Concurrent design of FI-IPM machines for self-sensing and electromechanical power conversion.

摘要

This thesis presents concurrent design of flux-intensifying interior permanent magnet (FI-IPM) machines that are suitable for self-sensing and electromechanical power conversion. Self-sensing capabilities primarily focus on position sensing at very low speeds (using saliency-tracking based methods), while power conversion capabilities focus on loss reduction in applications with duty-cycle loads, such as in electric vehicles (EVs). Systematic metrics used for evaluating machine self-sensing and power conversion aspects are presented. Simulations with finite-element analysis (FEA) are mainly used to gain insight of magnetic behavior in different types of evaluated IPM designs.;Q-axis flux-barriers are used in the concurrent design of FI-IPM machines due to their effectiveness in reducing saturation effects caused by stator load current. A saliency characteristic with Ld > Lq is presented as the key design objective in the concurrent design methodologies. Self-sensing capability can be improved as machine parameters become less sensitive to loading and variations in the fundamental saliency magnitude and orientation are small. As for power conversion aspects, induced saturation is decreased which can lead to a reduction in iron losses. In addition, a wide range in a manipulation of flux linkage can be achieved from flux-intensifying operation.;Investigation is also extended to cover design of FI-IPM machines with variable flux characteristics. Effects of associated topological structures in a rotor, such as flux-barriers, rotor iron bridges and magnet configurations, are evaluated to understand design tradeoffs in power conversion and self-sensing. Limitations of the proposed concurrent design methodologies are also evaluated with practical design constraints found in EV applications. Design approaches for dealing with identified issues are presented accordingly.