Search

The existing in-mold electromagnetic stirrers (M-EMS) that are widely applied in the steel industries have experienced low efficiencies due to the high operational temperatures and open system structures. Based on simple mechanical attachments and verified by detailed 3-D electromagnetic field analyses, this paper will propose a guided field path arrangement that can enhance the overall performance of an M-EMS system by a factor of 28% in the designated stirring directions while maintaining the same energy inputs. Such evident improvements will certainly provide a valuable design and adjustment guidance for the related metal industries. Index Terms--Continuous casting process, finite-element analysis (FEA), in-mold electromagnetic stirrer, molten steel.

This paper presents an axial-flux permanent magnet (AFPM) machine with an internal coreless stator and twin external permanent magnet (PM) rotors, based on the finite-element method (FEM) by robust design, call Taguchi method to the optimum design for minimum the torque ripple and maximum the ratio between torque ripple and average torque. The optimization is realized by analyses and simulations with finite-element analysis (FEA). The design optimization process is described and the results are presented in this paper. Index Terms--Axial flux permanent magnet (AFPM), finite-element analysis (FEA), Taguchi method, torque ripple.

This paper presents the use of genetic algorithms (GAs) and the Taguchi method in optimizing an surface-mounted permanent magnet (SPM) motor for use as a fan motor in air-conditioners. GAs were used to optimize the efficiency of the motor, and the Taguchi optimization method was used and the finite-element method (FEM) analysis was conducted to compute the performance of the motor design generated by the Taguchi design of experiments. Index Terms--Cogging torque, efficiency, finite-element (FE) analysis, genetic algorithms (GAs), surface-mounted permanent magnet (SPM) motor, Taguchi optimization method.

In this paper a traveling wave model for describing the lightning stroke is developed. Finite element method is used to derive the element equations and one -dimensional linear elements are used to discretize the field region. The implicit Newmark time integration algorithm is employed to obtain the recurrence formulas for the solution of field variables at each time step. Numerical examples are included and illustrated.

This paper presents a magnetic circuit model for an interior permanent magnet (IPM) synchronous machine. The model includes each portion of magnetic flux paths, especially the leakage flux paths around the magnets in the rotor. The magnetic field quantities are expressed analytically in terms of the reluctance ratio [Beta] and the leakage flux ratios [Eta] and [Lambda]. It is shown that the width and the iron saturation level of the iron bridge have an important effect on the magnetic field distribution within the motor. Numerical results confirm the validity of the analytical model. Index Terms--Finite-element (FE) analysis, interior permanent magnet (IPM) synchronous machine, leakage flux, magnetic circuit model.

In this paper a three-dimensional thermal model of an induction motor is presented. Excepting for providing a more accurate representation of the problem, the proposed model can also reduce computing costs. The finite element method is used to solve the three-dimensional steady-state and/or transient heat flow equation which describes the thermal model. A temperature-time method is employed to evaluate the distribution of loss in various parts of the machine. Using these loss distributions as an input for finite element analysis, more accurate temperature distributions can be then obtained. The validity and accuracy of the proposed method are checked by comparing the results with those obtained from test. Index Terms--Finite element method, heat rejection curves, induction motor, thermal analysis.

This paper presents a novel fiber-optic magnetic sensor based on a side-polished fiber Bragg grating coated with thin iron film. The Bragg wavelength shift of 0.08 nm was measured at the distance of 0.38 mm between fiber sensor and Nd-Fe-B magnet with remanent flux density of 1.115 T. We demonstrate the ability to measure magnetic fields using such a device. Index Terms--Fiber Bragg grating, magnetic sensor, side-polished fiber.

A multi-objective optimization design technique for a six-phase copper rotor induction motor is proposed. The amended particle swarm optimization (PSO) and Taguchi methods combined with finite element analysis are used in this design technique. The objectives in the first-stage optimization are the minimization of manufacturing cost and starting current. In the second-stage optimization, the objectives are the maximization of efficiency, power factor and output torque. The Taguchi method can optimize the machine parameters of performance characteristics in electrical discharge machining. The experimental results are further transformed into the signal-to-noise ratios and amended PSO coefficients based on amended PSO analysis with regard to multiple performance characteristics index values. The results of the optimizations showed significant reduction in terms of the use of magnets as well as improvement in the machine performance. Finally, the experimental results confirm the validity of the proposed optimization design approach. [ABSTRACT FROM AUTHOR]