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the purpose of this paper is to study the influence of the type of winding -double layer or single layer -to the global noise level of the machine. For this purpose, two variable speed induction motors have been studied, of the type M3AA 71 B4/8 manufactured by Electroprecizia S.A. Săcele, Romania, with Dahlander windings, star connected -for the low speed and double star connected -for the high speed. The motors are modelled from magnetic and mechanical point of view with finite element softwares. The investigated motors were placed in the semi-anechoic chamber in order to determine the noise-tofrequency characteristics (spectrograms).

The paper deals with an analytical model for hysteresis cycle representation. The hysteresis curve is decomposed in a series of arcs of circles and segments of lines. Each arc of circle or segment of line is expressed using analytical geometry as a function of some given parameters or calculated ones. The easiness of the model proposed is given by the small amount of input data needed to represent the hysteresis cycle in a satisfactory way. Using an inverse mapping function from major hysteresis branches the minor cycles, reversal curve of the first kind or curve of first magnetization can be obtained. Finally a comparison between the measured data and modelled ones was made

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