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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.
301

Modelování elektrických pohonů na platformě CompactRIO s využitím FPGA / Modeling of electrical drives on the CompactRIO platform using FPGA

Kozumplík, Karel January 2016 (has links)
This Master´s thesis engage in modeling of electric motions on CompactRIO platform with FPGA. Permanent magnet synchronous motor (PMSM) is namely described, modeled and tested here. This thesis demonstrates the complete work procedure for modeling of electric motion and testing behavior of motor in real time. Various types of discretization are described here and model si discussed from accuracy same as from FPGA utilization point of view. The last part of this project describes testing comparison between created model and real PMSM motor and results from this testing.
302

Carbon Nanotube and Nanoparticle Materials for Electromagnetics Applications

Ruff, Bradley M. 10 October 2013 (has links)
No description available.
303

An Integrated Design Approach of Rotor Assembly for Radial Flux Surface-Mounted Permanent Magnet Synchronous Motors

Manikandan, Akshay January 2023 (has links)
Enhancing the dependability and power density of a SPMSMs is crucial for its extensive utilization in the automotive and aerospace sectors. One major concern regarding these machines is the significant thermo-mechanical loads experienced by the overall rotating assembly due to high rotational speeds and a wide operational temperature range from $50^\circ C$ to $150^\circ C$. This poses a considerable challenge in maintaining structural integrity among the components. Redesigning components to reduce assembly complexity and weight necessitates careful consideration of boundary conditions and contact modeling to prevent catastrophic failures like magnet fly-by conditions. To reduce model complexity, a simplified approach involves integrating the hub and shaft; both machined from AISI 4340. Additionally, the application of a carbon fiber sleeve is investigated through 3-dimensional composite modeling to enhance structural integrity. The primary objective of this thesis is to scientifically justify the design and validation of an integrated rotor hub and shaft using efficient FEM and integration strategies, with the aim of maximizing the durability of a $150kW$ radial flux SPMSMs spinning at $20,000 rpm$. The integrated topology optimization is evaluated using a multiphysics platform alongside studies on motor assembly eigenfrequency. By employing the integrated approach and utilizing AISI 4340 for both the shaft and rotor hub, a weight reduction of $1.84kg$ is achieved, eliminating the need for standard components such as balancing end clamp plates, locknuts, and washers. Furthermore, introducing a carbon fiber sleeve enhances structural integrity, thereby reducing adhesive stress. The design and optimization of the rotating components ensure that the maximum von Mises stress is $50\%$ lower than the material's yield strength. Reduced masses lead to lower centrifugal forces, thereby diminishing radial stress and promoting component and assembly stiffness. / Thesis / Master of Applied Science (MASc) / This thesis aims to increase the reliability and power density of a surface-mounted permanent magnet synchronous machine (SPMSMs), a commonly used traction motor in the automotive and aerospace industries. One of these machines' main challenges is designing their components to withstand the high mechanical loads caused by their fast rotational speeds. The studies performed in this thesis use a computer modeling technique called Finite Element Modeling (FEM) to strategize and design an integrated rotor hub/shaft by maximizing the durability of a 150kW radial flux SPMSMs rotating at 20,000 rpm. Upon evaluating the integrated design using a variety of physics-based simulations, the design was found to save 1.84kg in weight, reducing centrifugal forces and improving the overall stiffness of the motor assembly. This research could lead to more efficient and durable electric SPMSMs for various applications.
304

Experimental and Numerical Study of Thermal Performance of a Self Contained Drum Motor Drive System (SCDMDS)

