio. "Monitoramento de Equipamentos El?tricos Industriais Utilizando IoT." Pontif?cia Universidade Cat?lica de Campinas, 2018. http://tede.bibliotecadigital.puc-campinas.edu.br:8080/jspui/handle/tede/1059.
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The objective of this work is to monitor the electrical equipment of a production line, aiming at monitoring in real time the state of the operation of the monitored machines, allowing the accomplishment of equipment management and early detection of operational deviations and faults. The developed system performs the measurement of the effective electric current through monitored equipment, use a network of sensors connected to a data concentrator module, which in turn performs the intermediate storage, the preliminary treatment of the data and the subsequent send an Internet platform of Things (Internet of Things - IoT). The preliminary treatment of data for analysis of the time series of values of electric currents to obtain an initial evaluation of the state of operation of the monitored machine. Then, the pre-processed information is sent via the internet, a usage platform for term storage, post-processing and real-time visualization of the data by users of interest. In the data platform, the data is formatted for visualization and evaluation of the users, allowing the presentation of alerts and knowledge when deviations are detected in relation to the normal operational parameters. When a current consumption behavior deviation is detected, correlating a potential failure type, the system signals additional information to a User's interest group (to the supervisor of the production line, for example), which in a planned manner, proceeds to some intervention without equipment, without prejudice of the production. The availability of the full-time series of stored data as well as the history of occurrences recorded throughout the use of the monitoring system but is still looking for correlations between data of other origins and nature, and the interpretation of the same data under other perspectives beyond the operation or maintenance of the machine. The monitoring system proposed in this work allows to provide a minimum of automation in old machines and opens the possibility of independent, parallel and non-intrusive monitoring in machines that already have a modern supervisory system. An industry that achieves the goal of making all its production equipment fully monitored is credited to take the next step towards Industry 4.0.
Este trabalho tem como objetivo apresentar um sistema de monitoramento de equipamentos el?tricos de uma linha de produ??o, visando o acompanhamento em tempo real do estado de opera??o das m?quinas monitoradas, permitindo a realiza??o da gest?o de opera??o desses equipamentos e a detec??o antecipada de desvios operacionais e de falhas. O sistema desenvolvido realiza a medi??o da corrente el?trica eficaz consumida pelos equipamentos monitorados, utilizando uma rede de sensores conectados a um m?dulo concentrador de dados, que por sua vez realiza o armazenamento intermedi?rio, o tratamento preliminar dos dados e o posterior envio a uma plataforma de Internet da Coisas (Internet of Things - IoT). O tratamento preliminar de dados visa ? an?lise da s?rie temporal dos valores das correntes el?tricas com o fim de obter uma avalia??o inicial do estado de opera??o da m?quina monitorada. Em seguida, essas informa??es pr?-processadas s?o enviadas via internet a uma plataforma de IoT com o objetivo de armazenamento a longo prazo, p?s-processamento e visualiza??o em tempo real dos dados pelos usu?rios de interesse. Na plataforma de IoT, os dados s?o formatados para exibi??o e avalia??o dos usu?rios considerando formatos gr?ficos compreens?veis, sendo poss?vel a emiss?o de alertas e de relat?rios ao serem detectados desvios em rela??o aos par?metros operacionais normais. Ao ser detectado um desvio de comportamento no consumo de corrente, correlacionando a algum tipo de falha em potencial, o sistema sinaliza informa??es adicionais a um usu?rio de interesse (ao supervisor da linha de produ??o, por exemplo), que de forma planejada, procede a alguma interven??o no equipamento, sem preju?zo da produ??o. A disponibilidade da s?rie temporal completa dos dados armazenados bem como o hist?rico de ocorr?ncias registrados ao longo do uso do sistema de monitoramento permite ainda a busca de correla??es entre dados de outras origens e naturezas, e a interpreta??o dos mesmos dados sob outras ?ticas em contextos al?m da opera??o ou manuten??o da m?quina. O sistema de monitoramento proposto permite prover um m?nimo de automa??o em m?quinas antigas e abre a possibilidade de monitoramento independente, paralela e n?o intrusiva em m?quinas que j? contam com um sistema supervis?rio moderno. Uma ind?stria que atinja o objetivo de tornar o conjunto de seus equipamentos produtivos totalmente monitorado se credencia para dar o pr?ximo passo rumo ? Ind?stria 4.0.
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Salatiel, Paulo César Mendes. "Técnicas de diagnóstico de avarias em motores de indução baseadas no quadro da corrente elétrica estatórica." Master's thesis, Instituto Politécnico de Setúbal. Escola Superior de Tecnologia de Setúbal, 2019. http://hdl.handle.net/10400.26/31369.
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Dissertação submetida como requisito parcial para obtenção do grau de Mestre em Engenharia Eletrotécnica e ComputadoresOs variados setores da indústria, tendo por objetivo otimizar os processos de produção e evitar custos substanciais devido a perdas de produção não programadas, têm exigido que os setores relacionados com a manutenção dos equipamentos adotem medidas que estão inseridas no âmbito da manutenção preventiva. O Motor de Indução Trifásico representa de momento a máquina elétrica rotativa mais utilizada nos setores industriais. Deste modo, existe a necessidade de adotar sistemas de detecção e diagnóstico de avarias para este tipo de máquinas. O trabalho que irá ser desenvolvido nesta dissertação apresenta, como objetivo principal, propor técnicas de diagnóstico de avarias que têm por base o uso do quadrado do sinal da corrente elétrica estatórica. Através das diversas técnicas apresentadas será efetuado um estudo pormenorizado para se concluir, por um lado, qual a técnica que apresenta um conteúdo espectral com maior informação e, por outro, estabelecer o conceito de índice de severidade e ainda concluir qual técnica que apresenta a melhor relação entre o valor percentual da carga e este índice. Para a implementação experimental deste trabalho, foi desenvolvido um sistema de aquisição de sinais, assim como, foram modificados fisicamente motores, de modo a realizar ensaios em vazio e em carga que se aproximassem das situações de avaria real.
