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Hitachi develops 11 kW permanent magnet motor without rare earth materials

Conventional industrial 11 kW induction motor (left) and Hitachi’s new 11kW motor (right). Source: Hitachi. Click to enlarge.

Hitachi has developed a high-efficiency 11 kW permanent magnet synchronous motor without using rare earth (neodymium, dysprosium) materials; the work follows on its 2008 announcement of a prototype 150 W motor that used cores made of amorphous metal coupled with ferrite magnet rotors. (Earlier post.)

Hitachi says the new 11 kW motor has an efficiency of about 93%, and delivers IE4 performance (the highest of the International Efficiency classes—Super Premium Efficiency—defined by IEC 60034-30) from a size smaller than that of a comparable conventional motor. The company is targeting commercialization for industrial applications in 2014.

The earlier 150 W prototype motor showed an efficiency of 86%.

Arrow points to the amorphous iron core. Source: Hitachi. Click to enlarge.   Laminated structure of the amorphous core. Source: Hitachi. Click to enlarge.

The new 11 kW double-rotor, axial-gap motor uses a laminated stator core based on a low-loss amorphous iron material. Hitachi says that the losses from its laminated material are about 10% of those of conventional electromagnetic steel laminations.

Amorphous metal has a disordered atomic structure in contrast to the crystalline structure of conventional metals, and features a high tensile strength and extremely low magnetic losses. As such, it has been a target of interest for motor development for decades. Its adoption, however, has been hampered by the cost of manufacturing—an issue which Hitachi says it is addressing.

To optimize the efficiency of the laminated design, Hitachi used 3D magnetic field analysis software to analyze the various characteristics of the core laminations.

Hitachi developed the technology with support from Japan’s New Energy and Industrial Technology Development Organization (NEDO).



axial-gap motor

Honda and Nissan have some patents on great axial gap motor designs, that have been recently issued. This magnet technique has yet to be proven on larger motors. EVs can have 100 kW to 150 kW motor designs and that is where the advantages can be realized.


eAssist uses a 15kW motor


That is inductive, like the Tesla. These are synchronous motors.


Right I am skeptical if this can be called "permanent magnets" motor, I also wonder how easy is to make the amorphous metal core, production of amorphous metal is quite tedious (deposition of very thin layer of metal on fast rotating cylinder for ultra-fast cooling) the rate of production is pretty slow.

But coming from Hitachi it is certainly something to take seriously


No rare earths?????!!!!

How dare they! Stealing one of the anti-ev/anti-renewable crowd's favourite talking points.


The large Tesla Motors inductive unit seems to do just fine with a single speed reducer, I think it is something like 6 to 1 or more.

1200 rpm at the wheels should get you more than 90 mph and the Tesla motor can run up to 13,000 rpm. It just depends on what you want to do.

Toyota and Honda went for permanent magnets. There are permanent magnet materials that do not use rare earth minerals, they are just not as strong a magnet.


Switched reluctance motors can be an alternative to permanent magnet when you want a high torque, you have to deal with the complex control of these engines and their not so smooth output, but we should see solutions coming in a no so distant future


"SJC says:
That is inductive, like the Tesla. These are synchronous motors."

so what difference does that make?.. its still driven by an AC 3 phase inverter that is ultimately powered by a DC battery. This could possibly replace the motors used in the Leaf and iMiev if needed.

The question is what is the curie temperature of these magnets?


It makes a lot of difference, but I won't go into that if you don't already know.


Im interrested to buy a hydrogen fuelcell car with this electric motor.


Well good AD, we are glad you are interested.


I don't see any reason why the curie temperature would be different in a metallic glass magnet than in a crystalline magnet.


its an induction motor with the squirrel cage replaced by PM, results?.. less heating in the rotor.. YAWNN

another PM motor driven by 3 phase AC



If that is what you want to believe the difference is, then that is your business. If you want to really learn, go find information on motors and learn.



You are simultaneously snotty and uninformative.

It seems thought that you are just interested in telling people that you are cleverer and better informed than them.

If you want to share informtion, do so.
If you have nothing else to share than your high opinion of yourself, no-one else cares.

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