This study concentrates on the modelling of three phase flow and miscible CO2 flooding in pore networks that captures the natural porous medium of a reservoir. That is to say, the network, that is a Matlab code, consists of different sided triangles which are located randomly through the grids. The throats that connect the pores are also created by the model. Hence, the lengths and the radii of the throats are varying. The network used in this research is assumed to be representative of mixed-wet carbonates in 2-D. Mixed wettability arises in real porous media when oil renders surfaces it comes into prolonged contact with oil-wet while water-filled nooks and crannies remain water-wet. The model developed is quasi-static approach to simulate two phase and three phase flows. By this, capillary pressures, relative permeabilities, saturations, flow paths are determined for primary drainage, secondary imbibition, and CO2 injection cases. To calculate the relative permeability, capillary entry pressures are first determined. Then, hydraulic conductances and flow rates of the network for each grid are obtained. Phase areas and saturations are also determined. It is accepted that the displacement mechanism in drainage and CO2 injection is piston-like whereas in imbibition it is either piston-like or snap-off. The results of the model are compared with the experimental data from the literature. Although, the pore size distribution and the contact angle of the model are inconsistent with the experimental data, the agreement of the relative permeabilities is promising. The effect of contact angle in the same network for three phase flow where immiscible CO2 is injected as a third phase at supercritical temperature (32 &deg / C) is investigated. And it is found that, the increase in the intrinsic angles causes decrease in relative permeability values. As another scenario, two phase model is developed in which miscible CO2 &amp / #8211 / water is flooded after the primary drainage of the same 2-D network at supercritical temperature (32 &deg / C). This case is compared with the previous case and the effects of miscibility are investigated such that it causes the relative permeability values to increase. Adsorption is another concern of which its effects are analyzed in a single pore model. The model is compared with the reported experimental data at high temperature and pressures. A reasonable fit is obtained.

No description available.

Constitutive relationships are developed to describe the water transport characteristics of the gas diffusion layer (GDL) of proton exchange membrane fuel cells (PEMFCs). Additionally, experimental fixtures and procedures for the determination of the constitutive relationships are presented. The water transport relationships are incorporated into analytical models that assess the impact of the water transport relations and that make PEMFC performance predictions. The predicted performance is then compared to experimental results. The new constitutive relationships are significantly different than the currently popular relationships used in PEMFC modeling because they are derived from experiments on actual PEMFC gas diffusion layer materials. In prior work, properties of the GDL materials such as absolute permeability, liquid water relative permeability, porosity, and capillary behavior are often assumed or used as adjustment parameters in PEMFC models to simplify the model or to achieve good fits with polarization data. In this work, the constitutive relations are not assumed but are determined via newly developed experimental techniques. The experimental fixtures and procedures were used to characterize common GDL materials including carbon papers and carbon cloths, and to investigate common treatments applied to these materials such as the bulk application of a hydrophobic polymer within the porous structure. A one-dimensional model is developed to contrast results based on the new constitutive relations with results based on commonly used relationships from the PEMFC literature. The comparison reveals that water transport relationships can have a substantial impact on predicted GDL saturation, and consequently a significant impact on cell performance. The discrepancy in saturation between cases can be nearly an order of magnitude. A two-dimensional model is also presented that includes the impact of the compressed GDL region under the shoulder of a bipolar plate. Results show that the compression due to the bipolar plate shoulder causes a significant increase in liquid saturation, and a significant reduction in oxygen concentration and current density for the paper GDL. In contrast, compression under the shoulder has a minimal impact on the cloth GDL. Experimental inputs to the 2-D model include: absolute permeability, liquid water relative permeability, the slope of the capillary pressure function with saturation, total porosity, GDL thickness, high frequency resistance, and appropriate Tafel parameters. Computational polarization curve results are compared to experimental polarization behavior and good agreement is achieved. / Ph. D.