Currently, the various sectors of industry to optimize production processes and avoid substantial costs to companies due to unscheduled production losses have required equipment maintenance sectors to adopt measures that fall within the scope of preventive maintenance. The Three-Phase Induction Motor currently represents the most widely used rotary electric machine in the industrial sectors. Thus, there is a need to adopt fault detection and diagnosis systems for this type of machines. The work that will be developed in this dissertation presents as main objective, to propose fault diagnosis techniques based on the use of the signal square. of the statistical electric current. Through the various techniques presented, a detailed study will be carried out to conclude, on the one hand, which technique has a spectral content with more information, on the other hand, to establish the concept of severity index and to conclude which technique has the best relation between the percentage value of the load and this index. For the implementation of this work, a signal acquisition system was developed, as well as motors that were physically modified to carry out electrical tests under load and nozzle that approached the actual fault situation.
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卓哉, 吉岡, and Takuya Yoshioka. "異常渦電流損を考慮したモータの鉄損予測手法に関する研究." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13127437/?lang=0, 2020. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13127437/?lang=0.
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近年、自動車の電動化が加速しており、車両駆動を担うモータのさらなる効率向上が求められている。高効率モータ設計に向けて、主な損失の１つである鉄損予測の精度向上が求められている。本論文では、鉄損を構成する各種損失の中から、実用的なモデル化手法が確立していない、異常渦電流損に関して、磁気測定から影響を与える諸因子を検討した。また、得られた知見に基づき、モータ鉄損予測にあたり、実用的なモデルを開発した。In recent years, electrification of automobiles has accelerated, and further improvement in efficiency of motors that drive the vehicles is required. For high-efficiency motor design, it is important to improve the accuracy of iron loss estimation, which is one of the main losses in the motor. In this paper, we investigated influencing factors of excess loss, which is one element that consists iron loss and has not been established as practical estimating modeling, from the magnetic measurement. In addition, based on the obtained knowledge, a practical model was developed for motor iron loss estimation.
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
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Frini, Marouane. "Diagnostic des engrenages à base des indicateurs géométriques des signaux électriques triphasés." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSES052.
Full textAbstract:
Bien qu’ils soient largement utilisés dans le domaine, les mesures vibratoires classiques présentent plusieurs limites. A la base, l’analyse vibratoire ne peut identifier qu’environ 60% des défauts qui peuvent survenir dans les machines. Cependant, les principaux inconvénients des mesures de la vibration sont l’accès difficile au système de transmission afin d’y placer le capteur ainsi que le coût conséquent de la mise en œuvre. Ceci résulte en des problèmes de sensibilité relatifs à la position de l’installation et ceux de difficulté pour distinguer la source de vibration à cause de la diversité des excitations mécaniques qui existent dans l’environnement industriel.Par conséquent, l’analyse des signatures du courant électrique des moteurs s’impose comme une alternative prometteuse à l’analyse vibratoire et a donc fait l’objet d’une attention grandissante au cours des dernières années. En effet, l’analyse des signatures électriques a l’avantage d’être une méthode techniquement accessible, non-intrusive au système et peu coûteuse. Les techniques basées sur le courant et la tension ne requièrent que les mesures électriques du moteur qui sont souvent déjà surveillées pour le contrôle et la protection des machines électriques. Ce processus a été principalement utilisé pour la détection des défauts de moteur tels que la rupture de barres du rotor et les défauts d’excentricité ainsi que les défauts de roulements. En revanche, très peu de recherches concernent la détection des défauts en utilisant l’analyse du courant. En outre, les signaux électriques triphasés sont caractérisés par des représentations géométriques particulières liées à leur forme d’onde qui peuvent servir en tant qu’indicateurs différents offrant des informations supplémentaires. Parmi ces indicateurs géométriques, les transformées de Park et de Concordia modélisent les composantes électriques dans un repère bidimensionnel et toute déviation par rapport à la représentation d’origine indique l’apparition d’un dysfonctionnement. Aussi, les équations différentielles de Frenet-Serret représentent la trajectoire du signal dans un espace euclidien tridimensionnel et indiquent ainsi tout changement dans l’état du système. Bien qu’ils aient été utilisés pour les défauts de roulements, ces indicateurs n’ont pas été appliqués dans la détection des défauts d’engrenages en utilisant l’analyse des signatures des courants électriques. D’où l’idée novatrice de combiner ces indicateurs avec des techniques de traitement de signal, ainsi que des techniques de classification pour le diagnostic des engrenages en utilisant l’analyse des signatures de courant et de tension du moteur électrique.Ainsi, dans ce travail, on propose une nouvelle approche pour le diagnostic des défauts d’engrenages en utilisant l’analyse des courants et des tensions électriques du stator de la machine et ceci en se basant sur un ensemble d’indicateurs géométriques (Transformées de Park et de Concordia ainsi que les propriétés du repère Frenet-Serret). Ces indicateurs font partie d’une bibliothèque de signatures de défauts qui a été construite et qui comprend également les indicateurs classiques utilisés pour un large éventail de défauts. Ainsi, un algorithme combine les acquisitions expérimentales des signaux électriques à des méthodes de traitement de signal avancées (décomposition modale empirique,…). Ensuite, celui-ci sélectionne les indicateurs les plus pertinents au sein de la bibliothèque en se basant sur les algorithmes de sélection de paramètres (sélection séquentielle rétrograde et analyse des composantes principales). Enfin, cette sélection est utilisée pour la classification non-supervisée (K-moyennes) pour la distinction entre l’état sain et l’état défaillantAlthough they are widely used, classical vibration measurements have several limitations. Vibration analysis can only identify about 60% of the defects that may occur in mechanical systems. However, the main drawbacks of vibration measurements are the difficult access to the transmission system in order to place the sensor as well as the consequent cost of implementation. This results in sensitivity problems relative to the position of the installation and the difficulty to distinguish the source of vibration because of the diversity of mechanical excitations that exist in the industrial environment.Hence, the Motor Current Signatures Analysis (M.C.S.A.) represents a promising alternative to the vibration analysis and has therefore been the subject of increasing attention in recent years. Indeed, the analysis of electrical signatures has the advantage of being a technically accessible method as well as inexpensive and non-intrusive to the system. Techniques based on currents and voltages only require the motor’s electrical measurements which are often already supervised for the purposes of the control and the protection of the electrical machines. This process was mainly used for the detection of motors faults such as rotor bars breakage and eccentricity faults as well as bearings defects. On the other hand, very little research has