The implementation of electric drivetrains into passenger vehicles is one of the promising ways for the automotive industry to reduce CO2 fleet emissions. The most important aim for the current developments is to increase range and performance while assuring affordability for the customer. In the field of electric motor development for traction applications, great efforts are necessary in order to improve electrical machines in terms of efficiency, power density and costs.The optimization of each individual field is a subject of research. Typically, there is a conflict of interest in simultaneously optimizing efficiency, power density and costs. This work presents a new approach to optimize the three fields for electric traction motors. The new approach combines an efficient direct cooling concept with the possibility of using lightweight polymer composites for the electric motor housing. The cooling concept increases the efficiency in a wide range of operation while enabling a high maximum continuous power output from the motor. To estimate the potential of the used cooling topology, the winding is optimized for using stator slot cooling. The electric motor is thermally simulated to verify the concept. These findings are used to design the cooling channels. Finally, a molded prototype stator is built and the newly designed concept was validated in a component test setup.The direct cooling with its short thermal path between the area of heat generation to the cooling system, enables the use of thermally insulating thermosetting composite materials for the electric motor housing. In this work the feasibility and potential of manufacturing the stator housing of an electric motor in an injection molding process is investigated. The design freedom of this manufacturing process enables complex and extensive functional integration such as the direct incorporation of the cooling channels in the stator slots, the phase connectors and the coolant supply.

Within the Fraunhofer innovation cluster "Regional Eco Mobility 2030" (REM2030) concept developments to improve the energy efficiency of regional eco mobility of the future are investigated. An AUDI A1 Sportback is used as a technology demonstrator with an entirely electric powertrain, completed to a serial hybrid by a fuel cell range extender. A methanol reformer provides hydrogen for the high temperature fuel cell. The main focus of this paper is the thermal management system of the car, which has to deal with different temperature levels and must be designed for zero emissions and energy efficiency. The model-based development of such a system using Modelica is described, comprising a conception, simulation and testing phase.

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The combination of additive manufacturing (LPBF) and plastic injection molding offers great benefits for functional integration and thereby the functionality of parts, components and systems. By manufacturing cooling channels as very thin-walled structures, short laser processing time is needed to produce these parts. The combination with plastic overmolding allows the mechanical loads to be absorbed, while at the same time utilizing the freedom of shape of the LPBF process. In order to prevent the structures from collapsing during overmolding or to ensure that they do not have to be very thick-walled in order to withstand the high injection pressures, the structures are closed, so that the base-powder is still contained in the structure during the overmolding. After opening the overmolded components, the powder can be extracted and reused. This technique offers great potential for high functional integration and new possibilities in terms of realizing internal cooling structures of electric traction machines. Other advantages that can be exploited are the thermally good connection due to the material bond and the possibility of local reinforcement due to the design freedom of the insert. Thanks to the injection-molded component, complex geometries can also be produced without additional unit costs.