| This thesis gives new modeling techniques for electromechanical devices with moving eddy current regions. The principal objectives of this thesis are: (1) the development of stable and accurate modeling techniques of nonlinear three dimensional and two dimensional devices which have moving conducting bodies; (2) improvement in the accuracy of determination of performance parameters particularly forces, torques and losses computed from finite elements.; Contributions are made in two general areas: more efficient models for three dimensional finite element analysis which save time and improve accuracy and a novel modeling approach for higher harmonic loss terms in induction machines due to moving eddy current regions.; Since the thesis is dealing with the moving eddy current problem, a new analysis based on coupled electric and magnetic potentials with remeshing techniques has been implemented to obtain braking torque in a Watt-hour meter. Even though the Watt-hour meter is a very well-known and old device, to model this complicated topology with all of its subtle effects is not an easy task and has been done for the first time.; The canned solid rotor induction motor problem is also considered. The main difficulties were the low efficiency of the machine and the unknown loss sources. The moving eddy current regions bring extra losses and the finite element model has also been used to analyze the harmonic components due to the tooth ripple. A new method for analyzing these loss components based on data obtained from a transient analysis of the machine is explored. Comparisons are made for different types of solutions and conclusions drawn as to how much improvement is made. The necessity of using a time domain solution with a sufficiently small time step, even in steady state, has been shown. A new modeling technique and equivalent circuit for this motor has been introduced to determine machine performance. The one-slot model has significant advantages over the time-stepping modeling.; Generally, this thesis gives new and improved modeling approaches in 2D and 3D problems with moving eddy current regions. It also shows the limitations and assumptions and provides rules to insure accurate results. |
