EV Motor Mania: The Strengths & Weaknesses of Induction vs Permanent Magnet
Вставка
- Опубліковано 8 лют 2025
- Today's video is sponsored by the Anker MagGo Wireless Charging Station! Shop now at bit.ly/49SJ5a2 and use code AKWDKOL15 for 15% off!
Anker MagGo Lineup: bit.ly/4c1sFhp
Paul explains the differences, strengths, and weaknesses between induction & permanent magnet motors.
Munro Live is a UA-cam channel that features Sandy Munro and other engineers from Munro & Associates. Munro is an engineering consulting firm and a world leader in reverse engineering, costing, and teardown benchmarking.
Munro Home of Lean Design
leandesign.com/
We would really appreciate it if you subscribe to our channel. The more subscribers we have, the more opportunities and teardowns we will be able to bring to you!
For more behind the scenes content:
X/Twitter: / live_munro
Instagram: / munrolive
LinkedIn: / munro-live
Munro Live Podcast: / @munrolivepodcast
Inquiries: Sales@leandesign.com
For Exclusive Content Join our Patreon!
Patreon: / munrolive
#tesla #cybertruck #electricvehicle
Retired Electronic Tech, Industrial Electrician here. I wish Paul had been my instructor when learning these concepts. His analogies and clear explanations of electromagnetic theory as applied to rotary motors is very well done. A great refresher for us old dogs.
I would love to hear an explanation of the use of each type of motor in regen mode.
Thanks!
Regen mode is huge! In automotive it’s used to slow the vehicle down while turning that kinetic energy back into stored energy in the battery.
current Hybrid Technology Prototype-Lab: Performance Dyno SME. BorgWarner.
Absolutely. Wish I had paul teaching my EE courses.
Just a layman here but also love his style of explaining the principles and practical use on the subject 👍
Yes, what an excellent analogy and clear explanation. I want to see more of this guy. I'm not so interested in the inverters (though maybe that's because I know a lot about them), but I'm very interested in more detailed description and differences of construction and the uses of these motors.
Also, not that I think it's essential, but I'd just love to see his explanation of three-phase power. I'd like to see him extend the analogy of the stadium placards in an understandable way.
@@babyschuerman*layman...
You asked if anybody would be interested in learning more about inverters... Absolutely! Especially if it's as solid and in depth as this video!
Me too, I’m about to do an essay on inverters applied to automotive engineering and I’d love to have a great basis of knowledge to work from.
Great content guys, and also a really good host today.
More of this kind of video!!!
Me too.
Always use a Pure Sinewave Invertor they are more expensive to make over the Cheaper Square Wave but are better for the Electronics Devices Longevity
Square Sinewave is Digital either On or Off real Quickly while a Pure Sinewave is Analog with a Gradual Increase and Decres, This leads too a Cooler device and no Sudden Surge that even if designed to Take will wear down Componentes (Resistors, Capacitors, Chokes even Copper Wires!) Much Faster!
* Pure Sinewave can Extend a Devices Life Span over No Invertor or a Square (aka False!) Sinewave Invertor by as much as 30 to 60% and can save Power Usage by 20 to 35% on Average but could be even Higher!
There is a Good Reason by Pure Sinewave Invertors are Always used for Important Computer Systems (Military Systems Including RADAR, Server Farms/Cloud Computing, Mainframes, Supercomputers, Banks etc.)
If and when you do speak about inverters, can you explain how the Coil Driver (inverter) is different from most inverters?
Me too
I would love to see more videos from this guy. Thanks.
You got it!
Now talk about how regen works with them please! @@MunroLive
@oof_Dad I was going to say it the reverse, but not sure that's right
DITTOS, WHERE HAVE YOU BEEN HIDING THIS GUY?
He good
This guy is fantastic. He could teach a rock.
He could rock at teaching
Hot damn, the ability to teach rocks while rocking. This guy is just great. As others have said: I'd have loved to have him as an instructor. Monroe take note: We want more of this guy!
Affirmative response
I giving a like just for the humble "thank you" to engineers. Not the salesman, not the marketing, the engineers.
This guy is brilliant. Please have him make additional videos, would love to hear about inverters!
I've trained 1000's of people in AC drives (inverters in the video) and electric motors and I never thought about using the example of people doing the wave as an example of what happens in the stator. That's really brilliant and I might have to "borrow" that for future trainings!
