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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Analysis and diagnosis of faults in the PMSM drivetrains for series hybrid electrical vehicles (SHEVs) / Analyse et diagnostic des défauts dans les chaînes de traction à MSAP pour les véhicules hybrides série

Moosavi Anchehpoli, Seyed Saeid 11 December 2013 (has links)
L'intérêt pour les véhicules électriques ne cesse de croitre au sein de la société contemporaine compte tenu de ses nombreuses interrogations sur l’environnement et la dépendance énergétique. Dans ce travail de thèse, nous essayons d’améliorer l’acceptabtabilité sociétale du véhicule électrique en essayant de faire avancer la recherche sur le diagnostique des défauts d’une chaine de traction électrique. Les résultats escomptés devraient permettre à terme d’améliorer la fiabilité et la durabilité de ces systèmes.Nous commençons par une revue des problèmes des défauts déjà apparus dans les véhicules hybrides séries qui disposent de l’architecture la plus proche du véhicule électrique. Une étude approfondie sur le diagnostic des défauts d’un convertisseur de puissance statique (AC-DC) ainsi que celle du moteur synchrone à aimants permanents est menée. Quatre types de défauts majeurs ont été répertoriés concernant le moteur (court-circuit au stator, démagnétisation, excentricité du rotor et défaut des roulements). Au niveau du convertisseur, nous avons considéré le défaut d’ouverture des interrupteurs. Afin d’être dans les mêmes conditions d’utilisation réelle, nous avons effectué des tests expérimentaux à vitesse et charge variables. Ce travail est basé aussi bien sur l’expérimentation que sur la modélisation. Comme par exemple, la méthode des éléments finis pour l’étude de la démagnétisation de la machine. De même, l’essai en court-circuit du stator du moteur en présence d’un contrôle vectoriel.Afin de réaliser un diagnostic en ligne des défauts, nous avons développé un modèle basé sur les réseaux de neurones. L’apprentissage de ce réseau de neurone a été effectué sur la base des résultats expérimentaux et de simulations, que nous avons réalisées. Le réseau de neurones est capable d'assimiler beaucoup de données. Ceci nous permet de classifier les défauts en termes de sévérité et de les localiser. Il permet ainsi d'évaluer le degré de performance de la chaine de traction électrique en ligne en présence des défauts et nous renseigner ainsi sur l'état de santé du système. Ces résultats devraient aboutir à l’élaboration d’une stratégie de contrôle tolérant aux défauts auto-reconfigurable pour prendre en compte les modes dégradés permettant une continuité de service du véhicule ce qui améliorera sa disponibilité. / The interest in the electric vehicles rose recently due both to environmental questions and to energetic dependence of the contemporary society. Accordingly, it is necessary to study and implement in these vehicle fault diagnosis systems which enable them to be more reliable and safe enhancing its sustainability. In this work after a review on problem of faults in the drivetrain of series hybrid electric vehicles (SHEV), a deep investigation on fault diagnosis of AC-DC power converter and permanent magnet synchronous motor (PMSM) have been done as two important parts of traction chains in SHEVs. In other major part of this work, four types of faults (stator winding inter turn short circuit, demagnetization, eccentricity ant bearing faults) of a PMSM have been studied. Inter turn short circuit of stator winding of PMSM in different speeds and loads has been considered to identify fault feature in all operation aspects, as it is expected by electric vehicle application. Experimental results aiming short circuits, bearing and eccentricity fault detection has been presented. Analytical and finite element method (FEM) aiming demagnetization fault investigation has been developed. The AC-DC converter switches are generally exposed to the possibility of outbreak open phase faults because of troubles of the switching devices. This work proposes a robust and efficient identification method for data acquisition selection aiming fault analysis and detection. Two new patterns under AC-DC converter failure are identified and presented. To achieve this goal, four different level of switches fault are considered on the basis of both simulation and experimental results. For accuracy needs of the identified pattern for SHEV application, several parameters have been considered namely: capacitor size changes, load and speed variations. On the basis of the developed fault sensitive models above, an ANN based fault detection, diagnosis strategy and the related algorithm have been developed to show the way of using the identified patterns in the supervision and the diagnosis of the PMSM drivetrain of SHEVs. ANN method have been used to develop three diagnosis based models for : the vector controlled PMSM under inter turn short circuit, the AC/DC power converter under an open phase fault and also the PMSM under unbalanced voltage caused by open phase DC/AC inverter. These models allow supervising the main components of the PMSM drivetrains used to propel the SHEV. The ANN advantages of ability to include a lot of data mad possible to classify the faults in terms of their type and severity. This allows estimating the performance degree of that drivetrains during faulty conditions through the parameter state of health (SOH). The latter can be used in a global control strategy of PMSM control in degraded mode in which the control is auto-adjusted when a defect occurs on the system. The goal is to ensure a continuity of service of the SHEV in faulty conditions to improve its reliability.
32