been focused on gear faults detection using the current analysis. In addition, three-phase electrical signals are characterized by specific geometric representations related to their waveforms and they can serve as different indicators providing additional information. Among these geometric indicators, the Park and Concordia transforms model the electrical components in a two-dimensional coordinate system and any deviation from the original representation indicates the apparition of a malfunction. Moreover, the differential equations of Frenet-Serret represent the trajectory of the signal in a three-dimensional euclidean space and thus indicate any changes in the state of the system. Although they have been previously used for bearing defects, these indicators have not been applied in the detection of gear defects using the analysis of electrical current signatures. Hence, the innovative idea of combining these indicators with signal processing techniques, as well as classification techniques for gears diagnosis using the three-phase motor’s electrical current signatures analysis is established.Hence, in this work, a new approach is proposed for gear faults diagnosis using the motor currents analysis, based on a set of geometric indicators (Park and Concordia transforms as well as the properties of the Frenet-Serret frame). These indicators are part of a specifically built fault signatures library and which also includes the classical indicators used for a wide range of faults. Thus, a proposed estimation algorithm combines experimental measurements of electrical signals with advanced signal processing methods (Empirical Mode Decomposition, ...). Next, it selects the most relevant indicators within the library based on feature selection algorithms (Sequential Backward Selection and Principal Component Analysis). Finally, this selection is combined with non-supervised classification (K-means) for the distinction between the healthy state and faulty states. It was finally validated with a an additional experimental configuration in different cases with gear faults, bearing faults and combined faults with various load levels
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BRUZZESE, CLAUDIO. "Harmonic current sideband indicators (HCSBIs) for broken bar detection and diagnostics in cage induction motors." Doctoral thesis, 2008. http://hdl.handle.net/11573/918592.
Full textAbstract:
Induction motor bar breakages have been increasingly studied in the last decades because of
economic interests in developing techniques that permit on-line, non-invasive, early detection
of motor faults in power plants. This work is specifically focused on
broken bar detection and fault severity assessment in three phase power cage motors fed by
non-sinusoidal voltage sources. In this work some new fault indicators for rotor bar breakages detection in squirrel cage
induction motors are proposed, mathematically developed and
experimentally proved.
They are based on the sidebands of phase current upper harmonics, and they are well suited
especially for converter-fed induction motors. The ratios I(7-2s)f/I5f and I(5+2s)f/I7f , I(13-2s)f/I11f and
I(11+2s)f/I13f are examples of such new indicators, and they are not dependent on load torque
and drive inertia, as classical indicators do. Their frequency-dependence has been also examined both theoretically and experimentally, and it was found less remarkable with respect to
other indicators. Moreover, their values increase linearly with the quantity of consecutive
broken bars, almost for not too much advanced faults; on 4-poles motors they were
found quietly like the per-unit number of broken bars (ratio on total bar number).
An original formulation is presented for motor mathematical modeling, based on the
Generalized Symmetrical Components Theory, for sidebands amplitude computation. A complete motor model (involving all the elementary machine
electrical circuits, as stator belts and rotor mesh loops) has been used for computer simulations; the same model was then transformed by using some complex Fortescue’s matrices to
obtain a steady-state linear solution, solvable for stator and rotor currents, in healthy and faulty
conditions. By exploiting the model, the formal definition of a set of new broken bar
indicators was finally obtained. Machine simulations carried out by running the
complete numerical model confirmed the accuracy of the model, and the theoretical previsions.
Experimental work was performed by using a square-wave inverter-fed motor with an
appositely prepared cage, for easy testing with increasing number of
broken bars and without motor dismounting. Moreover, extensive experimentation was carried out on three industrial motors with different power and poles number, with
increasing load, frequency and fault gravity for methodology validation.
Finally, the ideas exposed in this work led to a patent application, owned by the University of Rome “Sapienza”.
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Thirumarai, Chelvan Ilamparithi. "Non-invasive detection of air gap eccentricity in synchronous machines using current signature analysis." Thesis, 2012. http://hdl.handle.net/1828/4355.
Full textAbstract:
Air gap eccentricity fault is one of the major faults that afflict the life and performance of rotating machines. Eccentricity fault, in the worst case, causes a stator rotor rub. Thus, a condition monitoring scheme to identify eccentricity fault at its initial stage is necessary. The most widely practised air gap monitoring schemes for synchronous machines are expensive and invasive sensors based. This work has focussed on developing an inexpensive, non-invasive, air gap monitoring technique especially for salient pole synchronous machines. Motor current signature analysis has been mostly preferred for the above mentioned purpose. By monitoring the frequency spectrum of the machine’s current, faulty condition can be isolated provided the fault specific frequency components are known beforehand.
The research work, therefore, has developed a specific permeance function using binomial series for salient pole machines that can be used to identify eccentricity specific harmonic components in the line current spectrum. Then by performing the magneto-motive force – specific permeance analysis the characteristic frequency components have been predicted. In order to validate the prediction as well as to identify a trend in the variation of these harmonic components with changing levels of eccentricity, mathematical models of a three phase reluctance synchronous machine and a three phase salient pole synchronous machine based on modified winding function approach have been developed. The models have been made to incorporate static, dynamic and mixed eccentricity conditions of varying severity. Also time stepped finite element based models have been simulated in Maxwell-2D to verify the theoretical predictions. With the help of eccentrically cut bushings, experiments were then conducted in the laboratory to corroborate the proposed eccentricity detection scheme.
It has been observed that non-idealities such as supply time harmonics, machine constructional asymmetry, supply voltage unbalance etc. negatively impact the diagnostic technique. Consequently, a residual estimation based fault detection scheme has been implemented successfully to distinguish eccentricity fault from healthy condition. Moreover, detection logic have been put forth to discriminate the type of eccentricity and to estimate the severity of the fault.Graduate
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Duan, Fang. "Diagnostics of rotor and stator problems in industrial induction motors." Thesis, 2010. http://hdl.handle.net/2440/65202.
