Has anyone followed the hype around the new mahle motor ? Looks to me like a fancy induction motor. Other than that, how on earth is this thing supposed to be more efficient than a pmsm motor, using wireless power transmission and 2x induced magnetic fields instead of 1. Any feedback is most welcome.
New Mahle Motor ?
- Thread starter qwerkus
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They didn't specifically say it, but it might be a switched reluctance style, like the front motor on AWD Tesla's.
Neodymium magnets have been identified as a possible choke-point component in many current motors for EV's.
The Tesla motors have been independently tested, and at the very least, the performance is the same, if not slightly better.
Neodymium magnets have been identified as a possible choke-point component in many current motors for EV's.
The Tesla motors have been independently tested, and at the very least, the performance is the same, if not slightly better.
mxlemming
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Their statement is that it uses a copper coil to create an electromagnetic field. This is basically an excited 3 phase motor.
I'll bet they're just coupling an excitation current through a rotating transformer. One of my lecturers at uni mentioned this. Basically have a set of motor windings and iron/ferrite that makes a 2 ring transformer, feed it high frequency and you've got power on the rotor.
They say they've eliminated the sliding elements, which is why i suspect this.
It's not new, they've probably just packaged the concept a bit and generated hype.
It means you can change the mag field strength and therefore effectively the kV.
I'll bet they're just coupling an excitation current through a rotating transformer. One of my lecturers at uni mentioned this. Basically have a set of motor windings and iron/ferrite that makes a 2 ring transformer, feed it high frequency and you've got power on the rotor.
They say they've eliminated the sliding elements, which is why i suspect this.
It's not new, they've probably just packaged the concept a bit and generated hype.
It means you can change the mag field strength and therefore effectively the kV.
Thanks for your thoughts on the matter.
While an adjustable rotor magnetic field seems ideal to improve efficiency, my understanding is that the excitation losses and especially the extra weight makes it only useful at high power levels, like power generators. Maybe a car but I doubt this is as "scalable" for sub compact vehicles like an ebike as the company claims.
An interesting part is the wireless excitation. Won't the inductive "charging" of the rotor be disturbed by the the magnetic field generated by the motor ?
While an adjustable rotor magnetic field seems ideal to improve efficiency, my understanding is that the excitation losses and especially the extra weight makes it only useful at high power levels, like power generators. Maybe a car but I doubt this is as "scalable" for sub compact vehicles like an ebike as the company claims.
An interesting part is the wireless excitation. Won't the inductive "charging" of the rotor be disturbed by the the magnetic field generated by the motor ?
qwerkus said:
Not enough data...
Efficiency of PMSM can be in 97%.
[quote
The new electric motor is also characterized by a high degree of durability, because the necessary transmission of electrical currents between the rotating and stationary parts inside the motor takes place without contact and is therefore wear-free. This makes the engine maintenance-free and suitable for a wide range of applications.
/quote]
This is exactly the character of ACIM motor in which rotor field can be customized depending the phase conditions.
Except if they talk about multiphase (talking about 5 phase) SR motors where you use additional winding across stator to induce field inside rotor winding. In that case it would be something new because industry standard for SR are a pair of colector rings on the rear of the motor. If you eliminate rings there is somwhat less wearable assembly... But you need 2 inverters one for field excitation and one for motion.
Peak efficiency of a BLDC motor is 98.4% ( CSIRO axial flux motor, circa 2010 ).
Efficiency curves on motors like these might be broader despite a lower peak due to the variability of the second field, which is good, but not as earth shatteringly good as the press release would indicate
Efficiency curves on motors like these might be broader despite a lower peak due to the variability of the second field, which is good, but not as earth shatteringly good as the press release would indicate
mxlemming
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https://www.mahle.com/en/news-and-press/press-releases/mahle-develops-highly-efficient-magnet-free-electric-motor--82368
You do all realise that at the bottom of the page there is literally a video showing cross sections and exactly how it works?
And it's exactly like I said.
You do all realise that at the bottom of the page there is literally a video showing cross sections and exactly how it works?
And it's exactly like I said.
mxlemming said:
Ok i agree, this is a step forward actually. At least it eliminates collector rings.
So does that make this SR motor or more like separately excited SM = SESM not PMSM
?One thing i can accept is that now they are able to adjust rotor field in much more detail and with a seperate commutation process.
mxlemming
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I don't think this is a switched reluctance motor. There are electromagnets... It's basically the same as an alternator with the electromagnet in the middle, but they've eliminated the brushes/slip rings in favor of a coupling transformer.
In as much as a PMSM or SESM has a reluctance torque which is exploited in MTPA, it has some SR like properties (no more than SESM), but SESM with a nice slip ring replacement is the most accurate description.
In as much as a PMSM or SESM has a reluctance torque which is exploited in MTPA, it has some SR like properties (no more than SESM), but SESM with a nice slip ring replacement is the most accurate description.
I think it's an application of this paper: https://ieeexplore.ieee.org/document/6954203 Not sure if scihub linking is allowed here, but if you check the article, they describe the "contactless rotary transformer" used in the mahle motor and also claim 95%+ efficiency, though only at high speed.
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