By Kari Williamson
In comparison to conventional motors of the same class, Hitachi's 11 kW motor is smaller and achieves an energy efficiency of approx. 93%, fulfilling the highest standard of IE4 in the efficiency guideline set out by the International Electrotechnical Commission (IEC).
Hitachi and Hitachi Industrial Equipment Systems employed an amorphous magnetic metal in the core and developed basic technology for an axial gap motor which raises motor efficiency without a magnet containing rare-earth metals, resulting in a prototype small capacity 150 W class motor in 2008.
To achieve higher capacity and efficiency levels, however, Hitachi and Hitachi Industrial Equipment Systems optimised the structure of the axial gap motor to efficiently use low-magnetic ferrite material and a stratified core structure which efficiently draws out the low-energy loss characteristic of the amorphous metal, to achieve an industrial 11 kW permanent magnet synchronous motor without rare-earth metals.
Part of the work was supported by The New Energy and Industrial Technology Development Organization (NEDO), Japan as part of its support programme for the development of practical technology to substitute or reduce rare-earth metals.
Technology development will be pursued with view to product launch in 2014.
