I read our esteemed professor’s comment to another gentleman’s thread on LinkedIn. I was expecting a video that clarify the misconception. Here it is. Thank for teaching us all.
Hi professor. Related to this topic, DC-blocking capacitors in DAB converters.There are people that indicate that DC bias can be solved with a gap in the transformer, others say that DC capacitor is always necessary. I thing that resolution of PWM in microcontrollers is going to always generate some DC and in transients very likely a DC half-cycle applied, and hence saturation. Can you dedicate a video commenting misconceptions on this issue?
Very instructive video. It would be interesting to hear your take on how a gapped transformer compares with a transformer wound on a distributed gap material with the same relative permeability...
Nice refresher. While I agree with the effect of the gap on the B-H, I kinda don't get why people would introduce it the way you mentioned in the first part of the video. Sure, having a gap would allow higher current, but it changes the inductance as well whose value is crucial in power electronics.
@@sambenyaakov I am having the same confusion, let's say in a buck/boost converter we need to have enough L to store the energy to be used later and then by adding the gap we are reducing the overall L. I can wrap my head around it if I look at it in term of increasing the current margin without going to saturation but not when I try to analyze it with the amount stored energy in mind.
@@josephgharakhani5375 You can not store energy unless you reduce Ur (having a gap) since the core will saturate with very little current. So you have to add to "need to have enough L " WITHOUT SATURATING THE CORE
This was interesting. However I have issue with the statement that the voltage causes the saturation. The saturation is caused by magnetic flux density reaching a value where the all domains in the magmatic circuit are aligned. That saturation value (peak flux density)is proportional to V/f (slide 8). This to me seems better than "the saturation is caused by the voltage."
Yes, I agree in general. However, the domain explanation does not provide quantitative relationships. Or, why will be the domain more "aligned" at a lower frequency. I was said that the saturation is caused by the voltage because, as you might know, the presentation is an in fact an answer to a LinkedIn post that was related to line (fixed frequency) CTs. Thanks for the conversation.
Professor, thank you for your great video! I have a question which confuses me for a while. I am designing a transformer for a CLLC converter. For the same turns ratio, see 10:1, I can choose 10:1 or 20:2 in order to get the same output voltage. However, according to the Faraday's law, when I use 20:2 instead of 10:1 (keep inductance L the same by adjusting the air gap), I would have lower Bmax when the output voltage is kept constant. However, if I refer to Ampere's law, as the output current or even the magnetizing current is the same, n*i = H*le, the H would be higher and so the Bmax would increase. Where am I wrong?
I think I figure out :) when I increase ratio from 10:1 to 20:2, in order to keep L constant, I have to increase the air gap which affects the equivalent le.
@@sambenyaakov I think I confused myself in my original question. When I choose more turns, in order to keep the same inductance, the gap will change. So even though n*I will increase, however, as the the airgap increase, H might actually decrease. ：） sorry for the confusion!
Thanks, I really learned a lot from this! However, now I'm more confused than ever about the air-gapped transformers in Switch-mode power supplies, which I assume are voltage transformers, and use non-sinusoidal, pulsed waveforms; all of which you list as cons. Will you make another video explaining the use and the pros and cons of air gaps for flyback transformers and forward converters?
Excellent video. With the academic rigor that is due, and with the necessary pedagogy. Congratulations teacher. Keep it up.
Many thanks!
I read our esteemed professor’s comment to another gentleman’s thread on LinkedIn. I was expecting a video that clarify the misconception. Here it is. Thank for teaching us all.
🙂👍🙏
An wonderful video filled with very pertinent and useful information !
Thanks.
Muchas Gracias Maestro !!!! ❤❤❤❤❤🙏🙏🙏🙏🙏👍
Thanks😊
Hi professor. Related to this topic, DC-blocking capacitors in DAB converters.There are people that indicate that DC bias can be solved with a gap in the transformer, others say that DC capacitor is always necessary. I thing that resolution of PWM in microcontrollers is going to always generate some DC and in transients very likely a DC half-cycle applied, and hence saturation. Can you dedicate a video commenting misconceptions on this issue?
Will try. The best solution is to use current mode control.
Very instructive video. It would be interesting to hear your take on how a gapped transformer compares with a transformer wound on a distributed gap material with the same relative permeability...
Thanks. Good topic. Will try.
Nice refresher.
While I agree with the effect of the gap on the B-H, I kinda don't get why people would introduce it the way you mentioned in the first part of the video. Sure, having a gap would allow higher current, but it changes the inductance as well whose value is crucial in power electronics.
You need to accommodate I^2*L/2. The physics is such that a core with a gap will the smallest for a given energy.
@@sambenyaakov I am having the same confusion, let's say in a buck/boost converter we need to have enough L to store the energy to be used later and then by adding the gap we are reducing the overall L. I can wrap my head around it if I look at it in term of increasing the current margin without going to saturation but not when I try to analyze it with the amount stored energy in mind.
@@josephgharakhani5375 You can not store energy unless you reduce Ur (having a gap) since the core will saturate with very little current. So you have to add to "need to have enough L " WITHOUT SATURATING THE CORE
@@sambenyaakov Thank you Sam for taking the time. Much appreciated! You are amazing educator! simple, concise, right to the point. Awesome!
@@josephgharakhani5375 👍👍
This was interesting. However I have issue with the statement that the voltage causes the saturation. The saturation is caused by magnetic flux density reaching a value where the all domains in the magmatic circuit are aligned.
That saturation value (peak flux density)is proportional to V/f (slide 8). This to me seems better than "the saturation is caused by the voltage."
Yes, I agree in general. However, the domain explanation does not provide quantitative relationships. Or, why will be the domain more "aligned" at a lower frequency. I was said that the saturation is caused by the voltage because, as you might know, the presentation is an in fact an answer to a LinkedIn post that was related to line (fixed frequency) CTs. Thanks for the conversation.
Why not using less turn instead of a gap?
L=n^2 *mu*Ae/le If n is reduced by a factor of 2 Ae/le needs to be increased by a factor of 4
Professor, thank you for your great video! I have a question which confuses me for a while. I am designing a transformer for a CLLC converter. For the same turns ratio, see 10:1, I can choose 10:1 or 20:2 in order to get the same output voltage. However, according to the Faraday's law, when I use 20:2 instead of 10:1 (keep inductance L the same by adjusting the air gap), I would have lower Bmax when the output voltage is kept constant. However, if I refer to Ampere's law, as the output current or even the magnetizing current is the same, n*i = H*le, the H would be higher and so the Bmax would increase. Where am I wrong?
I think I figure out :) when I increase ratio from 10:1 to 20:2, in order to keep L constant, I have to increase the air gap which affects the equivalent le.
You mean you are going to have 1 turn in one case and 2 turns in the other case?
@@sambenyaakov yes professor
@@tangy1181 This seems unrealistic.
@@sambenyaakov I think I confused myself in my original question. When I choose more turns, in order to keep the same inductance, the gap will change. So even though n*I will increase, however, as the the airgap increase, H might actually decrease. ：） sorry for the confusion!
Thanks, I really learned a lot from this! However, now I'm more confused than ever about the air-gapped transformers in Switch-mode power supplies, which I assume are voltage transformers, and use non-sinusoidal, pulsed waveforms; all of which you list as cons. Will you make another video explaining the use and the pros and cons of air gaps for flyback transformers and forward converters?
The flyback element is NOT a transformer. It is a coupled inducror.
Hi Sir would you be making video on Flyback converter input filter connection post on LinkedIn??
Yes I plan
👍🙏❤️
Thanks🙂