Direct torque control of permanent magnet synchronous motors with non-sinusoidal back-EMF

Ozturk, Salih Baris 15 May 2009 (has links)
This work presents the direct torque control (DTC) techniques, implemented in four- and six-switch inverter, for brushless dc (BLDC) motors with non-sinusoidal back- EMF using two and three-phase conduction modes. First of all, the classical direct torque control of permanent magnet synchronous motor (PMSM) with sinusoidal back-EMF is discussed in detail. Secondly, the proposed two-phase conduction mode for DTC of BLDC motors is introduced in the constant torque region. In this control scheme, only two phases conduct at any instant of time using a six-switch inverter. By properly selecting the inverter voltage space vectors of the two-phase conduction mode from a simple look-up table the desired quasi-square wave current is obtained. Therefore, it is possible to achieve DTC of a BLDC motor drive with faster torque response while the stator flux linkage amplitude is deliberately kept almost constant by ignoring the flux control in the constant torque region. Third, the avarege current controlled boost power factor correction (PFC) method is applied to the previously discussed proposed DTC of BLDC motor drive in the constant torque region. The test results verify that the proposed PFC for DTC of BLDC motor drive improves the power factor from 0.77 to about 0.9997 irrespective of the load. Fourth, the DTC technique for BLDC motor using four-switch inverter in the constant torque region is studied. For effective torque control in two phase conduction mode, a novel switching pattern incorporating the voltage vector look-up table is designed and implemented for four-switch inverter to produce the desired torque characteristics. As a result, it is possible to achieve two-phase conduction DTC of a BLDC motor drive using four-switch inverter with faster torque response due to the fact that the voltage space vectors are directly controlled.. Finally, the position sensorless direct torque and indirect flux control (DTIFC) of BLDC motor with non-sinusoidal back-EMF has been extensively investigated using three-phase conduction scheme with six-switch inverter. In this work, a novel and simple approach to achieve a low-frequency torque ripple-free direct torque control with maximum efficiency based on dq reference frame similar to permanent magnet synchronous motor (PMSM) drives is presented.
33

Pour l'optimisation de la commande des machines synchrones à aimants permanents en régime de haute vitesse pour véhicule électrique / For the optimization of the control of permanent magnet synchronous motors in high speed mode for electric vehicles

