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This paper examines the relationship between rotor design, saliency-based signal injection sensorless control, and power conversion properties for four industrially relevant interior permanent-magnet machine configurations: a 36-slot 6-pole stator with v bar rotor, a 36-slot 6-pole stator with flat bar rotor, a 9-slot 6-pole stator with v bar rotor, and a 9-slot 6-pole stator with flat bar rotor. The influence of rotor geometric design variables over the range of current densities at the maximum torque per ampere angle was found using a design of experiments' methodology and standardized regression coefficients. Tradeoffs between sensorless control and power conversion properties are found using a Monte Carlo methodology. Power conversion and sensorless control properties were analyzed using hybrid static and time-stepping finite-element simulations. [ABSTRACT FROM AUTHOR]

The proposed hybrid method combines computationally efficient finite-element analysis (CE-FEA) with a new analytical formulation for eddy-current losses in the permanent magnets (PMs) of sine-wave current-regulated brushless synchronous motors. The CE-FEA only employs a reduced set of magnetostatic solutions yielding substantial reductions in the computational time, as compared with the conventional FEA. The 3-D end effects and the effect of pulsewidth-modulation switching harmonics are incorporated in the analytical calculations. The algorithms are applied to two fractional-slot concentrated-winding interior PM motors with different circumferential and axial PM block segmentation arrangements. The method is validated against 2-D and 3-D time-stepping FEA. [ABSTRACT FROM PUBLISHER]

Computationally efficient finite-element analysis (FEA) (CE-FEA) fully exploits the symmetries of electric and magnetic circuits of sine-wave current-regulated synchronous machines and yields substantial savings of computational efforts. Motor performance is evaluated through Fourier analysis and a minimum number of magnetostatic solutions. The major steady-state performance indices (average torque, ripple and cogging torque, back-electromotive-force waveforms, and core losses) are satisfactorily estimated as compared with the results of detailed time-stepping (transient) FEA. In this paper, the CE-FEA method is presented and applied to a parametric design study for an interior-permanent-magnet machine. Significant reduction of simulation times is achieved (approximately two orders of magnitude), permitting a comprehensive search of large design spaces for optimization purposes. In this case study, the influence of three design variables, namely, stator tooth width, pole arc, and slot opening, on three performance indices, namely, average torque, efficiency, and full-load torque ripple, is examined, and design trends are derived. One hundred candidate designs are simulated in less than 20 minutes on a state-of-the-art workstation. [ABSTRACT FROM PUBLISHER]