High efficiency remanufacturing of induction motors with interior permanent-magnet rotors and synchronous-reluctance rotors

The energy conservation of motors becomes one of the most important areas of industrial energy saving. At present, the majority of motors in industrial applications is induction motors (IMs) which has huge potential for the efficiency improvement. The IMs are nowadays widely used in transportation fields as traction motors or for other electrical devices such as compressors, integrated starter generator, etc. The high efficiency remanufacturing (HER) can be realized by replacing squirrel-cage rotors of IMs with optimally designed interior permanent-magnet (IPM) rotors without damping windings or further replaced with synchronous-reluctance (SynR) rotors without the permanent magnets in IPM synchronous motors (IPMSMs) which can further lower the cost. Meanwhile, other assemblies of IMs can be recycled and reused which will lower the cost and make sure the structure of remanufactured motors still suitable for previous applications. The efficiencies of remanufactured motors can reach IE4 according to the International Electrical Commission (IEC) 60034-30 standard. Various experiments are provided as verifications of effectiveness and practicability of the proposed method.