Also surfing, linear motor?
@@rogerstarkey5390 LOL Yes, nice
OK, try to explain PWM (pulse width modulation) in the stadium analogy.😀 But agreed, this novel (to us) analogy is great. Never seen any of this explained without showing the AC sine wave, which would just complicate this short explanation.
@@briansilver9652joke is on you, for Motors the Frequency is Modulated, not the Duty Cycle ;) :P (some "DC Motors"/Motor Controllers take a PWM signal as input, yes.. but its not passed to the Coils of the Motor itself)
@@unitrader403 oh contrare. The IGBTs output PWM power which is used to simulate the sine wave shape and frequency. But it is just square wave pulses. At least that was what we learned at VFD training 20 odd years ago. I'm retired from the game now so maybe they can produce actual sine wave inverters now.
Yes Id like to hear more about the controllers and the magnetic field concentration
People that really know their subject to great depth make it sound simple, they don't waffle. You sir are a true master of your subject, thank you.
I like waffles 🧇
Please do more of these videos it hard to find information like this on the internet.
We will!
Add another vote for videos like these, especially with this guy.
Yes. More please. This was great.
This was exceptionally well done in I believe one shot. Well done!
As an electrical engineer, that was by far the best explanation of how an induction motor works that I have ever heard. I always had a mental block on the subject and treated it as a bit of a black box. Thanks for the great run-down, Paul!
YES WE WOULD LOVE A VIDEO ON INVERTERS! I am just a hobbyist electrical engineer, I haven't done school for it and this information is really hard to find around the internet and I would love to see in depth into how an inverter creates a smooth sine wave.
Welcome Paul into the family of Munro presenters! (At least, it is a first time for me) I finally get the differences of those 2 motors. Great explanation and I love when engineers congratulate each other because nobody else will do it anyway!
This is a good executive summary induction vs. PM motors. Thanks for not turning it into an advertisement for any one manufacturer.
Yes, I saw him almost brand, he rethought. Much appreciated pure tech explanation.
That PM motor rotor sure looks like what’s in one of the two motors in my Tesla. I kinda wish he had mentioned where these parts came from. No harm in that.
@@Dave-ei7kkthese were both Tesla motor designs. If you look through the older Munro videos you’ll see them tearing down multiple Tesla models to look at the newest motor designs.
@@bgbrandvold I wasn’t sure about the induction motor rotors. Were they both Tesla designs? They were quite different from each other.
@@Dave-ei7kk Tesla used copper for their induction rotors, at least initially. I don't know if some of their later designs use aluminum.
Stadium Mexican Wave: perfect and very simple explanation of very complex electrical problem of induction motors work principle.
YES - How Inverters work would be a great Video please do one ... Thanks Great Content!
This is one of my favorite Munro videos. I've been learning about EVs for about 6 years and yet I learned a lot from this video. Yes, please do videos on magnet positioning in rotors and on inverter design.
Some OEMs have recently gotten excited about axial flux motors. It would be interesting to see them included as a part of this comparison.
But the configuration (axial-flux versus radial-flux) is irrelevant to the differences between induction and PM motors.
@@brianb-p6586 Agreed. I was adding a third because some OEMs are starting to embrace them.
@@arleneallen8809 but no OEMs are using axial-flux motors in mass production. Mercedes might, some day (since they bought YASA) but doesn't yet. Koenigsegg uses them, but every one of their cars ever built with an electric drive motor (Regera and Gemera) wouldn't add up to one day of production of an actual mass-production car.
And even if axial-flux motors were used, it still wouldn't be a third type; the YASA and whatever Koenigsegg is calling their variant of it are simply synchronous PM motors.
My professor of electrical engineering didn’t have the amazing analogies of this presenter. But he was able to explain ac theory in easy to understand ways. I never struggled with even the complex stuff (eg running alternators in parallel). He was that good.
Would love to hear where regen braking comes into this whole picture of motor design. When regen braking - what does the motor do and is it different between the 2 motor types?
Induction motors have a bit lower efficiency since you need energy to keep the rotor magnetised.
That would be interesting. I know the old teslas that have 2 induction motors actually has a small separate generator attached to the motor for regen. So the induction motor isn't used for regen at all.