Full textAbstract:
In this project, two kinds of induction motor faults, stator short circuit fault and broken rotor bar fault, are investigated by using motor current signature analysis (MCSA) and zero crossing time (ZCT) method. These methods are based on the detection of sidebands around the supply frequency in the stator current signal. The thesis starts by a review of these two common faults and two commonly used diagnostic methods. Before the motor stator short circuit faults experiments, baseline analysis is carried out on two same types of healthy motors. Meanwhile, signal processing programs, composed in MATLAB and LABVIEW, are verified to ensure the accurate diagnosis of motor faults. Through a control box, artificial turn to turn fault and phase to phase fault are structured in each test. MCSA and ZCT are utilized to extract broken rotor bar information from recorded stator current signal. Although an induction motor is highly symmetrical, it may still have a detectable signal
component at the fault frequencies due to imperfect manufacture, improper motor installation and so on. The misalignment experiments reveal that improper motor installation could lead to an unexpected frequency peak, which will affect motor fault
diagnosis. Furthermore, manufacture tolerance and working environment could also result in disturbing the motor fault diagnosis. Through both online and offline experiments, MCSA and ZCT methods could detect particular abnormal harmonics related to stator short circuit fault and broken rotor bar fault. Compared with the conventional MCSA method, the ZCT method has the advantage of reduced computational burden.Thesis (M.Eng.Sc.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2010
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Fernandez, Carlos Fernando Ferreira Mosquera. "Aplicação de Técnicas de Machine Learning no Âmbito do Diagnóstico da Ocorrência de Curtos-Circuitos Estatóricos em Motores de Indução Trifásicos." Master's thesis, 2021. http://hdl.handle.net/10400.6/11982.
Full textAbstract:
A Indústria 4.0 traz associado o conceito de fábricas inteligentes, que surgem para atender
a uma necessidade crescente de elevada flexibilidade e eficiência na fabricação dos
produtos. Os motores de indução trifásicos já são utilizados em larga escala pela indústria
e terão um papel primordial nas Smart Factories. A fim de mantê-los em funcionamento,
com elevado grau de fiabilidade, e de reduzir os custos associados a paragens e intervenções,
torna-se necessária a identificação de avarias, ainda em estágio precoce, de forma a
programar a manutenção antes da paragem total daqueles equipamentos.
Os métodos de diagnóstico de avarias online vêm sendo alvo de estudo há muitos anos. A
avaliação dos resultados da aplicação desses métodos de diagnóstico depende de um
especialista para uma interpretação e um diagnóstico precisos. Este trabalho aborda o uso
de Inteligência Artificial para a deteção de avarias em motores elétricos, de forma
automatizada, ainda em estágio precoce. Foram utilizados algoritmos de Machine
Learning, nomeadamente Support Vector Machines e Decision Trees para a deteção de
curtos-circuitos entre espiras, de forma preditiva, baseando-se em dados reais adquiridos
no Laboratório de Sistemas Electromecatrónicos do CISE - Centro de Investigação em
Sistemas Electromecatrónicos.
Como principal diferença em relação a outros trabalhos, será apresentada uma abordagem
baseada no Extended Park’s Vector Approach, que já é atualmente utilizada para esta
finalidade. Trata-se, portanto, de uma abordagem híbrida e tem como principal objetivo
obter o máximo de eficiência com o mínimo de features, a partir de uma ferramenta já
utilizada para este fim.
Como resultado, é apresentado um sistema de diagnóstico automatizado para a deteção de
curtos-circuitos estatóricos em motores de indução trifásicos que utiliza Support Vector
Machine e Decision Tree, contemplando cenários de funcionamento distintos,
nomeadamente condição normal e condição de desequilíbrio na rede de alimentação,
relativo ao deslocamento de fase ou à amplitude das tensões. Após a otimização dos
modelos, será realizada a validação em dados novos e os seus resultados serão discutidos.Industry 4.0 brings the concept of intelligent factories, that arise to meet a growing need for high flexibility and efficiency in the manufacture of products. Three-phase induction motors are already used on a large scale by the industry and will play a key role in Smart Factories. In order to keep them in operation with a high degree of reliability, and to reduce the costs associated with stoppages and interventions, it is necessary to identify faults at an early stage, in order to schedule maintenance before the electric machine stops completely. Online fault diagnostics methods have been studied for many years. However, the assessment of their results depends on an expert for accurate interpretation and diagnosis. This study addresses the use of Artificial Intelligence to detect malfunctions in electric motors, in an automated way, at an early stage. Machine Learning algorithms, namely Support Vector Machines and Decision Trees, were used for the detection of stator interturn short circuits, in a predictive way, based on real data acquired at the Laboratory of Electromechatronic Systems of CISE - Electromechatronic Systems Research Centre. As a main difference in relation to other works, an approach based on the Extended Park's Vector Approach, which is currently used for this purpose, will be presented. Therefore, it is a hybrid approach, and its main objective is to obtain maximum efficiency with minimum features, from a tool already used for this purpose. As a result, an automated diagnostic system, that uses Support Vector Machine and Decision Tree, is presented for the detection of stator short circuits in three-phase induction motors, which includes scenarios of normal and unbalance in the phase or amplitude of the supply voltages. After optimizing the models, validation will be performed on raw data and its results will be discussed.
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Chen, Jhih-Jhong, and 陳志忠. "Vibration Signature Analysis of Induction Motor Driven Machinery." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/vkek55.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
105
Many rotating machines are driven by induction motors and the life of induction motors usually lasts for decades. However, during certain conditions such as load variation, the bearing would suffer fatigue failures. These failures begin from incipient faults and would cause catastrophic disasters if unattended. Therefore, previous literatures concluded several failure modes of the rotating machine and developed condition monitoring techniques to achieve fault diagnosis and replacing abnormal components in advance. In order to understand the behavior of failure modes, several sensors were installed on the rotating machine in previous literatures to measure the vibration, current, and voltage of the bearing fault condition, and compared the measurement to the normal condition. The knowledge could be applied to the monitoring of the non-stop rotating machine in the industry. The failure mode and effect analysis of the rotating machine failures were elaborated in this thesis. Both the physical definition and frequency spectrum of the failure were discussed. The criterion to determine the machine condition were proposed by applying signal analysis technique on the vibration signal of the normal and faulty bearing. The electrical discharge through the oil film between the shaft and bearing were generated by applying AC current to the shaft and housing, and the time-domain, frequency spectrum, and enveloping spectrum of the vibration signals were analyzed. Amplitude modulation could be observed when there are inner and outer ring faults. Through the impact test and the sweeping test, the resonant frequency of the bearing could be found and used to develop enveloping spectrum. The fatigue failure test was conducted and an amplitude threshold was set.
