Improved Analytical Calculation for 2D Current Displacement in Rectangular Conductors

This paper describes an improved analytical closed calculation method for 2D current displacement effects in preformed windings in a rectangular stator slot of rotating electrical machines. In comparison to established analytical methods, the magnetic saturation of stator teeth and stator yoke, which can cause significant magnetic voltage drops in the iron core and significant longitudinal slot magnetic fields, is considered in the improved analytical calculation method presented in this paper. The horizontal and the longitudinal slot magnetic fields are determined using a magnetic equivalent circuit (MEC). The calculation of the copper loss and the loss ratio of the 2D current displacement is separated into a one-dimensional current displacement, which is caused by horizontal or longitudinal slot magnetic fields, and then combined again. Finally, a comparison to a finite element method (FEM) simulation of the total loss ratios of preformed windings in a rectangular stator slot validates the improved analytical calculation method.