To meet the goal of atmospheric stabilization of carbon dioxide (CO2 ) levels a technological transformation should occur in the energy sector. One strategy to achieve this is carbon sequestration. Carbon dioxide can be captured from industrial sources and sequestered underground into depleted oil and gas reservoirs. CO2 injected into geological formations, such as mature oil reservoirs can be effectively trapped by hydrodynamical (structural), solution, residual (capillary) and mineral trapping methods. In this work, a case study was conducted using CMG-STARS software for CO2 sequestration in a mature oil field. History matching was done with the available production, bottom hole pressures and water cut data to compare the results obtained from the simulator with the field data. Next, previously developed optimization methods were modified and used for the case of study. The main object of the optimization was to determine the optimal location, number of injection wells, injection rate, injection depth and pressure of wells to maximize the total trapped amount of CO2 while enhancing the amount of oil recovered. A second round of simulations was carried out to study the factors that affect the total oil recovery and CO2 &not / storage amount. These include relative permeability end points effect, hysteresis effect, fracture spacing and additives of simultaneous injection of carbon dioxide with CO and H2S. Optimization runs were carried out on a mildly heterogeneous 3D model for variety of cases. When compared with the base case, the optimized case led to an increase of 20% in the amount of oil that is recovered / and more than 95% of the injected CO2 was trapped as solution gas on and as an immobile gas. Finally, an investigation of the economical feasibility was accomplished. NPV values for various cases were obtained, selected and studied yielding in a number of cases that are found to be applicable for the field of concern.

The productivity of most gas condensate wells is reduced significantly due to condensate banking when the bottom hole pressure falls below the dew point. The liquid drop-out in these very high rate gas wells may lead to low recovery problems. The most important parameter for determining condensate well productivity is the effective gas permeability in the near wellbore region, where very high velocities can occur. An understanding of the characteristics of the high-velocity gas-condensate flow and relative permeability data is necessary for accurate forecast of well productivity. In order to tackle this goal, a series of two-phase drainage relative permeability measurements on a moderate permeability North Marmara &ndash / 1 gas well carbonate core plug sample, using a simple synthetic binary retrograde condensate fluid sample were conducted under reservoir conditions which corresponded to near miscible conditions. As a fluid system, the model of methanol/n-hexane system was used as a binary model that exhibits a critical point at ambient conditions. The interfacial tension by means of temperature and the flow rate were varied in the laboratory measurements. The laboratory experiments were repeated for the same conditions of interfacial tension and flow rate at immobile water saturation to observe the influence of brine saturation in gas condensate systems. The laboratory experiment results show a clear trend from the immiscible relative permeability to miscible relative permeability lines with decreasing interfacial tension and increasing velocity. So that, if the interfacial tension is high and the flow velocity is low, the relative permeability functions clearly curved, whereas the relative permeability curves straighten as a linear at lower values of the interfacial tension and higher values of the flow velocity. The presence of the immobile brine saturation in the porous medium shows the same shape of behavior for relative permeability curves with a small difference that is the initial wetting phase saturations in the relative permeability curve shifts to the left in the presence of immobile water saturation. A simple new mathematical model is developed to compute the gas and condensate relative permeabilities as a function of the three-parameter. It is called as condensate number / NK so that the new model is more sensitivity to temperature that represents implicitly the effect of interfacial tension. The new model generated the results were in good agreement with the literature data and the laboratory test results. Additionally, the end point relative permeability data and residual saturations satisfactorily correlate with literature data. The proposed model has fairly good fitness results for the condensate relative permeability curves compared to that of gas case. This model, with typical parameters for gas condensates, can be used to describe the relative permeability behavior and to run a compositional simulation study of a single well to better understand the productivity of the field.