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Su, Shih-Chieh, and 蘇士傑. "Design and Analysis of Characteristic Improvement for Brushless Direct Current Motor." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/ds7smq.
Full textAbstract:
碩士國立虎尾科技大學
機械與機電工程研究所
96
The permanent magnetic brushless DC motors are used widely in the recent years. The motors in the different construction design and the signal quality of the source will produce the cogging torque and the different torque, and then influence the operating characteristic and efficiency of motors. Therefore, this thesis uses finite element software to analyze the characteristic of motors for different construction and voltage signal. This thesis will analyze permanent magnet brushless DC motors in optimum design. Analyzing the cogging torque of surface permanent magnet in the brushless DC motors is the main purpose of the thesis. Comparing to the other models of permanent magnetic brushless DC motors which get smaller cogging torque. The following analytic problems are included: (1) the motors with different construction (2) apply different voltage source. Above problems will influence the cogging torque, magnetic flux density and magnetic field intensity of motors. The analytical data can be taken as reference to improve the cogging torque in the design and compared for design suggestions.
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Chu, Tsui-Yao, and 楚萃瑤. "Fisher’s Linear Discriminant Analysis Method for Motor Quality Types on Current Waveforms." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/12496296771120178812.
Full textAbstract:
碩士健行科技大學
電子工程系碩士班
102
This study proposes a Fisher’s Linear Discriminant Analysis (Fisher’s LDA) approach to analyze current waveform for determining the motor’s quality types. Fisher’s LDA comprises three main stages: (i) the preprocessing stage for enlarging motor’s current waveforms’ amplitude and eliminating noises; (ii) the qualitative features stage for qualitative feature selection of a motor’s current waveform; (iii) the classification stage for determining motor’s quality types using the Fisher’s LDA. In the experiment, the right rate is 99.92% (92.43%) for right judgment on good (defect) motor to be determined as good (defect), the error rate is 7.57%% (0.08%) for wrong judgment on defect (good) motor to be determined as good (defect). The average right rate is 99.72%.
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Hsieh, Cheng-Nan, and 謝政男. "Analysis and Implementation of Induction Motor Vector Control Drivers and Current Regulators." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/03313977499313174439.
Full textAbstract:
碩士淡江大學
電機工程學系
85
Due to the inherent disadvantages of DC motors, they gradually have to be replaced by AC motors in industrial applications. However, the mathematical model of induction motors is a highly degree of nonlinear and coupled system. The control of AC motors is considerably more complicated than it DC motors counterpart. Therefor, in this thesis, the analysis of the induction motor drive based on the vector control method, and the design of the current regulators are investigated. In this thesis the vector control theory is first introduced. The stationary frame current regulator is sensitive to the variation of the load so the synchronous frame current regulator is proposed in this thesis. The hysteresis current regulator which is widely used by the industrial world is also introduced. All the control methods proposed in this thesis are analysis and simulated by SIMULINK soft-ware. As to the hardware implementation, the 80196MC single-chip microcomputer is utilized for implementing the indirect rotor flux-oriented control theory.
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Chen, Guo-Xin, and 陳國鑫. "On-line monitoring of grinding processes with spindle motor current signals analysis." Thesis, 1986. http://ndltd.ncl.edu.tw/handle/04464891452109932803.
Full text
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Ho, Wei-Ming, and 何偉銘. "Analysis and Improvement of Commutation Torque Ripple in Brushless Direct Current Motor." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/38173087830922738494.
Full textAbstract:
碩士高苑科技大學
電機工程研究所
96
The electromagnetic torque is an important indicator of the performance of electrical machinery, and the torque ripple generated in commutation period is the main drawback of BLDC motor, which deteriorates the precision of BLDC motor. Therefore the torque ripple reduction is the key technology in the control of BLDC motor. An analytical study was developed concerning the torque ripple under 4 kinds of PWM schemes due to phase commutation. Experiments were conducted to validate the analytical work and the PWM-ON type was confirmed to be the best scheme in four types PWM scheme, including PWM-ON, H_PWM-L_ON, ON-PWM, and H_ON-L_PWM.
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Kwei-YuanChiou and 邱奎元. "Design and Analysis of Eddy-Current Retarder for Contactless Motor Characteristic Measurement System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/98118051797385420575.
Full textAbstract:
碩士國立成功大學
機械工程學系
102
The torque-speed characteristic measurements of electric motors are essential in design and manufacture of motor, and the coupling between motor under test and general dynamometer is the critical issue for high power electric motors. In this thesis, a contactless dynamometer is introduced by the design of a permanent magnetic retarder driven by the eddy-current, which has advantages in terms of reduction of vibration, friction, abrasion and without driven power. A theoretical model and design method are derived. In addition, an analytical method is introduced to analyze the design model. By controlling the gap of the magnetic retarder, the torque-speed characteristics of the motor under test can be measured. The experimental results showed that the maximum measuring error resulting from the presented approach can be reached within 6.48%, compared to that of using the general dynamometer.
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陳嘉俊. "Analysis, Fabrication and Testing of a Micro Reluctance Motor with Eddy Current Sensors." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/14021099117885124168.
