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 crosssectional area is consequently reduced which compromises lowspeed 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.

Improved hotspot monitoring method for thermal management system of automotive traction motor

“…The increase of end winding losses at AC input shows a fixed relationship with the amplitude of input current where l E is the average length of the end winding, K ac,end is the ac loss coefficient of the end winding, derived from the curve fitting of (5) to the end winding AC loss data derived from finite element analyses (FEAs) at the maximum frequency intended. Equations (4) and (5) are proven to have enough accuracy in AC loss estimation for the slot and end winding parts in the alternating armature field [8,19]. Besides, the rotation of the rotor will also cause additional AC loss in the winding [15].…”

“…Generally, the electromagnetic energy conversion in the stator windings of traction motors produces a much higher temperature rise than the other parts [5]. Meanwhile, the winding insulation is easy to be damaged by the excessive temperature rise.…”

Additive Manufacturing in Construction of Electrical Machines – A Review

“…Here, the authors reported electrical conductivity to be %51 IACS, which is even lower than that of aluminium conductors. Further work by the same authors has shown significant improvement in electrical conductivity of the coil material (43.5MS/m, 75% IACS) for CuCr1Zr (C18150) [39]. The above examples of coils fabricated using AM required further processing, which included coating with an appropriate electrical insulation (enamel) [38], [39].…”

“…Further work by the same authors has shown significant improvement in electrical conductivity of the coil material (43.5MS/m, 75% IACS) for CuCr1Zr (C18150) [39]. The above examples of coils fabricated using AM required further processing, which included coating with an appropriate electrical insulation (enamel) [38], [39]. This additional stage in the manufacturing process has been addressed in [40].…”

Towards Fully Additively-Manufactured Permanent Magnet Synchronous Machines: Opportunities and Challenges

“…In [34], the cross section of stator winding is customized according to the distribution of slot leakage flux path shown in FEA, as shown in Fig. 5.…”