EV motor system is smallest of its kind, says Mitsubishi

Mar 11, 2012 by Nancy Owano report

(PhysOrg.com) -- Mitsubishi Electric has announced it has a new motor system for electric vehicles with impressive gains in reduced size and efficiency. The EV motor system is the smallest of its kind, according to the company press release, measuring just half the dimensions of Mitsubishi Electric’s existing motor system. The new motor system has a built-in silicon carbide inverter. Mitsubishi Electric’s existing motor system uses an external inverter.

The smaller size of the system is intended to help auto makers turn out EVs with more passenger space and improved energy efficiency. The cylinder-shaped inverter matches the diameter of the motor, enabling it to be connected coaxially within a chassis, halving the size of the system, according to Semiconductor Today.

Consumer interest generally is shifting toward EVs and hybrid EVs (HEVs) with more information and public acceptance of the need to make buying choices that can contribute to a better environment, including reduced carbon dioxide emissions. At the same time, the EV future in the marketplace depends on overcoming some drawbacks including limited space for passenger comfort. EVs and hybrids namely require large spaces for their battery systems. The reduced size of the new system is promoted as an important move forward.

The material used for the inverter is another talking point from Mitsubishi. Its press release notes that the power chips in the inverter are silicon carbide-based. Silicon chips have been widely used in power devices for inverter switching. is seen as more suitable because of its electrical characteristics, including a breakdown electric field that is 10 times greater compared to silicon chips. This enables thinner chips, which reduces electrical resistance and lowers loss. says the silicon carbide chip-based inverter results in over 50% reduction of loss compared to the company's silicon-based inverter system.

The permanent magnet motor uses a neodymium magnet.

The size and configuration of stator and rotator poles were optimized. The company says that it used a magnetic design technology that brought about improved magnetic efficiency and a five percent increase in power output compared to its previous motors.

The new system is in prototype stage. Once further work is completed on technologies for motor/inverter cooling, downsizing and , the will be commercialized, says the company. According to reports in the Asahi Shimbun and House of Japan, the system, targeted for compact cars, will be commercialized in 2017.

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Newbeak
1 / 5 (2) Mar 11, 2012
I don't get it.Electric motors have always been much more compact and much more efficient than fuel burning engines.Increasing inverter efficiency is okay,but the number one thing needed is improvement in the energy density and cost of batteries.
nkalanaga
5 / 5 (7) Mar 11, 2012
True, but improving the inverter will allow the existing batteries to provide more useful capacity, thus buying time until better ones are available.
Bob_Wallace
4 / 5 (5) Mar 11, 2012
The solution to getting us off petroleum is complex, great batteries are just part of the answer.

Lighter cars, better aerodynamics, more efficient motors and drive trains mean that batteries don't have to be quite so "great". If we approach our energy problems with the attitude of killing the fossil fuel monster with a thousand tiny cuts we'll get to where we need to be sooner.
Newbeak
5 / 5 (1) Mar 11, 2012
The solution to getting us off petroleum is complex, great batteries are just part of the answer.

Lighter cars, better aerodynamics, more efficient motors and drive trains mean that batteries don't have to be quite so "great". If we approach our energy problems with the attitude of killing the fossil fuel monster with a thousand tiny cuts we'll get to where we need to be sooner.

You are on to something with the suggestion of better aerodynamics,lighter weight,etc. See: http://www.lowtec...nge.html
Sonhouse
not rated yet Mar 11, 2012
Smaller, lighter motors could be included in the wheels directly with no drive train, which increases the efficiency right there. Of course there will be a cost from the gyroscope effect of the motor but you already get that from the spinning tires.

With a 4 wheel drive you could have a zero slip system where the RPM's and such are measured so you minimize slippage and differences in RPM from tires going in turns.
Newbeak
3.7 / 5 (3) Mar 11, 2012
Smaller, lighter motors could be included in the wheels

Putting a motor in the wheel increases the unsprung weight of the wheel,and would create handling issues,but having said that,I've read of some concept cars experimenting with the idea.
antialias_physorg
3 / 5 (2) Mar 11, 2012
Brabus (the tuning company associated with Mercedes and Smart cars) is working on one.
http://www.speedf...e-basis/
Handling has alaways been top priority for Brabus so I expect that they'll come up with one exceptional critter.

