Powerful Knowledge 9 - Magnetics design for high performance power converters
Вставка
- Опубліковано 5 вер 2024
- Magnetics design is often the most overlooked aspect of the design of power electronic converters. This is episode 9 of our 'Powerful Knowledge' series and we go into some depths of how to approach magnetics design using energy storage as a starting point with an example of a mains input 50W flyback converter running at 100kHz switching frequency.
We cover aspects such as winding structure, basic core loss modelling, impacting of fringing fields near the airgap and practical characterization.
I started watching video just to take a look but I ended up taking notes and watching all video at once. Thank you for sharing those very useful pieces of information.
You are most welcome, great to hear it was useful!
Thank you for sharing, very useful.
Magnetics design is fascinating isn't it!
Nice video Ian!
Thanks Robert, glad you liked it!
thank you for sharing
You are welcome Mahmoud
Nice one ...but I was wondering if you show some practical demo of designing of magnetics
We do plan a new video soon which shows us winding and testing a flyback converter transformer so keep an eye out for when we release this.
@@ElectronicmindsUK Many Thanks eagerly waiting
hi thank you so much about your knowladle. can ı ask a question, in 100khz we calculate 0.21mm skin depth. after that how we select optimal diameter you said 0.42.Do we multiply the skin depth directly by 2? in video 37m
What I mean is, if there is a skin depth of 0.21mm, how can I calculate the cross-sectional area required to avoid skin effect?
The definition of skin depth is the distance into the conductor cross section where the current density falls to 1/e of that at the surface. You can't really avoid it but you can see that running a conductor with radius greater than the skin depth (i.e. diameter of twice the skin depth) means that very little of the current flows in the centre as the current density drops exponentially. We use 2x the skin depth for the diameter as a good starting point.
Grateful for what have you done. I have a small doubt though, how did you measure AC resistance i.e. @100kHz could help me figuring this out. I have designed a component but I wanted to it validate with my simulation results. So could you help me how to measure AC resistance. I have impedance analyzer with me but the real part of the impedance measured is giving effective resistance but not the winding resistance alone.............Thanks in advance
We used an impedance bridge, in our case the Keysight 4263B. It measures the real part of the impedance (I.e. the resistance at a few spot frequencies including 100kHz). Keep in mind that the measurement is only small signal so won’t necessarily capture non-linear losses such as the increase in loss with Bpeak.
@@ElectronicmindsUK Thank You for that. I am using Bode100 (from omicron labs) for the impedance measurement I am still unable to measure ac resistance accurately
how we determine the PF?
Do you mean power factor here or something else?
The design parameters are TOO BRIEIF outlined in 47:50/1:23 . Please indicate a justification for this choice. I realize that the presentation is for first time designers ,
hence the simplification is correct.
The focus of this video is to translate a set of electrical requirements for a magnetic component into a physical design (core, gap, turns etc). The justification for those electrical requirements comes from how the power stage itself is designed. In the case of the flyback converter example here, we do cover the topology design which leads to the electrical requirements of the magnetics in one of our other videos. Take a look at ua-cam.com/video/FvWyacXud_E/v-deo.html
he called my name :umesh" at 42:28