L’accident de Fukushima a démontré qu’aujourd’hui encore, malgré les progrès déjà réalisésdans le domaine de la sûreté nucléaire, une interruption prolongée du circuit de refroidissement primaire du réacteur (plusieurs semaines ici) était possible. La France s’est par conséquent vue contrainte de réévaluer le niveau de sûreté de ses centrales. Plus spécifiquement, le cas le plus défavorable qu’EDF considérait jusqu’alors, qui consistait en un arrêt total du système de refroidissement primaire de 24h, a été réévalué à deux semaines. Ce changement d’échelle temporelle a introduit des problématiques de fluage, d’évolution hygrométrique du béton ainsi que de flux de vapeur – celle-ci transportant les radionucléides – jusque-là laissées de côté. De ces considérations est né le projet ANR/RSNR MACENA (MAîtrise du Confinement d’une ENceinte en Accident), qui vise à évaluer le confinement d’une enceinte soumise à une température de 180°C et à une pression de 5 bar pendant deux semaines. Ce travail s’inscrit dans la lignée de celui entamé par Khaddour [2014] dans le but de parvenir à une meilleure prédiction des propriétés de transport des milieux poreux en se basant uniquement sur une caractérisation indirecte, la distribution des tailles de pore obtenue grâce à la technique de porosimétrie par intrusion de mercure. Si l’aptitude du modèle initial à estimer correctement les perméabilités intrinsèques a été confirmée sur des matériaux représentant une large gamme de perméabilités, il n’était pas, en l’état, capable de prédire les perméabilités relatives au gaz et au liquide. C’est pourquoi une approche dite redistributive a été développée, laquelle a montré de bons résultats sur diverses PSD. Enfin, un nouveau modèle a été développé pour essayer de s’affranchir de cette approche tout en améliorant la capacité à déterminer les perméabilités relatives. Bien qu’efficace sur des PSD monomodales, étroites ou larges, il a montré ses limites sur une PSD réelle bimodale. En parallèle, une étude de faisabilité a exhibé la possibilité de suivre un front de saturation à l’intérieur d’un matériau poreux, ce qui permettrait à terme de valider l’inclusion d’autres phénomènes dans le modèle, liés notamment à la pression de perçage. / The Fukushima catastrophe that struck Japan in 2011 demonstrated that despite significant progress in the field of nuclear safety a prolonged reactor primary cooling circuit breakdown was possible (several weeks in this specific case). With 4 nuclear power plants located on its shoreline, France therefore needed to reassess the safety level of its facilities. More specifically, the worst case scenario considered up until that point by EdF — which consisted in a 24h breakdown of the primary cooling system — was revised up to two weeks. This time-scale shift induced creep, drying and vapour flow problems previously left aside. Thus came to be the ANR/RSNR MACENA (MAîtrise du Confinement d’une ENceinte en Accident) project, which aims at bettering the tightness assessment of a nuclear containment vessel submitted to a temperature of 180°C and to a pressure of 5 bar for two weeks. This work falls in line with that initiated by Khaddour [2014], who set out to better predict porous materials’ transport properties based solely on an indirect characterisation of their topology, namely Pore Size Distribution (PSD) which is obtained via an experimental technique called Mercury Intrusion Porosimetry (MIP). The initial model’s ability to correctly estimate intrinsic permeabilities was confirmed on several different materials whose intrinsic permeabilities span several orders of magnitude. However, it was not fit to accurately account for gas and liquid relative permeabilities. This led to the introduction of a so-called redistributive approach, which yielded better results on various PSD and corresponding experimental datasets. Finally, a new model was developed to try and avoid said approach while bettering relative permeability predictions. Although it behaved well with monomodal pore size distributions, be they wide or narrow, it fell short when applied to a real bimodal PSD. In parallel, an experimental feasibility study demonstrated the possibility of tracking a saturation front within a porous material, which should ultimately allow for the implementation of several other phenomena into the model, linked among others to breakthrough capillary pressure.

