This thesis presents a systematic scheme to determine the optimal propulsive/axial force ratio of a single-sided permanent magnet axial-flux motor (SPMAM) along with its operational constraints on both the winding currents and the speed induced voltages. According to the rotating magnetic field theory with combining the recoil line characteristics of permanent magnet and the equivalent operational magnetic circuits, appropriate projection of the stator currents to achieve an optimal ratio of the machine propulsive/axial forces has been confirmed through detailed three-dimensional finite element analysis (3-D FEA) and numerical studies. From these evaluations, a feasible operational guidance for SPMAM field oriented control (FOC) scheme realizations can be suitably provided. Finally, based on the proposed optimal scheme, a DSP-based drive system has been successfully implemented, and the desired operational strategy realization can be achieved.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Two different types of tracking feeds are currently used in the majority of telemetry tracking antenna systems when autotrack operation is required. They are of the conical scanner or of the single channel monopulse family and they employ well known technologies. In broadband applications, these feeds all suffer from the same inherent degradation in efficiency caused by their inability to maintain a constant crossover loss value and by their failure to properly illuminate the reflector. In high dynamics situations they can also generate unwanted and sometimes detrimental modulation whenever on-axis tracking is not maintained. In addition, currently available versions of the conical scanner are not capable of high scan rates or of scan rate agility and they are ill-suited for use in tracking systems based on non-orthogonal axes positioners. This paper describes a new high efficiency tracking feed system based on proven conical scanner technology. Its design incorporates features such as variable crossover, steerable beam, high scan rates, scan rate agility as well as stable reference coordinate system. In addition to these features, this new feed is also capable of delivering, in all but one operational category, levels of performance superior to that achievable to date by any other implementation of the conical scanner or of the single channel monopulse technology.