Active metal brazed windings for coreless axial-flux permanent-magnet machines

Reducing costs and increasing power density is mandatory to support the penetration of EVs and HEVs. From the traction drive system's perspective, it is compulsory to explore the use of new materials and advanced manufacturing technologies. Coreless axial-flux permanent-magnet machines have not been used so far in mass-market high-power applications due to manufacturing and thermal challenges. This work investigate the use of active metal brazed windings to achieve a repeatable and robust design with excellent thermal capabilities. An equivalent lumped parameter thermal network is developed and used to predict machine thermal behaviour and output power capability with different cooling techniques. Three-dimensional electromagnetic and thermal finite element analyses are conducted to validate machine performances together with the proposed thermal network.