Dans cette thèse, nous nous sommes intéressés à la mesure et à la modélisation des propriétés d'écoulements diphasiques (perméabilités relatives) dans des milieux poreux carbonatés représentatifs de la zone de transition de réservoirs pétroliers carbonatés. Notre étude expérimentale a porté sur deux roches carbonatées de même minéralogie mais de propriétés pétrophysiques différentes (unimodale et bimodale). Les fluides utilisés sont une saumure, une huile minérale pour les expériences en mouillabilité franche à l'eau et une huile brute pour les expériences en mouillabilité altérée (obtenue par macération). Durant les expériences en « écoulements permanents », la perte de charge est mesurée continûment et le champ de saturation locale est mesuré en fin d'expérience par atténuation gamma. Les principaux résultats expérimentaux de cette étude sont les suivantes :- La mouillabilité dépend de la saturation initiale en huile et donc de la hauteur de la zone de transition. Elle a une influence sur les perméabilités relatives à l'huile ET à l'eau.- L'hystérésis des perméabilités relatives à l'eau est d'autant plus prononcée que la saturation initiale en huile augmente. Une observation similaire est faite sur la courbure des perméabilités relatives à l'huile.- Les évolutions des Sorw en fonction des Soi ne vérifient pas toutes, une loi monotone de type Land. Leur évolution dépend aussi de la structure poreuse.- Les deux types de roches carbonatés présentent une altération de mouillabilité différente, la structure vacuolaire favorisant l'altération de mouillabilité. Nos données expérimentales ont été interprétées en utilisant différents modèles d'hystérésis de la littérature. Il apparait clairement des différences entre les prédictions numériques et nos données expérimentales car ces modèles ne prennent pas en compte l'évolution de la mouillabilité. Nous avons proposé un modèle de calcul des perméabilités relatives qui décrit nos données expérimentales de manière satisfaisante. / In this work, we take an interest in measuring and modeling the multiphase flow properties (relative permeabilities) in different carbonate rock types that are representative of the transition zone of carbonate reservoirs. Our experimental study focused on two different carbonate rock types, with almost the same mineralogy, but different petrophysical properties (bimodal and unimodal). The system of fluids used is composed of brine, a mineral oil (for experiments at water-wet conditions), and a crude oil (for experiments including wettability alteration after an ageing process at high temperature). During the experiments performed by the steady-state core flooding method, the pressure drop is continuously measured along the core, and the saturation profiles are obtained at the end of the flooding, by gamma ray measurements. The main results of this study are as follows:- Wettability depends on the initial oil saturation and hence the heights above the oil-water contact. It affects the oil relative permeabilities AND water relative permeabilities- The hysteresis observed on water relative permeability is even more pronounced that the initial oil saturation increases. A similar observation is made on the curvatures of the oil relative permeability.- The evolution of Sorw as function of Soi does not always follow a classical Land correlation. Their evolution also depends on the pore structure.- The two rock types exhibit different responses to wettability alteration. The vuggy structure might promote oil-wetness.Our experimental data were interpreted using different hysteretic models of the literature. We observed significant differences between the results predicted by the models and our experimental observations which are attributed mainly to the failures to take into account the change in wettability. We proposed an improved hysteresis model, which described our experimental data satisfactorily.

