Electromagnetic Design and Analysis of High Speed Permanent Magnet Motor with Composite Rotor

For high-speed permanent magnet synchronous motors (HSPMSM), the rotor eddy current loss is generated by the time and the space harmonics, which results in the rotor temperature rise. This paper deals with the design and analysis of a 100kW, 20000r/min HSPMSM with novel composite rotor. The novel composite rotor includes a shaft, sintered permanent magnet, novel composite magnetic materials with low conductivity and carbon fiber sleeve. With the power supply and rotation speed unchanged, the effects of magnetizing methods, pole-arc coefficient and interpolar filling materials on rotor eddy current loss are analyzed based on finite element analysis (FEA). Finally, the electromagnetic (EM) performance and losses are compared with those of the different rotor structure.