Design of the Structure of the Rotor Containment Sleeve for High-Speed PM Machine

Due to high-speed of permanent magnet (PM) machines, large eddy current loss is caused by higher harmonics, so that the temperature of the permanent magnet rises rapidly, which may cause the permanent magnet demagnetization. As for the above problem, three schemes are designed for different protection measures based on a prototype of high-speed permanent magnet machine of 250kW, 65000r/min. Also based on 2D finite element method the eddy current loss of the three schemes is analyzed and compared. It is shown that the eddy current loss is least under the third scheme. The value of the eddy current loss is 1489.1W. The structure of the rotor containment sleeve of third scheme is with the inner carbon fiber thickness 1.5mm, the alloy steel thickness 0.6mm and the outer carbon fiber thickness 0.9mm. The internal magnet field of permanent magnet of the three schemes is analyzed and compared. It provides an important evidence for the research of rotor containment sleeve of the high-speed permanent magnet machine.