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The effect of winding topologies on the performance of flux-switching permanent magnet machine having different number of rotor poles

Chijioke Awah Ch., Inya Okoro O.

Archives of Electrical Engineering

2018

Vol. 67, nr 4

845--855

Comparison of the electromagnetic performance of a flux-switching permanent magnet (PM) machine having two separate stators as well as different winding topologies is investigated in this paper. Different stator and rotor pole combinations of these machines are also considered. The analysis includes the open-circuit and on-load characteristics of the analyzed machines. It is observed that, the largest fundamental values of electromagnetic torque, for each winding topology, is seen in the 11-rotor-pole and 10-rotor-pole machines having alternate- and all-pole-wound configurations, respectively. Moreover, significant ripple is observed in the waveforms of the even-number rotor pole machines compared to their corresponding odd-number rotor pole counterparts. Overall, the alternate-pole-wound machines essentially have larger torque-density than their equivalent all-pole-wound ones. The investigated machine is also tested for validation.

Analysis of the proximity and skin effects on copper loss in a stator core

Młot A., Korkosz M., Grodzki P., Łukaniszyn M.

Archives of Electrical Engineering

2014

Vol. 63, nr 2

211--225

Accurate prediction of power loss distribution within an electrical device is highly desirable as it allows thermal behavior to be evaluated at the early design stage. Three-dimensional (3-D) and two-dimensional (2-D) finite element analysis (FEA) is applied to calculate dc and ac copper losses in the armature winding at high-frequency sinusoidal currents. The main goal of this paper is showing the end-winding effect on copper losses. Copper losses at high frequency are dominated by the skin and proximity effects. A time-varying current has a tendency to concentrate near the surfaces of conductors, and if the frequency is very high, the current is restricted to a very thin layer near the conductor surface. This phenomenon of nonuniform distribution of time-varying currents in conductors is known as the skin effect. The term proximity effect refers to the influence of alternating current in one conductor on the current distribution in another, nearby conductor. To evaluate the ac copper loss within the analyzed machine a simplified approach is adopted using one segment of stator core. To demonstrate an enhanced copper loss due to ac operation, the dc and ac resistances are calculated. The resistances ratio ac to dc is strongly dependent on frequency, temperature, shape of slot and size of slot opening.

Loss estimation of a reactor with multi conductor coils by 3-D finite element analysis

Sawada M., Shindo Y., Tamiya T., Kawase Y., Yamaguchi T., Katagiri H., Ishigure H.

Przegląd Elektrotechniczny

2012

R. 88, nr 7b

110-112

In this paper, the effects of the coil division on copper loss, especially eddy current loss, of a reactor are quantitatively clarified. The eddy current of the coil of the reactor is numerically computed using the three-dimensional finite element method.

W artykule przedstawiono wpływ podziału cewki na straty wiroprądowe w dławiku. Prądy wirowe w cewce dławika obliczane są numerycznie przy użuyciu trójwymiarowej metody elementów skończonych.