Thank you! Not gonna lie, read the first sentence and totally thought it was going to be a burn haha

Thanks so much! So all my “drawing” is done in affinity photo and affinity design. The animation/movement is Apple motion, then its cut together in Final Cut Pro. I know you didn’t ask, but I’m case others wanted to know, all audio is edited in Logic Pro. You could do this just as easily if not easier in the adobe suite, it’s just a subscription service which I, as a grad student, don’t want to pay

While I can’t speak for all generators, my understanding (and I will do some more research to better inform myself) is that most are essentially motors being back driven. I have (I think) episode 15 outlines to be all about regeneration and how it works

Yes, several actually. Generally SVM doesn’t use halls, you either use an encoder with much higher resolution than halls (if you are doing some sort of feed back torque control), or you can run it in feed forward or using back emf as your angle estimation (obviously this requires slightly higher speeds)

Hi, thank you for your feedback, i will try to reply to each of your points. The notation i used here to define current as a vector is the method used when moving into the Clarke and Parke transforms which will be covered in a later episode. I agree that from a 3 dimensional perspective, it isnt "accurate" to the way current runs. However, this way of thinking about it and representing it will be useful when we start talking about those transforms in episode 9. I understand that thats not a winding diagram in the traditional sense, i just colloquially refer to a wye circuit that way in the context of clarke parke analysis. Thats why i put the disclaimer in there about how thats what i call it. I use resistors in the diagram just so that it looks like a standard wye illustration, so as not to confuse someone if they look up a wye circuit. I understand that the phases are not pure resistors, but they do have resistance, and that resistance is key to describing the current through the system. Note im not saying that inductance isnt. Again, the reason i define the current/magnetic field set up like this is because once you get into the d-q transformation, its super useful. This way you can intuitively think about angling your current direction along the quadrature direction such that your magnetic field points along the direct axis. In the same way, you can think of angling your current along the direct axis if you want to weaken your field, because then it aligns your induced field with that of your rotor (in the quadrature direction). I hope this adresses your concerns. As far as where i learned this stuff, and my credentials, formal education on it includes several grad classes and text books (which isnt to say that i have a completely perfect grasp on it and dismiss your concerns, i just dont want you to think that i am pulling this out of a hat). Additionally, the TI video series "teaching motors new tricks" was influential to these particular representations you have issue with. I am a Mech E by training, so i apologize if my notation isnt standard for other backgrounds. I will try to adress any other concerns you have as well.

There are no mistakes in the content. I am not sure if you are serious or just trying to be a troll, but I will try to address the two "issues" you are complaining about:: (1) You don't like that the author omitted the inductance and back-emf elements in the schematic representation. Well, it is a schematic! It is supposed to be a simplified model that can be used to demonstrate some interesting effects. It is visually easier to understand. In other videos, the author expands the electrical diagram for each phase and shows the inductance and back-emf elements when talking about the electrical dynamics. (2) You don't like how the current vector is defined (note, there was no "current vector" at 6:09). Honestly, it could have been defined in absolutely any way. As long as you are consistent and there is 120 deg from phase to phase, it really doesn't matter. Making it 90 deg out of phase with the magnetic field gives it more familiarity because it matches the right hand rule. It seems you are just annoyed that it doesn't match your textbook. On that note, THIS IS A UKposts VIDEO, not a textbook. This kind of content is exactly what electrical engineers need to motivate and get more young talent into the field. I remember when I was in college that there was a stereotype of EE students being weird no-life no-friends hermits. Your unnecessarily pedantic and abrasive comment does not help at all. You should be happy that this type of content is coming out in an accessible way, not be scoffing or making snarky comments about how the phases are not resistors.

​@@LeoVailati "There are no mistakes, just happy accidents." 1. Why exactly would I be upset about the omittment of inductance and back-EMF? They are not directly relevant for this issue and the critique was not directed at the lack of them. It is only your assumption, which was wrong. 2. Did you even watch the video? At 6:09 The current entering the phase is signified with a yellow arrow pointing at the side of a winding. At 7:50, the same yellow arrow is used accompanied with the sentence "At all times, the current in the motor will produce a magnetic field vector, which is 90 degrees counter-clockwise of the current vector". The yellow arrow (current) is 90 degrees counter-clockwise from the blue arrow (flux). The yellow arrow at 6:09 is obviously a current vector, even if it is not mentioned as such at that point. Do you disagree? More familiarity? I have never seen this definition used in ANY place. My "textbook" (experience + research) on this matter matches with the vast majority of industry and academia, which is not a surprise because this is pretty fundamental stuff. If anything, this would confuse the same students even more when they realize that the vast majority of the industry are actually treating the current vector as a collinear flux-producing vector. "It matches with the right-hand-rule?" Which right-hand-rule? The orthogonal one? In which situation would a coplanar current in a coplanar flux produce a non-zero coplanar force? Are the vectors in (7:55) coplanar or not? If youtube videos were as accurate as the best textbooks, we would need less textbooks. The video, for the most part, is decent. Just keep facts as facts and don't call a cat a goose just because someone might be allergic to cats. It is not useful.

