First “MotorBrain” prototype shown; lightweight electric motor system with no rare earth metals
11 April 2014
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| MotorBrain prototype. Integrated unit is on the left, the motor core is at the right. Click to enlarge. |
The four partners in the European research project ”MotorBrain”—Infineon Technologies, Siemens, the Institute of Lightweight Engineering and Polymer Technology at the Technische Universität (Technical University) Dresden and ZF Friedrichshafen—are presenting their first prototype of a lightweight electric motor system that requires no rare earth metals.
The €36-million (US$50-million) MotorBrain effort is one of the largest single European research projects in the area of electromobility. The MotorBrain prototype integrates the motor, gear drive and inverter. The prototype is three-quarters the size of models from 2011, the year when MotorBrain began; the prototype now being presented could fit in a conventional-sized laptop or notebook backpack.
The motor is also lighter than before. The integration of motor, gear drive and inverter enabled an approximate 15% reduction in weight of the powertrain from 90 kg (198 lbs) to less than 77 kg (170 lbs). A medium-sized vehicle with MotorBrain electric motor and performance of 60 kW (equal to about 80 hp) would be able to drive about 30 to 40 kilometers (19 to 25 miles) farther than today’s electric vehicles with their average range of approximately 150 kilometers per battery charge.
Rare earth metals are currently a fundamental cost driver in hybrid and electric vehicles. Today rare earth metals are an important component in the permanent magnet of any electric motor, generating a particularly strong, constant magnetic field. The stronger the magnetic field, the higher the performance capabilities of the motor.
However, obtaining rare earth metals is complicated and environmentally harmful. Also, rare earth metal prices are high and fluctuate widely. The MotorBrain electric motor therefore utilizes readily available and less expensive ferrite magnets. The lower performance level of ferrite magnets compared to those with rare earth metals is compensated for by the specially developed high-RPM (revolutions per minute) rotor of the MotorBrain electric motor.
The project. Led by Infineon, a total of 30 partners from nine European countries are conducting research in MotorBrain with the goal of increasing the range and safety of electric vehicles while at the same time reducing dependency on rare earth metals.
The team includes universities, non-university research facilities, semiconductor manufacturers, electric motor builders, automobile component suppliers and automobile manufacturers.
The MotorBrain project began in the fall of 2011, and will conclude in October 2014. The time beween now and October will be spent validating and proving the research results.
Pay no attention to the high-speed induction or switched reluctance machines that have existed for years, or that Tesla's motor/inverter assembly is integrated, or that MHI is running an integrated package using SiC, or... didn't I just read a comment that said the Euro power electronics and motor industrial giants were way ahead of the rest of the world?
Posted by: Herman | 11 April 2014 at 12:10 PM
"Today rare earth metals are an important component in the permanent magnet of any electric motor..." except not all electric motors require permanent magnets. Tesla uses and AC induction motor, and uses only Aluminum and Copper in their motor.
Posted by: Eletruk | 11 April 2014 at 12:50 PM
Nicola Tesla invented the induction motor more than 100 years ago, but those Europeans are so far ahead. Tesla was a Croatian, so I guess that counts.
Posted by: SJC | 11 April 2014 at 01:07 PM
Lighter improved e-motors and associated converters and controls will reduce cost and improve future EVs range.
Will it improve at a faster rate than ICEVs?
Posted by: HarveyD | 11 April 2014 at 01:14 PM
SJC
Once for ever: Tesla was ethnic Serb from Croatia.
Posted by: Predrag Raos | 11 April 2014 at 08:45 PM
Once for ever...is that profound?
Posted by: SJC | 11 April 2014 at 10:49 PM
Never mind that the ferrite magnets contain between 4 and 6% Lanthanum. Oh yeah, that is a rare earth.
Posted by: frankbank | 12 April 2014 at 06:18 AM
Never mind that lanthanum costs about a fifth of neodymium and less than half as both samarium and cobalt.
It pays off to do research before posting.
Posted by: Arne | 12 April 2014 at 01:55 PM
This is just stupid. Induction motors cost less and have no permanent magnets. They have copper which is both light and rather common. The Tesla's have induction motors...
Plus there are better concepts than the Tesla motor.
There's the Evans electric motor: http://green.autoblog.com/2013/07/29/evans-electric-unveils-monster-in-wheel-motor-down-under/
http://www.electric-vehiclenews.com/2013/03/wheel-motor-validation-testing-confirms.html
Posted by: avada | 13 April 2014 at 09:05 AM
The people at Remy have a PM design but can make it inductive if the customer wants. Remy makes the motors for the GM Spark EV and other models. They are very experienced and skilled at making several types. to suit the need.
Posted by: SJC | 13 April 2014 at 11:16 AM
From 2011-2014 eh !
You can believe all the propaganda you want about this being a European effort but I see this predominantly as a German rebuttal to Elon Musk's Tesla Model S powertrain. Just 60kw today but obviously they will be scaling it up so that Merc, Audi and BMW will have something to fight with - when the time comes.
