Electric Turbocharger
 

Purely hypothetical discussion ahead. Turn back all ye who may say "this is stupid!"

If an exhaust turbine and wastegate are installed on our engine, what is an example of turbine shaft torque and speed? How much energy (temperature and pressure above atmospheric) can be used for regeneration?

Two options for generating power:
- gear down heavily and employ a high-output alternator
- run a DC electric motor in reverse

Similarly, can an intake compressor be run from a DC motor? Not talking the tiny electric superchargers on eBay... I'm talking voltage step-up + 1/2 hp dc motor + centrifugal/twin screw compressor (a la Vortech).

The idea has been tossed around by Subaru: HERE for the next WRX.

I'm just trying to wrap my head around how challenging this would be.

Potential issues:
- Sizing a battery/capacitor bank
- Management of alternator clutching
- Management of battery/capacitor bank discharge rate
- Integrated BOV with instant pressure relief (compressor motor braking)
- Cost and hardware weight would be high.

Potential awesome:
- No lag, as long as you've got battery power.
- Boost pressure can be closely controlled via dedicated feedback controller.
- The system can be switched to "ECO" mode for regenerating energy to supplement the alternator (would require an isolator for starting battery).
- The system can be switched off completely.
- Combination of the above. ECO mode during low load, low rpm driving. Instantly switch on above X% load.

Comments? Discussion?

too many fancy words for me.

I am definitely interested in seeing the results of this.

There's been a lot talk about this from BMW aswell, though I haven't seen anything in a while. One of the biggest problems was moving the electrical power around at the current 12 volt automotive standard. A few OEM's were lobbying to move to 48 volt systems, or even 48 volt partial systems. It seemed from what I read that the infrastructure became a lot more manageable at the voltage.

to keep power up couldn't you essentially make an alternator that is dedicated to power the electric super/turbo charger?

At that point it just becomes a supercharger with a remote pulley.....

Not to mention the losses in creating the electricity and then converting it back into mechanical energy. Supercharger is going to be much more efficient in terms of process than what you are describing @frostbitten.

Yes in theory it can work. Most often it's proposed as a dual stage setup by manufacturers where the electric blower would kick in first, then the actual turbo. It's probably pretty tricky to implement since as far as I know it hasn't made an appearance on any production car even though its been talked about forever.

An arc generator should work as a viable power source right?

On a serious note, how about instead of an alternator dedicated to power the electric supercharger, an alternate battery instead charged by solar cells or "ram air miniature windmills"

though I still think an arc generator would be better...

Actually, BMW is set to release the next gen M3's with a Tri-Turbo system with one of the turbo's being electric supercharger, most likely to spool one of the other two turbos.

What's the big deal designing a controlled electric compressor? Just need a circuit with power sufficient to drive said compressor. Let the engineers figure out the controller. Keep a separate higher voltage circuit, possibly with separate power storage. Regeneration could be the icing on the cake if there are significant gains.

I am a geek.

Call me ginea pig..

Anyone can add one to their cars http://www.turbomagazine.com/tech/04...r/viewall.html

It's brilliant. It's kind of like a supercharger/turbocharger hybrid but with incredible tuning capabilities.

No SC-ish engine drag, uses exhaust to capture energy to spin generator and uses electricity from said generator to spin turbine.

No Turbo lag because the electric motor won't have lag

No need for BoV because the turbine speed can be computer controlled.

Dear Subaru/BMW or whomever... please make this work.