People are paying many $ bills to get a teaching from this dude. We up here getting arguably a better experience then the class room in some ways, for free(ish). Awesome time we live in.
Thank you Professor Kelly. You have made it possible for those of us in the developing world (I am in Ghana) to also learn and have an understanding of the new tech underneath the EV drivetrains. These videos are an absolute germ and it is my hope that we can all contribute to ensure its sustenance. Thank you once again.
Long video? Yes. But if you want to explain something right down to the details, time has to be taken. Thanks for another insightful and clearly explained bit of Tesla technique!
@WeberAuto I realize this video is a year old now and without checking all the comments, I don't know if someone already mentioned this but there are two different rotors for the LDU. The Base & Sport LDU's have different rotors. The Base rotor has less copper fill than the Sport rotor. The Sport rotor is completely full to the ends of the rotor. The Base rotor has a bit of a "bowl" where there's a void of copper. I think there's a lot of internet lore floating around that says both LDU motors "are the same" and that only the inverter is different but the rotors are definitely different. The LDU stators may or may not be the same. That's much harder to check since the stators are encapsulated.
I'm very impressed with the level of knowledge transfer, and honesty when he says details about things he doesn't know. I wish when I had go to school, I had more professors like this that were driven for a quest for knowledge and not their ego or reputation. He also understands, as shown in these videos, that he could know everything in the world, but if he doesn't share it, that knowledge is useless. In his case, he shares what he knows, and honestly wants people to help him learn even more where he may not know something in as far a depth as he would like.
Thank you (again!) professor for another illuminating session on the Tesla system. I know that there are many, many hours (days or weeks) of research and disassembly/re-assembly, editing and other real, unseen work that goes into your presentations. Thank you so much for these condensed, easy-to-understand tutorials on these very complex systems. Great nutrition for curious minds!
Been watching since the 2nd Gen Volt videos. Now with a CyberTruck pre-order I’m enjoying the detailed dives into Tesla’s tech. Thank you so much for producing these!
i can only imagine the hours that have gone in to clean all these parts. You are opening my eyes to the amazing engineering that goes into these cars. Who would know your front wheels are a different size than the back, I'm sure owners would just rotate the tires thinking them the same?
Professor John Kelly, I was once an Electronics Tech at Weber State College, working for Sid Jensen back in 1969 through 1973. I wish I am younger to attend your classes on line or in person. I am a life long techie and find your teaching as excellent. The circular lecture hall was brand new in 1969. I did a Google Map of Weber State University, showing Engineering Technology Centre with what seems tobe new construction of Engineering Tech buildings.
Phenomenal reverse engineering presentation on a variety of Tesla electric motors and gears. Thank you for creating these extremely informative technical video's.
Great videos. The high performance motors are induction machines to get around the problem of back EMF caused output power loss at higher speeds. Comes down to a tradeoff: Constant power over the full operational span at the cost of increased overall energy losses, or higher efficiency for decreased output power as speed increases? A magnet moving past a field creates a voltage proportional to the magnet strength and speed (back emf). A permanent magnet always has a strong magnetic field in the rotor. So, at some speed, the back emf exceeds the bus (battery) voltage and no more torque can be generated (flux weakening can help this, but eventually, no useful work can be done). But, because no rotor magnetization current is needed, PM based motors are much more efficient. None of the current in the motor is spent creating a magnetic field in the rotor. No rotor losses. For induction machines, the rotor acts as the secondary of a transformer. The current induced in the rotor (from the stator, primary) creates the rotor magnetic field that can then be used to create torque (via a process described as slip). This means the current in the rotor can be controlled. Because the current in the rotor can be controlled, the back emf can be controlled. Because the magnetic field in the rotor is controllable, constant mechanical power can be output until the variable frequency drive (VFD, converter) can no longer output higher frequencies. The penalty is rotor loses. Because there is current flowing in the rotor, induced by the stator, this power is lost in the form of rotor current (resistance of the rotor circuit). You have to pay, in terms of input electrical power, to create the rotor magnetization, therefore, less overall efficiency. But, constant mechanical power for the full operational frequency of the VFD. You can see this by spinning a motor by itself. A PM motor will generate a voltage as it freewheels, DMM between any two leads. (No current, because there's no circuit. Completing the circuit will make it a generator and the PM motor will act as a brake) An induction machine won't. (There will be a small residual voltage if it's an iron core, because of residual rotor margination, but not much) Applying a constant (DC) current to the windings of an induction machine (current limited power supply between one of the phase pairs, be sure to limit the power to something that won't damage the stator by too much heat), and spinning the rotor will make it feel like it turning thru peanut butter, the shaft will get stiffer as you try and spin it faster. Doing the same to a PM machine will make it 'cog' or make it unable to spin (by hand) at all. Be carefully at startup. It may turn very quickly with great force when current is first applied. If it's an IPM machine, there might be some cogging due to the motor saliency, e.g. the Nissan Leaf does this. I hope this was understandable and useful.
found this reply, very cool. was wondering if u know how induction motor can create regen. i just don't get how it can power the motor to induce field n receive current from motor at the same time...