Teamah, Ahmed M. January 2023 (has links)
The main focus of this work is to investigate thermal performance of self-contained drum motor drive systems (SCDMDS). All components of a SCDMDS are contained inside a rotating drum including the electric motor, gearbox, and an air/oil multiphase flow. A considerable amount of heat is generated within the SCDMDS from various sources, namely, the electric motor losses, the oil viscous dissipation and the gearbox losses. In meantime, a limited amount of heat is dissipated through the surface of the rotating drum and the side flanges. Therefore, a SCDMDS sometimes encounters a serious overheating problem, which often results in electric motor failure. The different heat generation and dissipation mechanisms as well as the two-phase flow within the SCDMDS have been studied experimentally and numerically under different operating parameters, namely, the oil level (OV), the drum rotational speed (N), the torque (ζ), the number of motor poles (n) and the electric motor dimensions. The effects of rubber lagging material and thickness as well as the use of rubber belts have been investigated as well. The numerical part of the present study has been carried out using Ansys-CFX and was validated using experimental data. Results showed that the optimum oil level (OV) for the best thermal performance is about 65%. The increase in the rotational speed (N) enhanced the heat transfer within the SCDMDS due to the improved oil splashing. Viscous dissipation (VD) between the motor stator and the rotating drive drum was found to be almost negligible. However, oil viscous dissipation within the gap between the motor rotor and stator was found to have an important effect on the thermal performance. An analytical model has been developed and implemented using MATLAB to estimate VD within the motor. The losses from the gearbox were studied experimentally and numerically considering planetary and co-axial gear trains. The numerical work was carried out using the KISSsoft and KISSsys software. Results showed that the increase in the drum rotational speed (N) or the drum torque (ζ) increased the gearbox losses. In the planetary gearbox, any increase in the OV increases the churning losses, however, the increase in OV increased the losses in the co-axial gearbox up to OV = 31% beyond which the losses remained constant. After understanding the complex interplay between all the heat generating and dissipating mechanisms within the SCDMDS, a number of possible modifications have been proposed in order to resolve the overheating problem. The effect of cooling the electric motor by using an axial air flow has been investigated. The effect of adding fins along the inner surface of the outer rotating drum has also been studied. Correlations of the various contributing mechanisms have been developed. Based on a thermal resistance network, a SCDMDS sizing and performance assessment computer software tool in the form of a digital twin (DT) has been developed. A user-friendly interface has been developed using Visual Basics and Excel. The DT estimates temperature distribution and the amount of heat generated and dissipated from each component within the SCDMDS and hence it identifies whether the case is considered safe to operate or overheating is expected. In overheated cases, the DT also suggests several possible modifications the user could consider to resolve the overheating problem. The DT has been validated against several experimental case studies and found to be very reasonably accurate. / Thesis / Doctor of Philosophy (PhD) / This study is focused on investigating heat transfer and fluid flow inside a self-contained drum motor drive system (SCDMDS). The problem of interest involves multiple heat sources enclosed inside a tight space of the rotating drum. There is an electrical motor, gearbox and a multiphase (oil/air) flow inside the rotating drum of the SCDMDS. In this thesis, experimental test rigs were constructed to investigate the effect of a number of operating and geometrical parameters. In addition, numerical analysis of the multiphase oil/air flow was carried out using Ansys - CFX. The KISSsoft and KISSsys software packages were used to determine various types of heat losses within the geartrain. Due to the presence of multiple heat sources inside a confined space, overheating of a number of SCDMDS has been reported. The overheating problem worsened even more when rubber lagging is used to increase traction between the drive drum and the belt. Several correlations have been developed for various heat transfer mechanisms governing the overall thermal performance of the entire SCDMDS. An analytical model (a digital twin) has been developed using Visual Basics and Excel. The digital twin estimates the temperature distribution and the amount of heat generated and dissipated inside the SCDMDS. It has been validated against many case studies provided by the industrial partner. The model identifies the possibility of overheating and provides the user with several potential modifications to resolve it. Hence, the model can be used as a performance and design tool of various models of SCDMDS.
305

Electric Propulsion System for Exceptionally Short Takeoff and Landing Electric Air Vehicles

Mahvelatishamsabadi, Parisa January 2019 (has links)
Over the past few years, electric propulsion systems have been widely used in automotive applications. The next decade is likely to see the electrification of aerial vehicles. In the past 20 years, the passengers demand in the aviation industry has increased by roughly 5% annually. Drastic increment in the passengers demand leads to many problems such as emission, noise pollution, airports capacity shortage, and high fuel consumption. An electric airplane that can take off and land in an extremely short runway can solve all the mentioned problems. Also, an airplane that is smaller and lighter with the ability to take off and land from an extremely short runway can be used as a new transportation system in congested cities and solve the urban road traffic and compensate for people’s time wasted in traffic. With this in mind, in this thesis, the feasibility of converting a conventional fixed-wing direct-drive propeller airplane to an electric extremely short takeoff and landing airplane has been examined. An overview of the history of electric aerial vehicles and flying cars is conducted where some of these vehicles are still under development phase. The main aim of this thesis is to address the effect of takeoff and landing runway length on the electric motor main specifications, including power, torque, and speed. Also, the effect of cruising speed on the motor specifications are investigated, and it is observed that there is a considerable difference between the amount of required power for the cruising mode and takeoff mode. In the end, the impact of the braking system and airplane weight on the landing distance are examined, and It is found that for an airplane with a cruise-efficient propeller, usage of thrust reverser is not practical and hence it is not recommended. Although if the propeller is designed to have high efficiency at takeoff and landing, the thrust reverser can be a good solution to make the landing runway shorter. / Thesis / Master of Applied Science (MASc)
306