A bit more on the research side is the frecc0 study and integration platform being built by the Fraunhofer institute.
http://www.gizmag...e/14886/
Callippo
2 / 5 (7) Mar 11, 2012
It's a natural evolutionary step from germanium over silicon transistors into diamond ones. We should just congratulate the Mitsubishi for this important technological step.
I don't get it...Increasing inverter efficiency is okay,but the number one thing needed is improvement in the energy density and cost of batteries.
It enables to decrease the current with increasing the voltage while maintaining the same power density. It will save the material for copper wires, which are forming the substantial part of engine mass, not to say about its price. The replacement of silicon with siliconcarbide is therefore very environmental step in its consequences.
RitchieGuy
1 / 5 (4) Mar 11, 2012
All well and good. However, the EV batteries still have to be charged from the grid, and the grid still necessitates the usage of fossil fuels, unless it is powered by hydro, wind, solar, thermal, ethanol from biomass, or nuclear. If the engineers could design a system to recharge the batteries as the car goes along the road by a combination of a solar panel on the roof and a small wind turbine installed out in front or under the hood. It would then be better able for the car to get to the next recharge station without the batteries discharging first and stranding the driver. HEVs have the edge by switching to gasoline.
But I agree with the idea of a small motor attached to each wheel in a 4 wheel drive. The motors can generate electricity for the batteries as long as the car is moving. Correct me if I"m wrong.
RitchieGuy
1 / 5 (4) Mar 11, 2012
Callippo
1 / 5 (6) Mar 11, 2012
the EV batteries still have to be charged from the grid, and the grid still necessitates the usage of fossil fuels, unless it is powered by hydro, wind, solar, thermal, ethanol from biomass, or nuclear
Of course, this is what the cold fusion is waiting for. The wider exploitation of cold fusion could bring the quite opposite problem: we would generate too much energy, so we will generate true global warming. The energy efficient solutions will always have its place here, but they should be material efficient as well. The contemporary approach is not sustainable, because we do replace the power hungry with material expensive technologies, like the neodymium magnets. From this reason the Japanese are developing the reluctant asynchronous motor, which wouldn't require any rare earth metals at all. Just for this type of motors the silicon carbide would be very useful.

http://www.eetime...h-metals
Callippo
1 / 5 (3) Mar 11, 2012
The switched reluctance motors work best at the higher voltage and this voltage must be switched very fast. It would require the development of IGB transistors at the silicon carbide basis. These transistors connect advantage of unipolar and bipolar transistors, but this technology isn't easy to develop even at silicon platform, not to say about silicon carbide. Nevertheless, this is just the way, in which the future technology should go.
Urgelt
not rated yet Mar 11, 2012
This looks useful, but only for eeking out a few more miles of range. It's not a breakthrough.

For a breakthrough, we need batteries an order of magnitude better than we currently have.

Unfortunately, Moore's Law doesn't seem to be working on battery technology. (Yet.)
Callippo
1 / 5 (7) Mar 11, 2012
For a breakthrough, we need batteries an order of magnitude better than we currently have.
At the case of cold fusion power you'll need the battery only for few miles of ride. Maybe just a supercapacitors will be sufficient for cold fusion hybrids, because it seems the cold fusion can be controlled with pressure of hydrogen rather easily. Actually, it's the only technology, which would allow the development of flying cars, which are energy hungry. If we would be more engaged in cold fusion research, we would have these futuristic devices already.
DirtySquirties
2.6 / 5 (5) Mar 11, 2012
This might be dumb, but would solar panels on the roof of a car squeak out a few more miles or just help when it's sitting in the parking lot? I always look at buses and big trucks thinking of all that space on top.

