High-Performance Fault Tolerant Halbach Permanent Magnet Vernier Machines for Safety-Critical Applications

This paper proposes new fault-tolerant permanent magnet vernier (FTPMV) machines with Halbach array. By utilizing a flux concentration of Halbach array, the performances of the proposed machines are significantly enhanced. In addition, influences of rotor yoke materials on performances of the proposed machines are investigated, revealing that both ferromagnetic and nonmagnetic rotor yokes can be applicable to the FTPMV machines. Significant torque and power factor enhancements can be achieved in the proposed FTPMV machines with a ferromagnetic rotor yoke and a nonmagnetic rotor yoke, respectively. In addition, the reduced magnetic gearing effect in the proposed nonmagnetic rotor yoke machine can be compensated by the flux concentration of Halbach array, thus enabling the machine to obtain comparable torque capability with the existing one. The electromagnetic performances of the existing and proposed machines are analyzed and compared by using the time-stepping finite-element method, verifying the effectiveness of the theoretical analysis.