IPMSM with Adjustable PM Armature Flux Linkage for High Efficiency and Wide Range Operation

抄録

With the rapid development of power electronic devices, rare earth permanent magnet (PM) and motor control technology, interior permanent magnet synchronous motor (IPMSM) is being widely used in various applications. In some applications such as electric vehicles and compressors, except for high efficiency, extensive constant-power operating range is also desired. This paper discusses an IPMSM with adjustable PM armature flux linkage by means of adapting flux-shortening iron pieces in the space of rotor's flux barriers. The performance of the proposed IPMSM is studied using normalized analysis for general meaning. It shows that the operating range of the proposed IPMSM can be greatly extended by lowering the PM armature flux level through the iron pieces. Due to the possibility of decreasing the PM armature flux linkage, the proposed IPMSM requires less d-axis armature current in the area of flux-weakening control, so the efficiency and power factor can be improved, especially at light load and high speed operation. The variations of efficiency relating to operating conditions and PM flux level are discussed. The efficiency and power factor map of the proposed IPMSM is presented. The maps show that the high-efficiency and high-power factor operating area of the proposed IPMSM is larger than that of the conventional one, indicating the advantage of the proposed IPMSM in improving efficiency. Based on the analysis of the efficiency performance at various decreasing rates of PM armature flux linkage, optimal decreasing pattern of PM armature flux linkage is obtained corresponding to various operating conditions.