NOV 23

Electric Turbochargers to Improve Engine Efficiency

Written by on November 23, 2014

turbo-cutaway
In the ongoing quest to improve, electrically powered turbochargers may be the next step in increasing engine efficiency for automobile engines.  The first such to be included in a production model is slated to come in 2016 from Audi on its SQ7 SUV.

Turbo boost has been a popular way of increasing the power of an engine without increasing its size.   Ford’s EcoBoost is an example of this approach, using 3-, 4-, and 6-cylinder engines in vehicles which had previously used larger engines.  Turbocharging an engine increases the amount of air, and therefore fuel, being fed into the engine, providing better performance from a smaller-sized engine.

Conventional turbos use exhaust gasses to spin the turbine that forces more air into the engine.  This is efficient, but it produces “turbo lag” as the engine needs to increase speed in order to develop the boost.  But an electric turbo can respond almost instantaneously, providing added power without any delay.  Furthermore, as Green Car Reports notes, “a more responsive turbo will help the engine produce more low-end power, meaning drivers won’t have to venture higher into the rev range–and increase fuel consumption–as much.”

This becomes a more viable option with the increased computerization of engine control systems, which can read the driving conditions and trigger small amounts of boost as needed.

Whichever kind of turbo is used, the benefits come from having a smaller engine, both in terms of the overall displacement of the cylinders, as well as the mass of the engine itself.  Smaller engines mean less weight the car has to move, which helps in efficiency.  And the smaller displacement means less fuel is routinely used, while the power that would have been available is still there, thanks to the boost of the turbo.

via:  Gas 2.0

image credit: Wikipedia/NASA

 



One response to “Electric Turbochargers to Improve Engine Efficiency”

  1. pd says:

    I may be wrong but I believe this was part of the many efficiency-focused changes that were introduced into Formula 1 this year. The “Power Units” now consist of a turbo-charged 1.6 litre V6 combustion engine plus electric motors attached to the rear axle and turbochargers to generate electricity. The electric motor attached to the turbo can be used to ‘spin-up’ the turbocharger to reduce lag.

    The combined changes have annoyed traditional racing fans (not me) because the smaller combustion engine and turbos combine to muffle the traditional high-pitched whine.

    However these Power Units now use 33% less fuel but supply similar power, but much more torque, than the previous generation 2.4 litre V8 engines with just the common regenerative braking system.

    There are some impressive achievements to get these units working. One electric motor deals with AC, the other DC, so a converter is required. The turbos spin at up to 100,000 RPM so some seriously impressive bearings are required!

    Some more info can be found here:

    http://www.racecar-engineering.com/articles/f1/2014-f1-the-power-unit-explained/3/

    amongst many other places.