​@@jtlee1108 Thanks for the reply. You do not need to shift the flux by 90 degrees to make the coordinate transformations work. I suspect that you intend to keep the age-old "dc motor" geometry and that you would define the torque-producing current to be at the d-axis so that you would have a "classic DC motor" at all times and the "current of interest" would be the one at the d-axis. The classic DC motor is incredibly useful as a conceptual tool and you even have the equivalence at 6:22. Defining the current vector to be collinear to the magnetic axis has the following benefits. 1. You have one less thing to remember (was the magnetic field now counter-clockwise or clockwise and was the current into the paper or out of the paper) because you only need to remember the curling right-hand rule defining the magnetic axis 2. The approach would not only would work with this classic DC motor model, but also modern ones with the teeth. You would still get to enjoy the simplicity from the DC motor model for these demonstrations, but use the actual terminology and control concepts. 3. Slightly related to 2, but the collinear magnetic axis also explains reluctance better. Actually, explaining how motors work by the reluctance and magnets has been incredibly successful even among complete novices. Even my 5-year old nephew can explain how vector control works (yup.. been there) because of that. Explaining the orthogonal right-hand rule, while mechanically simple, is not at all intuitive. Do you know WHY exactly the orthogonal right-hand rule works? Explain that to a 5-year old. That stuff flies over the head. When I google the "wye connection", the first few rows are actually ones with inductors and one with general impedance. Is that just me? Nope. In the context of motors, calling the windings as resistors is just bad, no way around that, sorry. External resistors actually were used (maybe in some places still) with motors for control purposes and they were far from optimal. You call a cat a goose and I simply called you on it. No excuses, no further discussion, now you know. Alright, this became very interesting, and possibly solved the mystery. Your stator current produces a flux at 90 degrees to the current, yet you still use id for field weakening? *And if I understand correctly, here your rotor magnets are aligned along the q-axis?* As a great source of confusion, that last line is probably the source of the issues. You see, at least what I have encountered, for the common PMSM, the rotor flux direction is the d-axis. In synchronous reluctance motors without magnets, the excited rotor part that behaves like a magnet is still at the d-axis. Some motors, typically with both reluctance and alignment torque instead have the magnets pointing to the q-axis. The motor still overall behaves more or less like a synchronous reluctance machine with the magnets assisting torque production. Defining the q-axis as the rotor flux axis is something that I sometimes see in some papers, but that is incredibly rare. I have used TI C2000 chips for several motor control projects and have always used the rotor flux as the d-axis direction. The programs would not have worked if the rotor flux was defined as the q-axis. Even from the TI video series, see ukposts.info/have/v-deo/jnlopJqCqZmZrmQ.html#t=24m35s, you will see that that the rotor magnetic axis is the d-axis. If I were you, I would consider your choice of rotor flux definition very carefully along with the stator current vector definition in relation to the magnetic axis.

​@@corruptedflakes I apologize, I re-read your previous comment and saw that you had mentioned using inductors in place of the resistors, not adding inductors and back-emf. Your point is fair, but I don't agree that it is a "mistake" to use resistors. Again, it is just a schematic, and the author makes it very clear that it is actually a winding. I will insist that the yellow arrows at 6:09 are not meant to represent vectors. Notice the crooked yellow arrow on the motor on the right, it wouldn't make any sense for that to be the current vector. The arrows just indicate that there is current flowing. The author chose to use the diagram on the left as a basis for the electric schematic and coordinate system, which makes magnetic field and current be 90 degrees out of phase because the windings are wrapped around the motor (as more explicitly shown in previous videos). That is why I mentioned the right hand curl rule. Everything is very well explained and builds up nicely, I disagree that it will cause confusion. In fact, what you are saying would be the case if the author had chosen to use the motor on the right (at 6:09) as a basis for the coordinate system. I agree that the motor on the right is more common in practice, but the motor on the left was the one built up from first principles in the previous videos.