AC Copper Losses in Edge-Wound Coils in a YASA Motor

Abstract

When carrying an alternating current, the windings in an electrical machine experience increased losses, due to proximity and skin effects. Quantifying these is necessary to fully understand the impact of motor efficiency, requiring the use of finite element analysis of the winding. For an axial flux machine with a three-dimensional flux path, this usually requires the use of threedimensional finite element analysis (FEA). This work presents a method of using simplified 2D FEA as an alternative to full 3D FEA, a dimensionless analysis argument to account for changing winding conductivities and a frequency-scaling is verified with FEA. The time required to characterise a windings AC losses is reduced by a factor of three orders of magnitude.