<div>Thermal management in next generation power electronic devices, radar applications and semiconductor packaging architectures is becoming increasingly challenging due to the need to reject localized high heat fluxes as well as large total powers. Air cooling has been considered as a simple and reliable method for thermal management compared to architectures that incorporate liquid cooling. However, air-cooled heat sinks typically require effective heat spreading to provide the requisite level of area enhancement to dissipate high heat fluxes. Compared to solid metallic heat spreaders, advanced heat sinks that incorporate two-phase heat transfer devices such as vapor chambers can significantly enhance the power dissipation capabilities in such configurations. Vapor chambers are devices that utilize evaporation/boiling processes within a sealed cavity to achieve efficient heat spreading. In high-heat-flux applications, boiling can occur within the internal wick structure of the vapor chamber at the location of the heat input (i.e., the evaporator). The maximum dryout heat flux and thermal resistance of the device is dictated by the resulting two-phase flow and heat transfer in the porous evaporator due to boiling. While various works in the literature have introduced new evaporator wick designs to improve the dryout heat flux during boiling, the enhancement is limited to small, millimeter scale hotspots or at a very high thermal resistance. In additixon, the effective design of such evaporator systems requires mechanistic models that can accurately predict the dryout limit and thermal performance. </div><div> This thesis first explores the usage of a novel ‘two-layer’ evaporator wick for passive high heat flux dissipation over large heater areas at a low thermal resistance. Moreover, a new mechanistic (first principles based) model framework is introduced for dryout limit and thermal performance prediction during boiling in capillary fed evaporators, by considering the resulting simultaneous flow of two phases (liquid and vapor) within the microscale porous media.</div><div> The novel two-layer wick concept uses a thick ‘cap’ layer of porous material to feed liquid to a thin ‘base’ layer through an array of vertical liquid-feeding ‘posts’. Vapor ‘vents’ in the cap layer allow for vapor formed during the boiling process (which is constrained to the base layer) to escape out of the wick. This two-layer structure decouples the functions of liquid resupply and capillary-fed boiling heat transfer, making the design realize high heat flux dissipation greater than 500 W/cm2 over large heat input areas of ~1 cm2. A reduced-order model is first developed to demonstrate the performance of a vapor chamber incorporating such a two-layer evaporator wick design. The model comprises simplified hydraulic and thermal resistance networks for predicting the capillary-limited maximum heat flux and the overall thermal resistance, respectively. The reduced-order model is validated against a higher fidelity numerical model and then used to analyze the performance of the vapor chamber with varying two-layer wick geometric feature sizes. The fabrication of the proposed two-layer wick is then presented. The thermal performance of the fabricated wicks is characterized using a boiling test facility that utilizes high speed visualization to identify the characteristic regimes of boiling operation in the wicks. The performance is also benchmarked to conventional single-layer wicks. </div><div> It is observed that single-layer wicks exhibit an unfavorable boiling regime where the center of the heater area dries out locally, leading to a high value of thermal resistance. The two-layer wicks avoid local dryout due to the distributed feeding provided by the posts and enhance the dryout heat flux significantly compared to single-layer wicks. A two-layer design that consists of a 10 × 10 array of liquid feeding posts provided a 400% improvement in the dryout heat flux. Following a parametric analysis of the effect of particle size, two-layer wicks composed of 180 – 212 µm particles and a 15 × 15 array of liquid feeding posts yielded a maximum heat flux dissipation of 485 W/cm2 over a 1 cm2 heat input area while also maintaining a low thermal resistance of only ~0.052 K/W. The effect of vapor venting and liquid-feeding areas is also experimentally studied. By understanding these effects, a parametrically optimized design is fabricated and shown to demonstrate an extremely high dryout limit of 512 W/cm2. We identify that the unique area-scalability of the two-layer wick design allows it to achieve an unprecedented combination of high total power and low-thermal-resistance heat dissipation over larger areas than was previously possible in the literature.