Design, modeling, fabrication, back-to-back test of a magnetic bearing system for high-speed BLDCM application

This paper describes in detail the design, construction, and testing of an active magnetic bearing (AMB) system for high-speed permanent magnet (PM) brushless DC motor (BLDCM) application. A back-to-back (BTB) test setup which consists of two BLDCMs connected by a high-speed flexible coupling is designed and built: the first one acts as the motor and the other one acts as the generator with resistive load. The dynamic model of the rigid rotor supported by AMBs, and its electromagnetic and feedback control design aspects are also provided. Mechanical design aspects are rotor assembly, radial AMB (RAMB), and thrust AMB (TAMB). Finally, full-loaded test results of the AMBs are given using the BTB experimental test setup that adopts two 100 kW electric machines supported by AMBs.