Multi-flux Barriers Research Articles

Electromagnetic–Mechanical Coupling Optimization of an IPM Synchronous Machine with Multi Flux Barriers

In this paper, an interior permanent magnet (IPM) synchronous machine with multiflux barriers is proposed to meet the wide speed regulation application requirements of electric vehicles. Based on the flux barrier characteristic, an electromagnetic–mechanical coupling optimization strategy is employed for the machine design. In order to facilitate the optimization design, the rotor barriers are divided into two optimization zones, the maximum stress zone and the maximum deformation zone. The electromagnetic–mechanical coupling optimization strategy is divided into two stages accordingly. In the first stage, the machine is regarded as a synchronous reluctance machine by ignoring permanent magnets, where the dimensions of the arc-shaped barriers are optimized to achieve a large reluctance torque and small stress. In the second stage, the dimensions of the arc-shaped PMs and the elliptical barrier are optimized with three objectives of minimum torque ripple, minimum flux linkage, and minimum deformation. After machine optimization, the comparison investigations are carried out on the basis of finite-element analysis by considering both the electromagnetic performances and mechanical performances.

Design and Analysis for Torque Ripple Reduction in Synchronous Reluctance Machine

The rotor of transversally laminated synchronous reluctance motor is constructed with multi-flux barriers by stamping the laminated steel sheets and the machine is short for TLR-SynRM. It has obvious advantages of smooth rotor surface, and the lower copper loss, et al. [1]. Nevertheless, TLR-SynRM has the drawback of high torque ripple, and one of the main reasons is the non-sinusoidal distribution of the air-gap flux density caused by the spatial harmonics of stator magnetic potential and flux-barrier rotor configuration. In [2], it has been carried out the genetic algorithm (GA) optimizations to improve the angles of the flux-barrier ends to reduce the torque ripple. In this paper, it proposes the step-shaped gradient flux barriers in TLR-SynRM for torque ripple reduction.A method is presented to compute the reluctances of each layer of flux barriers through conformal mapping method. Based on this calculation, it is shown how the air-gap flux density distribution of TLR-SynRM can be analytically computed through magnetic equivalent circuit (MEC) method. Combining with the two methods, the flux-barrier parameters for torque ripple reduction can be improved and the final improved flux-barrier parameters are obtained.

Synchronous Reluctance Machine Optimization for High-Speed Applications

The synchronous reluctance machines with transversally laminated rotor and multi flux barriers per pole reach a high torque density, so that they are proposed as a valid alternative to permanent magnet machines. Such machines have been analyzed for different applications, mainly home appliance, industrial tool, traction, up to low-speed high-power generators. On the contrary, the use of synchronous reluctance machines for high-speed applications remains almost unexplored yet. The aim of this paper is to investigate the potential of a high-speed synchronous reluctance machine. An optimization is carried out so as to maximize the machine performance (high power, proper power factor, low vibration) at a given speed. The machine size is fixed and the focus is on the rotor geometry, with the purpose of maximizing the electromagnetic torque, according to the necessary thickness of the ribs. It is shown that, even if the ribs are thick, it is possible to reach a proper torque density. It is shown that different solutions exist, which allow to reach high torque and minimum torque ripple. However, the optimal solutions are quite sensitive to the geometrical variations, so that a particular care is required in the manufacturing of the machine. Finally, the power limit of the synchronous reluctance motor with barrier rotor is found.

Eccentricity in Synchronous Reluctance Motors—Part I: Analytical and Finite-Element Models

In recent years, there is a growing interest for synchronous reluctance machines. This is due to their high torque density, flux-weakening operation capability, and high fault-tolerance capability. This paper deals with the analysis of a synchronous reluctance machine when eccentricity occurs. Both static and dynamic eccentricity are considered. An analytical model to predict the machine performance is described. As an example, a four-pole reluctance machine is analyzed, considering single, as well as multi flux-barriers per pole. The finite-element analysis confirms the results achieved by means of the proposed analytical model.

Synchronous Reluctance Motors Design And Performance PredictionUsing An Analytical Procedure

A procedure for the design of Synchronous Reluctance Motors with multi flux barriers rotors is proposed. It uses an analytical model that takes into account the cross magnetization and saturation effects. An optimization algorithm has been integrated in the design refinement process and it represents a useful tool for a fast and efficacious fulfillment of motor specifications. The proposed software has been tested for the design of different sizes of SRMs, whose performance have been compared with the Finite Element analysis ones.

Mover design and performance analysis of linear synchronous reluctance motor with multiflux barrier

AbstractA synchronous reluctance motor has many advantages because it has no permanent magnet, such as low back emf in high‐speed operation, maintaining performance in a high‐temperature environment, and so on. Therefore, many rotor constructions have been studied and developed. The rotor with multiflux barrier structure has the merit of easy construction and high performance.The linear synchronous reluctance motor has been developed. It is necessary to improve the performance of the mover design for industrial use, because of its low power factor.In this paper, we propose a novel configuration of mover for the linear synchronous reluctance motor, and examine the static characteristics of the motor with reluctance equalization design by means of the finite element method. From analytical results, it is demonstrated that the static characteristics of the linear synchronous reluctance motor are greatly improved by the reluctance equalization design at the iron layer in the mover. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 61–69, 2002; DOI 10.1002/eej.1139

Mover Design and Performance Analysis of Linear Synchronous Reluctance Motor with Multi-flux Barrier

A Synchronous reluctance motor has many advantages because it has no permanent magnet, such as low back emf in a high speed operation, keeping performance in a high temperature environment and so on. Therefore, many rotor constructions are studied and developed. The rotor with multi-flux barrier structure has the merit of its easy construction and high performances.The linear synchronous reluctance motor have been developed. It is necessary to improve the performance by the mover design for industrial use, because of its low power factor.In this paper, we propose a novel configuration of mover for linear synchronous reluctance motor, and examine the static characteristics of linear synchronous reluctance motor with reluctance equalization design by using finite element method. From analytical results, it is cleared that the static characteristics of the linear synchronous reluctance motor is greatly improved by the reluctance equalization design at the iron layer in the mover.

Rotor Design and Performances of a Multi-Flux Barrier Synchronous Reluctance Motor

It is demonstrated that the rotor design of multi-flux barrier synchronous reluctance motors can be optimized in terms of a key geometric parameters, i.e., the optimum number of flux barrier and the ratio of the flux barrier width to the iron rib width so as to obtain maximum torque production. The results indicate the 6-layer flux-barrier rotor is optimum design considering practical use. An experimental motor has been fabricated and the results of measurements of the motor parameters prove the validity of the rotor design optimization.