Key Words: LPBF, Design for Manufacturing, Stator, Hairpin, E-Mobility, Winding Design

Optimized Solutions for E-Mobility

The acceptance of battery electric vehicles has increased exponentially over the last few years. This is also shown by the corresponding registration figures. E-mobility is seen as a push factor for innovations and, thus, generates ever higher demands on the electric powertrain. Additive Manufacturing (AM) is a key technology for realizing these innovations and meeting the increased demands on products and production. In addition to the development of a variantflexible hairpin stator production by means of AM – within the framework of a project funded by the MWIDE – the DAP chair researches the optimization of electric machines using AM technologies. The electric traction drive as the heart of the electrified powertrain, offers numerous optimization potentials. Using AM as an initial process with its associated potentials such as design freedom and shortened product development cycles, results in innovative production process chains. For instance, AM can already be used today to realize an optimized winding design of copper conductors that leads to an increased power density of electric machines by around 30 %.

In addition to reducing losses due to electro-magnetic effects and winding head heights, an innovative cooling concept can optimize the thermal characteristics of the e-machine. The combination of state-of-the-art design software and AM enable the production of design optimized, internally cooled copper windings. They make it possible to avoid critical temperature limits of the winding and prevent the so- called derating of the e-machine. During derating, the power is temporarily throttled due to excessive temperature development Another decisive advantage of an additively manufactured, hollow and directly cooled copper winding for electric machines is the sustainability of the use of copper: around 10 – 15 % of the necessary amount of copper per stator can be saved compa-red to conventionally wound stators.
Carsten Putz, M. Sc.

Carsten Putz, M. Sc.

RWTH Aachen Chair
Digital Additive Production DAP
Campus-Boulevard 73
52074 Aachen