Yes, your hypothesis was correct - the more efficient PM motor is used to supply most (all?) torque under certain conditions (e.g. highway cruising). Elon said this was how they are able to get increased range out of the AWD version of the S. It would be interesting to know more details on when this is done (I suspect it's not as often as possible, since the driven wheels affect the handling). Great series. Thanks for all the effort you put into these. I'd love to see more details about the power electronics (inverter) - maybe bring in an EE professor to go deep on the circuit-level design?
Model 3 perf ir mostly rear wheel driven in the winter (and thus unmistakably appears less stable on a slippery roads), model s vice-versa - feels primarily front wheel driven. In the wintery conditions ir is very obvious by vesicle behaviour. Thus your hypothesis that the more efficient motor is predominantly used in daily low performances scenarios agrees with winter driving observations. You are spot on.
Another great video from professor! Thank you! I live in Russia, where electric cars not considered a popular transport. But I try to understand this direction because this is the future of individual transport.
@@asherdie some days ago i'm played with engine analyzer software. And notice than thermal efficiency of classic internal combustion engine is about 36-38 percent. Electric vehicle has two time better efficiency. That's because it is future for city transport. Sorry for my english.
@@chenus6544 not everyone lives in the city. But the aristocracy has a plan to force us into cities. Where is your efficiency measured at? Just the vehicle? Are you figuring generation and transmission of power and it's losses, storage of power and it's inefficiencies, infrastructure environmental and monetary cost, mining for resources to fuel power generation, mining for raw materials for the manufactue of batteries and then the disposal of batteries? Internal combustion engine can be much more efficient but pollution controls hinder it. VW proved it to the world. Limited range and long recharge times make electric vehicles a reasonable choice for those who choose to live like rats in a city, but are a noose around the neck of those who dont.
thanks Prof. Kelly for your and team's work on this video and for sharing it. I am so amazed at the the 17,000 RPM operating speed of the motor. I suppose that is what you can do when nothing reciprocates! Your videos about Tesla vehicles specifically also make it abundantly clear why they generally cost so much: it takes so many precision parts and so much design work! 😅 Happy Easter too 🌄
As you drive down the road it puts the induction motor in 'torque sleep' mode (0 torque). It uses the PM motor only to drive the car. At some point in the application of the accelerator it starts using moth motors. I think torque sleep puts enough power to the induction motor so the output torque is 0 reducing drag and increasing efficiency.
@@justinmallaiz4549 I did not invent the term 'Torque Sleep' but read it in a Tesla document. I assume it has a purpose. Perhaps turning the motor ~9 times faster than the axles while the rotor is covered in oil creates/requires enough axle torque to require nulling out.
The use of induction motors as secondary motors has the advantage that they do not generate any voltage (and do not introduce any drag) when they are not used but driven from the wheels. The inverter simply does not feed any current or voltage to the stator in this case and thus introduces no energy losses.
Ive watched a lot of your videos to learn about EV tech. If it helps me get a job in the future then I will definitely come back to make a donation. This content is worth much more than Netflix or Disney.
Simply invaluable, as an ME that wanted to learn more about how these systems work, this level of quality and no BS is a Jahsend. Regarding HX, I would assume counterflow, so if you know the oil flow direction you know the coolant probably flows the other way
Prof. Kelly I didn't know that the electric parts of the motor are lubricated too, I always thought these motors are complete dry and I wondered how it's possible to cool them. Thank you for the great details you offer. Tesla uses only one permanent magnet motor, because if you have two of them, they give you resistance by being a generator, the iduction motor can run free without inducing any currents. So I guess, when the vehicle is cruising at constant speeds, it will just be powered by the high efficiency reluctant permanent magnet motor, while the induction motor is just idling. Greetings from Bavaria Germany, I bet you have german roots! ;)
I know that your time, painstaking effort and expertise is very much appreciated. This is so interesting and you present it so well - thank you Professor. I like the fact that, notwithstanding your great knowledge, this is also rather a journey of discovery for you - it accentuates your enthusiasm which is as infectious as it is genuine. May I wish you a very Merry Christmas.
Hi John When you have a spur gear, yes one tooth is engaged but if it is a helix gear it depend on the angle and often the angle is so great that more then one tooth is engaged. Makes it a lot stronger and a lot more silence but the downside is axial pressure. I am almost sure that all gear wheels are ground. In that way you avoid debris from hardening in the oil. About the motor, that is a long long text... anyway the short story is to increase the current you must increase the voltages however that can't just be done, you have to take the frequency in to consideration. Here we are talking about Volt/Hz relationship and for the induction motor you also have the slip between the stator and rotor to account for, that is normal done by IR Compensation. anyway now it is starting to be a long story. I highly appreciate your videos. 🙏🙏🙏
@@WeberAuto Well I have made hobbing machines for many yers. I just finished producing a 9 Ton spur gear muddle 22 for a prototype win turbine so gears and AM and PM motor including servo drive is my speciality and electronic as well. Anyway I am sure that you already know. It is difficult to create a long fine detailed video on a complex matter such as this, even though you look at the video through more than once, small mistake will occur. I am astound over the brilliant videos you make. Respect and 🙏
Heads up, my 2022 model long range Model S has two permanent magnet motors, which produce 670hp combined. The performance model s top speed is 200 mph, the long range Model S is 149mph. Thank you kindly for your videos.
