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Start Over Language english Journal ieee transactions on magnetics Publisher ieee institute of electrical and electronic engineers
2 results

1. Attenuation of harmonic rotor vibration in a cage rotor induction machine by a self-bearing force actuator

Author

Kari Tammi, Antero Arkkio, Kai Zenger, Juha Orivuori, Antti Laiho, and Anssi Sinervo

Subjects
Physics, rotor-dynamics, Rotor (electric), Squirrel-cage rotor, Acoustics, active control, bearingless drive, electromagnetic actuator, Rotordynamics, Wound rotor motor, Electronic, Optical and Magnetic Materials, law.invention, law, induction machine, Harmonic, Electrical and Electronic Engineering, mechanical vibration, Actuator, self-bearing machine, Induction motor, Machine control
Abstract

In this paper, attenuation of flexural rotor vibration in electrical machines is considered. In order to generate force on the machine rotor, an electromagnetic actuator based on self-bearing machine working principle is examined. A control method for attenuating harmonic rotor vibration components is applied in a 30 kW two-pole cage induction machine. The machine is equipped with a four-pole supplementary winding for generation of lateral force on the rotor. Experimental results for the two-pole induction motor are presented. The main contribution of this paper is to apply a control method, specially designed for compensating harmonic excitations, by using a built-in electromagnetic actuator in an induction machine.

Published
2009

2. Interdependence of hysteresis and eddy-current losses in laminated magnetic cores of electrical machines

Author

Jenni Pippuri, Emad Dlala, Antero Arkkio, and Anouar Belahcen

Subjects
Materials science, Magnetic domain, Finite elements, finite element analysis, law.invention, Damper, Nuclear magnetic resonance, Rotational field, law, Electrical machines, Eddy current, Electrical and Electronic Engineering, interdependence, Eddy currents, hysteresis losses, Mechanics, Magnetic hysteresis, Finite element method, laminated cores, Electronic, Optical and Magnetic Materials, Lamination (geology), Hysteresis, eddy-current losses, Core losses, Vector Preisach model, Excitation
Abstract

This paper investigates the interdependence of hysteresis and eddy-current losses in magnetic cores. Based on the results of a numerical model developed for the analysis, the magnetodynamic loss phenomena are found to be distinctly interdependent. Because of the effects of eddy currents on the flux distribution in the lamination depth, hysteresis and excess losses show a dependence on eddy currents, and hence, on the excitation frequency. Eddy-current and excess losses, on the other hand, are affected by the magnetic characteristics of the material where hysteresis plays the role of a damper. An application of the model to a rotating electrical machine has showed that the interdependence between the losses is quite significant.

Published
2010