Though full electrification might not be in the cards for most consumers, those looking for turbo power for their vehicles could find a little bit of that black magic in the turbo itself down the road.
A report by Navigant Research posits that the best way to eliminate lag without using a supercharger to make up for said lag — at the expense of increased friction at higher speeds — an electric turbocharger may be the best bet yet. The technology offers a handful of improvements over exhaust-driven units, including packaging of components, responsiveness and flexibility.
Supplier Valeo recently unveiled such a piece — for 12V and 48V electrical systems — with the first applications coming online in 2016. According to their findings, the best application for the turbo is with an engine that uses cylinder deactivation to maintain fuel economy. As power is reduced with cylinder count, an electric turbo can help with small boosts in power to tackle situations that would otherwise switch all of the cylinders back on, such as mild-and-above inclines.
Meanwhile, engineers wouldn’t have to figure out where to package all of the plumbing required for an exhaust-driven turbo with an electric unit, allowing for a placement that provides the best peformance and setup.
Very interesting article. Turbo-lag has been one of my big issues with turbocharged engines, if that can be reduced or eliminated it would certainly make a convert out of me
Of course, you don’t just have it be electrically driven, you also have it be a generator as a classic turbo not just an electrically driven supercharger: When you need more boost you drive it forwards, when you need less you scavenge energy: if the wastegate ever opens, somethings wrong.
As a bonus, if Honda/Mercedes/Nissan/Ferrari is the first to bring that version to market, they can advertise it as Formula 1 technology…
@ Nicholas Weaver
The generator concept does seem to be superior. Matched with various levels of electric drive, you could have large vehicles with small engines but plenty of power and torque and much less wasted energy.
It doesn’t even need electric drive to benefit. A system like Mazda’s capacitor would permit disconnecting the alternator when the turbo operates as a generator.
Indeed, this is what the Volt should have had, coupled with an Atkinson cycle motor and wide-ranging fuel injectors, so that you could operate in Atkinson efficient mode for much of the time, while enabling Miller mode for high-demand situations. So, basically, you’d have a 1l 3cyl 50+mpg 25-35kW motor for steady-state highway driving, and a 100kW+ Miller motor for hills and high-speed shenanigans.
“As power is reduced with cylinder count, an electric turbo can help with small boosts in power to tackle situations that would otherwise switch all of the cylinders back on”
Then why even have the extra cylinders in the first place?
For the bigger boosts in power
This has the ability to run like a lightly boosted 4cyl at light loads and a moderately boosted 8cyl when you drop the hammer down. It’s another step forward in having major power without the heavy fuel penalty.
An example would be adding this to GM’s 5.3L Silverado. It would be able to pull a higher OD gear in 4cyl mode because the smart turbo would give it some boost when needed, improving highway fuel economy. When you need power (towing, passing, etc) it would be able to provide enough boost to make power that would embarrass the already stout GM 6.2L.
If this works as you say, I’m in
I’m betting you’ll find that it can lightly boost a 4 cylinder and won’t be able to keep up, let alone moderately boost an 8. I’ve seen a couple of electric turbo charger concepts in the past, but none in the 12v range. Most where 100+V that used exhaust scavenging or something similarly clever to recharge.
Think of it this way, if a supercharger needs 50+hp (v-8 moderate boost) an electric turbo will too.
….bragging rights…..?
I wonder if they’ll add logic to detect the EPA test cycle and keep the thing shut off during the test.
Acceleration is so mild that it wouldn’t ever be needed. Same issue with lots of small-engine turbocharged cars today. Ford Ecoboosts are never running under boost in the normal Federal test procedure.
And that should tell one all one needs to know about the usefulness of the feds…
Where is the turbine? Why do people call chargers without turbine “turbo”?
Some accuracy in using technical terms would be great. I can get slang terms on USAToday. This is TTAC where in the past journalism was superior.
I think a hybrid solution would probably be best, to be honest
Don’t be a pedant though, its unbecoming
Yeah, pedant makes you look persnickety
“Never argue nomenclature with a pedant. It wastes your time and annoys the pedant.”
Probably marketing slang used by the manufacturer in much the same way auto makers have started calling swoopy sedans four door coupes.
When I first heard about this I was under the impression that an electric motor had been inserted between the compressor and the turbine using the motor to get the compressor up to speed then handing it off to the exhuast.
Didn’t some old WRC cars use that with a motor to keep the turbo spun up to reduce lag?
Makes more sense to call it an “Electric Supercharger” than “Electric Turbocharger”
How about electrically boosted turbocharger
“Turbo” means it uses a turbine in the exhaust to drive the compressor (the charger part). Turbocharger is short for turbosupercharger.
It’s sorta like the difference between a bicycle and motorcycle.
An electrically boosted turbocharger would be great (if it could be made to work reliably and with longevity)… but would that be the “moped” of electro-turbo-superchargers??