</div><div> The results from the characterization of two-layer wicks revealed that the overall performance of the design was limited by the boiling process in the thin base wick layer. A fundamental model-based understanding of the resulting two-phase flow and heat transfer process in such thin capillary-fed porous media was still lacking. This lack of a mechanistic model precluded the accurate prediction of dryout heat flux and thermal performance of the two-layer wick. Moreover, such an understanding is needed for the optimal design of advanced hybrid evaporator wicks that leverage capillary-fed boiling. Despite the existence of various experimental works, there are currently no mechanistic approaches that model this behavior. To fill this unmet need, this thesis presents a new semi-empirical model for prediction of dryout and thermal resistance of capillary-fed evaporator systems. Thermal conduction across the solid and volumetric evaporation within the pores are solved to obtain the temperature distribution in the porous structure. Capillary-driven lateral liquid flow from the outer periphery of the evaporator to its center, with vapor flow across the thickness, is considered to obtain the local liquid and vapor pressures. Experiments are conducted on sintered copper particle evaporators of different particle sizes and heater areas to collect data for model calibration. To demonstrate the wider applicability of the model for other types of porous evaporators, the model is further calibrated against a variety of dryout limit and thermal resistance data collected from the literature. The model is shown to predict the experimentally observed trends in the dryout limit with mean particle/pore size, heater size, and evaporator thicknesses. This physics–based modeling approach is then implemented into a vapor chamber model to predict the thermal performance limits of air-cooled heat sinks with embedded vapor chambers. The governing energy and momentum equations of a low-cost analytical vapor chamber modeling approach is coupled with the evaporator model to capture the effect of boiling in the evaporator wick. An example case study illustrating the usage of the model is demonstrated and compared to a purely evaporation-based modeling approach, for quantifying the differences in dryout limit prediction, signifying the need to account for boiling in the evaporator wick. </div><div> The understanding gained from this thesis can be utilized for the prediction of dryout and thermal performance during boiling in capillary limited evaporator systems. The work also suggests the usage of a universal relative permeability correlation for the two-phase flow configuration studied herein for capillary-fed boiling, based on a wide calibration to experimental data. The modeling framework can also be readily leveraged to find novel and unexplored designs of advanced evaporator wicks. From an application standpoint, the new vapor chamber model developed here can be used for the improved estimation of performance limits specifically when high heat fluxes are encountered by the device. This will enable better and informed design of air-cooled heat sink architectures with embedded vapor chambers for high performance applications. </div><div><br></div>

[pt] Em reservatórios de gás retrógrado com pressões inferiores à pressão de orvalho, a produtividade dos poços pode ser comprometida devido ao aparecimento e acúmulo da fase líquida nas suas imediações. Este fenômeno é conhecido como bloqueio por condensação retrógrada e está associado à uma série de desafios para compreendê-lo. Um deles é a determinação da permeabilidade relativa das fases líquida e gasosa, que comumente advém de curvas de permeabilidade obtidas a partir da extrapolação de poucos dados experimentais. Dessa forma, elas tendem a não representar fielmente efeitos importantes para o escoamento, comprometendo a precisão da modelagem do fluxo no meio poroso. A fim de investigar o efeito das curvas de permeabilidade relativa sobre a formação de bancos de condensado, foi desenvolvido um modelo composicional em escala de reservatório para o estudo do escoamento de gás e condensado. Com o modelo, o uso de curvas de permeabilidade relativa obtidas através de simulação do escoamento de gás retrógrado na escala de poros e de correlações propostas na literatura foi avaliado. Considera-se: sistema isotérmico, escoamento bifásico e incorporação dos efeitos de forças capilares por meio do modelo de permeabilidade relativa. Equações de balanço molar e consistência de volume formam um sistema não linear resolvido pelo método de Newton que fornece pressão e número de mols de cada componente, em todos os volumes de controle do modelo, a cada passo de tempo. Para o equilíbrio de fases, a equação de Peng & Robinson foi implementada com uma rotina de flash a pressão e temperaturas constantes. O modelo foi validado contra a solução analítica para sistema monofásico e por fim, o simulador obteve a evolução temporal das curvas de pressão e saturação em função da distância do poço, a fim de comparar o efeito dos diferentes modelos de curvas de permeabilidade relativa na predição do bloqueio por condensado. Os resultados foram obtidos variando-se a permeabilidade absoluta do meio e a vazão de gás imposta