Sepulchre, Leopold 28 March 2017 (has links)
Dans ce travail nous cherchons à développer des algorithmes de commande adaptés au fonctionnement à haute vitesse d’une machine synchrone à aimants permanents (MSAP) et de son onduleur en optimisant l’efficacité énergétique de l’ensemble. Bien que la vocation soit très large, le domaine de la traction électrique est priorisé. Les MSAP tournant à haute vitesse sont de plus en plus utilisées dans les véhicules électriques en raison de leur forte densité de puissance. La haute vitesse implique une force électromotrice élevée et requiert la réduction du flux (défluxage) dans l’entrefer. Lors d’un fonctionnement de la machine en régime défluxé, si la contribution de l’aimant peut-être totalement compensée alors nous pouvons utiliser une stratégie Maximum Torque Per Volt (MTPV) pour générer les consignes de courant qui respectent les limites électriques théoriques quelle que soit la vitesse de rotation de la machine. En l’absence de boucle de vitesse, le couple de référence doit être limité aux points de fonctionnement atteignables, calculés en fonction des limites de courant (limites onduleur et machine), tension (batterie) et puissance (batterie et partie mécanique). Nous proposons ainsi dans cette thèse de calculer les références de courant avec une stratégie MTPA (Maximum Torque Per Ampere) à basse vitesse et d’utiliser un algorithme de défluxage basé sur une régulation de la norme de la tension associée à une stratégie MTPV à haute vitesse sans commutation d’algorithme mais par une action continue sur la valeur de la saturation de courant. Concernant la boucle de courant nous réalisons une commande numérique dans le repère d-q qui tient compte de la discrétisation, du retard (dû au temps de calcul), et du fort couplage inter-axes à haute vitesse sous des critères de précision, stabilité et rapidité. Nous étudions les stratégies de découplage minimal et de découplage discret avec prédiction de la variation du courant. Les approches par régulateurs avec structure RST et par commande prédictive-optimale sont développées. Une prédiction de la position réelle du rotor est incluse afin de conserver la stabilité à haute vitesse. Finalement nous réalisons une maquette avec une MSAP à échelle réduite sur laquelle nous testons ces stratégies de commande. Nous validons par expérience que l’algorithme proposé dans la thèse est capable de piloter la machine à haute vitesse en respectant les limites électriques et nous vérifions qu’il améliore les performances (couple, vitesse maximale, pertes) obtenues à haute vitesse. / In this work we search to develop control algorithms adapted to the high speed operation of a permanent magnet synchronous motor (PMSM) and its inverter by optimizing the energy efficiency of the set. Although the vocation is very broad, the field of electric traction is prioritized. High speed PMSMs are increasingly used in electrical vehicles because of their high power density. The high speed implies a high electromotive force and requires the reduction of the flux (fluxweakening) in the air gap. When the motor is running in flux-weakening mode, if the contribution of the magnet can be fully compensated then we can use a Maximum Torque Per Volt (MPTV) strategy to generate the current references that meet the theoretical limits regardless of the machine rotation speed. In the absence of a speed loop the reference torque must be limited to the achievable operating points, calculated according to the current limits (inverter and machine limits), voltage (battery) and power (battery and mechanical part). We propose in this thesis to calculate the current reference with Maximum Torque Per Ampere (MTPA) strategy at low speed and to use a flux-weakening algorithm based on a regulation of the voltage norm associated with a MTPV strategy at high speed without switching algorithms but by a continuous action on the value of the current saturation. Concerning the current loop, we carry out a numerical control in the d-q frame which takes into account the discretization, the delay (due to the computation time), and the high inter-axis coupling at high speed under criteria of precision, stability and speed. We study the strategies of minimal decoupling and discrete decoupling with prediction of the variation of the current. The approaches by regulators with RST structure and predictive-optimal control are developed. A prediction of the actual rotor position is included to maintain the stability at high speed. Finally a real model with a reduced scale PMSM is realized on which these control strategies are tested. We validate by experiment that the algorithm proposed in the thesis is able to control the machine at high speed respecting the electrical limits and verify that it improves the performances (torque, maximum speed, losses) obtained at high speed.
34

Conception intégrée par optimisation multicritère d’un système d’actionnement pour le conditionnement d’air d’un avion plus électrique / Integrated design by multiobjective optimization of an actuation system for air conditioning systems of a more electric aircraft

Andrade, André de 29 January 2013 (has links)
Dans le contexte de l'avion plus électrique, de nouveaux défis technologiques apparaissent dans le développement des systèmes embarqués afin d'augmenter leur puissance électrique. Une optimisation visant la sécurité, l'efficacité énergétique et une diminution du volume et de la masse est ainsi nécessaire. A cet effet, les dispositifs doivent être considérés dans leur ensemble et non par éléments séparés. Pour faciliter l'intégration des systèmes de puissance et assurer la qualité du réseau de bord avion, cette thèse propose de tenir compte de la mission de vol et d'étudier la CIO « Conception Intégrée Optimale » du système complet comprenant le filtre d'entrée et l’onduleur de tension alimentant l'actionneur synchrone à aimants permanents haute vitesse « HSPMSM ». L'application est dédiée au système de conditionnement d'air cabine « ECS – Environmental Conditioning Systems » comprenant le compresseur d'air étudié, d'une puissance nominale de 70 kW. La thèse est structurée en trois parties principales: le dimensionnement des composants de la chaîne de conversion électromécanique ; la conception locale et séquentielle de chacun des composants du système (boucle d'optimisation actionneur puis boucle d'optimisation « onduleur de tension + filtre d'entrée » ; la conception simultanée de tous les composants du système (boucle d'optimisation globale). Les fronts « Pareto-optimaux » des solutions obtenues à partir des méthodes de conception séquentielles et simultanées sont présentés, analysés et comparés. Les résultats mettent clairement en évidence l'avantage d'utiliser une boucle d'optimisation unique pour l'amélioration de la masse et de l'efficacité énergétique du système. / The concept of More Electric Aircraft (MEA) implies new challenges especially due to the increase of the electrical embedded power. By this way, necessary improvements in terms of safety, energy efficiency and weight reduction are required. For this reason, the design of devices should be more approached with a view to the whole system than as separated elements. In order to facilitate power system integration and to ensure power quality aboard, this dissertation proposes an Integrated Optimal Design (IOD) of the input filter and the inverter feeding the High Speed Permanent Magnet Synchronous Motor (HSPMSM) by taking the flight mission into account. The Environmental Conditioning System (ECS) is equipped of the studied cabin air compressor with a rated power of 70 kW: a Multiobjective Genetic Algorithm (MOGA) is applied to achieve the CIO process. Considering the ECS as a whole, this thesis can be divided into three main parts: components sizing of the electromechanical conversion chain; local and sequential design of each system components (HSPMSM optimization loop followed by “voltage source inverter + input filter” optimization loop); simultaneous design of all system components (global optimization loop). Pareto-optimal solutions obtained from sequential and simultaneous design approaches are presented, analyzed and compared. Results clearly highlight the advantage of using a single optimization loop for the whole system in order to improve mass and efficiency.
35

