Design and analysis of a dual-stator permanent magnet machine for the refrigerator linear compressor

In the application of household refrigerator, the linear compressor is popularly adopted due to its no crank mechanism and directly oscillated by the inside drive machine and the helical coil springs. Therefore, a series of linear permanent magnet (PM) machines are developed for the linear compressor drive, which can effectively eliminate the additional cost and losses caused by crank mechanism and gearbox compared to the rotational machines. One production of them is the high-grade LG linear compressor with a linear PM machine inside, which can be 20~30% more efficient than most efficient current crank driven compressors. Dual-stator design is one effective way to improve machine output performance with limited design dimensions. Therefore, based on the topology and dimension of the linear permanent magnet machine in LG linear compressor, an optimized dual-stator permanent magnet machine with two groups of stator tubular windings is proposed in this paper.