Mercedes-AMG, Garrett developing 48V electric exhaust gas turbocharger
18 June 2020
Mercedes-AMG is moving ahead with electrification through innovative developments while also benefiting from motorsport know-how. An electric exhaust gas turbocharger, which in future will be used for the first time in a series production model, is already in the final stages of development.
Developed in partnership with Garrett Motion, this technology comes straight from Formula 1 and resolves the conflicting goals between a small, fast-reacting turbocharger which achieves relatively low peak performance and a large turbocharger with a high peak performance but which on the other hand can suffer from turbo lag.
This new turbocharging system features a slim electric motor, measuring about 4 centimeters, which is integrated directly on the charger shaft between the turbine wheel on the exhaust side and the compressor wheel on the fresh air side. This electronically-controlled electric motor drives the compressor wheel before this accepts the exhaust gas flow.
The electrification of the turbocharger significantly improves immediate response from idle speed and across the entire engine speed range. Turbo lag—the delayed response of a conventional turbocharger—is eliminated by the electric motor. The result is that the combustion engine responds even more spontaneously to accelerator pedal input, and the entire driving feel is significantly more dynamic and agile.
In addition, electrification of the turbocharger enables higher torque at low engine speeds, which also enhances agility and optimises acceleration capability from a standstill. Even when the driver takes the foot off the accelerator or applies the brakes, the technology of the electric turbocharger is able to maintain the boost pressure at all times, so that a continuous direct response is guaranteed.
The turbocharger achieves speeds of up to 170,000 rpm, which enables a very high rate of air flow. It can be operated via a 48-volt on-board electrical system. The turbocharger, electric motor and power electronics are connected to the combustion engine’s cooling circuit to create an optimum temperature environment at all times.
We have clearly defined our goals for an electrified future. In order to reach them, we are relying on discrete and highly innovative components as well as assemblies. With this move we are strategically supplementing our modular technology and tailoring it to our performance requirements. In a first step this includes the electrified turbocharger - an example of the transfer of Formula 1 technology to the road, something with which we will take turbocharged combustion engines to a previously unattainable level of agility.
—Tobias Moers, Chairman of the Board of Management of Mercedes-AMG GmbH
Is this for Mercedes in general, or just AMG ?
Posted by: mahonj | 18 June 2020 at 04:16 PM
Turbos heat up, magnets don't like heat.
Posted by: SJC_1 | 20 June 2020 at 06:45 AM
A you can see, the turbine side is (double) insulated. The turbine center is water cooled. So the magnets might get hot a bit, but i guess MB-AMG & Garrett are noobs at building these things...
Likely to be for AMG models only at first, but no doubt this will trickle down to regular MB models also.
Posted by: Ing. A.S.Stefanes | 22 June 2020 at 12:10 AM
Some short comments are (I can provide more if anyone is interested…):
The e-machine significantly increases the inertia compared to a conventional turbo. Therefore, considerable power is needed just to maintain equal transient response compared to a conventional turbo. Of course, even higher power will improve response and for that, you need a 48 V system. In essence, this is why we have not seen the e-turbo in production so far. Boost pressure at low engine rpm is limited by pumping of the compressor and that potential is more or less exploited already today. Probably the biggest gain might be engine power at high rpm; for sure an important feature for AMG. A bigger turbine than a conventional turbocharger will not choke and reduces backpressure at high engine speed. This facilitates higher power, although boost pressure is not much affected. Will the gain be worth the effort? Well, let’s see if anybody else will adopt the e-turbo... It looks expensive but this is the case also for twin-turbo, e-compressor, and some other options.
Posted by: Peter_XX | 23 June 2020 at 07:10 AM