High-speed Electrical Machine with Active Magnetic Bearing System Optimization

High-speed (HS) electrical machines provide high system efficiency, compact design, and low material consumption. Active Magnetic Bearings (AMBs) bring additional benefits to the high-speed system, such as elimination of the friction losses, reduced wear and maintenance, and a built-in monitoring system. High-speed drivetrains are usually designed for specific applications and require a high level of integration. This paper describes a design method of the HS electrical machine supported by AMBs, considering their mutual influence on the system performance. The optimization procedure, which takes into account both the electrical machine and bearing designs is developed. The optimization is based on a multiobjective differential evolution (DE) algorithm. The selected optimization parameters include the AMB and machine dimensions. The optimization objectives cover the electrical machine performance and the rotordynamics. The results of the proposed optimization algorithm are implemented in the constructed 350kW, 15000rpm induction machine with a solid rotor supported by AMBs. The prototype tests verify the design and optimization results.