Additive Manufacturing of Shaped Profile Windings for Minimal AC Loss in Electrical Machines

Abstract

Concentrated wound, open slot, permanent magnet electrical machines are an attractive topology for automotive and aerospace applications as they exhibit compact end-windings, resulting in high power-density, facilitate fault tolerant operation through, physical, thermal, magnetic and electrical isolation of phase windings, and the open slot structure eases manufacture. However, a significant disadvantage of this topology is the interaction between the armature reaction field and winding conductors leading to elevated AC losses. A common mitigation technique is to reduce the height of the winding in the slot to minimise this interaction, however, the conductor cross-sectional area is consequently reduced which compromises low-speed performance. This paper investigates the use of additive manufacturing to produce shaped profile windings which exhibit minimal AC loss whilst maximising the utilisation of the slot area, thereby improving low-speed performance while maintaining high-speed performance.