Maybe solar power isn't quite there yet? I dunno how much power solar panels can really make for vehicles.
Jeddy_Mctedder
2 / 5 (4) Mar 12, 2012
anyone talking about batteries on here is an idiot. the point is you need to maximize the performance , price , design, reliability, cost to produce, and efficiency of the electric motor system, which includes electricity generation onboard, batteries, fuel cell , capacitors, recharging of batteries from breaking, and anything else that could interact with the motor.

this is about the MOTOR because you can say good bye to pistons. this ISNT about batteries you dolts.
you could run a car off gasoline with an electric motor and still do almost as well as a combustion motor despite using an intermediary generator ( a combustion motor of its own )
because electric motors are THAT much better than piston driven motors. and they will get FAR better.

low hanging fruit?
Liquid cooled electric motors.
superconducting electric motors ( albeit likely not going to be developed for cars, but perhaps for trucks because they are already developed for ships)

this is about electomag-kinetics
Callippo
1 / 5 (5) Mar 12, 2012
Maybe solar power isn't quite there yet? I dunno how much power solar panels can really make for vehicles
The power of Sun is not sufficient enough to run the air-conditioner, not to say about some comfortable ride. Even if we would improve the effectiveness of solar cells ten times, the factor of ten would be still missing.
RitchieGuy
1 / 5 (6) Mar 12, 2012
The solar panel(s) would actually only be for the EV (electric vehicle) as a backup method, kind of insurance to keep the car's batteries from discharging completely before the car reaches the station for a full recharge. . .for as long as the sun still shines on the panel. The other backup would use wind energy, also for the same reason.
The only drawback to an EV is the low amount of weight it can carry as passengers and cargo, which would also affect speed.
Callippo
1 / 5 (5) Mar 12, 2012
The solar panel(s) would actually only be for the EV (electric vehicle) as a backup method
Briefly speaking, nobody is prohibiting anyone to construct the solar powered car from combination of commonly accessible electromobile and solar panels - but just the fact, no one even attempted for it indicates, the technology is not capable of it.
Howhot
1 / 5 (1) Mar 12, 2012
ItchieGuy says
the grid still necessitates the usage of fossil fuels


You know, as much as you would like that to be true, there is only 50 years worth of Natural Gas from fracking. Where are the other 20,000 years of future human energy going to come from? Your hot air?

It has to come from solar. There is no other source of energy for mankind 20 thousand year out.
Howhot
1 / 5 (1) Mar 12, 2012
Oh Callippo, I left out cold fusion because it's unproven technology (not science btw).

88HUX88
not rated yet Mar 12, 2012
what about improving public transport, the roads are already full
Vendicar_Decarian
not rated yet Mar 12, 2012
The roads are full of 2 people wide cars containing 1 person.

Reduce the width of the car to that sufficient for 1 person, and reduce it's drag coefficient by 30 percent and it's weight by 50 percent as a result.

Do so and you get a triple positive whammy. You add a lane or two to each road, and you get the above improvements in efficiency.

Eikka
1 / 5 (3) Mar 12, 2012
Smaller, lighter motors could be included in the wheels
Putting a motor in the wheel increases the unsprung weight of the wheel,and would create handling issues,but having said that,I've read of some concept cars experimenting with the idea.


Putting the motor in the wheel also forces it to operate at unfavorable speed, too slow to be efficient, because power needs to be generated by high torque, and electric motors are bad at producing torque efficiently. The result is that the in-wheel motor has worse power to weight ratio, and higher energy use.

Because of the speed-torque problem, electric cars too need a gearbox for optimal energy use even when the motor is inboard. The smaller system weight and size for the motor and inverter makes good room for including a two-speed box to optimize for both city and highway speeds, and will have a great effect since everything from regen brakes to acceleration will work better when the motor gets to run at high speed.
Eikka
2 / 5 (4) Mar 12, 2012
Do so and you get a triple positive whammy. You add a lane or two to each road, and you get the above improvements in efficiency.


What about heavier vehicles, trucks, busses and vans that would still need the full width of the lane?

