Toshihiko NOGUCHI

• High-speed rotating motor
• Various motors
• Inverter control and hardware

Takaharu TAKESHITA

• High voltage source
• Non-contact power supply
• High voltage power conversion

Junichi ASAMA

• Permanent magnet motor
• Electro-magnetic actuator
• Magnetically levitated bearingless motor

3-kW, 150,000-r/min Ultra High-Speed Permanent Magnet (PM) Motor

This is an ultra high-speed permanent magnet (PM) motor, which has specifications of 3-kW output power and 150,000-r/min maximum speed.

This motor also achieves the world highest level power density.

The motor is operated with a quasi-current-source inverter whose power source is 12 V; hence a low-voltage, a high-current and a high frequency are the most important keywords to describe its design approach.

Therefore, ultra low-inductance design is introduced to design the motor magnetic circuit, resulting in very high-efficiency of the electromechanical energy conversion.

Super thin and high-silicon electromagnetic steel plates are employed in the stator core, which contribute significant reduction of the
iron losses.

On the other hand, Nd-Fe-B permanent magnet is mounted on the
rotor to make a wide air-gap of few mm design possible.

Thanks to the above original design and theory, the maximum electrical efficiency excluding a mechanical loss reaches 97.6 %.

This motor can be applicable to superchargers and vacuum cleaners by combination with centrifugal compressors as load machines.