Featured Awesome axial flux motor

Note that you here have fully entered straw-man territory, as there wasn't anybody in the thread who ever claimed the percentage reduction in loss equated to a numerically identical percentage increase in range or reduction in pollution. I was addressing only the reduction in power wasted as heat in that component, and that's what I wrote.

And you know what? You know, if you ever had achieved 99.999995% and then managed to improve that to 99.999996%, you really would have reduced your power going to heat by 20% again, and you really would be able to shrink your (by then quite small) cooling capacity by 20% again, and among the kinds of possible refinements of your machine you might be evaluating at that point, that still would be pretty cool.

 

Every little bit helps. So yes, making the motor a little smaller would help. The pancake isn't necessarily more efficient, but if it is, every little bit helps there too.

But it's still important to realize how small these improvements can be compared to what could be reduced. But I guess as long as people are fixated on buying ginormous SUVs, then making the motor a little smaller and making little $50 radiators now $49 radiators because you reduced the heat output by 20%. And saving a few dollars a year on electricity is better than nothing too. I'm not sure it justifies the R&D expense and ultimate car cost, but maybe it will someday.

To me, it still makes way more sense to reduce these things by much higher factors. Just get rid of the permanent magnets altogether. They aren't necessary for high efficiency. You can do that with an iron rotor reluctance motor Make it an axial reluctance motor if you wish.

 

Google AI tells me that the YASA axial flux motor is a synchronous motor, not an induction motor. Is it hallucinating?

I was thinking that induction motors need an electric current path in the rotor, but I'm noticing only a magnetic flux path on this one.

Many large improvements have been achieved by stacking a series of small improvements atop each other. A percent here, a fraction of a percent there, repeated in dozens of difference places.

 

True, but not so much when we're talking about pushing the envelope to 99.9999999% efficiency because you're running out of improvement capabilities. To think that a 20% drop in cooling capacity from 99.999995% efficient to 99.999996% is going to make some sort of real world improvment is abusurd. I'm not saying that if it can be done, don't do it. But don't try to sell me a car because it uses a fraction of a penny less of electricity per year than the previous model.

Yeah, I've don similar things. But that doesn't mean it makes sense for someone like me to go buy a Tesla right now just because I can put pizza pans on the rims. I've always wanted to add an aerodynamic tail to a car like the AeroCivic. Aptera is the only car company doing that.

I like the idea of lower rolling resistance tires. But where I live, I can't use them because we get snow any month out of the year, so they'd have to be all-weather rated, and I don't know of any that are. What does really bother me is that there used to be a train that you could take to go to the city in here in my town. But they took that out, so now it's either car, bus or airplane. Rail and metal wheels are the best rolling resistance you can get. Weight is also a huge factor when it comes to rolling resistance. I keep telling myself that one of these days I'll get something with two wheels as my second "car."

 

It is energy being sent to the motor, not power. The motor turns the energy into power. Just a quibble.

Another is that the loss isn't all to heat. There is still friction, momentum, magnetic braking, etc. working against efficiency.

But impact does that have on an EV? Does it make a difference when there is still a large battery to cool?

Permanent magnets are needed for efficiency in the main drive motor. An induction motor is going always use energy to power the temporary magnets. Compare an early year Model S to the latest one to see the difference.

Rare earths are used to increase the heat tolerance of the magnet. An iron magnet is going to need more cooling. It will also be heavier for the same field strength.

The gen2 Volt did use an iron magnet for the MG1 equivalent motor. Doing so cut costs, but it also isn't the main drive motor.

Does it have a permanent magnet? Induction motors don't; they turn hunks of metal into temporary magnets with current.

 

I'd wager a bet that synchronous iron core reluctance motors need way less cooling than permanent magnet motors since they are both of similar efficiencies but iron can withstand much higher temperatures and still maintain both physical strength and magnetic field strength whereas permanent magnets lose their magnetism at high temperatures.

The main drawback to iron-core synchronous reluctance motors is that they do have a lower field strength which makes them less efficient and have less torque at lower speeds making them have a rather narrow speed band as far as electric motors are concerned. Tesla and Toyota get around this by adding permanent magnets for low speed operation, although at high speeds the permanent magnets are shifted out of the rotating magnetic field where they have no effect which turns the motor into a synchronous reluctance motor, the kind of motor I'm talking about.

What I'm saying is that a high efficiency, iron-core, synchronous reluctance motor without permanent magnets is perfectly feasible. But the drawback is this: it would either require some sort of magical engineering to mitigate lower efficiencies at lower speeds (Tesla and Toyota do this with permanent magnents) or you'd have to add a two, or maybe three speed transmission.

Me: My dream EV car would have a synchronous reluctance motor along with a two or three speed manual transmission.

 

You may be relying on different definitions on energy and power than I am.

I am following the usage where power is a rate of energy delivered over time, or equivalently energy is the integral of power with respect to time. You would use units like joules, ergs, watthours, calories, BTU, or therms to measure energy (all different units measuring the same thing), and you would use units like watts, horsepower, erg/second, BTU/hour to measure power.

I maintain that the definitions I'm using are widely-used and established.

You can notice a relationship between the units used for measuring energy and those for measuring power: if there is a simple name for a power unit (like watt), there is a corresponding energy unit with a time dimension (like watt hour); likewise, if there's a simple name for an energy unit (like BTU), there's a corresponding power unit with a time⁻¹ dimension (like BTU/hour), just as the definitions would imply.

My use of the terms would be to say that electrical power is sent to the motor and converted to mechanical power.

Friction losses end up as heat. Magnetic braking effects are from magnetically-induced currents flowing on resistive paths, ending up as heat. Momentum may need to be treated more carefully than just as a type of loss.

 

You are out in straw-man territory again. Or is that reductio ad absurdum?

That is just a matter of viewpoint. Math-wise, the later is just the time derivative of the former. Or the former is just the time integral of the later. We can do this work in either domain.

If that doesn't jog any memories from calculus and physics, then remember that "power" is just "energy per second" (or whatever time unit one desires). The added "per second" on the units doesn't change the basic physics.

All those still end up as heat in the zone of interest, absent the addition of something carrying momentum and kinetic energy out of the zone being analyzed.