From his explanation it is not clear to me how induction motors would create regen since if you don't pass current through the coils it will just spin freely not creating any current at all. But I don't know.
@@audunskilbrei8279 As long as the magnetic field in the stator is rotating at a different speed than the rotor the rotor remains magnetized. And with the rotor magnetized it will induct current into the stator coils. So you need to supply a low current in the stator to keep the rotor magnetized and then the rotor will strengthen the current in the stator coil via induction.
@@audunskilbrei8279if you short the motor it will work like a break, if you put a smaller /variable load on it that is how you do braking.
That stadion analogy is brilliant! I HAVE to steal that! Eddy Current says "Thank You!". 😁
My man Paul! Glad to see your talents and knowledge shared with the community, now everyone gets to sit at your desk and learn, just like I had the pleasure at GM! Thanks!
3:25 Yes! I would love to know why the magnets are arranged the way they are.
Munro tears down this PM motor about two years ago…so you can see how/why they arranged the magnets in this manner if you go back to watch that video.
@@bgbrandvold Thanks! Can you attach a link please?
What a great way to explain these concepts, thank you!
Glad it was helpful!
I vote to go deeper into inverter design and function in a future video. Besides having a deep understanding and expert level EE knowledge, you have tremendous instruction skills and a very pleasant voice❤
Paul reminds me of my Industrial Electronics instructor when I was in Technical High School many years ago.
Well done 💯.
You can tell this guy really understands the subject in depth. I've been wanting someone to properly explain induction vs PM motors for years. Finally someone does it in sufficient detail to be be useful amd in a way that makes sense. Thank you (and Munro for putting him 'on stage'). I look forward to more videos on inverters and regen (at least).
This is brilliant. My husband is a manufacturing engineer who makes electric motors. He’s explained motors to me so many times, but this is even better. Thanks. Well done.
Looking forward to this discussion by Munro when I discovered BMW went with non perm magnet motors because of their apprehension to supply chain concerns of permanent magnets.
It seems to me that if you have a dual motor platform (like bmw i4 m50 and others) , it makes sense to have permanent magnet in the rear and induction in the front. This way you can reduce power to zero on the front.
Excellent explanation, clear concepts and applications. Please have this person explain other parts of the EV.
What a brilliant teacher you are sir !!!!
Excellent explanation. Far clearer than my motor's class 40 years ago. Thanks!
Excellent tech talk that is super approachable and easy to understand. I would love to hear more about axial v radial and new combined designs as well as more about the invertors and rotor designs like carbon wrapped etc to keep things together at high speeds. A discussion on the transaxle gear reduction design and friction efficiencies between bearings and gears and fluids would be interesting too. Also some explanation on the benefits of field weakening and how that is accomplished and why/when would be great.
Excellent video and we want MORE! As for spin loss, for dual motor applications, some vendors would like to 'disconnect' one of the motors when going at constant speed on the highway to reduce energy use, so in that case, induction as one of the two motors is also an advantage.
Very Interesting. When the Model 3 was introduced in 2017, the "internet talk" described the rear permanent magnet motor as the efficiency motor. They described the front induction motor as the performance motor. There then began the discussion of why Tesla would put a stronger motor on the front, rather than the rear. The internet consensus was that because Tesla was also building just a single rear motor Model3, the efficiency motor would always be on the rear.
Nice tidbit. In return, on 27:50. He made a slight inaccuracy that computers decide when to use between PM and induction motors which is wrong. PM motors are always engaged or on (at least on a Tesla) while the induction motor is on-demand.
@@zodiacfml indeed, PM motors need to be engaged at all times since they generate back EMF which puts a strong disruptive load on the inverters. If one would design a system where you 'switch' between induction and PM motor you would need a clutch type or other means of decoupling the PM motor from the rotating components, adding complexity and cost. The minor disadvantages of the induction motor over a PM motor can be compensated by a 2 gear system giving higher torque at low rev and extending efficiency out to higher revs
Like most internet speculation, that was incorrect - the front (induction) motor of the Model 3 is not "stronger".
Yes, like all the deep dive, including inverters too. Always something great (small or big) to learn and to look for. I am also curious about yield strength calculation and yield strength monitoring during the years of usage of the carbon wrapping of Tesla rotor.
Fantastic analogies. Protec this man!
