Many different Flexible AC Transmission System (FACTS) devices have been studied in recent years in order to control the flow of power through transmission lines and reduce the overall burden on the power grid. The net results of these devices are decreased utility costs, increased system stability, and improved system flexibility. The main issues with most currently available FACTS controllers are the high costs of installation, and operation. The Sen Transformer (ST) is a new FACTS device that decreases these costs by using relatively inexpensive and industry familiar transformer technology to independently control the active and reactive power in a transmission line.<p> This thesis introduces the first full transient model for the ST developed in an ElectroMagnetic Transients Program (EMTP) using a hybrid transformer modeling approach. This technique handles all the non-linearities of the core, including losses and saturation effects, as well as inter-phase coupling, and zero sequence effect with an attached topographically correct core model. This new model can be used in a variety of power system studies such as transient and dynamic simulations, and protection analysis. The flexibility of the hybid ST model allows for different core and winding configurations as well as response to very fast transients with little modification. Fault analysis studies are presented to showcase the capabilities of the transient ST model developed.<p> The first ST transient model using the Finite Element Analysis (FEA) technique is also created for comparison with the hybrid ST model. This method uses Maxwells equations, material non-linearities and coupled electric circuits to obtain a precise transient solution for the ST. There is good agreement between the two models in a test system for multiple types of fault scenarios. The hybrid ST model is therefore the preferred model to use for fault analysis since it reduces simulation time drastically when compared to the FEA ST model.<p> The hybrid ST model is then used to develop and test differential, and ground protection schemes that ensure device safety during faulted scenarios. The protection schemes are analyzed and compared with analogous Phase Angle Regulator (PAR) schemes that have been implemented for many years.

Diffraction Enhanced X-ray Imaging (DEI) uses synchrotron X-ray beams prepared and analyzed by perfect single crystals to achieve imaging contrast from a number of phenomena taking place in an object under investigation. The crystals used in DEI for imaging requires high precision positioning due to a narrow rocking curve. Typically, the angular precision required should be on the order of tens of nanoradians.<p>One of the problems associated with DEI is the inability to control, set, and fix the angle of the analyzer crystal in relation to the beam exiting the monochromator in the system. This angle is used to interpret the images acquired with an object present and the usual approach is to determine where the image was taken after the fact. If the angle is not correct, then the image is wasted and has to be retaken. If time or dose is not an issue, then retaking the image is not a serious problem. However, since the technique is to be developed for live animal or eventually human imaging, the lost images are no longer acceptable from either X-ray exposure or time perspectives.<p>Therefore, a mechanical positioning system for the DEI system should be developed that allows a precise setting and measurement of the analyzer crystal angles. In this thesis, the fundamental principles of the DEI method, the DEI system at the National Synchrotron Light Source (NSLS) and the sensitivity of the DEI system to vibration and temperature has been briefly studied to gain a better understanding of the problem. The DEI design at the NSLS was analyzed using finite element analysis software (ANSYS) to determine the defects in the current design which were making the system dimensionally unstable. Using the results of this analysis, the new analyzer support was designed aiming to eliminate the problems with the current design. The new design is much stiffer with the natural frequency spectrum raised about eight times. <p> This new design will improve the performance of the system at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory, New York, USA and should assist in the development of a new DEI system for the Bio-Medical Imaging and Therapy (BMIT) beamline at the Canadian Light Source (CLS), Saskatoon, CANADA.

The objective of this work was to develop an analysis framework for the structural design of the Human-Powered Ornithopter (HPO). This framework was used in a kinematicaerostructural optimizer for apping-wing ight (Ornithia), as well as analytically to design the HPO, and focused on three goals. First was the development of an accurate and computationally inexpensive nite-element method, to be integrated with Ornithia, which would capture the geometric nonlinearity of the aerostructural interaction of the wing when subjected the large deformations in ight. Second was the assembly of a model by which the aircraft primary structure, the wing main spar especially, could be exactly characterized and designed. Third was the establishment of a process and toolbox for failure analysis which could be applied universally in the design of the HPO. The validation and tuning of these models involved extensive testing on prototype carbon ber composite components.