Weber! Been up there for some auto competitions back in the day and met you YEARS ago. Glad you guys are still one of the top schools for auto tech out there. Keep killing it WSU!
Permanent magnet motors are very efficient when operated close to max torque, but not so much on partial loads. That happens because the rotor magnetic field can't be reduced at will. Induction motors are different, the rotor field can be reduced or augmented at will, modifying the slip frequency. That means at small loads, and induction motor correctly controlled can be more efficient than a PM one. Same applies to externally excited motors, like the Renault Zoe one.
Another amazing video Professor. Thank you for sharing with the world. I have the bluetooth dongle and ScanMyTesla app in my Model Y AWD. It shows that the front motor rarely gets used. Looking at the first log file that I could find it only used power starting at 30% accelerator. I had a Chevrolet Volt prior to the Tesla and during regen braking (in "low" gear as I usually drove) on icy roads the front tires would lose traction and cause some scary situations. After that experience I specifically wanted my next EV to be AWD to keep it from happening. Looking at the Tesla's log data it appears that it still only uses the rear motor for regen almost all of the time even though it has the ability to use the front for regen. The good news is that Tesla's software is smart enough to recognize when the regen is causing an unsafe situation and adjusts as I have never felt tires lose traction during regen braking. Tesla's regen braking on icy roads is more steady than the ABS when you need to use the mechanical brakes.
Excellent information! I just purchased the app and cable for our Model S. I look forward to gathering and sharing some data related to these motors. Thanks for watching
30:36 To heat cold batteries of not moving cars, the stators are powered with about 1-3 kW and are used as heat source when necessary. The stator heat will also heat up the lubrication fluids in the gear box.
This is only the case on Model 3 and Y, where Tesla puts DC current on the stator to use it as a heater. But also while driving (to a SuperCharger for preconditioning the battery) modulating some part DC current onto the AC current. The Model S and X have a seperate heating device, for heating the water by battery-DC.
John, you ARE the best! Yours is the only Channel I can't walk away from. You are so talented that someone is going to hire you away and that wiĺl be a sad day for the rest of us.
From the owner's manual of the 2020 Model S and Model 3 for the EU market, I can see that there are 4 versions of the PMa-SynRM: The first one is a 239 kW and 420 Nm motor with 350 V operating voltage, used in the single motor RWD Model 3 The second one is a 203 kW 330 Nm with 335 V operating voltage, used in the base dual motor AWD Model 3 The third one is a 219 kW 420 Nm with 320 V operating voltage, used in the Performance version of the Model 3 AWD The fourth and final one is a 205 kW 420 Nm with 320 V operating voltage, used in the entire Model S lineup from the base model to the Performance model (P100D)
Yes it's the back motor thats there for main propulsion. Once you floor it, both of the motors engage instantly. Wish there was an option to lock into awd for snowy/icy conditions.
And what is worse, their efficiency rolls off steeply at lower loads. A model S P85 uses 2.7kW going 32mph! Combined with the eddy currents going through the axle, they are the least suited type of motor for an EV. There is an alternative which is the line-start motor (LSPMSM) which still has a squirrel cage but also interior magnets, so it starts as an induction motor but runs as a syncronous PM motor at lower load. That way it preserves its peak torque but also has good low load efficieny, and it can still be driven by a simple VFD like an induction motor. I my opinion, when Tesla decided to scrap the 3 LR model with only one motor, they should instead have offered a version with a single LSPMSM motor instead!
@@Stefan_Dahn You did not understand what I wrote: The Octavalve has nothing to do with drive efficiency. However using a big induction motor, far too high power for an EV, results in piss poor efficiency at low loads. Even a model 3 with its PM motor, still only has 72% combined efficiency from the socket at 60 MPH (EPA). Had Tesla chosen smaller motors in their lineup, they would have made more efficient EVs! Tesla attracts the wrong kind of customers. They don't buy EVs to reduce their footprint, they simply don't care. Because then they would know that driving a Tesla in the US with its rather dirty grid emits as much CO2 as a compact car on diesel or gasoline! There exist EVs you can buy today that use around 160Wh/mi, half that of a any Tesla.
@weberauto - To answer your question on how the car utilizes power distribution to the motors; Teslas primarily use the rear motor until throttle % or motor load reaches a certain limit, then it powers up the front motor as well. We can see this in ScanMyTesla, or any other OBD scanning tool while driving and logging. Cruising speeds and light load is always isolated to the rear motor only. Hard acceleration or when traction control is activated on the rear axle, is when the front motors engage.
I know I'm late to the party. In my 2023 Model Y, the rear motor (permanent magnet reluctance motor) is used almost exclusively in every day driving. The front motor is only used for a few seconds when accelerating from a stop or when a lot of power is needed. Same for regen. Almost all of regen deceleration is done by the rear motor, whit the front motor helping out just a little for short moments. This behavior makes the car most efficient as it rear drive unit is more efficient. There is an exception. When the ambient temperature is close to or below freezing, both motors will be used almost all the time. This helps getting more equal torque on all 4 wheels which helps in slippery conditions. In my 2015 dual motor Model S, the front and rear motor were both the small induction motors. The rear motor was used exclusively at speeds up to 60 mph. At 60 mph the car then switched to the front motor for higher speeds. If you pay attention, you can actually feel the shift. Both motors were used when you accelerate hard. Again, when the temperatures were close to freezing, the car switch to using both motors equally (exact 50/50 split in power for front and rear motor). I"m not sure why Tesla decided to using only the back motor at lower speeds and the front motor for higher speeds in the old Model S.