🙋♂️THANKS PAUL,AND THE MUNRO TEAM FOR SHARING THIS 🥶 AND INTERESTING 🧐💚💚💚
Paul made it so easy to understand. He's a keeper.
Good stuff Paul - thanks. You should next explain EESM (wound rotor). These motors are quickly gaining traction and can already be found in a few production EVs (Nissan Airya, BMW I7, Renault ZOE...). In 5 years, they will dominate Induction motors as the secondary motors in EVs. And in 10 years, after battery prices fall further and therefore motor efficiency becomes less important, they will dominate IPM motors as the primary motor in EVs.
interesting point but then there is also progress on none rare earth metal permanent magnets. I roughly heard that it uses iron as permanent magnet but requires a little of induction.
Thanks for explaining about efficiency tradeoffs at high speed.
Great video, can we please 🙏 get a video explaining the the winding pattern that goes through the stator slots, how the 3 windings overlap, and an explanation of the direction the current flows through the windings showing how the polarity changes??? Man that would be awesome!
Absolutely brilliant explanation. Best I have ever viewed. Thank you.
Thank you for watching!
I'm watching it during my lunch break. This is very educational. Thanks for sharing this.
Thanks for watching!
This was an absolutely brilliant free lesson. Thank you
very goood video, this was usefull, one of the best video ever..... not as cool, but very educational but not boring. Thank you very much!!!!
Thanks for watching!
I didn't realized that i tuned in for almost 30 minutes straight.
Things that was thought in college was meaningless to me until now.
Thanks munroe team for this effort.
One of the best Munro videos ever!
Thanks
Agreed
Really enjoyed this video. I've seen people talk about what motor type is in a certain EV but I never really knew why that was important. Love your content.
Excellent video, thank you! I've got lost a bit when you mentioned the torque curves. I thought it was the IPMSM motor the power of which has to drop due to field weakening trick that the controller has to start doing when the back-EMF reaches the voltage of the battery rails.
On the other hand, by controlling the induction motor's slip, it is possible to lower the induced current in its rotor and therefore its magnetic field and back-EMF as well. This also leads to a lower power (because of lower torque) but is not as lossy as when IPMSM must use electricity to fight with its own magnet's field.
Could you please explain it more deeply in the next video?
Yes, an interior permanent magnet synchronous machine (IPMSM) does require field weakening for operation at high speeds. The field weakening current increases the loss in the machine, but it only reduces the peak power by a few percent.
This is the best expalanation ever!
i understand the differece and working principle as pensioned a Marine Chief engineer but i could never fully explain it to others!
And as for my proffecional curiosity, could you do the regenerative braking efficiency differecy as well? As a generator?(Yes i know its the oposite but still im unable to explain it to myself and other people )
It would be great to have deep dive on inverter that drivers EV so quick and do regeneraton
Easily the best video from Munro ever. Informative, easy to understand and no talking down. Very well made.
Glad you liked it!
Thanks for a great talk on this subject, I really learned a lot. I really love it when a true expert like this guy talks about the science, and not how one manufacturer is clueless while another can do no wrong.
I love all of your videos. I have been designing 3 different types of true DC motors that are no phase, simple, easy to make, and cheap. They are more efficient, low heat production, no eddy current generation, no flipping magnetic fields,no need for electronic commutation. These motors are going to open the doors to new discoveries in electronic thrusters and different types of propulsion and types of transportation. I plan to take them to TESLA and SPACE X, when prototypes are completed and calibrated. Hopefully very soon.😊😊😊😊GOD BLESS. OUR FUTURE IS LOOKING GREAT FOR ALL OF US.
Thanks Paul. Excellent presentation.Your explanation that 'DC' motors are really AC when in operation is one I have been telling people myself but you are the first instructor I have heard make that point.
I had not heard the term "spin loss" as opposed to "cogging loss" applied to the PM motor's problem when unpowered. One question I had while watching was how my single motor Tesla maintains its good efficiency during coasting, if it does. I have wondered if Tesla applies a small synchronous drive field current to neutralize those spin losses as much as possible, if such a strategy could work to advantage. The display indication of whether my car is in regen or in drive mode seems to indicate no middle between the modes.
