Cast windings

The advancement of electrification represents a central future topic for the industry. Technological progress in the field of electric drives has not only led to broader acceptance of this technology but also to increased demand for more efficient and powerful drive systems. In this context, cast coils made of aluminum and copper have been developed at Fraunhofer IFAM. The casting production of coils not only enables electric motors with higher power density but also allows for more cost-effective, efficient, and lightweight designs.

Advantages of cast windings

Unlike conventional wound or wire-formed windings, Cast Coils have no limitations regarding conductor cross-section. This allows the available space in the slot to be utilized optimally, leading to a maximization of the slot fill factor. Additionally, recesses in the individual conductors can form cooling channels within the winding to enable direct conductor coolingFurthermore, the flat conductor structure of the cast coils offers superior cooling properties, as the heat transfer between the conductors and to the magnetic core is improved by large heat transfer surfaces.

The integration of more current-carrying material in the slot and the improved cooling properties enable the development of new machines with higher power density and increased efficiency. Moreover, the copper coils can be replaced with a lighter aluminum coils, as the aforementioned advantages can compensate for the conductivity disadvantage of aluminum.

Transfer to industrial application

Our research and development focus is on advancing this manufacturing innovation and transferring it to industrial applications. This includes process and design improvements in coil and winding manufacturing, as well as evaluating the technology for specific use cases and designfor manufacturing the entire magnetic circuit, considering manufacturing constraints.

Prototypical manufacturing and quality assurance of electric drives

Fraunhofer IFAM has an interdisciplinary team with extensive expertise in calculating, designing, and prototyping electric machines with cast coils. The team uses methodical approaches for integrated multidisciplinary development across domain boundaries and combines these with long-standing know-how in automating design processes for highly accelerated development. Our specific manufacturing knowledge of casting and coating processes for producing cast coils is directly incorporated into this work.

With our in-house equipment for laser cutting and stacking of electrical steel sheets, as well as for die casting, we can prototype entire stators with cast coils. For quality assurance, we have a metrology lab equipped with manufacturing measurement technology and facilities for testing electrical components. If needed, we can also build complete functional demonstrators and test them on our in-house electric motor test bench.

With our expertise and equipment, we are leaders in the field of cast coils and are driving the development of electric drives for a more sustainable future.

Further information on the field of “Electric Drives”