الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
The competition criteria between different motor drive techniques can generally be grouped into three main categories. The First is the torque and speed performance. The second is the full-load efficiency and power factor. The third is the initial, running and maintenance costs. The advent of low cost high remanence rare-earth permanent magnets with linear demagnetization characteristics led to an evolution in electrical machines and drives technologies. This thesis studies a group of these new machines named the Permanent Magnet Synchronous Machines (PMSM). The huge diversity of PMSMs has almost satisfied all the low-voltage industrial demands from fractional horsepower to multi-megawatt ratings with unparalleled efficiency, high torque density and zero steady¬state speed regulation eliminating the need for bulky and complex control algorithms. However, as new comers, these machines lack sufficient study necessary to properly introduce them to the Egyptian market. The researcher aims from this study to master these promising machines from different scientific aspects.
The study begins with introducing the PMSMs, its applications and advantages. Then a quick overview to the underlying permanent magnet technology is tackled. Different constructions of these machines are described. Then their transient and steady-state mathematical models are derived. The thesis then studies a promising non-linear control strategy known in the literature as the adaptive backstepping technique, and applies it to a suitable Surface mount PMSM. The thesis also tackles the well-known Field Oriented Control (FOe) strategy applied to the same machine. The simulation results for both techniques demonstrate their usefulness to control the selected motor. An experimental setup is built to study the performance of an industrial Line-Start Interior PMSM as a case study. The weakness of the derived mathematical models to handle highly non-linear phenomena like saturation and space harmonics moved the research towards employing the finite element analysis to this machine. The simulation results obtained from this numerical analysis technique show good matching with the results obtained experimentally. Furthermore, with the help of this powerful technique, the study managed to make parameters sensitivity analysis that could not be studied with the classical machine analysis techniques. Such analysis includes the effect of temperature variation and iron core saturation on the parameters and performance of the machine, the accurate assessment to the iron loss density in the machine, the field solution of the machine at different operating conditions and the possibility of permanent magnet demagnetization.