Wait, my ICE car wouldn’t do poop without being electrically started. Aren’t we talking about a similar thing
It does make more sense to call it “electric supercharger” though the electric supercharger could use either a fan or a turbine to drive the extra air into the combustion chamber. You can also have a turbine generator in the exhaust stream scavenging energy when appropriate as Nicholas Weaver alluded to. Think of it as regenerative braking for the airflow.
I’ll side with the Krauts: It’s a bloody Kompressor. Just electrically powered this time.
What are we to do if that’s what the manufacturers call it?
Announced plans to market an electrically driven air impeller under the name “electric turbocharger”.
“Where is the turbine?”
Driving a generator. Look at current F1 turbos.
They did it! they finally managed to fit an electric hair dryer to a car engine. All kidding asside, it’s sounds like a good idea, no lag and no heat problems.
If it works for F1 then hey why not. The concept is simple, the only problem is you need a lot of juice to pressurize the air. 12V ain’t going to cut it. I believe F1 is using their system to augment normal turbo charging (exhaust driven) and to reduce lag. This is different.
Someone posted awhile back that you can already get an electric supercharger for your FR-S:
http://www.ft86club.com/forums/showthread.php?t=39719
My understanding of the “electric turbocharger” is that the electric motor is only used to accelerate the rotor up to partial speed. The serious work of compressing air is still done by the exhaust turbine. If you tried to replace the exhaust turbine with an electric motor altogether, the power draw would be on the order of 40 HP or more, which would require on the order of 50 HP draw from the alternator, plus there would be the size of the motor. I guess it would be 2 or 3 times the size of the alternator. And the cables to it would probably be two or three times the diameter of battery cables. But a small motor to accelerate the shaft up to partial speed, thus reducing turbo lag, would make some sense.
By the way, a “turbocharger” is correctly termed a “turbo-supercharger” though no one uses that terminology any more. It consists of a turbine, which extracts energy from the waste heat in the exhaust, and a compressor which compresses the charge air. If you replace the turbine with mechanical drive (either by belt from the crankshaft or an electric motor) you have a “supercharger”. If you use an electric motor to assist the exhaust turbine you have an “electrically assisted turbocharger” not an “electric turbocharger”. The term “electric turbocharger” is inherently self-contradictory; if there’s no turbine there can’t be any “turbo”.
That actually answers some questions I had from the article.
@turf3. Wish we had a like button for that comment. I would have said something but didn’t want to be called a pedant.
I think someone was doing something with a supercharger and a turbo to take care of the lag. Can’t remember who which is typical.
If the exhaust turbine drives a generator, and a motor drives the compressor, you have an electric turbo charger or electric “turbo-supercharger”
Then it is not a turbocharger but is a supercharger.
Why can’t it be both?
If you need 40-50 horsepower to drive a supercharger full out, most hybrids generate that much power for their electric drive motors. If you shift that horsepower to forced induction for the ICE, you could have one fast Prius on your hands. Of course, you engine would have to be racing-spec to handle the power, but why let practicalities rule one’s imagination?
Is there any reason to make an electrical turbo-hybrid system, rather than using compound turbocharging with a BAS hybrid system? If you’re going to have energy recapture and electrical motors onboard, why not hook everything up to the crankshaft?
TW5,
why not go full bore and go to sleeve valves which eliminate detonation as well?
Of course, we just built a ludicrously expensive engine, but think of the power or the economy.
Volvo recently used an electric turbo-charger (or whatever the B&B decide to call it) on a one-off prototype 2.0L 4-banger. The electric turbo was used to spool up two conventional turbos, thereby eliminating turbo lag (reportedly). They also claimed said motor delivered 450HP. Yowza.
Now, if it gets 50 mpg to boot the oil companies will come in and squash it and a new conspiracy will be born
On the first glance this seems bogus because the electric energy to drive the turbopump comes from the power produced by the engine, whereas in traditional turbocharger the otherwise wasted energry of the exhaust gases is used. Scavenging the waste heat is what drives the research in exotic extra-expansion engines (such as “5-cycle”) or the BMW’s steam-compound engine. From the elementary thermodynamic considerations, this devices could help a lot with the turbo lag, but will not help efficiency at all.
I invented just such a system in 1988, with parallel air flows from what was termed the Electrocharger and a regular turbo. A spring-pressure activated vane at the V junction allowed whichever air stream was stronger to use the vane to close down the path from whichever compressor produced lesser dynamic flow. When the turbo was really puffing, the vane would close off the pipe from the electrocharger, activate a microswitch, and through a control system turn off the electrocharger’s motor.
No doubt dozens of other people have had similar ideas for decades. It is hardly revelatory. The problem that stopped me was the huge horsepower required to operate the electric motor, the gigantic wiring needed for thousands of amperes at 12 volts, and how the battery would react to almost short- circuit conditions repeated time and again.
I’m going to be most interested to see how this thing works in practise.
Isn’t this similar to what Audi put in the RS5 TDI concept? In that case providing pre-boost before the ‘real’ turbos come online.
http://autophorie.de/wp-content/uploads/2014/05/audi-rs5-tdi-electric-turbocharger-3.jpg
Particularly useful to alleviate traditional turbo lag…