Field Oriented Control of Induction Motors

In this video I talk about field oriented control (FOC) of induction motors.
0:00: Intro
0:46: Video topics
0:55: How do induction motors work?
2:19: Open-loop Voltage over frequency control
3:50: Closed-loop Voltage over frequency control
5:15: Voltage over frequency VS Field oriented control
6:38: Field oriented control of induction motors
9:50: Maximum torque per ampere (MTPA)
There's a lot of material online explaining about FOC when talking about permanent magnet motors, but I barely found any intuitive explanations regarding FOC of induction motors.
This video aims to fill that hole.

[@6earth6]

It's like I see a summary of my senior year project back in the university 3 years ago. Back then we don't have clear explanation of this control method we only have to read though IEEE and textbooks to understand these things. Your video will be such a great help to fellows who wants to learn more about motor control methods.

[@adnaneakk1068]

im realy astonished on how much information i got from your video. i can tell that you have a Phd. -You explane very well from step A to Z -You compare and tell why method X is better than method Y -You update the information by actualy looking at whats new (what researchers have found) -in 12 minutes you saved me the time of maybe 12 hours or more ! Most importante thing is you SIMULATE what you SAY Thank you man i realy do appreciate the work you did.

[@adnaneakk1068]

and i have a simple question : why we call that 8:44 (26) equation as a filter ? what does it filter ?

[@matanpazi3777]

Thanks! I appreciate the kind words. I working on keeping the videos coming. I definitely don't have a PhD :), just a BSc majoring in control engineering and curiosity.

[@matanpazi3777]

Once you inject Id, the rotor's magnetic flux won't change immediately, it'll change based on the motor parameters, kind of like a 1st order low pass filter.

[@HoneyPotJnr.]

I would like to see more videos like this. As someone that works in the controls industry but is not a researcher its often difficult to find more accessible explinations for things. It would be great to see topics such as the effect of modulation depth or flat top modulation vs SVM. I've always found it impossible to find information on these topics without resorting to reading university papers.

[@matanpazi3777]

Thanks, same here, I also work in the controls industry. I'm planning to make a video about field weakening soon, I'll think about making one about different modulation techniques, thanks for the idea.

[@marisolvalencia2589]

very nice explanation

[@michawojcieszek1316]

really great helpful video, seeing more videos like this would be awesome

[@HoneyPotJnr.]

This is a great video, thanks.

[@Alireza-mf1lz]

Very informative and useful. Nice work. 👏 👏 👏

[@aboodsawalha3531]

Thank you for your efforts !

[@OrionFH]

Most important factor is rotor and stator winding temperature, these might be estimated well enough using a good thermal model. That improves accuracy dramatically, provided the thermal model is good

[@thedeathengineer]

Nice!

[@AlonSmil]

Woww thanks man 🙂🙂🙂

[@cesargrimm]

is it me or is the current in the squirrel cage moving in the wrong direction? at 1:49

[@fablearchitect7645]

There is also the issue of axis decoupling. The problem is that the d and q axis do not operate independent of each other. There are terms in each of the dq axis ODEs that cross corelate. This means that the d control loop will effect the q control loop and vice versa. One must use feedforward control to decouple these terms so that each control loop can act independent of each other.

[@nguyenthanh1485]

I have some questions: 1. How to align iD with rotor's magnetic flux (alpha axis) ? (With BLDC, PMSM I just simply let the Rotor return to Phase A by enabling HA = 1, HB = HC = 0) 2. At 8:45, (26) how to determine S ? Is this equation belong to laplace domain ? 3. Tr is sampling rate and Lm is inductance of 1 coil (from Line to N or Line to Line) , right ?

[@adnaneakk1068]

About your Second Question : if i understand correctly that was in laplace domaine so you need to inverse it to obtain => Ids * (Lm/tr) * exp(t/Tr)

[@robertpeters9438]

It would be interesting to see how to control a doubly fed AC motor for position and variable speed. I understand it is related to controlling phase and frequency of one or both feeds.

[@LamantinoElettronico]

Probably it would be very similar to controlling a pmsm, because if the machine is doubly fed it means there is a constant rotor field and so it is synchronous

[@srirammech100]

Can please you put video for foc Pmsm also ?

[@alquz3a92]

Great video, could you please put names and authors of the reference papers in the article

[@matanpazi3777]

Thanks. I mentioned the sources in the video itself in red text. In the future I'll simply add links to the sources in the description.

[@paulz8750]

He said at the beginning, he'd keep the equations to a minimum. 🤣 Not long after that, my brain went into overload, short circuited & blew a phase.