Search

This paper proposes a novel tubular double-stator vernier permanent-magnet (TDS-VPM) motor for artificial hearts. The key of the proposed motor is double-stator and vernier structures. Due to its vernier structure, more PMs can be adopted in the proposed TDS-VPM motor and the useful harmonics of the air-gap flux density are increased, thus improving thrust density. Furthermore, double stator, namely inner stator and outer stator, has an appropriate 90° (electrical degree) angle difference. Since the inner stator is located inside the mover, the motor space is fully used. Hence, the thrust density is enhanced and the axial direction length is reduced. Meanwhile, the angle difference between the inner and the outer stator can reduce the cogging force of this TDS-VPM motor. The electromagnetic characteristics of the proposed motor are analyzed using the time-stepping finite-element method, confirming the validity of the theoretical analysis. [ABSTRACT FROM PUBLISHER]

The aim of this paper is to design and investigate two fault-tolerant interior-permanent-magnet motors for high reliability operation. The first one is the spoke type, while the second one has V-shape magnets embedded in the rotor. The structures and features of both motors are presented and the optimal designs are performed. The electromagnetic performances, such as $dq$-axis inductances, torque, flux weakening, and partial demagnetization, are investigated and compared. In order to calculate the $dq$-axis inductances accurately and segregate the torque components, the frozen-permeability method is adopted. Additionally, a method to obtain the maximum flux-weakening speed is introduced. Moreover, the partial demagnetization performances of both motors are evaluated under no-load, on-load, overload, and short-circuit conditions. Also, the fault-tolerant capacities of both motors are compared. Finally, both motors are built for exemplification. The analysis is confirmed by experimental results. [ABSTRACT FROM PUBLISHER]

This paper proposes a new type of motor with hybrid permanent magnet material (HPMM); termed HPMM motor. The key of the proposed HPMM motor is the excitations, which combined rare-earth PM (REPM) with ferrite PM (FPM). To investigate the HPMM motor extensively, the HPMM motors with parallel magnetic circuit (PMC) and serial magnetic circuit (SMC) are designed. Because of the property difference between the REPM and the FPM, both PMC-HPMM motor and SMC-HPMM motor can offer low total harmonic distortion at high winding factor. Besides, the PMC-HPMM motor needs low consumption of REPM and offers low cogging torque, while the SMC-HPMM motor needs the extraordinary consumption of FPM, but offers little lower cogging torque. In addition, the reliabilities of both PMC-HPMM motor and SMC-HPMM motor are improved because of the single-layer concentrated winding and fault-tolerant teeth. Finally, the demagnetization of two motors has been studied, which indicates that the partial demagnetization will occur in the FPM. All these theoretical analyses are evaluated by the time-stepping finite element method. [ABSTRACT FROM AUTHOR]