Yaa He didn't cover region, which would have been nice to hear what he thinks about. What happens between the motors in regen
I think he is wrong about DC motors. Every time a coil on the rotor is energized the brushes connecting to commutor bars create a field in that coil which repells the like poles and is attracted to the opposite poles in the stator causing it to rotate till the next coil is connected to do the same thing. The reason it will also work on AC is that both the stator and armature windings and changing polarity at the same time so the combined effect is the same.
@@MrGlenferdHe was talking about feeding with DC power. In order to let the rotor rotate in a static field in the stator, it needs a switch of current direction in the rotor. That is done by the commutator.
Love these educational videos!
More to come!
Fantastic masterclass in EV motors. I would really appreciate a video on how inverters and resolvers work. Thank you so much for all the good stuff you all at Munro put out there for us mechanics to re-learn powertrain technology as we put the ICE’s to rest.
It is RARE to see such an amazing teacher/tutor who presents the information in extremely clean/ simple /short / easy to understand way! BIG KUDOS!!!
I would love to see a tear down of the BMW brushed motor. They are seriously efficient. We have an i7 xDrive60 and I averaged 3.4mi/kWh in this 6000lbs beast the other day in a mix of heavy stop and go traffic and then a cruise on the highway at 80MPH for about 30 miles. Average lifetime consumption is 3.0mi/kWh on 20” wheels which is quite impressive for such a large and tall sedan that punches quite a big hole through the air considering most of the miles are done at high speed on the interstate and it’s such a huge car. Friend of mine with an i4 xDrive40 gets over 350 miles of range in summer around town and about 300 miles on the interstate.
It is NOT a brushed motor.
@@ABa-os6wm BMW is using (in some models) a synchronous motor with externally excited wound rotor, rather than permanent magnet; that means that it does have brushes and slip rings. It is not a "DC" motor, and does not have a commutator. Renault also uses this style of motor in at least some models, and now Nissan does as well (in the Ariya).
The brushes and slip rings carry only rotor excitation current (not the full motor power), so they are like the similar components in a typical automotive alternator, and will have similar long life.
@@brianb-p6586 all of their cars using their “5th generation e-drive motors” are using the brushed externally excited design. I’m really wanting to see a high mileage teardown. BMW claims the brushes last 180,000 miles or so. Would love to see how things look after 50,000 miles, 100,000 miles, 150,000 miles.
@@ABa-os6wm BMW has used externally-excited brushed motors in their 5th generation eDrive units instead of permanent magnet or induction motors. The brushes are supposed to last the life of the car (180,000 miles or so). The i4, i5, i7 and iX all use the motors, as does the iX3 and new China-only i3.
I'm an electronic engineer with experience in both VFDs and motors, and I love your video. Simply explained but very informative.
Great examples to show how different types of electric motors work. I certainly have a better understanding of the principles of electric motors after watching this video. It would be great to have a lesson on how DC to AC inverters work.
Yes! to making another video on various designs and tradeoffs of the internal magnet placement inside permanent magnet rotors.
Renault Zoe uses synchronous motor by having 4 winding inside the rotor and excitation circuit with carbon brushes.
So motor can turn off, can run much hotter than permanent magnet motor. It has low cost.
But downside is that brushes wear out.
Thank you. I got some of it to sink in. I'll have to watch this a few times but thank you so much and yes a bigger thanks to the builders of these awesome motors. I have both in my model S 85d
Great job explaining the difference between induction and permanent magnet motors!!
facinating....id love you to explain how an invertor works.... my Dad was a royal electrical mechanical engineer and you remind me of how he explained things
If I remember rightly, one of the limiting factors of the permanent magnet motors in the Model S Performance was the very small change in the geometry of the rotor at very high speeds, which caused it to stop working well enough to continue accelerating. This was solved with the carbon fiber wrapping of the rotors in the Plaid to maintain proper shape until even higher speeds.
I understand Porsche gets around this by having a two-speed transmission.
Yes! Magnet arrangements and how they influence motor performance would be nice to see!
I am an electrical engineering bachelor graduate I'm learing care more than what you learn the University it would be great if you keep explaining this topic
We are getting a lot here
Thank you for the great explains
And thanks for Sandy for bringing you here
Excellent teacher. I have watched many videos to try and understand these concepts, and this guy nailed it. Tesla Model 3/Y's use induction front and permanent magnet rear motors. Because the front induction can be idled with low loss, there is no mechanical axle decoupling required like on a Hyundai/Kia car that use magnet front and rear motors.
