Basics of PWM Converters Controller Design.Part II. Phase compensation
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- Опубліковано 23 сер 2024
- An intuitive explanation of the basic concepts and theory of PWM converters controller design. This is a second part of a three parts lecture. Please watch first part first at:
• Basics of PWM Convert...
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Dear Professor,
Sincere gratitude for sharing this valueable knowledge. I work as a control engineer for Xray high voltage generator. The control systems these days are mostly implemented digitally, but have been derived from analog electronics like this. These days, not a single digital engineer learns the analog equivalent in detail and blindly simulates in MATLAB. I hope more digital engineers learn and pass on the knowledge of analog equivalent to understand the subject properly.
Again, sincere thanks for the work you are doing. My best wishes 🙏
Thank for the comment and sharing.
Thanks for the lesson. You're the only person on youtube I have to watch in slow motion!
👍😊
Express gratefulness and appreciation to Prof. Ben-Yakov for these excellent videos that are explained very nicely.
Thanks
Dear Professor, I love your lectures, my great appreciation.
😊🙏
These videos are really a gem - Thank you VERY much for sharing. Your presentations are so effective - great information and complete.
Thanks. Comments like yours keep me going.
Excellent explanation. Very helpful to intuitively understand the concepts. Thank you
Very nice lectures on the topic of loop stability - thanks for making them available!
😊
Sir thanks a lot for your highly intuitive lecture. it has helped me a lot to understand the complex control system without so many complex equations. once again hats off to you
Thanks for the comment.
I have found an answer to the first question in your RHPZ lecture. Thanks!
👍
Excellent. That is great. Thank you professor
👍😊🙏
Thanks professor for the very helpful lectures.
Thanks
Fantastic lecture, thank you.
Thanks
Thank you for the thorough explanation...
😊
Dear Prof. Ben-Yaakov, regarding slide 32, you talked about cutting the plant transfer function with the curve denoted as (3) and mentioned that this would result in a very narrow control bandwidth. Is this due to the fact that the integral gain cannot be chosen too large, because of for example limit cycling (I believe one no-limit cycling condition for digital controllers was that this gain be between 0 and 1)? Also, what would be your strategy when controlling a buck converter with two output LC filter stages? Would you try to cut the plant transfer function between the two pole locations (resonance peaks) of the transfer function?
Many thanks for all the valuable lectures!
The cross over frequency determines the closed loop BW. Or I did not understand your question?
Sir thank you for the explanation, I did have one question though. After designing the 1/B curve how are we supposed to convert that into circuit form using op amps (basically how should one start off the op amp circuit design just by seeing the gain plot)
Isn't it explained at ua-cam.com/video/yJucyH3WOvU/v-deo.html and on?
Thank you Prof. Ben-Yaakov. Excellent video once more. Could you do a video explaining the inner current loop and outer voltage loop control? I would like it for EV fast charging station connection to the grid studies and I am not quite understanding how to bring everything together from all the resources I have gone through.
Thanks for the comment. I am planning a current feedback control video that will cover inner and outer loop.
Thank you so much sir. I will be eagerly awaiting it.
Also could you give us an example of how to implement dq0 (although this is power systems) to represent the grid and finally connect this with a converter? This part is currently challenging for me to implement.
Is there any video talking about closed loop controller design of Sinusoidal PWM three phase inverter ?
See if these are of help
ua-cam.com/video/7J6EdhPMDoI/v-deo.html
ua-cam.com/video/io5f-kcd0mU/v-deo.html
@@sambenyaakov thanks you Sir
Thank you Professor
Thanks for input
Thank you!
😊
Dear Prof. could you please make a video explaining how to compensate constant on-time (only with comparator and ripple generator) PWM controller .
Will try
Sir, it's a great lecture thank you very much for your efforts, but I have some questions that i don't clearly understand it.
1- How the Gain of open-loop transfer function for buck converter can be greater than 0 dB (amplification) and buck circuit can only attenuate voltage?
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2- Can we use PID Controller instead of Lead-Lag compensator, and if Yes, what will be the difference in results?
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3- Why we work on small signal and not the total signal. I think the average value also important for analysis ?
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4- Why don't we just put another op amp with gain = 1, for inverting the signal 180 degree phase shift instead using complex technique in phase compensation?
Would you please post these questions at
www.linkedin.com/groups/13606756
so members can benefit from answers by me and others
You will need to register if not a member.
שלום,
ממש תודה על ההרצאות המועילות.
I want to ask two questions:
1. I have built a current mode boost DCDC model according to your lectures. Now I am trying to add a compensator. I see the loop gain as it should be a 1st order system then adding compensator with the right gain at the desired frequency. All look fine from the magnitude aspect but I am ending with 9 degrees PM. (The breaking point of the compensator is at 60KHz and the 0dB point is 300KHz. the compensator is totally flat when crossing the converter response.) What can be the reason?
2. The type of the compensator you are showing here "consumes" current from the feedback network. Do you have another lecture showing high impendence compensator type?
Thanks a lot,
(דרך אגב יש אימייל או טלפון בו אפשר לשאול שאלות?)
Send me more detailed information. Ican not follow the questions. You can conta t me at sby@bgu.ac.il
sir, Could I use a dc motor instead of just a resistive load?BTW one more thing is before designing compensator, we surely have to know the transfer function of the existed system right?accordingly, we need to compensate the system.