38:20 I might be late to the party here: Tesla does use the rear and front motor differently depending on situation to improve range. Main parameters are: how heavy is your right foot when accelerating and travelling speed. Related material: ruclips.net/video/vvw6k4ppUZU/видео.html
Thank you for the informative video! I'm a bit surprised that Tesla would change the lubricant between revisions. I wonder if they were being cautious initially and decided that it wasn't necessary or whether they changed bearings in newer revisions that allowed them to go with a less expensive and lower quality lubricant.
Thank you. I wondered after shooting the video if the Dexron VI is for the 2019 and newer PM motor drive unit. Revision J is the one I am looking for now. Thanks for watching.
Fantastic and exciting to see this--thank you. I wonder if there is an attitude like a steep hill at which the motor's lubricant pump gets starved for oil; this would probably be helpful for owners to know so they could avoid motor damage.
People are paying many $ bills to get a teaching from this dude. We up here getting arguably a better experience then the class room in some ways, for free(ish). Awesome time we live in.
You can tell that the man loves teaching :
WOW, Professor Kelly is a wealth of information. He does an excellent job of explaining the inner workings of Teslas. Great job Professor.
This guy is the absolute best. I have watched his amazing videos and was able to pass my L3. Thank you so much!
That is awesome! Congratulations on passing your ASE L3 exam
@@WeberAuto thank you, i learned so much from you and cant thank you enough. You are an amazing teacher
@@user-ru2hf1sg4e Thank you
If all teachers in the school system had been as good as you at explaining, .... Thank you professor
Wow, thanks! Thanks for watching!
Was waiting for this one! You are an excellent teacher!
Thank you very much
Another excellent presentation.
Thank you, professor !
You are very welcome. Thanks for watching
Thank you Professor Kelly for your efforts to keep us informed! They are much appreciated!
Glad you like them!
Thank you Professor Kelly. You have made it possible for those of us in the developing world (I am in Ghana) to also learn and have an understanding of the new tech underneath the EV drivetrains. These videos are an absolute germ and it is my hope that we can all contribute to ensure its sustenance. Thank you once again.
Long video? Yes. But if you want to explain something right down to the details, time has to be taken.
Thanks for another insightful and clearly explained bit of Tesla technique!
Thank you very much
That time flew by, really. Definitely didn't feel like a 46 minute video at all.
This is the most comprehensive video about tesla motor! Thank you very much!
Thanks for watching!
@WeberAuto I realize this video is a year old now and without checking all the comments, I don't know if someone already mentioned this but there are two different rotors for the LDU. The Base & Sport LDU's have different rotors. The Base rotor has less copper fill than the Sport rotor. The Sport rotor is completely full to the ends of the rotor. The Base rotor has a bit of a "bowl" where there's a void of copper. I think there's a lot of internet lore floating around that says both LDU motors "are the same" and that only the inverter is different but the rotors are definitely different. The LDU stators may or may not be the same. That's much harder to check since the stators are encapsulated.
The best explanation of the Tesla motor set on Internet. Thank you
Wow, thanks!
I'm very impressed with the level of knowledge transfer, and honesty when he says details about things he doesn't know. I wish when I had go to school, I had more professors like this that were driven for a quest for knowledge and not their ego or reputation. He also understands, as shown in these videos, that he could know everything in the world, but if he doesn't share it, that knowledge is useless.
In his case, he shares what he knows, and honestly wants people to help him learn even more where he may not know something in as far a depth as he would like.
Thank you very much!
Thank you (again!) professor for another illuminating session on the Tesla system.
I know that there are many, many hours (days or weeks) of research and disassembly/re-assembly, editing and other real, unseen work that goes into your presentations.
Thank you so much for these condensed, easy-to-understand tutorials on these very complex systems.
Great nutrition for curious minds!
You are an excellent person who has the ability to explain complex concepts in a captive dialogue. Thank you. From Mal R
You are very welcome
Been watching since the 2nd Gen Volt videos. Now with a CyberTruck pre-order I’m enjoying the detailed dives into Tesla’s tech. Thank you so much for producing these!
Thanks for your long time support!
i can only imagine the hours that have gone in to clean all these parts. You are opening my eyes to the amazing engineering that goes into these cars. Who would know your front wheels are a different size than the back, I'm sure owners would just rotate the tires thinking them the same?
Thanks for watching
Excellent video. I love seeing these parts exposed.
Glad you enjoyed it, Thanks for watching
Professor John Kelly, I was once an Electronics Tech at Weber State College, working for Sid Jensen back in 1969 through 1973. I wish I am younger to attend your classes on line or in person. I am a life long techie and find your teaching as excellent. The circular lecture hall was brand new in 1969.
