At the beginning of a project, basic technical questions have to be answered: What technologies should be used? What are the customer’s general requirements? How should the stationary part of the engine (stator) interact with the rotating part (rotor)? Should the rotor follow the magnetic field of the stator (asynchronously) or move with it (synchronously)?
This also depends on how the rotor is designed. For permanent magnet rotors in a synchronous motor, the material itself generates the necessary magnetism, thus ensuring a high level of efficiency. In contrast, for a rotor in an asynchronous motor, the magnetic field has to be generated by electricity. Which is better?
These days, for passenger car applications, we usually prefer the 3-phase permanent magnet synchronous motors. However we are also able to rely on a broad technical portfolio of other machine topologies.