CONTROLE POR MODOS DESLIZANTES E OBSERVADOR DE DISTÚRBIOS APLICADOS AO MOTOR SÍNCRONO DE ÍMÃS PERMANENTES / CURRENT CONTROL PERMANENT MAGNET SYNCHRONOUS MOTOR

Gabbi, Thieli Smidt 20 August 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This master thesis proposes a current control technique based on sliding mode strategy and disturbance observer for high-performance drive applied to permanent magnet synchronous motors and can be extended to other systems. The combination of sliding mode control and disturbance observer applied to the current control presents the characteristics necessary to minimize the coupling between the axes, rejection of external disturbances and parametric variations. A continuous time control scheme is developed, the stability proofs are performed from the Lyapunov analysis. The performance of the propose technique is evaluates through simulation results. Moreover, this master thesis presents a discrete-time sliding mode controller combined with a discrete-time disturbance observer. The development in discrete-time enables the implementation in digital processors. The conditions of reach of the proposed controller considering the transport delay of digital implementation are still evaluated. The stability proofs of the proposed scheme are presented. Simulation results are shown. In addition, it is developed an experimental platform for drive and control of the permanent magnet synchronous motor in which the experimental results are obtained. / Esta dissertação propõe uma técnica de controle de corrente baseada na estratégia por modos deslizantes e observador de distúrbios para acionamento de alto desempenho aplicada a motores síncronos de ímãs permanentes, podendo ser estendida a outros sistemas. A combinação do controle por modos deslizantes e do observador de distúrbio aplicada ao controle de corrente apresenta as características necessárias para minimização do acoplamento existente entre os eixos, rejeição a distúrbios externos e variações paramétricas. É desenvolvido um esquema de controle em tempo contínuo, são apresentadas as provas de estabilidade a partir de critério de Lyapunov. O desempenho da técnica proposta é avaliado através de resultados de simulação. Além disso, é apresentado um controlador por modos deslizantes associado ao observador de distúrbio em tempo discreto. O desenvolvimento em tempo discreto possibilita a implementação em processadores digitais de sinais. Ainda são avaliadas as condições de alcance do controlador proposto considerando o atraso de transporte da implementação digital. Provas de estabilidade do esquema proposto e resultados de simulação são apresentados. Este trabalho faz o desenvolvimento de uma bancada experimental para o acionamento e controle do motor síncrono de ímãs permanentes na qual são obtidos os resultados experimentais apresentados.
36

Estudo do acionamento do motor síncrono de ímãs permanentes: abordagem baseada no controle vetorial com ângulo de torque constante