I did a Google Map of Weber State University, showing Engineering Technology Centre with what seems tobe new construction of Engineering Tech buildings.
Incredible content. I can't believe this is free. You sir, are an amazing instructor.
A man that can except his errors…is someone I will trust with the information given 😌
Phenomenal reverse engineering presentation on a variety of Tesla electric motors and gears. Thank you for creating these extremely informative technical video's.
Thank you very much
Great videos.
The high performance motors are induction machines to get around the problem of back EMF caused output power loss at higher speeds.
Comes down to a tradeoff:
Constant power over the full operational span at the cost of increased overall energy losses, or higher efficiency for decreased output power as speed increases?
A magnet moving past a field creates a voltage proportional to the magnet strength and speed (back emf). A permanent magnet always has a strong magnetic field in the rotor. So, at some speed, the back emf exceeds the bus (battery) voltage and no more torque can be generated (flux weakening can help this, but eventually, no useful work can be done). But, because no rotor magnetization current is needed, PM based motors are much more efficient. None of the current in the motor is spent creating a magnetic field in the rotor. No rotor losses.
For induction machines, the rotor acts as the secondary of a transformer. The current induced in the rotor (from the stator, primary) creates the rotor magnetic field that can then be used to create torque (via a process described as slip). This means the current in the rotor can be controlled. Because the current in the rotor can be controlled, the back emf can be controlled. Because the magnetic field in the rotor is controllable, constant mechanical power can be output until the variable frequency drive (VFD, converter) can no longer output higher frequencies. The penalty is rotor loses. Because there is current flowing in the rotor, induced by the stator, this power is lost in the form of rotor current (resistance of the rotor circuit). You have to pay, in terms of input electrical power, to create the rotor magnetization, therefore, less overall efficiency. But, constant mechanical power for the full operational frequency of the VFD.
You can see this by spinning a motor by itself. A PM motor will generate a voltage as it freewheels, DMM between any two leads. (No current, because there's no circuit. Completing the circuit will make it a generator and the PM motor will act as a brake)
An induction machine won't. (There will be a small residual voltage if it's an iron core, because of residual rotor margination, but not much)
Applying a constant (DC) current to the windings of an induction machine (current limited power supply between one of the phase pairs, be sure to limit the power to something that won't damage the stator by too much heat), and spinning the rotor will make it feel like it turning thru peanut butter, the shaft will get stiffer as you try and spin it faster.
Doing the same to a PM machine will make it 'cog' or make it unable to spin (by hand) at all. Be carefully at startup. It may turn very quickly with great force when current is first applied.
If it's an IPM machine, there might be some cogging due to the motor saliency, e.g. the Nissan Leaf does this.
I hope this was understandable and useful.
found this reply, very cool. was wondering if u know how induction motor can create regen. i just don't get how it can power the motor to induce field n receive current from motor at the same time...
Yes, your hypothesis was correct - the more efficient PM motor is used to supply most (all?) torque under certain conditions (e.g. highway cruising). Elon said this was how they are able to get increased range out of the AWD version of the S. It would be interesting to know more details on when this is done (I suspect it's not as often as possible, since the driven wheels affect the handling).
Great series. Thanks for all the effort you put into these. I'd love to see more details about the power electronics (inverter) - maybe bring in an EE professor to go deep on the circuit-level design?
Thank you and thanks for the suggestion
Most extra range is from putting more batteries in the car.
Model 3 perf ir mostly rear wheel driven in the winter (and thus unmistakably appears less stable on a slippery roads), model s vice-versa - feels primarily front wheel driven. In the wintery conditions ir is very obvious by vesicle behaviour. Thus your hypothesis that the more efficient motor is predominantly used in daily low performances scenarios agrees with winter driving observations. You are spot on.
Thanks for the great information
Thanks!
Thank you for your kind gift Udaya. I greatly appreciate it
These videos are amazing. The have so much information in them which you dont get normaly.
Glad you like them!
Another great video from professor! Thank you!
I live in Russia, where electric cars not considered a popular transport. But I try to understand this direction because this is the future of individual transport.
Thank you and best wishes
It is the future, because it being forced by the aristocracy and swallowed by dupes like you.
@@asherdie some days ago i'm played with engine analyzer software. And notice than thermal efficiency of classic internal combustion engine is about 36-38 percent.
Electric vehicle has two time better efficiency. That's because it is future for city transport.
Sorry for my english.
@@chenus6544 not everyone lives in the city.
But the aristocracy has a plan to force us into cities.
Where is your efficiency measured at? Just the vehicle?
Are you figuring generation and transmission of power and it's losses, storage of power and it's inefficiencies, infrastructure environmental and monetary cost, mining for resources to fuel power generation, mining for raw materials for the manufactue of batteries and then the disposal of batteries?
Internal combustion engine can be much more efficient but pollution controls hinder it. VW proved it to the world.
Limited range and long recharge times make electric vehicles a reasonable choice for those who choose to live like rats in a city, but are a noose around the neck of those who dont.
@@asherdie why don't you do us and yourself favor a keep these mental farts for yourself? Nobody in here is interested.