And the other doubt was, is it by default we have to use lag-lead compensation network to rectify the stability?or we can also go for other compensation networks like lead or lag?Sir,it also helps us immensely if you tell us how to do all these things in MATLAB or simulink.I really appreciate the work you are doing,it may not help everyone but the ones who have been doing research will surely help a lot.
Google:
state space averaging
average simulation of PWM
I guess AC sweep is another solution to generate a bode plot which you don't need to know any equation. But you need to understand which kind of transfer function you want to get.
At 8:08 the plus terminal of the op amp should go to earth or zero potential.
Not really, connecting the plus input to the reference realizes the feedback summing junction at which the output is compared to the reference. If the positive input will be grounded you will have to do subtraction somewhere else.
Dear Professor,
Is there an intuitive way to understand
why the transfer function will become
a first order system in DCM mode?
In DCM, the inductor is charged and then completely discharged. This makes it a current source which, with the RC is first order.
Dear Professor,
thank you very much for this explanation. I just have one question:
How do you derive the transfer function of the open-loop buck converter at 1:20?
If I have a fixed D, my d would be zero, or am I wrong?
Dis the operating point around which there is a perturbation od d. See ua-cam.com/video/ne9loX-0Zws/v-deo.html
Thank you for this superb lecture
Thanks😊
Is the frequency taken on bode plot is switching frequency or the input frequency?
In this case we are talking about the frequency of the "probing" small signal (disturbance) around the feedback loop.
10:28 ... I think there's an error. A2/A1 (real values) = 1/5. With A1dB=-25, then A2dB= A1dB + 20log(1/5)= -35-14 = -49dB.
What minute in video are you referring to?
@@sambenyaakov 10:28 - as mentioned
@@cuchulainkailen I am not quite clear about that calculation. Based on the slope formula m = (y1-y2)/(x1-x2) you have a couple of things to consider, the slope value is in DB/dec, therefore x1-x2 need to be expressed in decades. Meaning that x1-x2 = 0.25 dec. From 2KHz to 5KHz there is only 0.25 dec. Therefore based on the slope formula you can say -20 DB = (-35DB - Y2)/(-0.25 decade) therefore Y2 = B = -40 DB.
Thank you prof for great videos.
My question is how the output capacitor can improve the stability of the converter ?
One more question is ESR will increase the output voltageand, so how to select the output capacitor?
And increase of output capacitance is generally a poor way to stabilize converters. The ESR increases the ripple and causes a voltage drop under a load step
Hello sir thank you for the nice licture. There's a thing which i still don't understand quite good: lets takes the buck example in CCM, we got second order output filter which gives us 2 pole and one zero. Well if we want to use a type 2 compensator we can at least cross the H with -40dB/dec slope, is it true? But this mean we can't get enough PM, so how to get away? Thank you very much
You need a double zero controller (sometime referred to as type 3)
This will give phase advane
Thank you very much for reply! Another doubt i have is the PM must be checked just only on the crosspoint or on every frequency under it.
Only at the cross over frequency
This is quite interesting, ever tought that even before the corner frequency there were needed phase margin. What if a signal at fcross/2 eg and so gain>1 has 180 phase delay?
I am a big fan of all your videos... You explain very well.... but these two videos related to Control strategies are totally out of my scope ........... I really am not able to grasp all that what you share in these two videos
This IS a tough subject. Take a break and then watch it again. I am sure you will fully grasp it. It is a very important subject. Not many practicing power electronics engineers understand it.
I would appreciate if could tell me a bit about your educational background so I can better understand the reason for my "overdoing" it with this video.
Very nice video, but I must admit, it's quite a difficult subject for me.
This IS a tough subject. Take a break and then watch it again. I am sure you will fully grasp it. It is a very important subject. Not many practicing power electronics engineers understand it.
One more thing: try to prepare a primer that will cover just the core of the subject.
I would appreciate if could tell me a bit about your educational background so I can better understand the reason for my "overdoing" it with this video.
I can see that it's a very important subject, I'm trying my best to fully understand it, but I think I simply don't even fully understand the basics. What I fail to understand is that at some points I don't really know what you are talking about. It could be because of my lack of knowledge and that you expect the viewers to actually know the basics and instantly see what some slides are about.
Was your second comment for Muhammad Adeen? Well, I'll answer it anyway. Yes, I should further research the core of the subject, which I will. Do you have tips on where to start? For my educational background, I am currently studying mechanical engineering at the Technical University of Delft. However, I have a heated passion for electrical power systems, your subject of expertise. I know that everything you discuss is very important in power electronics design, therefore I want to understand, sometimes even too fast.
I don't think there was any overdoing. I do think you assume your viewers to have atleast seen these topics a couple of times before. There were some terms in this slide I had literally never heard about or even the basics of them. So on somethings I can't put a connection to, there isn't a well established link in my head.
I will make sure to further research this topics and rewatch the videos. Therefore your effort has not been for nothing! I will understand this topic completely, I promise.
Hi, Thanks for sharing your concerns. The background required is Bode Plots and Laplace Transform and Domain or in general: what is usually referred to as Theory of Dynamic |Systems. Your self improvement efforts are commendable.
Ah, thank you very much, I will come back when I understand those
subjects better! Yes, I like everything about anything that handles
great amounts of power. Especially with the rise of electric cars and
stuff like Tesla, I think it's very important that these subjects are
well understood, even as a mechanical engineer. You are helping me
there.
Where is the link sir
?the link to this video?
@@sambenyaakov I was asking about the link to part 1, though I found it in description. Thanks
Sir your video is very useful I request to you pl. Your video translate for hindi lagwe
How can I do that ???