RESEARCH ON HIGH EFFICIENCY INTERIOR PERMANENT MAGNET SYNCHRONOUS MOTOR WITH ADJUSTABLE PM ARMATURE FLUX LINKAGE

随着电力电子器件、稀土永磁材料和电机控制技术的快速发展，内置式永磁同步电机（IPMSM）在各种应用领域得到了广泛的应用。在某些应用中，如电动汽车和压缩机，除了高效率外，还需要广泛的恒定功率工作范围。为进一步扩大永磁同步电机的工作范围和提高效率，研究了几种新型转子结构。提出了通过在转子两侧设置短磁链铁板或在隔磁空间内设置铁件来实现永磁电枢磁链可调的永磁同步电动机。有限元分析和实验结果表明，该方法可以有效地调节永磁电枢磁链。它被验证，建议的IPMSM的操作范围可以大大扩展，通过降低永磁电枢磁通水平以上的基本速度。降低永磁电枢磁链允许建议的IPMSM提请更少的d轴电枢电流在弱磁控制的区域。因此，所提出的IPMSM的效率以及功率因数可以显著提高，特别是在轻负载和高速操作。讨论了效率随运行条件和颗粒物流量水平的变化。效率图和功率因数图表明，新型IPMSM的高效率和高功率因数工作区域远大于传统IPMSM，在提高效率方面具有优势。通过对永磁电枢磁链在不同下降率下的效率特性分析，得到了对应于各种运行工况的永磁电枢磁链最佳下降模式。对铁板和铁片的驱动方式进行了简化研究。所提出的IPMSM的性能进行了验证，在几个测试电机的实验。

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. Several novel rotor structures are studied to further extend operating range and improve efficiency of IPMSM. IPMSM with adjustable PM armature flux linkage by adapting flux-shortening iron plates at both sides of rotor or iron pieces in the space of flux barriers is suggested. FEM analysis and experiments show that the PM armature flux linkage can be effectively adjusted by using these methods. It is verified that the operating range of the proposed IPMSM can be greatly extended by lowering the PM armature flux level above base speed. The lowered PM armature flux linkage allows the proposed IPMSM to draw less d-axis armature current in the region of flux-weakening control. As a consequence, efficiency of the proposed IPMSM as well as power factor can be significantly 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 maps show that the high efficiency and high-power factor operating area of the proposed IPMSM is much larger than that of the conventional one, indicating the advantage in improving efficiency. Based on the analysis of 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. Investigation is also done to simplify the driven pattern of iron plates and iron pieces. The performances of the proposed IPMSMs are verified with experiments on several testing motors.