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ABSTRACT: The paper reviews the progress in understanding and modeling the noise and vibration and the stray fields produced by electric machines. In machines that are already quiet, numerical methods are necessary to find the smaller sources of vibrations or emitted electrical signals. Several examples are given for permanent magnet machines and induction motors.
IEEE Transactions on Magnetics 04/2009; · 1.36 Impact Factor
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ABSTRACT: A method is proposed to find eddy currents in massive bodies with relative motion. An integral equation solution in the time domain is proposed in this paper. This method can also be applied to magnetic-resonance imaging magnets to study transient effects occurring due to the sudden application of current. These effects may include perturbations of the homogeneity of the main field or the far field.
Journal of Applied Physics 05/2005; 97(10):10E104-10E104-3. · 2.17 Impact Factor
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ABSTRACT: We present an alternative method for calculating the magnetic field from a set of permanent magnets in a permanent-magnet motor. The method uses a cylindrical coordinate system to model the geometry of the structure enclosing the magnets. A Fourier series expansion yields an alternative to the more familiar multipole expansion given in spherical coordinates. The expansion is developed by using Green's function in cylindrical coordinates. A technique called charge simulation allows computation of an equivalent point charge distribution. Finally, Coulomb's law is applied to express the magnetic scalar potential in a mathematically tractable form.
IEEE Transactions on Magnetics 10/2004; · 1.36 Impact Factor
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ABSTRACT: Eddy current analysis finds wide application in electrical machinery and devices, in power system analysis, nondestructive testing, continuous casting, ship board applications, and others. Finite-element methods such as T-Ω, A-φ and A-V methods do provide solutions of acceptable accuracy for small problems where the element size is comparable to skin depth. Even for this, a large number of elements are required to model the entire space of the conducting medium and the surrounding air region. Integral equations require modeling of only the conducting parts and therefore offer an alternative approach to the problem. This paper presents an integral equation analysis and its application to a conducting body with and without a crack excited by a transmission line source.
IEEE Transactions on Magnetics 10/2003; · 1.36 Impact Factor
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ABSTRACT: We discuss spherical harmonic analysis (SHA) - frequently quoted as a key method for the substitution of a magnetic source by its multipole image and to combine flexibility of commercial FEM package with numerical procedure for SHA.
Magnetics Conference, 2003. INTERMAG 2003. IEEE International;
