Design & Control of High-Speed PMSM

In this PhD dissertation the design of a novel High-Speed Ferrite-based Permanent Magnet Synchronous Machine suitable for automotive application is presented. In particular, a sleeved surface-mounted HS-PMSM configuration has been chosen, since it enables higher peripheral speeds compared to the other configurations. Therefore, mechanical and electromagnetic modelling has been considered at first, based on which the design of the HS-PMSM has been carried out. This is done through a novel multi-parameter analytical design procedure, which has been developed with the aim of achieving a preliminary machine design that takes into account both design targets and constraints; the former have been set in accordance with electric vehicle application requirements, whereas operating constraints are related mainly to high-speed operation and PM demagnetization issues. The proposed design approach has been validated through extensive simulation studies, which have been performed by means of Finite Element Analyses (FEAs) that regard both mechanical and electromagnetic aspects. In addition, a Permanent Magnet Brushless DC Machine (PMBDCM) configuration has been chosen with the aim of achieving higher torque density and/or lower Joule losses compared to Permanent Magnet Brushless AC Machines (PMBACMs). In this regard, the second part of this PhD dissertation focuses on an improved three-phase-on (3PO) control approach, which benefits from appropriate zero-sequence currents in order to further increase PMBDCM exploitation. In particular, the injection of a suitable zero-sequence current allows a further reduction of Joule losses compared to those achievable by means of the original 3PO. Furthermore, a suitable Space Vector Control (SVC) has been developed based on a novel synchronous reference frame, which has been defined in accordance with the 3PO control approach previously mentioned. The effectiveness of the proposed SVC in driving the designed HS-PMSM has been verified through numerical simulations, which have been carried out in the Matlab Simulink environment. These regard also the implementation of a conventional Current Commutation Control for comparison purposes.