Personally I believe they are already late for this party and the only thing I see holding back Tesla sales would be Teutonic Pride. Low cost powertrain packaging in the car is only one front they will have to defend. Not to forget that a good many of the 'no fee' superchargers have now been installed across Germany and the Bavarian region, prospective Tesla owners, like anyone else, will find the ability to avail themselves of this "Free stuff" compelling.
Induction motors are the way to go since they are more resilient to high temperatures allowing them to tolerate a higher power density. Sure at low revs they don't compete well with magnet machines which provide flux fields with zero power loss. However the copper loss they incur to maintain unit torque remains constant, so as the induction motor spins up this loss becomes a smaller and smaller component of the increasing power being developed, ipso facto efficiency will improve proportionally with increasing rotational speed.
I have found that the big problem is getting people to understand this since they are educated in an academia which is immmersed in the 60Hz world where slip is often referred to as a percentage rather than a constant which it in fact happens to be.
Posted by: T2 | 14 April 2014 at 11:26 AM
SJC - the Spark EV motor is designed and made by GM. http://media.gm.com/media/us/en/gm/news.detail.html/content/Pages/news/us/en/2013/Apr/0416-spark-electric.html Remy has nothing to do with it. Remy used to make the two mode motors for GM, but no longer make any motors for GM, I think.
Arne - good homework on the price or rare earths. But my point is that the title of the article is plain wrong - "First “MotorBrain” prototype shown; lightweight electric motor system with no rare earth metals", since their are rare earth metals in this motor.
Induction machines are fine, but efficiency and size lags PM motors by a solid 2% over the range of driving, even when using modern designs and variable frequency control. When EV batteries are cheap enough to enable high EV volume, the efficiency hit will be more tolerable, and induction or other motor tech will prevail.
Posted by: frankbank | 14 April 2014 at 08:27 PM
Ferrite magnets ? It occurred to me that maybe we are misconceptioning the use of ferrite here.
My familiarity with ferrite in applications is with high frequency transformers, specifically for its low hysterisis loss at high frequency, certainly not for its flux density or remanence. So that would make ferrite not a good candidate, I would think, to utilise on the rotor of a synchronous motor.
However its use as stator material particularly at excitation frequencies approaching 600Hz would be an entirely different matter, especially since the stator is a lot easier to apply methods for cooling. Of course you would be looking at 18000 rpm with 4 pole machines although I would not rule out 6 pole machines for increased torque as long as the extra thermal load can be mitigated.
My own preference is for the use of silicon steel since it will support flux densities up to 3X those of ferrite i.e. ~ 1.2T.
I won't dispute the 2% efficiency advantage over ordinary induction motors, frankbank, but I wonder whether that figure allows for the fact that Field Oriented Controllers will automatically decrease the applied V/Hz on the stator when it is detected that the vehicle has attained its cruising speed and thus significantly reduce stator iron losses.
Finally in the bigger picture, incremental aero losses at the upper speed range are more significant than motor efficiency. The problem is to find the most meaningful way to inform the driver. A Watt-hr per mile display doesn't quite cut it. Who knows what that figure should be ? Even the amperage is not the best indicator for the average driver as it will vary from vehicle to vehicle.
OTOH if the expected Watt-hr per mile at 60mph, say, could be represented as 100% then at other vehicle speeds above/below this then specific consumption rate could be displayed as a percentage. The value rising above 100% as the driver slows down or falling below 100% as the driver begins to exceed 60mph. The hope is that the effect of the cube law on aero would be more dramatic in its presentation.
Posted by: T2 | 15 April 2014 at 03:49 PM
T2,
Modern automotive electric drives are among the most advanced in the world. All major OEM machines are field oriented controlled and most are more than 4 poles. The Prius motors are 8 pole, the Leaf is 8 pole, Fusion motors are 6 and 8 pole, the Spark uses a 10 pole machine, and the Volt Motors are 12 and 16 pole. Even the little Buick eAssist motor uses an 8 pole (induction) design.
The ferrite used in the motor brain and other motors have somewhat harder magnetic properties than the ferrite transformer cores that you are thinking about. Slightly different formulation. Ferrite magnets like these are used extensively - just about every car has a pound of the stuff in the starter motor. The problem is that ferrite has lower energy than a Nd based magnet, so for the same output, you need more silicon steel and more copper to get the job done. It is not necessarily cheaper overall, and certainly not as compact as conventional Nd magnet machines for the same torque and power.
Agree that aero is the dominant factor for efficiency at speed. The adjustable ride height control, like the Tesla S, is a great idea that brings the car down at speed to improve Cd.
Posted by: frankbank | 15 April 2014 at 04:13 PM
frank,
GM makes the Spark EV motor, but it is Remy's design.
Remy says they can make induction motors as well if customers want them.
Posted by: SJC | 25 April 2014 at 05:18 PM
Has anyone considered to re-design the motor-frame to be lightweight?
Sten
Posted by: Sten | 07 September 2015 at 07:07 AM