Saddle-Shaped Post-Assembly Magnetization Coil for a 300 kW 2-Pole High-Speed Permanent Magnet Rotor

This paper presents the design and test results of a saddle-shaped post-assembly magnetization coil for a 2-pole high-speed permanent magnet (PM) rotor. The magnetization coil can generate pulsed transverse magnetization fields of magnitude equal to 6 T/10 ms in a bore having a diameter of 85 mm and a length of 280 mm, thus meeting the needs of parallel magnetization of a 300 kW 2-pole high-speed PM rotor. The saddle-coil structure improves the coupling between the coil and the rotor, and its magnetic energy reduces to 61% compared to the existing triple-coil structure. The influence of eddy current on the magnitude and direction of the magnetization field is analyzed and the pulse-width and coil supporting structure are optimized. The energy storage of capacitor bank pulse power supply is reduced to 230 kJ, which is 50% of the triple-coil structure's storage. The coil is fabricated and tested, and it is shown that it can successfully magnetize a 300 kW 2-pole high-speed PM rotor.