A new, highly-efficient permanent magnet synchronous motor has been unveiled by Hitachi. Nothing unusual so far. The only big and important difference between Hitachi’s new motor and everything that exists in the industry is that this one doesn’t have neodymium magnets.
Neodymium magnets contain a rare-earth material, which is the cause for its high price (but also the high performance). However, Hitachi’s new 11 kW motor is being presented as equally efficient to any neodymium motor, doing mechanical work with an efficiency of 93 percent.
That level of efficiency gives it the equivalence to “IE4” – the highest rank in the motor energy efficiency guidelines.
An amorphous metal iron core is used for the stator, while the rotor’s neodymium magnet is replaced with ferrite magnet – much cheaper and more abundant than neodymium.
As for the structure of the motor, Hitachi and Hitachi Industrial Equipment Systems employed an “axial gap method” that uses two rotors to sandwich a stator in the direction of the axis of rotation in the aim of increasing the amount of ferrite magnet used for the motor. In 2008, the two companies used a similar technique to prototype a motor with an output power of 150W and an efficiency of 85%.
This kind of motor will, of course, affect the electric vehicle industry and the price of electric vehicles.
It’s always funny to see how people are able to invent good things only when in need, and not proactively. For this particular case, the motor is addressing the export restriction imposed by China, where 90% of the rare-earth materials are located, and fixes the high prices associated with that restriction.