no poço, e o impacto desses parâmetros no acúmulo de condensado foi avaliado. / [en] In gas-condensate reservoirs with pressures below the dew pressure, the productivity of wells can be compromised due to the accumulation of liquid in their surroundings. This phenomenon is known as condensate blockage and there are many challenges to understanding the formation of condensate banks. One of them is the determination of the relative permeability of the liquid and gas phases, which commonly comes from permeability curves obtained from the extrapolation of few experimental data. Thus, they tend not to reliably represent important effects for the flow, compromising the precision of the flow modeling in the porous medium. In order to investigate the effect of relative permeability curves on the formation of condensate banks, a reservoir-scale compositional model was developed for the study of flow of gas and condensate. With the model, the use of relative permeability curves obtained by simulating the gas-condensate flow at the pore-scale and with correlations proposed in the literature was evaluated. It is considered: isothermal system, two-phase flow and incorporation of capillary force effects through the relative permeability model. Molar balance and volume consistency equations form a nonlinear system solved by Newton s method that provides pressure and number of moles of each component, in all control volumes of the model, at each time step. For the phase equilibrium, calculations of the Peng & Robinson equation was implemented in a constant pressure and temperature flash routine. The model was validated against the analytical solution for single-phase flow and, finally, the simulator obtained the temporal evolution of the pressure and saturation as a function of the distance from the well, in order to compare the effect of different models of relative permeability curves in the prediction of condensate blockage. The results were obtained by varying the absolute permeability of the medium and the gas flow imposed in the well, and the impact of these parameters on the accumulation of condensate was evaluated.

The introduction of inverters utilizing wide band-gap semiconductors allow for higher switching frequency and improved machine drive energy efficiency. However, inverter switching results in fast voltage surges which cause overvoltage at the stator terminals and uneven voltage distribution in the stator winding. Therefore, it is important to understand how next generation machine drives, with higher switching frequency, affect the voltage distribution. For this purpose, a lumped-parameter model capable of simulating winding interturn voltages for the wide frequency range of 0-10 MHz is developed for a slotless PMSM. The model includes both capacitive and inductive couplings, extracted from 2D finite element simulations, as well as analytically estimated resistive winding losses. The developed model of a single phase-winding is used to investigate how machine design aspects such as insulation materials and winding conductor distribution affects both voltage distribution and winding impedance spectrum. Validation measurements demonstrate that the model is accurate for the wide frequency range. The sensitivity analysis suggests that the winding conductor distribution affect both impedance spectrum and voltage distribution. For the slotless machine, capacitance between the winding and the stator is several times smaller than capacitance between turns. Therefore, the high-frequency effects are dominated by the capacitance between turns. Insulation materials that affect this coupling does therefore have an impact on the impedance spectrum but does not have any significant impact on the voltage distribution. / Nästa generations inverterare för styrning av elektriska maskiner, baserade på bredbandgaps komponenter, tillåter högre switchfrekvenser vilket skapar en energieffektivare drivlina. Nackdelen är att snabba spänningsflanker från den höga switchfrekvensen skapar överspänning på stators anslutningar och en ojämn spänningsfördelning i statorlindningen. Det är därför betydelsefullt att förstå hur dessa nya drivlinor påverkar lindningens spänningsfördelning. I denna rapport används en modell kapabel att simulera lindningens spänningsfördelning i det breda frekvensspektrumet 0-10 MHZ. Modellen är framtagen för en faslindning av en PMSM, utan statoröppning, som inkluderar både kapacitiva och induktiva kopplingar samt analytiskt beräknade lindningsförluster. Modellen används för att undersöka spänningsfördelningen i lindningen samt inverkan från designparametrar som isolationsmaterial och lindningsdistribution. Känslighetsanalysen visar att lindingsdistributionen har en signifikant påverkan på både impedansspektrumet och spänningsfördelningen. För den studerade maskintypen är det kapacitansen mellan varv som är dominerande för högfrekventa fenomen. Isolationsmaterial som påverkar denna koppling har en påverkan på impedansspektrumet men är liten för spänningsfördelningen.