The objective of this work was to develop an analysis framework for the structural design of the Human-Powered Ornithopter (HPO). This framework was used in a kinematicaerostructural optimizer for apping-wing ight (Ornithia), as well as analytically to design the HPO, and focused on three goals. First was the development of an accurate and computationally inexpensive nite-element method, to be integrated with Ornithia, which would capture the geometric nonlinearity of the aerostructural interaction of the wing when subjected the large deformations in ight. Second was the assembly of a model by which the aircraft primary structure, the wing main spar especially, could be exactly characterized and designed. Third was the establishment of a process and toolbox for failure analysis which could be applied universally in the design of the HPO. The validation and tuning of these models involved extensive testing on prototype carbon ber composite components.

Many different Flexible AC Transmission System (FACTS) devices have been studied in recent years in order to control the flow of power through transmission lines and reduce the overall burden on the power grid. The net results of these devices are decreased utility costs, increased system stability, and improved system flexibility. The main issues with most currently available FACTS controllers are the high costs of installation, and operation. The Sen Transformer (ST) is a new FACTS device that decreases these costs by using relatively inexpensive and industry familiar transformer technology to independently control the active and reactive power in a transmission line.<p> This thesis introduces the first full transient model for the ST developed in an ElectroMagnetic Transients Program (EMTP) using a hybrid transformer modeling approach. This technique handles all the non-linearities of the core, including losses and saturation effects, as well as inter-phase coupling, and zero sequence effect with an attached topographically correct core model. This new model can be used in a variety of power system studies such as transient and dynamic simulations, and protection analysis. The flexibility of the hybid ST model allows for different core and winding configurations as well as response to very fast transients with little modification. Fault analysis studies are presented to showcase the capabilities of the transient ST model developed.<p> The first ST transient model using the Finite Element Analysis (FEA) technique is also created for comparison with the hybrid ST model. This method uses Maxwells equations, material non-linearities and coupled electric circuits to obtain a precise transient solution for the ST. There is good agreement between the two models in a test system for multiple types of fault scenarios. The hybrid ST model is therefore the preferred model to use for fault analysis since it reduces simulation time drastically when compared to the FEA ST model.<p> The hybrid ST model is then used to develop and test differential, and ground protection schemes that ensure device safety during faulted scenarios. The protection schemes are analyzed and compared with analogous Phase Angle Regulator (PAR) schemes that have been implemented for many years.

This Master’s thesis is summery of a comparative study of 2 commercial CAD-integrated FE-programs. These FE-programs were CATIA v5 and ABAQUS 6.3-7. The primary objective of this study is to investigate the basic FEA capabilities of CATIA and ABAQUS 6.7-3 in performing the linear static analysis and to identify whether there are any differences and similarities between results the both Finite Element FE codes give. The overall research question in the present thesis is: Do different FE programs, here CATIA and ABAQUS, give the same results for FE analysis giving the same models if subjected to the same boundary conditions? This research seeks to achieve its aims through making a comparative qualitative study. Certain pre-selections were performed in advance of conducting Finite element analysis and the comparison process to ensure that results would reflect only the most relevant and meaningful differences and similarities between the both FE-codes. Five different 3D solid models have been selected to perform linear static Finite element analysis on. All these models (case studies) are created in CATIA V5 and the linear static analysis conducted on using FE-codes CATIA v5 and ABAQUS 6.7-3. Three static responses (results) of the linear static analysis have been adopted as criteria for comparisons purposes. These criteria were: (1) displacements, (2) Von Mises stress, and (3) principal stress. The results of comparisons showed that there is a very good agreement in most cases and small gap between in a few cases. Results of this study demonstrate that the both FE-programs CATIA v5 and ABAQUS 6.7-3 have good capabilities to perform FE-analysis and they give very near results. Reason behind differences is that each of them uses a different algorithm for solving problems. The final answer for the research question is given with valuable recommendations for future work in the scope of this research.