Sá, Franciéli Lima de 30 July 2010 (has links)
Made available in DSpace on 2016-12-12T17:38:37Z (GMT). No. of bitstreams: 1 FRANCIELI LIMA DE SA.pdf: 957791 bytes, checksum: 54a198d079685e3726016b54e682ffdc (MD5) Previous issue date: 2010-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work is introduced a study of Permanent Magnet Synchronous Motor (PMSM), involving issues about constructive characteristics, modeling, control and simulation. Initially, are studied the constructive characteristics, principally in that refers of the magnets disposition in the rotor. Then, are shown some applications for the PMSM. The mathematic model of PMSM is developed starting of stationary reference frame and utilizing the rotation transformation for obtain the equations of currents and voltage in the rotor reference frame. The feed shape of the PMSM is an analysis of extreme importance in the study of this motor, for this reason also is show in this work. The vector control is analyzed in the sequence, utilizing the direct method for the rotor flux and considering the approach with Constant torque control. Are presents some techniques for the design of controllers of speed and current loops. Through the performed simulations, are analyzed and compared the several technical approached. The results obtained show that the vector control approach with constant torque angle applied to the PMSM presents a good dynamic response for motor drive. / Neste trabalho, é apresentado um estudo do Motor Síncrono de Ímãs Permanentes (MSIP) envolvendo questões pertinentes às características construtivas, modelamento, controle e simulação. Inicialmente, são estudadas as características construtivas, principalmente no que se refere à disposição dos ímãs no rotor. Em seguida são mostradas algumas aplicações para o MSIP. O modelo matemático do MSIP é desenvolvido partindo do referencial estacionário e utilizando a transformação de rotação para se obter as equações de corrente e tensão no referencial girante. A forma de alimentação do MSIP é uma análise de extrema importância no estudo deste motor, e por esta razão também é mostrada neste trabalho. O controle vetorial é analisado na seqüência, utilizando o método direto pelo fluxo de rotor e considerando a abordagem com controle de torque constante. São apresentadas algumas técnicas para o projeto dos controladores das malhas de corrente e velocidade. Através das simulações realizadas, são analisadas e comparadas as diversas técnicas abordadas. Os resultados obtidos mostram que o controle vetorial com abordagem do ângulo de torque constante aplicado ao MSIP apresenta uma boa resposta dinâmica para o acionamento do motor.
37

Simulace pohonu hybridního automobilu / Simulation of hybrid car drive

Byrtus, Jiří January 2013 (has links)
This thesis deals with analysis of electric drive parts from hybrid electric vehicle, namely interior permanent magnet synchronous motor and inverter with control. First part describes a basic theory. Further, motor and inverter computer models are shown, specified simulations are performed on this models. Results are compared with values measured on real machines from accessible literary sources.
38

Fault Detection in Permanent Magnet Synchronous Motors using Machine Learning

Lennartsson, Alexander, Blomberg, Martina January 2021 (has links)
In the aviation industry, safety and robustness are the number one priorities, which is why they use well-tested systems such as hydraulic actuators. However, drawbacks such as high weight and maintenance have pushed the industry toward newer, electrical, actuators that are more efficient and lighter. Electrical actuators, on the other hand, have some reliability issues. In particular, short circuits in the stator windings of Permanent-Magnet SynchronousMotors (PMSMs), referred to as Inter-Turn Short Faults (ITSFs), are the dominating faults, and is the focus of this thesis. ITSFs are usually challenging to detect and often do not become noticeable until the fault has propagated, and the motor is on the verge of being destroyed. This thesis investigates the possibility of detecting ITSFs in a PMSM, at an early stage when only one turn is shorted. The method is limited to finding the faults using ML algorithms. Both an experiential PMSM and a simulated model of the experimental PMSM, with the ability to induce an ITSF, were used to collect the data. Several Machine Learning (ML) models were developed, and then trained and tested with the collected data. The results show that four of the tested ML models, being: Random Forest, Gaussian SVM, KNN, and the CNN, all achieve an accuracy exceeding 95%, and that the fault can be found at an early stage in a PMSM with three coils connected in parallel in each phase. The results also show that the ML models are able to identify the ITSF when the simulated data is downsampled to the same frequency as the experimental data. We conclude that the ML models, provided in this study, can be used to detect an ITSF in a simulated PMSM, at an early stage when only one turn is shorted, and that there is great potential for them to detect ITSFs in a physical motor as well.
39

Sensorless Control of Synchronous Machines in Python Using Signal Injection : An implementation of a High-Frequency Square-Wave Injection Algorithm on a Linear and Non-Linear Synchronous Machine Model in open-source Software Motulator

