For a lot of electrical and mechanical machines, there are nominal and peak ratings for energy output or input. If you’re in marketing or advertising, you’ll typically look at the peak rating and move on with your day. But engineers need to know that most things can only operate long term at a fraction of this peak rating, whether it’s a power supply in a computer, a controller on an ebike, or the converter on a wind turbine. But this electric motor system has a unique cooling setup allowing it to function at nearly full peak rating for an unlimited amount of time.
The motor, called the Super Continuous Torque motor built by German automotive manufacturer Mahle is capable of 92% of its peak output power thanks to a unique oil cooling system which is able to remove heat and a rapid rate. Heat is the major limiter for machines like this; typically when operating at a peak rating a motor would need to reduce power output to cool down so that major components don’t start melting or otherwise failing. Given that the largest of these motors have output power ratings of around 700 horsepower, that’s quite an impressive benchmark.
The motor is meant for use in passenger vehicles but also tractor-trailer style trucks, where a motor able to operate at its peak rating would mean a smaller size motor or less weight or both, making them easier to fit into the space available as well as being more economically viable. Mahle is reporting that these motors are ready for production so we should be seeing them help ease the transportation industry into electrification. If you’re more concerned about range than output power, though, there’s a solution there as well so you don’t have to be stuck behind the times with fossil fuels forever.
Thanks to [john] for the tip!
So if it can run continuously at X watts, why can’t you push it a little further for a short period? Is the peak power limited by other (mechanical?) factors?
The article says it can run fulltime at 92% its peak power. It means you have a 8% margin where you can get more power for a short time, as I understand it.
The value of the “peak” is a fuzzy definition isn’t it?
For this article you could also state that with this new “unique cooling setup” the peak power value was underrated and therefore it could be used continuously, I’m pretty sure it still has a peak, it’s value just has shifted.
Well, that’s not a “peak power” anymore but they designed a new motor (old + improved cooling) with a higher rated power. And the peak power of it is still 8% points higher …
This “peak power” talk is just stupid marketing BS
Question is: of what peak? Peak of your diesel engine? Hydraulik pump thingy? Pipes? Hydraulic motor thing? (Thinking of a conventional hydraulic driven farm/forst/work device.) Electric Motor thingy? Bearings? Wiring? Bearing fluid system? Control electronics?
All chained after ech other and all depending on each other… Peak is the limit that the weakest part can handle.
And they shiftet one limitation up to a higher level.
So marketing bullshit.
I think it is pretty clear what “peak power” (along with things like “duty cycle”) means when one talks about an electric motor. That is an established engineering term and has nothing to do with the rest of what you are mentioning.
Whether the rest of the assembly (one rarely uses a motor alone) will handle the increased power or whether even the motor itself will survive it long term due to the increased mechanical wear and tear (cooling is only one part of the equation) is a different problem. I am also rather skeptical there. We have seen this “downsizing” trend in the combustion engines for a long time. With the result the smaller engines being cheaper to manufacture and easier to make fulfill the emission standards – and dying left and right prematurely because they can’t handle the extra load long term. But that’s the customer’s problem …
OTOH, heat is one thing – but the motors aren’t rated as they are only because of heat but also because running 100% at peak power would put too much mechanical strain on the assembly and massively reduce the lifetime of the aggregate.
It reminds me of the Ford EcoBoost – a 1 liter engine that is brought up to usable power levels by turbochargers and what not. With the result that these engines are dying left and right after only few years of use, in some cases even while the cars are still in warranty.
Bigger motor is not only about better cooling but also bigger bearings, more “metal” in the critical parts, etc. So I would be rather skeptical over claims that one could use much smaller/cheaper motors, “they only need better cooling.” Some manufacturing savings can certainly be made – but probably running the motor non-stop at 92% of the peak power of the original one would do “wonder” to maintenance costs. Of course, those are born by the sucker err customer buying such vehicle …