There are, of course, stability problems with long and narrow cars, just as there are problems with short and wide cars. It doesn't mean cars can't be narrower than they are now, but cutting it in half would change the handling of it rather dramatically and make the car less safe to drive.
Eikka
2 / 5 (4) Mar 12, 2012
electric motors are THAT much better than piston driven motors. and they will get FAR better.

low hanging fruit?
Liquid cooled electric motors.
superconducting electric motors


It becomes an issue of cost and return. Electric motors are generally over 90% efficient, and if you add fancy technology like superconducting magnetics, you run into diminishing returns where the system cost increases more than it saves, because there's only that 10% headroom that you can improve no matter how much money and resources you throw at the problem.

Nay. The proper solution is to simplify the system, make it more robust and cheaper to produce. It doesn't matter if you lose 1-2% in efficiency if you can drop $1000-2000 off the price of the finished product. That's what matters first and foremost with electric cars, because they are far too expensive to be feasible right now, and well into the future.
antialias_physorg
2 / 5 (1) Mar 12, 2012
Currently it's really the battery pack that's the most expensive. So dropping 1-2 percent efficiency off the electric motor my save you 1000$ in material - but if that means that you have to pack in 2000$ more in batteries to compensate for the lost range then that's not a good deal.
Eikka
1 / 5 (3) Mar 12, 2012
This might be dumb, but would solar panels on the roof of a car squeak out a few more miles or just help when it's sitting in the parking lot? I always look at buses and big trucks thinking of all that space on top.

Maybe solar power isn't quite there yet? I dunno how much power solar panels can really make for vehicles.


If your car is sitting outside with a 1 sq-m panel flat on the roof, you'll get roughly 1 mile of extra range per day on average throughout the year. In summer you get more, in winter you get less, but the total will be on the order of 300-400 miles a year.

The panel won't be worth it economically, because the car will get scrapped before it has a chance of producing enough energy to justify the price.
Kinedryl
1 / 5 (3) Mar 12, 2012
..the panel won't be worth it economically
Flat panel at the roof would increase the consumption of fuel significantly because of worse aerodynamics..
Eikka
1 / 5 (2) Mar 12, 2012
Currently it's really the battery pack that's the most expensive. So dropping 1-2 percent efficiency off the electric motor my save you 1000$ in material - but if that means that you have to pack in 2000$ more in batteries to compensate for the lost range then that's not a good deal.


Well, that assumes that the battery cost you something like $200,000 to begin with. In reality, it costs you roughly $20,000, which means losing 2% of capacity costs you $200 to add it back, while saving you $800 in the total system cost.

That's simple optimization really. The best is usually worse than the good.
Eikka
2.3 / 5 (3) Mar 12, 2012
Flat panel at the roof would increase the consumption of fuel significantly because of worse aerodynamics..


That's assuming you don't laminate it into the roof, which is trivial. It doesn't have to stick out. Solar panels are made of smaller cells that are wired together and pressed between sheets of glass or plastic, which means you can easily make them follow a curved surface if you want to.

Still, it will cost much more than it's worth.
tpb
1 / 5 (1) Mar 12, 2012
There seems to be a few misconceptions here.

Mitsubishi decreased the inverter loss by 50%.
Modern inverters are already better than 95% efficient, so they saved maybe 2%.

It appears they also improved the motor efficiency, but they don't say how much, only that the output power of the new motor is 5% greater than the old motor. Efficiency and size/weight are not directly correlated.
A modern electric motor is 95% efficient.

They are using permanent magnet motors, not switched reluctance.

The battery charge-discharge efficiency with electrochemical and charging circuit losses is typically less than 90%, way less if they go to inductive charging.

Improved batteries are very important, more so than improvements in the motor or inverter because the vehicle carries the weight of the batteries at all times, even when running on the internal combustion engine.

tpb
1 / 5 (1) Mar 12, 2012
I'm kind of surprised we haven't seen a car with an optimized internal combustion engine and a motor/generator to replace the transmission.
All that would be needed is a battery or Supercap large enough to recover braking energy and to accelerate the car once to 70MPH.
This should be smaller lighter and more efficient than the non-hybrids,
and also more efficient than plug in hybrids, if you include the coal generator, transmission line, transformer, and charger and battery losses.
Voleure
1 / 5 (1) Mar 12, 2012
20 thousand years out there still will be geothermal as well, the most neglected of energy sources imho.
antialias_physorg
not rated yet Mar 12, 2012
Still, it will cost much more than it's worth.