Lundberg, Simon January 2022 (has links)
The importance of accurately controlling the speed and torque of Synchronous Machines (SMs) in industry, transportation, aerospace, to name a few, can not be overstated. The driving unit to control the machines are called Variable Speed Drives (VSDs) and they can be designed in many different ways. In this project, a speed sensorless drive using high-frequency square-wave voltage injection is implemented in a open-source Python software called Motulator, developed by Prof. Marko Hinkkanen at Aalto University. The drive is first tested on an already existing linear model of a Permament Magnet Synchronous Machine (PMSM). An equivalent model is built in Matlab/Simulink to benchmark the performance of the implementation in Python. The results suggest that the performance Motulator implementation is satisfactory when compared to the Simulink implementation. Next, a non-linear Synchronous Reluctance Machine (SynRM) is implemented, using data from Finite Element (FEM) simulations of the non-linear flux-current relation. By using the injection scheme (with some tweaks), the speed of the motor is accurately controlled, but a steady-state position error is observed at all operating points. The error is produced due to the cross-saturation effect and a compensation strategy is implemented in an attempt to remove this error. however without full success. / Det är av avgörande betydelse att kunna kontrollera varvtal och vridmomentet hos synkrona elektriska maskiner (SM) inom transport, flyg och rymd, för att nämna några tillämpningar. Drivsystem för att styra de elektriska maskinerna kallas för varvtalsreglerade drivsystem och kan konstrueras på många olika sätt. I det här projektet implementeras ett varvtalsreglerat drivsystem, utan sensor för mätning av varvtalet. Varvtalsestimeringen bygger på att en fyrkantsvåg med hög frekvens injiceras varur det är möjligt att estimera hastigheten. Implementering görs i Python i en open-source programvara kallad Motulator, utvecklad av professor Marko Hinkkanen från Aaltouniversitetet. Regleringen testas först på en redan existerande linjär modell av en permanentmagnetiserad motor. Som jämförelse utvecklas även en motsvarande implementering av regleralgoritm och motor i Matlab/Simulink. Resultaten visar att Motulatorimplementeringen fungerar väl och att simuleringarna stämmer väl överens med Matlab/Simulink-modellen. I nästa steg implementeras en icke-linjär modell av en synkron reluktansmaskin. Det icke-linjära förhållande mellan flöde och ström modelleras med hjälp av data från finita elementsimuleringar (FEM). Simuleringar i Motulator visar att varvtalet i denna motormodell kan kontrolleras för alla olika laster och varvtal. Däremot noteras ett stationärt rotorpositionsfel vid vissa driftpunkter. Felet beror på mättningen av statorinduktansen och en algoritm implementerats för att kompensera effekten av mättningen och därmed eliminera felet. Det visar sig dock att kompenseringsalgoritmen endast fungerar vid vissa driftpunkter.
40

Identifiering av lagerströmmar i elmotorer för framdrivning av tunga fordon : Utveckling av metod och programvara för att detektera lagerströmmar / Identification of Bearing Currents in Electric Motors for Heavy Vehicles : Development of Methodology and Software to DetectBearing Currents

Lindström, Jessica January 2023 (has links)
Klimatutmaningar, lagändringar och ett ökat miljötänk har tvingat transportsektorn att ställa om till eldrift. Batterier och elmotorer har utvecklats kraftigt och är nu ett alternativ även för tunga fordon. Ett vanligt förekommande problem med elmotorer i fordon är lagerströmmar, här kallat gnista eller blixthändelser. Dessa uppstår på grund av oönskade urladdningar i motorn och förorsakar skador på lagren i motorn. Syftet med motorlager är att avlasta och minska friktionen kring motoraxeln. För att förebygga problemet och se förbättringar eller försämringar av olika åtgärder som görs krävs att lagerströmmar kan identifieras utifrån mätdata. Detta examensarbete analyserar relevant forskning inom området för att sedan introducera en metod och en algoritm för att identifiera lagerströmmar i samarbete med Scania CV. Algoritmen består av tre olika parametrar som påverkar identifieringen av de oönskade strömmarna på olika sätt. Verktyget lyckades identifierade lagerströmmar i olika mätdata, och hittade skillnader i antalet blixthändelser mellan olika körningar av provobjektet. Dock krävs vidare utveckling av verktyget och möjligheten att bearbeta annan typ av data som exempelvis spänningar i motorn för atthitta bättre samband. / A changing climate, changing laws and an increased environmental consciousnesshas forced the transport sector to transition to electric power. Batteries and electric motors have seen a quick and powerful development which means that they are now an alternative even for heavy vehicles. A common problem with electric motors forvehicles is bearing currents. The bearing currents occur as a result of electrical discharges in the motor and can damage the bearings inside the motor. The purpose of motor bearings is to offload and reduce friction for the motor shaft. To prevent the issue and to see improvements or deteriorations from different preventativemeasures it is critical to be able to identify bearing currents from data. This thesis analyzes relevant research in the area before introducing a method and an algorithm for detecting bearing currents in cooperation with Scania CV. The algorithm is composed of three different parameters which affects the identification in different ways. The tool was able to identify bearing currents from various data and found differences between the number of bearing currents between different test runs of the motor. However, more development of the tool and the possibility to process different kinds of data like voltages inside the motor is needed to be able to find better patterns in the data.

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