Full textAbstract:
碩士國立高雄應用科技大學
機械與精密工程研究所
92
The purpose of this thesis is to design, analyze, fabricate and test a micro reluctance motor (µRM) integrated with eddy current sensors. The thick film process and micro electroplating are utilized to combine the µRM stator and eddy current sensors into the same fabrication processes so the motor can be made with miniature size and high precision. The µRM is designed and analyzed using the finite element software for optimal output performance. The rotor, stator, sensor and bearing are fabricated by the thick film process and micro electroplating. The 4-phase motor has a 6-pole rotor and 8-pole stator. The overall size has an outer diameter of 5mm and thickness of 2mm. The embedded eddy current sensor has a total of 7 turns with a line width of 13µm, line space of 13µm, thickness of 10µm, and footprint of approximately 500µm×500µm. The sensors can be used to detect the position and rotational speed of the motor. A semiconductor compatible manufacturing process is proposed in this thesis so the µRM can be successfully fabricated, assembled and tested. The motor achieves a maximum speed of 750 rpm with an open loop controller under an exciting frequency of 300 Hz.
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薛鈺霖. "The Measurements and Current Controller Design Analysis of an FPGA-Based BLDC Motor Drive." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/82841693819752040572.
Full textAbstract:
碩士明新科技大學
電機工程研究所
97
Advances of semiconductor manufacturing process and magnetic materials make brushless DC motor have good control technology, high efficiency, small size and light weight. They can replace the general DC motors to be used in precision electrical equipment or electric vehicles. In this thesis, a motor drive control module with small size and light weight is employed to design an FPGA-based digital controller to achieve brushless DC motor control. Firstly, Powersim PSIM software tool is used for simulation. Then Altera's Quartus II is used for the design of digital citcuit. The design is downloaded to an Altera Cyclone EP1C12F256 of FPGA chip. The designed PWM control circuit is to drive a 3.5 HP brushless DC motor and connected to a Motor Testing and Data Acquisition system for the measurements of the performance. The current controller design is analyzed. The controlled model of the brushless DC motor is derived, and then a PI controller is designed. Matlab/Simulink and ModeSim are used for the controller simulation. Then the motor controlled structure for PSIM is linked to complete the current controller design verification primarily. Key words : Brushless DC motor, FPGA chip, Current controller.
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Lin, Chun-Chieh, and 林俊傑. "Design, Analysis and Fabrication of a Micro Switched Reluctance Motor with Eddy Current Sensors." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/24122293175455617359.
Full textAbstract:
碩士華梵大學
機電工程研究所
91
The purpose of this thesis is to design, analyze and fabricate a micro switched reluctance motor integrated with eddy current sensors. The semiconductor techniques and micro electroforming are utilized to combine the micro motor stator and eddy current sensors into the same fabrication processes so the motor can be made with low cost and high precision. The 4-phase motor is an axial air gap design with a 6-polar rotor and 8-polar stator. The motor has an outer diameter of 5mm, thickness of 1.5mm, air gap of 0.1mm, and step angle of 15°. The micro motor is designed with “pile” assembly concept for simplicity. A two-layer SU-8 supporting structure is used to maintain a constant axial air gap. The magnetic circuit design is analyzed and optimized using ANSYS software. The motor stator and rotor are made by the LIGA-like processes and sacrificial layer etching. The motor base and magnetic connectors are made by precision machining. By applying the above techniques the motor achieves simple mechanical design, low fabrication cost, and good system stability. One of the major contributions of this research is to combine the micro motor stator and eddy current sensors into one piece. The sensor coils are fabricated on the top of the stator so there is no need for assembly. Each sensor coil has a total of 9 turns with a line width of 7µm, line space of 7µm, thickness of 7µm, and footprint of approximately 500µm×500 µm. The eddy current sensors can be used to measuring the position, velocity, and direction of the motor.
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Shah, Dhaval. "Stator inter-turn fault detection of doubly-fed induction generators using rotor current and search coil voltage signature analysis." Thesis, 2008. http://hdl.handle.net/1828/2589.
Full textAbstract:
Wind energy conversion is the fastest-growing source of renewable electric power generation in the world and it is expected to remain so for some time. Doubly Fed Induction Generators (DFIGs) hold more than 50% market share of wind power generators due to its unique benefits of low cost, control capability and scalability. Recent trend of DFIGs installed in wind power are within power range of 200KW-2MW and have stator windings rated at 690V, which are highly susceptible to inter-turn faults. This fault type account for more than 40% of the total failure causes of the generator. A reliable fault diagnostic system to detect this fault at incipient stage is highly in demand to prevent catastrophic failures and reduce preventive maintenance costs, since regular inspection is expensive and rewinding of generator takes time in period of days and costs nearly 20% of the original generator cost. Conventional techniques developed for detecting stator inter-turn faults in induction motor are not directly applicable for this machine partly due to difference in construction and their operating characteristics. Research for fault diagnosis in last 5 years has lead to variety of techniques, but none have proved to be feasible either due to need for dedicated sensors and high computing needs or they fail to account for operating conditions which lead to ambiguous fault triggering. This absence of any proven technique to detect stator inter-turn faults in DFIG and the dire necessity for a fault diagnostic system to promote their reliability in wind power generation has motivated the research of this thesis.
A novel technique to detect stator inter-turn faults in a DFIG is proposed by analyzing rotor current and search coil voltage in this thesis. Our recent observations suggested that harmonics induced in the rotor circuit are very promising in detecting stator inter-turn faults in DFIGs. Hence. in this study, an in-depth investigation was conducted to determine the origin of various harmonic components in the rotor currents and their feasibility to detect inter-turn stator faults unambiguously. The theory is verified by modeling the DFIG and simulating various operating conditions of healthy state. severity of faults and unbalance loading conditions that cause ambiguity. Further to verify the concept, an experimental test-bed was created and tests were carried out on DFIG under varying speed operations, fault severity and loading conditions. The experimental results achieved from analyzing the frequency spectrum of rotor current and search coil voltage have been compared and discussed.
To verify feasibility of the proposed technique for detecting stator inter-turn faults and obtain results on speed sensitivity of fault detection, a prototype of DSP based Fault Diagnostic device was developed. Further discussion is made on challenges of realizing the proposed fault diagnostic technique in the industry and scope for further improvement.
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Lin, Hsin-Chia, and 林信嘉. "Design, Analysis, Fabrication, and Testing of a Magnetically Suspended Micro Motor with Eddy Current Sensors." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/10737994029477986635.