Design of a PC based Data Acquistion System for a Switched Reluctance Motor

Chandramouli, G. 07 November 2012 (has links)
The Switched Reluctance Motors(SRM) have gained considerable attention in the variable speed drive market mainly due to the simple construction of the motor and the possibility of developing low cost converters and controllers. As these machines are under development, a considerable amount of research effort is directed to the experimental performance evaluation of the SRM drives. System efficiency, electromagnetic torque, torque ripple, output and losses are some of the required measurements. / Master of Science
307

Sensorless starting of a brushless D.C. motor

Ghosh, Ramit 22 June 2010 (has links)
Permanent magnet brushless DC motors that have found wide application in high performance servo drives need absolute rotor position sensors. However, the cost of the position sensor limits the use of brush less DC motors for low performance applications such as automotive and home appliances. A sensorless starting scheme for brushless DC motors is studied in this thesis. A hardware implementation of the starting scheme has been instrumented. The modeling and simulation of the sensorless starting performance of brushless DC motors have been accomplished to gain the insight into the process. The experimental results confirm the theoretical prediction that the permanent magnet brush less DC motor can be started without a position sensor. The experimental setup with individual subsystems are described in detail. / Master of Science
308

Stored waveform adaptive motor control

Beall, Jeffery C. 15 November 2013 (has links)
This study investigates an adaptive control scheme designed to maintain accurate motor speed control in spite of high-frequency periodic variations in load torque, load inertia, and motor parameters. The controller adapts, stores and replays a schedule of torques to be delivered at discrete points throughout the periodic load cycle. The controller also adapts to non-periodic changes in load conditions which occur over several load cycles and contains inherent integrator control action to drive speed error to zero. Using computer simulations, the control method was successfully applied to a 3Φ synchronous motor and a permanent magnet D.C. motor. The D.C. motor (or A.C. servo-motor) controller has superior characteristics and this system performance was compared to P, PI and PID control for two severe load cases - a periodic step load and a four-bar linkage load. Simulation studies showed the schedule control method to be stable and in comparison to the PID controller to have 1) nearly the same speed of response but without the overshoot found in PID control, 2) nearly the same mean speed error (~ O), 3) 12-50 times better reduction in speed fluctuation, and 4) the schedule controller gains were much easier to find than PID gains for this low-order, highly responsive system. / Master of Science
309

A heat transfer finite element model of a high speed DC electric motor

Grosse, Ian Royce January 1983 (has links)
A finite element heat transfer model of a high speed direct current electric motor is presented. The two dimensional axisymmetric model incorporates the motor rotor assembly, stator windings, stator laminations, stator end windings, and the motor housing. Power dissipation is modeled as Joule heating in the motor winding elements and iron core losses in the stator laminations. The two-dimensional axisymmetric model is preprocessed using a two dimensional mesh generator. Results are postprocessed with a two-dimensional contour plotting routine and compared to experimental results. Based on experimental data adjustments are made and overall correlation is good. / M.S.
310

On design methods for mechatronics : servo motor and gearhead

Roos, Fredrik January 2005 (has links)
<p>The number of electric powered sub-systems in road-vehicles is increasing fast. This development is primarily driven by the new and improved functionality that can be implemented with electro-mechanical sub-systems, but it is also necessary for the transition to electric and hybrid-electric drive trains.</p><p>An electromechanical sub-system can be implemented as a physically integrated mechatronic module: controller, power electronics, electric motor, transmission and sensors, all integrated into one component. A mechatronic module, spans, as all mechatronic systems, over several closely coupled engineering disciplines: mechanics, electronics, electro-mechanics, control theory and computer science. In order to design and optimize a mechatronic system it is therefore desirable to design the system within all domains concurrently. Optimizing each domain or component separately will not result in the optimal system design. Furthermore, the very large production volumes of automotive sub-systems increase the freedom in the mechatronics design process. Instead of being limited to the selection from off-the shelf components, application specific components may be designed.</p><p>The research presented in this thesis aims at development of an integrated design and optimization methodology for mechatronic modules. The target of the methodology is the conceptual design phase, where the number of design parameters is relatively small. So far, the focus has been on design methods for the electric motor and gearhead, two of the most important components in an actuation module. The thesis presents two methods for design and optimization of motor and gearhead in mechatronic applications. One discrete method, intended for the selection of off-the-shelf components, and one method mainly intended for high volume applications where new application specific components may be designed. Both methods can handle any type of load combination, which is important in mechatronic systems, where the load seldom can be classified as pure inertial or constant speed.</p><p>Furthermore, design models relating spur gear weight, size and inertia to output torque and gear ratio are presented. It is shown that a gearhead has significantly lower inertia and weight than a motor. The results indicate that it almost always is favorable from a weight and size perspective to use a gearhead. A direct drive configuration may only be lighter for very high speed applications. The main contribution of this thesis is however the motor/gear ratio sizing methods that can be applied to any electromechanical actuation system that requires rotational motion.</p>

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