If it's enough to run your AC it's worth it. Better have that going in a traffic jam than running out of juice because you kept feeding in energy from the main battery pack.

With solar cells being dirt cheap these days I think it would be worth it. Won't extend your range. But will keep you comfy and your sound system operational.
RitchieGuy
1 / 5 (4) Mar 12, 2012
howhot says:
ItchieGuy says
the grid still necessitates the usage of fossil fuels


You know, as much as you would like that to be true, there is only 50 years worth of Natural Gas from fracking. Where are the other 20,000 years of future human energy going to come from? Your hot air?

It has to come from solar. There is no other source of energy for mankind 20 thousand year out.

howhot. . .you really need to lay off that crack pipe. . .your understand of what I said above is all wet. We are talking about the EV. . .an electric car, howhot. . .This car has to be recharged after a certain amount of miles and at this time in our history, electricity from the "grid" is what will recharge the batteries in said car.
What I proposed in order to try to prevent the electric car's batteries from discharging completely, is to use SOLAR PANEL(S) up on the car's roof to keep the car's batteries from draining completely before the car gets to the recharge station (outlet).
RitchieGuy
1 / 5 (4) Mar 12, 2012
cont'd
As you, howhot, must be well aware, the grid is still run on fossil fuels, UNLESS your recharge station or other outlet place is capable of using electricity by hydro, solar, wind, thermal, ethanol from biomass, etc., from the power company. If it does not use those alternate sources of energy, you STILL will recharge your batteries from the grid which draws its electricity from a power plant that uses coal, oil or gas.
I do hope you understand it now. I thought I made it clear the first time around.
RitchieGuy
1 / 5 (3) Mar 12, 2012
It certainly would've been nice if Obama's favored "green" corporations had been able to supply us with actual working solar panels instead of taking our money and run, then laying off all those employees. But it happened and we're poorer for it. Other solar companies will rise up and, with improved solar products, give us the advantage over oil, coal and gas. But until that time, we will just have to muddle through somehow. I understand your feverish and emotional need to rush into solar and wind because of your dire predictions of AGW. But the technology still eludes us for the most part, howhot. No amount of arm twisting and hysteria will make it happen any sooner. When the tech boys have the stuff ready, we will know about it, believe me. Until then, don't have a heart attack. None of us are putting down solar or wind.
TheGhostofOtto1923
1 / 5 (4) Mar 13, 2012
Speaking of cracked pipes you really need to address this richie

As I've said before, I will be planting sweet sorghum soon, and the resulting sugars will be fermented into ethanol...to store the ethanol locally blah
Funny. U of Arizona is only just now working on a pilot plant project for sweet sorghum. They've grown 40 acres (coincidence?) but couldn't manage the logistics for even this test project because the intermediate support is not yet available.
http://obpreview2...t%20.pdf

-So without further research (I don't feel like wasting an additional 5 minutes) I feel confident in reiterating the conclusion that I share with most everyone who reads your posts, that you are a liar. Unless you can disprove it? Come on, prove you're not the lying imbecile you apparently are. IMO. LOL.
TheGhostofOtto1923
1 / 5 (4) Mar 13, 2012
What I proposed in order to try to prevent the electric car's batteries from discharging completely, is to use SOLAR PANEL(S) up on the car's roof to keep the car's batteries from draining completely blah
If dumbass Ritchie wasn't quite so lazy he would find out by using GOOGLE that his 'proposal' is not new.
http://en.wikiped...ile_site
http://www.treehu...ids.html
TheGhostofOtto1923
1 / 5 (4) Mar 13, 2012
But the technology still eludes us for the most part, howhot. No amount of arm twisting and hysteria will make it happen any sooner. When the tech boys have the stuff ready, we will know about it, believe me.
And if Ritchie wasn't so embarrassingly dim he would recall the last time he was directed to this link
http://en.wikiped...an_Union

Euro countries generate a significant percentage of their energy using alternative means. You dumbass.