Comparison Study on High Force Density Linear Motors for Compressor Application

This paper presents the modular topologies of the dual-stator dual-winding permanent magnet (PM) linear motors for linear compressors used in the electrified transportation application. Compared to the conventional PM linear motor in compressor, the proposed modular model is designed with the same volume but a higher thrust force density and a further higher air pressure in air cylinder, which are competitive in the compressor industry. The proposed compact PM linear motors are constructed with tubular windings in both inner and outer stators, as well as the ring-type magnet in mover. Simulation results of motor characteristics are compared by three-dimensional finite element method (3D FEM). Finally, the prototypes of the proposed PM linear motors are manufactured and tested for the linear compressor application.

Design and analysis of a novel variable flux spoke-type motor for washing machines

This paper deals with the design and analysis of a novel variable flux spoke-type motor (VFSM) for washing machines by focally considering the performance at the laundry and spin-drying operating modes. The key design goal is to obtain the high efficiency for the two operating modes. At the laundry mode, the ferrite and AlNiCo magnets are utilized together as the excitations to obtain a high magnetic loading, thus to obtain high torque and efficiency. At the spin-drying mode, the AlNiCo magnets are demagnetized by a pulse negative d-axis current to reduce magnetic flux density, thus to obtain low iron loss and high efficiency. The outer rotor structure with the spoke-type magnet configuration is utilized to enhance the high output performances. The D2L method is utilized to design the key parameters of the VFSM. To demonstrate the superiority of the designed VFSM, the electromagnetic characteristics are predicted by the finite element method (FEM). As a result, the volume size of the proposed VFSM is decreased by 19.4%, and the efficiency at the low-speed laundry mode is increased by 25.4%, when compared to the referenced commercial washing machine motor.