So glad I found your channel! Thanks prof. Kelly for yet another great video
You are so welcome!
my eyes are on a rav4 prime... but i still love learning about how teslas do what they do. thank you for sharing your knowledge!
thanks Prof. Kelly for your and team's work on this video and for sharing it.
I am so amazed at the the 17,000 RPM operating speed of the motor. I suppose that is what you can do when nothing reciprocates!
Your videos about Tesla vehicles specifically also make it abundantly clear why they generally cost so much: it takes so many precision parts and so much design work! 😅
Happy Easter too 🌄
Thank you, Happy Easter
Professor kelly, your tutorial is very well produced, it is excellent, thank you very much for sharing it, from Peru
My pleasure. Thanks for watching
Tak!
Thank you René!
Thank you sir for the video. I really admire your dedication.
So nice of you
As you drive down the road it puts the induction motor in 'torque sleep' mode (0 torque). It uses the PM motor only to drive the car. At some point in the application of the accelerator it starts using moth motors.
I think torque sleep puts enough power to the induction motor so the output torque is 0 reducing drag and increasing efficiency.
That is what I suspected, thanks for the information
I don't think induction motors have any rolling drag ( besides bearings) .. The permanent magnet motor obviously do
@@justinmallaiz4549 I did not invent the term 'Torque Sleep' but read it in a Tesla document. I assume it has a purpose. Perhaps turning the motor ~9 times faster than the axles while the rotor is covered in oil creates/requires enough axle torque to require nulling out.
The use of induction motors as secondary motors has the advantage that they do not generate any voltage (and do not introduce any drag) when they are not used but driven from the wheels. The inverter simply does not feed any current or voltage to the stator in this case and thus introduces no energy losses.
Ive watched a lot of your videos to learn about EV tech. If it helps me get a job in the future then I will definitely come back to make a donation. This content is worth much more than Netflix or Disney.
Thanks for your great effort and making this material publicly available! Excellent! Top marks, it i may! 😀
Thank you
I thought those vehicle motors were much bigger.
259 hp on that little motor is amazing!
They are amazing! Thanks for watching
I find these videos fascinating! Thank You
Thanks for watching!
So glad you are doing these videos! Top notch quality. Are you still doing the one week class?
Yes I am. We have four more scheduled this year. See www.weber.edu/evtraining for the schedule
@@WeberAuto great! Thank you!
Really good explanation of how the system is working thank you man for transfering tour knowledge
Excellent presentation professor
Glad you liked it!
Simply invaluable, as an ME that wanted to learn more about how these systems work, this level of quality and no BS is a Jahsend. Regarding HX, I would assume counterflow, so if you know the oil flow direction you know the coolant probably flows the other way
Thank you. Good point!
Prof. Kelly I didn't know that the electric parts of the motor are lubricated too, I always thought these motors are complete dry and I wondered how it's possible to cool them.
Thank you for the great details you offer.
Tesla uses only one permanent magnet motor, because if you have two of them, they give you resistance by being a generator, the iduction motor can run free without inducing any currents. So I guess, when the vehicle is cruising at constant speeds, it will just be powered by the high efficiency reluctant permanent magnet motor, while the induction motor is just idling.
Greetings from Bavaria Germany, I bet you have german roots! ;)
Thank you and thanks for the great information. I suspected that was the situation.
You can use two PM motors. Other AWD production EVs use PM for both axles.
I know that your time, painstaking effort and expertise is very much appreciated. This is so interesting and you present it so well - thank you Professor. I like the fact that, notwithstanding your great knowledge, this is also rather a journey of discovery for you - it accentuates your enthusiasm which is as infectious as it is genuine. May I wish you a very Merry Christmas.
Wow this was so good, learnt a lot huge Tesla fan and they have some amazing tech chemistry going on in their motors.
Thanks for watching
Hi John
When you have a spur gear, yes one tooth is engaged but if it is a helix gear it depend on the angle and often the angle is so great that more then one tooth is engaged. Makes it a lot stronger and a lot more silence but the downside is axial pressure. I am almost sure that all gear wheels are ground. In that way you avoid debris from hardening in the oil.
About the motor, that is a long long text... anyway the short story is to increase the current you must increase the voltages however that can't just be done, you have to take the frequency in to consideration. Here we are talking about Volt/Hz relationship and for the induction motor you also have the slip between the stator and rotor to account for, that is normal done by IR Compensation. anyway now it is starting to be a long story. I highly appreciate your videos. 🙏🙏🙏
Thanks for the information. I was wrong about the gear tooth on the helical gears.
@@WeberAuto Well I have made hobbing machines for many yers. I just finished producing a 9 Ton spur gear muddle 22 for a prototype win turbine so gears and AM and PM motor including servo drive is my speciality and electronic as well.
Anyway I am sure that you already know. It is difficult to create a long fine detailed video on a complex matter such as this, even though you look at the video through more than once, small mistake will occur.
I am astound over the brilliant videos you make. Respect and 🙏
@@A2an Thank you very much
Very Educational....Keep up the Good Work.
Thanks, will do!
Thank you sir
Even with some mistake you still the greatest
Stay safe
Thanks 👍
My covid quarantine now consist only by eating, smoking weed and watching your fantastic videos. I was waiting for this one
I am happy the videos are helping you through the quarantine! Thanks for watching
Thanks for another great video. It's nice to get reliable, well researched information. Thanks for sharing.
