Current-Controlled Multiphase Slice Permanent Magnetic Bearingless Motors With Open-Circuited Phases: Fault-Tolerant Controllability and Its Verification

The fault-tolerant control of bearingless motors is vital for their safe and robust operation. In this paper, the operation of current-controlled multiphase slice permanent-magnet bearingless motors (PMBMs) with different open-circuited faulty phases is analyzed, and their fault-tolerant controllability in the general case is investigated. As an example, the feasibility of fault-tolerant control with arbitrary single, double, or triple open-circuited faulty phase(s) for a six-phase slice PMBM is discussed in detail. Simulation results from finite-element analysis are presented to demonstrate the operation of the motor under the proposed fault-tolerant control strategy. Moreover, experimental results are also provided to further verify the theoretical development.