Full textAbstract:
碩士華梵大學
機電工程研究所
90
The study is to design, analysis, fabricate and test a magnetically suspended micromotor system using eddy current sensor feedback so the friction problem in micro system can be eliminated. The rotor is suspended by magnetic force. The micromotor has a stator outside diameter of 25mm, rotor outside diameter of 8mm, air gap of 0.3mm and thickness of 0.5mm. The eddy current sensors are made by semiconductor thick film processes. The sensor coil is a 2-layer and 15turns per layer design with line width of 15mm, line space of 5mm, and thickness of 8mm. Finite element method analysis software ANSYS is used for magnetic analysis of the micromotor. Eddy current sensors can be used for detecting rotor displacement, rotational speed, direction and angular position. The sensor characteristics are tested for various target materials, exciting frequencies and distances. The Cu foil is proven the best sensor target so the rotor is added a circular shape of Cu foil on the top. The rotor is successfully suspended and rotated using PD controller and achieves a maximum speed of 1300rpm. In this paper we demonstrate that the motor can be made by semiconductor fabrication process in the future with low cost and high performance.
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Chen, Shaotang. "Bearing current, EMI and soft switching in induction motor drives a systematic analysis, design and evaluation /." 1995. http://catalog.hathitrust.org/api/volumes/oclc/34266695.html.
Full textAbstract:
Thesis (Ph. D.)--University of Wisconsin--Madison, 1995.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 220-225).
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Tripathi, Avanish. "Low Switching Frequency Pulse Width Modulation for Induction Motor Drives." Thesis, 2017. http://etd.iisc.ernet.in/2005/3688.
Full textAbstract:
Induction motor (IM) drives are employed in a wide range of industries due to low maintenance, improved efficiency and low emissions. Industrial installations of high-power IM drives rated up to 30 MW have been reported. The IM drives are also employed in ultra high-speed applications with shaft speeds as high as 500; 000 rpm. Certain applications of IM drives such as gas compressors demand high power at high speeds (e.g. 10 MW at 20; 000 rpm).
In high-power voltage source inverter (VSI) fed induction motor drives, the semiconductor devices experience high switching energy losses during switching transitions. Hence, the switching frequency is kept low in such high-power drives. In high-speed drives, the maximum modulation frequency is quite high. Hence, at high speeds and/or high power levels, the ratio of switching frequency to fundamental frequency (i.e. pulse number, P ) of the motor drive is quite low.
Induction motor drives, operating at low-pulse numbers, have significant low-order volt-age harmonics in the output. These low-order voltage harmonics are not filtered adequately by the motor inductance, leading to high total harmonic distortion (THD) in the line current as well as low-order harmonic torques. The low-order harmonic torques may lead to severe torsional vibrations which may eventually damage the motor shaft. This thesis addresses numerous issues related to low-pulse-number operation of VSI fed IM drives. In particular, optimal pulse width modulation (PWM) schemes for minimization of line current distortion and those for minimization of a set of low-order harmonic torques are proposed for two-level and three-level inverter fed IM drives.
Analytical evaluation of current ripple and torque ripple is well established for the induction motor drives operating at high pulse numbers. However, certain important assumptions made in this regard are not valid when the pulse number is low. An analytical method is proposed here for evaluation of current ripple and torque ripple in low-pulse-number induction motor drives. The current and torque harmonic spectra can also be predicted using the proposed method. The analytical predictions of the proposed method are validated through simulations and experimental results on a 3:7-kW induction motor drive, operated at low pulse numbers. The waveform symmetries, namely, half-wave symmetry (HWS), quarter-wave symmetry (QWS) and three-phase symmetry (TPS), are usually maintained in induction motor drives, operating at low switching frequencies. Lack of HWS is well known to introduce even harmonics in the line current. Impact of three-phase symmetry on line current and torque harmonic spectra is analyzed in this thesis. When the TPS is preserved, there are no triplen frequency components in the line current and also no harmonic torques other than those of order 6, 12, 18 etc. While TPS ensures that the triplen harmonics in the three-phase pole voltages are in phase, these triplen frequency harmonics form balanced sets of three-phase voltages when TPS is not preserved. Hence, triplen frequency currents flow through the stator windings. These result in torque harmonics of order 2, 4, 6, 8, 10 etc., and not just integral multiples of 6. These findings are well supported by simulation and experimental results.
One can see that two types of pole voltage waveforms are possible, when all waveform symmetries (i.e. HWS, TPS and QWS) are preserved in a two-level inverter, These are termed as type-A and type-B waveforms here. Also, QWS could be relaxed, while maintain-ing HWS and TPS, leading to yet another type of pole voltage waveform. Optimal switching angles to minimize line current THD are reported for all three types of pole voltage wave-forms. Theoretical and experimental results on a 3:7-kW IM drive show that optimal type-A PWM and optimal type-B PWM are better than each other in different ranges of modulation at any given low pulse number. In terms of current THD, the optimal PWM without QWS is found to be close to the better one between optimal type-A and optimal type-B at any modulation index for a given P . A combined optimal PWM to minimize THD is proposed, which utilizes the superior one between optimal type-A and optimal type-B at any given modulation index and pulse number. The performance of combined optimal PWM is shown to be better than those of synchronous sine-triangle (ST) PWM and selective harmonic elimination (SHE) PWM through simulations and experiments over a wide range of speed.
A frequency domain (FD) based and another synchronous reference frame (SRF) based optimal PWM techniques are proposed to minimize low-order harmonic torques. The objective here is to minimize the combined value of low-order harmonic torques of order 6, 12, 18, ..., 6(N 1), where N is the number of switching angles per quarter cycle. The FD based optimal PWM is independent of load and machine parameters while the SRF based method considers both load and machine parameters. The offline calculations are much simpler in
case of FD based optimal PWM than in case of SRF based optimal PWM. The performance
of the two schemes are comparable and are much superior to those of synchronous ST PWM
and SHE PWM in terms of low-order harmonic torques as shown by the simulation and
experimental results presented over a wide range of fundamental frequency,
The proposed optimal PWM methods for two level-inverter fed motor drives to minimize
the line current distortion and low-order torque harmonics, are extended to neutral point clamped (NPC) three-level inverter fed drive. The proposed optimal PWM methods for the NPC inverter are compared with ST PWM and SHE PWM, having the same number of
switching angles per quarter. Simulation and experimental results on a 3:7-kW induction
motor drive demonstrate the superior performance of proposed optimal PWM schemes over ST PWM and SHE PWM schemes.
