No description available.

No description available.

No description available.

No description available.

No description available.

The work presented in this thesis is concerned with the development of an on-line technique for detecting and locating partial discharges in the stator winding of a high voltage electrical machine. This technique forms part of an on-line health monitoring strategy for the insulation of high voltage machines. Existing diagnostic techniques and partial discharge measurement systems are reviewed. The requirement for an on-line partial discharge location technique is discussed. An experimental investigation was carried out into the propagation characteristics of partial discharge pulses within a model stator winding. This allowed identification of the main propagation characteristics which were used as the basis for the development of a partial discharge location technique. In the development of a location technique, a means of on-line detection of discharge signals at the motor terminals is required. A study was therefore made on the use of the Rogowski coil for the non-invasive measurement of partial discharges. A partial discharge location system was developed based on the correlation of partial discharge pulses detected at the two ends of a motor phase winding. The performance of the location system was investigated by injecting artificially generated discharge pulses into the model stator winding. Further verification of the ability of the technique to locate the position of discharges was done by injecting high voltage discharges. The final part of the research work was to develop a theoretical model to predict the propagation behaviour of partial discharge pulses in the stator winding of an electrical machine . The effect of electromagnetic propagation through the endwinding region is incorporated in the model of two adjacent coils in a winding.

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

No description available.

In an increasingly urgent climate crisis, the use of electric powertrains in smaller, purpose-built vehicles can expedite the global adoption of electrification. This thesis discusses the detailed design of an axial-flux switched reluctance motor for application in a light electric vehicle, such as an E-motorcycle. A vehicle application is studied based on typical driving conditions in an urban environment. The requirements of the propulsion motor are extracted, and a baseline machine topology is analyzed for its performance and manufacturability, towards the goal of a functional prototype. The prototype design includes a self-supporting foil winding, designed to maximize the use of axial space and allow for good conductive heat transfer to the machine casing. The rotor structure is found to be a limiting factor, where maximum speed is limited by the mechanical stresses. The performance of the motor is analyzed in detail, beginning with a numerical iron loss model that is implemented to provide faster simulation time of the machine efficiency than FEA. The efficiency is found to peak at 90%, comparable with other traction motors of similar size on the market. The switching angles are studied, and the trade-offs between torque quality and efficiency are quantified over the drive cycle. It was determined that the vehicle could save 19.6 Wh/km by accepting poor torque quality and operating with the most efficient control parameters. Thermal analysis is performed to determine the realistic performance limitations. The machine was found to have power ratings of 7.12 kW instantaneous and 4.76 kW continuous. The final temperature of the winding during the drive cycle was predicted not to exceed the temperature ratings of the insulation system. Finally, the prototype is assembled, and a test plan is outlined for qualification of the motor. / Thesis / Master of Applied Science (MASc) / This thesis documents the design of a new type of electric motor that is intended to be used in a small electric vehicle. The electric motor is different from the majority of motors used in this application for two reasons: firstly, the motor is a switched reluctance motor, which means that it does not contain any permanent magnets, offering cost savings and additional robustness. Secondly, the machine takes the form of a disk, where the magnetic interface between rotating and stationary components is on the face perpendicular to the axis of rotation. Normally, electric motors have the magnetic interface on the cylindrical surface which is parallel to the axis of rotation. The disk form factor presents multiple design challenges, which when coupled with the switched reluctance motor type, are addressed. A series of mathematical models are built to predict the performance of the motor in the vehicular application. Finally, a prototype of the motor is constructed.

Tightening systems are used in several industries, including assembly in the auto- motive industry and installation of computer hardware. Both the company mak- ing the tools and the customers need to know the performance of the tightening system to ensure that the screw joints tighten as desired. This can be done using a test joint system. High demands on safety as well as fast assembly speeds, puts high demands on the test equipment. The problem with the existing test joints is that they are hard to do repeatable tests on. The most common test joints are constructed us- ing mechanic or hydraulic systems. The mechanical systems have problems with wear of screws, changes in lubrication etc., while the hydraulic systems some- times are too slow. This master’s thesis is a study of whether it would be possible to construct a test joint using an electric motor. The electric motor together with a controller should simulate a screw joint so that the tool would perceive it as a real one. All investigation has been performed by system modeling and simulations in MATLAB. Four different control structures have been evaluated: a PID controller, one combined controller which uses feedforward from reference as well as distur- bance, one which is based on the same structure as the second but with an added inner current loop and the last one is an LQ controller. The conclusion is that it is possible to make a test joint using an electric motor and that the LQ controller seems to be the best choice. To prove the result, a few more aspects could be investigated more closely. One is to add a dynamic model of the tool, now only the reference to the tool is used. Another is to implement it on hardware.