Just getting around to watching. To a mechanical engineer, like me, this guy is fantastic. Very informative. Thanks for sharing.
Great video and explanations by Paul!
Glad you liked it!
@@MunroLive I liked it too, usefull , not cool, not boring, not short , not long, to the point, one of the best video on this channel
Yes....Please do discuss magnetic field line angle choices, and inverters. Thank you....., thank Sandy , and thank the Munro Leadership team there for sharing knowledge. When my products need evaluation and validation I know who to call on as a way of giving back to Munro and Associates.
Excellent explanation about how these motors work and how they are different. I finally understand what “AC induction” is all about. Thank you!
Great content and delivery, Paul. Please continue and help us understand inverters.
Paul, I am tipping my hat for this performance - well received explanation and summary. Thanks a lot!
Fantastic video. Thank you for creating it.
Regarding the question, would we like further content created explaining more details, the answer is always yes please.
Beautifully explained specifically the pmm problem with idle moving, that thing even i didn't knew and i am an electrical engineer. Deep respect to u paul
I’ve watched many videos about motors and their differences and this was by far the best such video. I could really understand how the two motors worked and their advantages and disadvantages. Thank you.
Wow this is probably the most informational released by ya'll. Would love to hear about inverters as well!
Paul a truly educational episode! I appreciate EV motors and how they work with new insight, thank you for sharing your expertise!
OK, the merry-go-round explanation made me "click" and now I do REALLY understand how the electric motor works! Thank you!
This was a very good and simple to understand educational video that covered most aspects of motors. Great work
Thank YOU for making this very informative yet easy to follow presentation. Please cover all the subjects you mentioned and more!
Paul is just the best teacher I have ever seen. Brilliant
One of the best videos ever made on this topic. It reminds me days when I was in college studying for electrical engineering. Way to go ! Please continue the series of lectures it’s great
ANOTHER topic to consider: The robustness of contacters and how electronics prevent arching when the contacts open/close.
I agree, I always wondered if that was a wear item longterm.
Fast movement is the key thing.
No contactors in an EV should be opened while current is flowing or closed with a load connected, except in an emergency shutdown... and they only need to do that once.
I am an EE going into this discussion. I am glad I already understood these concepts as it didn't come out easily from this speaker. Yes, he did cover everything but you needed a certain amount of background to follow along and understand. It wasn't a bad job, but it would have left beginners confused. When abstract concepts like these need to be explained, dynamic graphical illustration tools would have been helpful, like for the moving magnetic fields. The wave in the sports stadium, although somewhat apt, it shows mostly one wave. and not several waves. For example it would be interesting to show the inverter delivering slowly moving fields first and then speeding them up and showing the effect on the rotor.
A deeper dive on inverters and motors would be fantastic. Plus where can they really be improved. Axial motors and how they can be used and improved would be great.
Yea a look into YASA Axial Flux motors and the likes of the EQXX would be great
I think it should be mentioned there's also a difference in regenerative braking. But otherwise a perfect presentation!
I would love to hear More about inverters. I'm a former nuclear submariner electronic field. The Highlander PS kindness is always free.😊
Love these technical videos. This is the second electric motor video I have watched and I will any more produced, whether on investors or regen braking, whatever.
Another amazing video, thank you very much and we will need the other videos mentioned! Again thanks for sharing all this knowledge.
Two thumbs up for Paul. I'd love his take on the latest motor controllers (inverters). I'm curious about all kinds of brushless motors used for "transportation". Use model airplane or RC car motors to demonstrate their configurations. I'm super curious about Koenigsegg's new electric motors.
I definitely want to see more of this guy with the other videos he mentioned
I think this is a very good explanation for those who don't have detailed knowledge the Highlander.😊
Love the arena wave analogy for RMF. Are their two more advantages to induction motors. One, In city and mountain driving the low "spin loss" allows the driver to take advantage of the kinetic energy of the car and avoid some of the inherent losses of regenning. Two, if each wheel of a car has its own asynchronies motor (no differential) all driven by a single inverter, would induction motors elegantly torque vector without an algorithm?
As an owner of a Dual Motor Model Y, this was an OUTSTANDING video!!! Thank you greatly!!