FEM – analysis of current displacement phenomena in slot embedded solid conductor
In the paper the low-frequency eddy currents into solid conductors embedded in a slot are theoretically analyzed. The electromagnetic field in conductors has been calculated using numerical method with a program based on finite element method (FEM) in order to compute the eddy factors in some practical cases. One estimates the critical height of a single layer solid conductor embedded in a slot at different current frequency. Also, for multi-layer cases with solid conductors on top of the other or side by side one calculate the eddy factors using FEM. Because one found considerable differences between numerical results and similar analytical results obtained through classical approach it is evident that some coefficients and curves used in classical design stage must be reconsidered. For these purpose modern techniques like numerical computation of the electromagnetic field with FEM in order to assess accurately the copper losses of electrical machines.