Thanks for watching!
Woo, another amazing video! Thanks a lot Professor Kelly! Your explanation makes the complicated stuff easy to understand!
Excellent Professor John -hope to join you soon in person
謝謝！
Thank you Chin-Jen! I am very appreciative of your support
Heads up, my 2022 model long range Model S has two permanent magnet motors, which produce 670hp combined. The performance model s top speed is 200 mph, the long range Model S is 149mph. Thank you kindly for your videos.
Easter 🐣 is early this year. Thank you for another great video professor :)
So nice of you, Thanks for watching
Weber! Been up there for some auto competitions back in the day and met you YEARS ago. Glad you guys are still one of the top schools for auto tech out there.
Keep killing it WSU!
Awesome! Thank you very much
I’m drooling, great detail, clear delivery and hella good vid!
Thanks for watching
I learn more from these videos than from my university's laboratory modules
Permanent magnet motors are very efficient when operated close to max torque, but not so much on partial loads. That happens because the rotor magnetic field can't be reduced at will.
Induction motors are different, the rotor field can be reduced or augmented at will, modifying the slip frequency. That means at small loads, and induction motor correctly controlled can be more efficient than a PM one.
Same applies to externally excited motors, like the Renault Zoe one.
Great information, thank you!
Thank you sir for fine instruction. Truly enjoyable presentation.
You are very welcome
Another amazing video Professor. Thank you for sharing with the world.
I have the bluetooth dongle and ScanMyTesla app in my Model Y AWD. It shows that the front motor rarely gets used. Looking at the first log file that I could find it only used power starting at 30% accelerator.
I had a Chevrolet Volt prior to the Tesla and during regen braking (in "low" gear as I usually drove) on icy roads the front tires would lose traction and cause some scary situations. After that experience I specifically wanted my next EV to be AWD to keep it from happening. Looking at the Tesla's log data it appears that it still only uses the rear motor for regen almost all of the time even though it has the ability to use the front for regen. The good news is that Tesla's software is smart enough to recognize when the regen is causing an unsafe situation and adjusts as I have never felt tires lose traction during regen braking. Tesla's regen braking on icy roads is more steady than the ABS when you need to use the mechanical brakes.
Excellent information! I just purchased the app and cable for our Model S. I look forward to gathering and sharing some data related to these motors. Thanks for watching
30:36 To heat cold batteries of not moving cars, the stators are powered with about 1-3 kW and are used as heat source when necessary. The stator heat will also heat up the lubrication fluids in the gear box.
Great information, thank you
This is only the case on Model 3 and Y, where Tesla puts DC current on the stator to use it as a heater. But also while driving (to a SuperCharger for preconditioning the battery) modulating some part DC current onto the AC current. The Model S and X have a seperate heating device, for heating the water by battery-DC.
Great information from a great teacher
Thanks for watching
I would love to see you do a tear down with the new model 3, with the octo valve and heat pump. Great videos.
Coming soon! Thanks for watching
John, you ARE the best! Yours is the only Channel I can't walk away from. You are so talented that someone is going to hire you away and that wiĺl be a sad day for the rest of us.
Thank you very much
Love your videos! I believe Tesla does impose a rear biased at low speeds and then transition to a front biased at higher speeds for efficiently.
Thank you and thanks for the info!
Very informative and detailed video. Thank you for sharing it Prof. Kelly.
You are so welcome!
Thank you for making these excellent videos.
Thank you
Superb video! I suggest Tesla Inverter assembly video because its shape is unique than other ev vehicles.
Great suggestion! Thanks for watching
From the owner's manual of the 2020 Model S and Model 3 for the EU market, I can see that there are 4 versions of the PMa-SynRM:
The first one is a 239 kW and 420 Nm motor with 350 V operating voltage, used in the single motor RWD Model 3
The second one is a 203 kW 330 Nm with 335 V operating voltage, used in the base dual motor AWD Model 3
The third one is a 219 kW 420 Nm with 320 V operating voltage, used in the Performance version of the Model 3 AWD
The fourth and final one is a 205 kW 420 Nm with 320 V operating voltage, used in the entire Model S lineup from the base model to the Performance model (P100D)
Great information! Thanks for watching
@@WeberAuto thank you too for this video, you always bring great content!
Long video, but vveeerrryyy satisfying!
It would be sweet if that was the model s in the background...😊 (thanks for sharing John!)
Yes it's the back motor thats there for main propulsion. Once you floor it, both of the motors engage instantly. Wish there was an option to lock into awd for snowy/icy conditions.
Great information, thank you
U R the best!! tanks from Argentina
Thanks for watching
Brilliant and thanks (Mike from Australia)
Thank you!
Another Great video
I appreciate that
Hi - great video. I have same size tires on front and back on my winther 19". Summer is 21" with different sizes as you mention. All original.
Thank you for sharing knowledge captain!
Tesla rules the world now, thanks for putting this video together i learned alot, cheers
Thanks for watching
Thanks a lot for your explanations this is really handly
You are welcome!