Infrared (IR) imaging is a key technology in a variety of military and civilian applications, especially for night vision and remote sensing. Compared with cryogenically cooled IR sensors, uncooled infrared imaging devices have the advantages of being low cost, light weight, and superior reliability. The electro-thermal analysis of a microbolometer pixel is critical to determine both device performance and reliability. To date, most microbolometer analysis research has focused on performance optimization and computation of thermal conductance directly from the geometry. However, modeling of the thermal distribution across the microbolometer pixel is critical for the comprehensive analysis of system performance and reliability. Therefore, this thesis investigates the electro-thermo-mechanical characteristics of a microbolometer pixel considering the effects of joule heating and incoming IR energy. The contributions of the present research include the electro-thermal models for microbolometer and methods of validating thermal distribution using experimental results. The electro-thermal models explain the effect of microbolometer material properties and geometry on device performance and reliability. The research also contributes methods of estimating the thermal conductivity of microbolometer, which take into account different heat transfer mechanisms, including radiation and convection. Previous approaches for estimating the thermal conductance of uncooled microbolometer consider heat conduction via legs from the geometry of the pixel structure and material properties [2]. This approach assumes linear temperature distribution in the pixel legs structure. It also leaves out the various electro-thermal effects existing for multilayer structures. In the present research, a different approach is used to develop the thermal conductance of microbolometer pixel structure. The temperature distribution in the pixel is computed from an electro-thermal model. Then, the average temperature in the pixel microplate and the total heat energy generated by joule heating is utilized to compute the thermal conductance of the structure. The thesis discusses electro-thermal and thermo-mechanical modeling, simulation and testing of Polysilicon Multi-User MEMS Process (PolyMUMPs®) test devices as the groundwork for the investigation of microbolometer performance and reliability in space applications. An electro-thermal analytical and numerical model was developed to predict the temperature distribution across the microbolometer pixel by solving the second order differential heat equation. To provide a qualitative insight of the effect of different parameters in the thermal distribution, including material properties and device geometry, first an explicit formulation for the solution of the electro-thermal coupling is obtained using the analytical method. In addition, the electro-thermal model, which accounts for the effect of IR energy and radiation heat transfer, spreading resistance and transient conditions, was studied using numerical methods. In addition, an analytical model has been developed to compute the IR absorption coefficient of a Thin Single Stage (TSS) microbolometer pixel. The simulation result of this model was used to compute absorbed IR energy for the numerical model. Subsequently, the temperature distribution calculated from the analytical model is used to obtain the deflections that the structure undergoes, which will be fundamental for the reliability analysis of the device. Finite element analysis (FEA) has been simulated for the selected device using commercial software, ANSYS® multiphysics. Finite element simulation shows that the electro-thermal models predict the temperature distribution across a microbolometer pixel at steady-state conditions within 2.3% difference from the analytical model. The analytical and numerical models are also simulated and results for a temperature distribution within 1.6% difference. In addition, to validate the analytical and numerical electro-thermal and thermo-mechanical models, a PolyMUMPs® test device has been used. The test results showed a close agreement with the FEM simulation deflection of the test device.

Diffraction Enhanced X-ray Imaging (DEI) uses synchrotron X-ray beams prepared and analyzed by perfect single crystals to achieve imaging contrast from a number of phenomena taking place in an object under investigation. The crystals used in DEI for imaging requires high precision positioning due to a narrow rocking curve. Typically, the angular precision required should be on the order of tens of nanoradians.<p>One of the problems associated with DEI is the inability to control, set, and fix the angle of the analyzer crystal in relation to the beam exiting the monochromator in the system. This angle is used to interpret the images acquired with an object present and the usual approach is to determine where the image was taken after the fact. If the angle is not correct, then the image is wasted and has to be retaken. If time or dose is not an issue, then retaking the image is not a serious problem. However, since the technique is to be developed for live animal or eventually human imaging, the lost images are no longer acceptable from either X-ray exposure or time perspectives.<p>Therefore, a mechanical positioning system for the DEI system should be developed that allows a precise setting and measurement of the analyzer crystal angles. In this thesis, the fundamental principles of the DEI method, the DEI system at the National Synchrotron Light Source (NSLS) and the sensitivity of the DEI system to vibration and temperature has been briefly studied to gain a better understanding of the problem. The DEI design at the NSLS was analyzed using finite element analysis software (ANSYS) to determine the defects in the current design which were making the system dimensionally unstable. Using the results of this analysis, the new analyzer support was designed aiming to eliminate the problems with the current design. The new design is much stiffer with the natural frequency spectrum raised about eight times. <p> This new design will improve the performance of the system at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory, New York, USA and should assist in the development of a new DEI system for the Bio-Medical Imaging and Therapy (BMIT) beamline at the Canadian Light Source (CLS), Saskatoon, CANADA.