The di_erent optimal PWM schemes proposed for two-level and three-level inverter fed
drives, having di_erent objective functions and constraints, are all analyzed from a space vector perspective. The three-phase PWM waveforms are seen as a sequence of voltage
vector applied in each case. The space vector analysis leads to determination of optimal
vector sequences, fast o_ine calculation of optimal switching angles and e_cient digital
implementation of the proposed optimal PWM schemes. A hybrid PWM scheme is proposed
for two-level inverter fed IM drive, having a maximum switching frequency of 250 Hz. The
proposed hybrid PWM utilizes ST PWM at a _xed frequency of 250 Hz at low speeds. This
method employs the optimal vector sequence to minimize the current THD at any speed in
the medium and high speed ranges. The proposed method is shown to reduce both THD as well as machine losses signi_cantly, over a wide range of speed, compared to ST PWM
Position sensorless vector control of IM drive also becomes challenging when the ratio
of inverter switching frequency to maximum modulation frequency is low. An improved
procedure to design current controllers, and a closed-loop ux estimator are reviewed. These are utilized to design and implement successfully a position sensorless vector controlled IM drive, modulated with asynchronous third harmonic injected (THI) PWM at a constant switching frequency of 500 Hz. Sensorless vector control is also implemented successfully, when the inverter is modulated with synchronized THI PWM and the maximum switching frequency is limited to 500 Hz.
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Farooqi, Quazi Mohammed Rushaed. "Injector Waveform Monitoring of a Diesel Engine in Real-Time on a Hardware in the Loop Bench." 2011. http://hdl.handle.net/1805/2922.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)This thesis presents the development, experimentation and validation of a reliable and robust system to monitor the injector pulse generated by an Engine Control Module (ECM) and send the corresponding fueling quantity to the real-time computer in a closed loop Hardware In the Loop (HIL) bench. The system can be easily calibrated for different engine platforms as well. The fueling quantity that is being injected by the injectors is a crucial variable to run closed loop HIL simulation to carry out the performance testing of engine, aftertreatment and other components of the vehicle. This research utilized Field Programmable Gate Arrays (FPGA) and Direct Memory Access (DMA) transfer capability offered by National Instruments (NI) Compact Reconfigurable Input-Output (cRIO) to achieve high speed data acquisition and delivery. The research was conducted in three stages. The first stage was to develop the HIL bench for the research. The second stage was to determine the performance of the system with different threshold methods and different sampling speeds necessary to satisfy the required accuracy of the fueling quantity being monitored. The third stage was to study the error and its variability involved in the injected fueling quantity from pulse to pulse, from injector to injector, between real injector stators and cheaper inductor load cells emulating the injectors, over different operating conditions with full factorial design of experimentation and mixed model Analysis Of Variance (ANOVA). Different thresholds were experimented to find out the best thresholds, the Start of Injection (SOI) threshold and the End of Injection (EOI) threshold that captured the injector “ontime” with best reliability and accuracy. Experimentation has been carried out at various data acquisition rates to find out the optimum speed of data sampling rate, trading off the accuracy of fueling quantity. The experimentation found out the expected error with a system with cheaper solution as well, so that, if a test application is not sensitive to error in fueling quantity, a cheaper solution with lower sampling rate and inductors as load cells can be used. The statistical analysis was carried out at highest available sampling rate on both injectors and inductors with the best threshold method found in previous studies. The result clearly shows the factors that affect the error and the variability in the standard deviations in error; it also shows the relation with the fixed and random factors. The real-time application developed for the HIL bench is capable of monitoring the injector waveform, using any fueling ontime table corresponding to the platform being tested, and delivering the fueling quantity in real-time. The test bench made for this research is also capable of studying injectors of different types with the automated test sequence, without occupying the resource of fully capable closed loop test benches for testing the ECM unctionality.
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Ochoa, Mayorga Victor Manuel. "Geometric approach to multi-scale 3D gesture comparison." Phd thesis, 2010. http://hdl.handle.net/10048/1530.
Full textAbstract:
The present dissertation develops an invariant framework for 3D gesture comparison studies. 3D gesture comparison without Lagrangian models is challenging not only because of the lack of prediction provided by physics, but
also because of a dual geometry representation, spatial dimensionality and non-linearity associated to 3D-kinematics.
In 3D spaces, it is difficult to compare curves without an alignment operator since it is likely that discrete curves are not synchronized and do not share a common point in space. One has to assume that each and every single trajectory in the space is unique. The common answer is to assert the similitude between two or more trajectories as estimating an average distance error from the aligned curves, provided that the alignment operator is found.
In order to avoid the alignment problem, the method uses differential geometry for position and orientation curves. Differential geometry not only reduces the spatial dimensionality but also achieves view invariance. However,
the nonlinear signatures may be unbounded or singular. Yet, it is shown that pattern recognition between intrinsic signatures using correlations is robust for position and orientation alike.
A new mapping for orientation sequences is introduced in order to treat quaternion and Euclidean intrinsic signatures alike. The new mapping projects a 4D-hyper-sphere for orientations onto a 3D-Euclidean volume. The projection uses the quaternion invariant distance to map rotation sequences into 3D-Euclidean curves. However, quaternion spaces are sectional discrete spaces.
The significance is that continuous rotation functions can be only approximated for small angles. Rotation sequences with large angle variations can only be interpolated in discrete sections.
The current dissertation introduces two multi-scale approaches that improve numerical stability and bound the signal energy content of the intrinsic signatures. The first is a multilevel least squares curve fitting method similar to Haar wavelet. The second is a geodesic distance anisotropic kernel filter.
The methodology testing is carried out on 3D-gestures for obstetrics training. The study quantitatively assess the process of skill acquisition and transfer of manipulating obstetric forceps gestures. The results show that the multi-scale correlations with intrinsic signatures track and evaluate gesture differences between experts and trainees.