Microwave absorbing properties of ferrites and their composites: A review

High-speed permanent-magnet synchronous machines (HS PMSMs) are a popular topology among modern electrical machines. Suitable applications for such machines are low-power vacuum pumps, compressors, and chillers. This paper describes a systematic design methodology for an HS PMSM using two case studies. The design process for such high-speed (HS) machines is multidisciplinary and highly iterative due to the complex interaction of the many design variables involved. Consequently, no single optimum solution exists, and multiple possible solutions can meet the customer requirements. Practical solutions should be within acceptable thermal limits, should be energy-efficient, and should be rigid enough to withstand the forces exerted during operation. The proposed design flow is divided into steps that are presented in this paper in the form of a flowchart with emphasis on mechanical aspects. Each step represents a task for a thermal, mechanical, or electrical engineer. The features of each step and the prerequisites for moving to the next step are discussed. The described methodology was implemented in the design of two HS PMSMs. The output performance results of the design flow are compared with measured results of the prototypes. The design process described in this paper provides a straightforward procedure for the multidisciplinary design of HS permanent magnet electrical machines.

Multidisciplinary Design Process of a 6-Slot 2-Pole High-Speed Permanent-Magnet Synchronous Machine

Analytical models play an important role in the design of electromagnetic devices by providing computationally efficient solutions. In this paper, by combining magnetic equivalent circuit approaches and Faraday's and Ampere's laws, a model for radial-flux eddy-current couplers is developed, which can easily handle complex geometries as well as account for iron saturation, all material properties, and three-dimensional (3-D) parameters. The characteristics and the design considerations of a surface-mounted permanent-magnet structure are presented. Also, a procedure aimed at an optimal design of the yoke thicknesses is utilized. Moreover, 2-D and 3-D finite-element methods are employed in the analyses and evaluation of the model. Finally, sensitivity analysis is performed to explore the impacts of the machine parameters on the device performance.

Nonlinear Modeling of Eddy-Current Couplers

In this paper, the design optimization of a nonsalient high-speed permanent magnet synchronous machine (PMSM) for electric vehicle applications is presented. It will be shown how, with a new approach, it is possible to find a deterministic solution to solve the sizing of the machine from a given driving cycle. The optimal geometry and the optimal control strategy over the cycle minimizing both the energy losses and the volume of the machine will be calculated. At first, the one-dimensional analytical model used is presented and validated for the most significant point of the driving cycle using a finite element method. Then, the design methodology and the results through a specific application are detailed. Particularly, it will be shown how the flux weakening, directly given by the design process via the optimization of the control strategy, allows reducing both the energy losses and the constraints on the power converter. At last, in order to validate the solution considering the whole cycle while keeping a reduced computation time, a reluctance network model of the PMSM is used. This model validate the energy losses and the flux densities in the steel parts over the cycle. The study will be done considering the urban dynamometer driving schedule.

Design Optimization with Flux Weakening of High-Speed PMSM for Electrical Vehicle Considering the Driving Cycle

A directly coupled magneto-mechanical model is proposed for simulating the effect of the magnetostriction and electromagnetic stress in iron. The model is based on the general balance laws of electromagnetism, mechanics, and continuum thermodynamics. It is implemented in 2-D by using a conforming finite element method for the magnetic vector potential and the displacement field. The method is applied to two different types of induction machines.

FEM for directly coupled magneto-mechanical phenomena in electrical machinesKatarzyna

Electromagnetic force and torque computations for a bearingless synchronous reluctance motor presents multi-input complexity, which can be challenging to handle by look-up table. A novel methodology of choosing efficient snapshots for the model order reduction is proposed in this paper to compute the torque and electromagnetic forces on rotor with much less computational burden.

Force computation of a synchronous reluctance motor by model order reduction with constraint based uneven snapshot matrix

This paper presents a method to minimize the resistive losses in bearingless linear motors. A minimization algorithm is developed for calculating reference currents for a range of reference forces while the effect of spatial harmonics on force production is considered. The results from the algorithm are implemented in the form of lookup tables and artificial neural networks. A comparison between the two implementation methods is presented. Time-domain simulation results are given for motion control of a bearingless linear flux-switching permanent-magnet motor system while using optimal reference currents. Index Terms–Artificial neural networks, bearingless, energy efficiency, linear actuator, magnetic levitation, table lookup.

Energy-Efficient Control of Bearingless Linear Motors

A stress dependent excess loss model is developed based on the correlation of the excess loss and the hysteresis loss.

Effect of stress on excess loss of electrical steel sheets

An Energy-Based Anisotropic Vector Hysteresis Model for Rotational Electromagnetic Core Loss

In this paper, we determine analytically the demagnetization field within a uniformly magnetized ellipsoid embedded in an infinite anisotropic media. The anisotropic boundary condition consists of decomposing the external magnetization into an isotropic part parallel to the external field and an anisotropic part. The resulting demagnetization field within the ellipsoid is then calculated by superposing the demagnetization fields produced by the ellipsoid magnetization, the isotropic part of the external magnetization and field, and the anisotropic part of the external magnetization. Such computation is needed in developing accurate anisotropic multi-scale models of electrical steel sheets, for example.

Floran Martin

Papers

Force computation of a synchronous reluctance motor by model order reduction with constraint based uneven snapshot matrix

Energy-Efficient Control of Bearingless Linear Motors

Effect of stress on excess loss of electrical steel sheets

An Energy-Based Anisotropic Vector Hysteresis Model for Rotational Electromagnetic Core Loss

Demagnetization field in a uniformly magnetized ellipsoid embedded in an infinite anisotropic media