The growth of embedded generation and portable electrical installations has led to an increased demand for low cost, flexible and reliable generator systems for military and commercial applications. An interior permanent magnet (IPM) machine has high power density due to its reluctance torque and magnetic torque components so it can produce a large constant power-speed range. However, an IPM machine needs demagnetizing current at high-speed during the flux-weakening region and thus develops an inverter shutdown problem in an uncontrolled generator mode operation. In order to overcome the disadvantages of the IPM machine, the permanent magnet assisted synchronous reluctance generator (PMa-SynRG) can be a good solution for low cost, high efficiency reliable generator systems. A PMa-SynRG can produce a high efficiency drive by utilizing the proper amount of magnet and reluctance torque. This work proposes a PMa-SynRG with two flux barriers and permanent magnets embedded in the second layer of the rotor. A neodymium magnet (NdFeB) was used as permanent magnets in the rotor to prevent demagnetization. Finding the minimum amount of magnet is one of the goals of the optimization process. The objectives of this work are to build an optimal design for the 3kW generator and an advanced power electronics converter for the PMa-SynRG drive system. In order to find the optimized 3kW machine, a Lumped Parameter Model (LPM) was used to achieve fast computation, and Differential Evolution Strategy (DES) was used to embed the LPM in an efficient numerical optimization routine to identify optimum designs. Finite Element Analysis (FEA) was used for test performance of optimum designs. On the basis of differences between LPM and FEA, model predictions were used to fine tune the LPM model. For new optimum design converges, numerical optimizations and iterations were performed to produce LPM and FEA predictions. For the drive system, the thyristor based, current-fed drive is much simpler and has lower power losses compared to the pulse width modulation (PWM) drive. Eliminating the requirement for self-controlled switches is a distinct advantage for lower cost. Another feature of the developed current-fed drive is its inherent capability to provide generating action by making the PMa-SynRG operates as a generator, rectifying the phase voltages by means of the three-phase rectifier and feeding the power into the load. These features make the current-fed drive a good candidate for driving any type of synchronous generators including the proposed PMa-SynRG.

Potential applications such as high intensity focused ultrasound in medical therapeutics require larger output pressures. To offer unprecedented acoustic output pressure in transmit without the limitations, Capacitive Micromachined Ultrasonic Transducer operation modes of collapse and collapse-snapback are introduced in literature. Both operation modes require the membrane to contact the substrate surface, which poses a problem on the durability of the membrane in terms of structural integrity and tribological property. Based on the additional requirements of these modes, diamond is proposed as the ultimate solution to be used as the membrane material. Mechanical, thermal, and electrical properties of diamond are all in favor of its use in the microfabrication of CMUTs. This thesis introduces the design and test results of the first diamond-based CMUTs as an alternative to silicon and silicon nitride based CMUTs. Simulations are performed using Finite Element Methods (FEM) using a commercially available software package, ANSYS. The diamond-based CMUT is operated successfully both in air and immersion for the first time. Fully customizable in-house software is developed to command and control the test setup equipments for current dissertation and future work. Fresnel and Fraunhofer regions of the CMUT are characterized in sunflower oil using a combination of advanced hardware and software. The experimental results of radiation and diffraction for the diamond-based circular CMUT are verified by the theoretical calculations for a circular piston transducer. The results obtained from the first generation diamond-based CMUTs presented the diamond as a promising material for membranes in CMUTs.