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A magneto-structural combined dimensional and topology optimization approach for interior permanent magnet synchronous machine (IPMSM) rotor design is proposed using the solid isotropic material with penalization (SIMP) density-based topology optimization method. This method optimizes the location and dimensions of the permanent magnets (PMs) embedded in the rotor, while simultaneously optimizing the lamination flux barriers using topology optimization. To allow for the location and dimensions of the PMs to change a Laplace smoothing mesh deformation technique is used. Three examples of IPMSM rotor optimizations are presented to demonstrate the proposed approach. In addition, a geometric template-based optimization is carried out for a comparison to one of the dimensional and topology optimized examples to better illustrate the difference. [ABSTRACT FROM AUTHOR]

This article presents the simultaneous magnetic and structural topology optimization of a transverse laminated synchronous reluctance machine rotor using a solid isotropic with material penalization (SIMP)-based approach with the globally convergent method of moving asymptotes (GCMMA) optimization algorithm. Magneto-structural single and multi-objective optimization formulations are presented. The single objective formulation maximizes the average torque subject to constraints on torque ripple, Von Mises stress, and compliance. The multiobjective formulation simultaneously maximizes average torque and minimizes compliance subject to constraints on torque ripple and Von Mises stress. In both optimization formulations, the electrical steel densities in the rotor mesh elements are the control variables. Including stress and compliance in the optimization formulation ensures a structurally feasible design. The design-dependent centripetal force contributed by each element in the rotor mesh is considered dependent on its density and mass. An intermediate density material issue is observed where the density of the material in a mesh element does not converge fully to air or electrical steel. This issue is addressed through the use of a thresholding mass function which forces the convergence of the mass but not the density. The two optimization formulations are compared for rotors operating at 4000 and 12 000 r/min. An initial magnetic only topology optimization is used to seed the magneto-structural topology optimization to decrease the computational time. The impact of the magnetic only seed and rotor mesh density on the optimization outcomes is also examined. [ABSTRACT FROM AUTHOR]

This paper studies the design of electric machine windings with reduced magnetomotive force (MMF) space harmonic content by adjusting the slot distribution and coil turns. Closed-form expressions for the winding factor and harmonic magnitudes established from a mathematical representation of winding functions are used to formulate the MMF space harmonic suppression problem. The framework is applicable to both distributed windings and fractional-slot concentrated windings (FSCWs) and can be solved with different techniques. No special requirements on the slot/pole combination and the number of layers are necessary. One example uses a linear algebraic technique to solve simultaneous equations and the result is a mixed-layer distributed winding. The process also reveals the criterion when multiple requirements on the winding factor and harmonic magnitudes can be satisfied concurrently. Contour plots are included to provide additional graphical insight. Another example designs a 24-slot 22-pole FSCW subset with numerical optimization. The resultant winding is a four-layer FSCW with two subsets and 3/4 of the harmonic orders are eliminated. The performance improvement of this winding is verified with finite-element simulations. [ABSTRACT FROM PUBLISHER]

This paper describes the modeling, optimization, mechanical design, and experimental characterization of a high power density wound field synchronous machine (WFSM) for electric vehicle traction applications. The WFSM is designed for brushless rotor field excitation using an axial flux hydrodynamic capacitive power coupler (CPC). The flexible design environment, which was used for large-scale multiobjective optimization of the WFSM, is described. A prototype WFSM, spray cooled with automatic transmission fluid, with an 80-kW output at a base speed of 4000 r/min has been tested. The prototyped WFSM achieves volumetric torque and power densities of 17.22 N·m/L and 7.19 kW/L referred to the envelope cylindrical volume of the active materials plus spray cooling rings. The specific torque and power densities are 4.69 N·m/kg and 1.95 kW/kg referred to the mass of the active materials and the shaft. The prototyped CPC provided up to 1-kW excitation power with a mass 600 g and volume of 0.271 L. [ABSTRACT FROM AUTHOR]

This paper proposes a systematic approach for the development of electric machine windings with reduced magnetomotive force (MMF) space harmonic content. By identifying the levels and slot position angles in the winding function of an electric machine winding, the winding factor, the magnitudes of individual harmonic components and thus the MMF spectrum of a winding can be represented mathematically as functions of the levels and angles. With numerical optimization, these functions can act as the constraints and the objective function. A typical formulation is to limit the magnitudes of undesired harmonics and to maximize the winding factor of the working component. The result of the optimization is often a new winding layout with potentially unequally pitched slots and different turns for the coils within a phase, and reduced or even eliminated harmonic orders of design interest, while maintaining a reasonable winding factor. The mathematical representation and design approach is applicable to both distributed windings and fractional-slot concentrated windings (FSCWs), with no special requirements on the slot/pole combination and the number of layers. Two design examples, a mixed-layer distributed winding and a 24-slot, 22-pole double-layer FSCW, are shown to have improved electromagnetic performance with finite element simulations. [ABSTRACT FROM AUTHOR]