Analyses of Circulating-current Loss in Armature Windings and In-plane Eddy-current Loss in Electrical Steel Sheets of Permanent-magnet Synchronous Machines

Abstract

The quantification of stray load losses such as circulating-current loss in armature windings and in-plane eddycurrent loss in electrical steel sheets is important for developing rotating machines with high efficiency. The circulatingcurrent loss in parallel-connected armature windings is analyzed by using the two-dimensional finite element method. We investigate the losses caused by the in-plane eddy-current in the stator cores of permanent-magnet synchronous machines by using the three-dimensional finite element method. The influences of the coil-end structure, skew structure, and carrier harmonics of a pulse-width-modulated inverter on the in-plane eddy-current loss in the stator core are described. The accuracy of the analyses is confirmed through comparison with experimental results.

Comprehensive study on in‐plane eddy‐current loss in permanent‐magnet synchronous machines

“…Permanent‐magnet synchronous machines are driven by inverters. In the case of pulse‐width modulation (PWM) mode, the inverter output current contains carrier harmonics, which may increase the in‐plane eddy‐current loss [8], as well as the iron loss of the core, and the carrier frequency dependence of the in‐plane eddy‐current loss is still unclear. In the case of one‐pulse mode, the output voltage waveform of the inverter is rectangular.…”

“…We have evaluated the influence of the coil‐end shape in ref. [8]. However, the coil‐end height of the connected winding model was constant.…”