Vibration Optimization in High Power Electric Machines with Lightweight Plastic Stator Housing

New investigations on noise, vibration and harshness (NVH) of a permanent magnet synchronous motor partly fabricated of thermoset plastic revealed performance characteristics of these novel materials: At high rotational speeds, the NVH behavior improves, at low speeds, it is inferior to a reference motor. A methodical approach to significantly improve the NVH behavior of this type of electrical machine is presented. First, the source of the vibration is identified. Second, the electrical machine is optimized to overcome these drawbacks. The results in this work are built on previous work in the DEmiL project (Directly cooled Electric motor with integrated Lightweight housing, funded by the Vector Stiftung). The overall scope of the project promises a higher continuous power density by a more efficient cooling using plastics within the stator and housing with low vibrations.