Thank you for this well done video! Makes me appreciate my P85D more 😅
Nice to see you again sir thank you very much for the after long time thank you for the The video is rich in information god bless you always 🇴🇲
So nice of you
easy understanding introduction
Thanks for watching
As always great video, good explanation, thank you very much!
Thanks for watching
Very interesting video ( as your videos generally are). Thank you!
Glad you like them! Thanks for watching
Thank you for this awesome informative video.
Glad you enjoyed it!
I suspect you are correct about the perm motors in the Tesla cars.Great series :)
Thank you and Thanks for watching
Hello from Ukraine. Great videos! Very interesting to listen
Hello there! Thanks for watching.
Have you already done the Model 3 front/rear motors? I looked, but couldn't find videos on those. Can't wait for them!!!!
Coming soon!
@@WeberAuto Can't wait! Videos should be a hit. There are way more of those cars out there with curious owners.
The "SynRM" synchronous reluctance motor is the magnetically better design.
Induction motors have magnetic slip, and generate large heat.
Thanks for the information!
And what is worse, their efficiency rolls off steeply at lower loads. A model S P85 uses 2.7kW going 32mph! Combined with the eddy currents going through the axle, they are the least suited type of motor for an EV. There is an alternative which is the line-start motor (LSPMSM) which still has a squirrel cage but also interior magnets, so it starts as an induction motor but runs as a syncronous PM motor at lower load. That way it preserves its peak torque but also has good low load efficieny, and it can still be driven by a simple VFD like an induction motor. I my opinion, when Tesla decided to scrap the 3 LR model with only one motor, they should instead have offered a version with a single LSPMSM motor instead!
@@Tore_Lund Well, the MiC Model 3 has now a 60 kWh LFP battery and has a huge range and is extremly efficient with it's octovalve.
@@Stefan_Dahn You did not understand what I wrote: The Octavalve has nothing to do with drive efficiency. However using a big induction motor, far too high power for an EV, results in piss poor efficiency at low loads. Even a model 3 with its PM motor, still only has 72% combined efficiency from the socket at 60 MPH (EPA). Had Tesla chosen smaller motors in their lineup, they would have made more efficient EVs! Tesla attracts the wrong kind of customers. They don't buy EVs to reduce their footprint, they simply don't care. Because then they would know that driving a Tesla in the US with its rather dirty grid emits as much CO2 as a compact car on diesel or gasoline! There exist EVs you can buy today that use around 160Wh/mi, half that of a any Tesla.
@weberauto - To answer your question on how the car utilizes power distribution to the motors; Teslas primarily use the rear motor until throttle % or motor load reaches a certain limit, then it powers up the front motor as well. We can see this in ScanMyTesla, or any other OBD scanning tool while driving and logging. Cruising speeds and light load is always isolated to the rear motor only. Hard acceleration or when traction control is activated on the rear axle, is when the front motors engage.
Great information, thank you!
Hello Professor. thank you for your efforts and great videos!!!
I know I'm late to the party. In my 2023 Model Y, the rear motor (permanent magnet reluctance motor) is used almost exclusively in every day driving. The front motor is only used for a few seconds when accelerating from a stop or when a lot of power is needed. Same for regen. Almost all of regen deceleration is done by the rear motor, whit the front motor helping out just a little for short moments. This behavior makes the car most efficient as it rear drive unit is more efficient. There is an exception. When the ambient temperature is close to or below freezing, both motors will be used almost all the time. This helps getting more equal torque on all 4 wheels which helps in slippery conditions.
In my 2015 dual motor Model S, the front and rear motor were both the small induction motors. The rear motor was used exclusively at speeds up to 60 mph. At 60 mph the car then switched to the front motor for higher speeds. If you pay attention, you can actually feel the shift. Both motors were used when you accelerate hard. Again, when the temperatures were close to freezing, the car switch to using both motors equally (exact 50/50 split in power for front and rear motor).
I"m not sure why Tesla decided to using only the back motor at lower speeds and the front motor for higher speeds in the old Model S.
AMAZING VIDEO AS ALWAYS... GREAT JOB PROFFESOR... THANK YOU SO MUCH ☝️🤓🤓🤓🤓🤓🤓🤩🤩
Thank you very much
38:20 I might be late to the party here: Tesla does use the rear and front motor differently depending on situation to improve range. Main parameters are: how heavy is your right foot when accelerating and travelling speed. Related material: ruclips.net/video/vvw6k4ppUZU/видео.html
Thank you for the informative video! I'm a bit surprised that Tesla would change the lubricant between revisions. I wonder if they were being cautious initially and decided that it wasn't necessary or whether they changed bearings in newer revisions that allowed them to go with a less expensive and lower quality lubricant.
Thank you. I wondered after shooting the video if the Dexron VI is for the 2019 and newer PM motor drive unit. Revision J is the one I am looking for now. Thanks for watching.
Fantastic and exciting to see this--thank you. I wonder if there is an attitude like a steep hill at which the motor's lubricant pump gets starved for oil; this would probably be helpful for owners to know so they could avoid motor damage.
Regards from Athens Greece...
Thanks for watching
PM motors are used always to propel the car. IM motors usually coast. Bjorn nyland (teslabjorn) had videos about this subject.
Thanks for the info!