For decades, the internal combustion engine (ICE) has been the dominant automotive powertrain. But, signs of a shift towards electrified powertrains are now apparent. The uptake rate of electric vehicles largely depends on technological developments, where the electric motor as the primary source of propulsion is the focus. In the form of a partnership between small- and medium-sized enterprises and research institutes working to develop a new generation of electric motors, the project EMPATHY (Electric motor based on parallel path effect) aimed to exploit the full potential of magnetic flux switching motors. Project partners created two different prototypes for automotive applications. The first is a single motor to provide extra power to a smaller ICE, resulting in fuel economy without sacrificing performance. The second is an innovative system of in-wheel motors to be installed in each wheel so that power is transmitted to the wheels without any shafts. Both motors were based on parallel path technology, allowing magnetic fields from permanent magnets to be switched from one path of a magnetic circuit to another. The parallel path technology is simple at its core, which is why permanent magnet engines are used in different applications. Nonetheless, their control is rather complicated and cannot be realised without knowledge of their operation. For design of the EMPATHY motors, researchers used numerical tools simulating their geometry, materials and electromagnetic behaviour. The simulation model allowed scientists to identify the optimal set of parameters for the design of the prototypes. Proper design should allow improvement of motor efficiency compared to conventional motors by optimising the operation to make maximum use of the switched magnetic flux. The gradually increasing momentum behind electric vehicle adoption – from both the automotive industry and consumers – suggests that the newly developed electric motors can play a key role in Europe's mobility going forward. Motors based on the parallel path effect can also be used in industrial fans and blowers, hydraulic and oil pumps, machine tools and automatic pressure systems.
Motor efficiency, electric motor, magnetic circuit technology, parallel path, magnetic flux