Definitions of ‘Inductance’, ‘AC inductor’ and ‘DC inductor’: Correcting some misconceptions

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  • Опубликовано: 15 сен 2024

Комментарии • 55

  • @iridiandot
    @iridiandot Год назад +4

    It's always magical to find the very best uploading a video explaining a topic which I need exactly at the time of me needing it. Thank you !

  • @정동훈-y9f
    @정동훈-y9f Месяц назад

    Thank you for your amazing lecture. I think you are a great teacher and god of power electronics. I always appreciate for your amazing lecture.

    • @sambenyaakov
      @sambenyaakov  Месяц назад

      Wow, thank you. Too much. I will settle for angel 😊

  • @zaneenaz4962
    @zaneenaz4962 Год назад +1

    Magical when all the piece come together. Thank you.

    • @sambenyaakov
      @sambenyaakov  Год назад +1

      👍Thanks. I am still amazed to see that circuits you scribble down will work as foreseen.

    • @luisfelipecolquemiranda9832
      @luisfelipecolquemiranda9832 2 месяца назад

      @@sambenyaakov That's the beauty of all of this :)

  • @volleswerkfullorganpower249
    @volleswerkfullorganpower249 24 дня назад +1

    The best explanation !

  • @32bits-of-a-bus59
    @32bits-of-a-bus59 Год назад +1

    I get it now. Thanks once again for the paper. So, even though Lt inductance would be physically more appropriate (as an analog to mass in Newton's law with a special relativity correction, i.e. F=d(m(v)∙v)/dt being an analogy to V=d(Lt(I)∙I)/dt) it is actually more practical to define a different inductance Ld (I) so that we could use a simple formula V=Ld(t)∙dI/dt to obtain the same results. Very clever trick! Probably also more numerically stable as it eliminates the addition that could in some circumstances lose significant digits.

  • @leinadshAlpha
    @leinadshAlpha Год назад +1

    Thank you so much professor. Clear and informative as always. It would be interesting to explore the effect inter-winding capacitance has on CM currents in HF application, coping mechanisms and the trade-offs between low leakage design and low parasitic capacitance design. It would be interesting to hear the opinion of an expert such as yourself.

    • @sambenyaakov
      @sambenyaakov  Год назад +1

      These are intricate issues not easily modeled. Perhaps I will in the future present a video on that.

  • @pbaemedan
    @pbaemedan Год назад +1

    Thank you professor, your videos are very informative and helpful.

  • @diegorodrigues1297
    @diegorodrigues1297 Год назад +2

    Thank you very much Professor!
    Please, could you provide a lesson explaining the effects of increasing the switching frequency in a ferrite transformer using the full-bridge topology, and the phenomenon that allows for power gain, potentially resulting in a physical reduction in core size with frequency increase? An example would be increasing the frequency from 100 kHz to 500 kHz.

    • @sambenyaakov
      @sambenyaakov  Год назад +1

      See ruclips.net/video/fFQ7lwvEaGE/видео.html

  • @neethus3294
    @neethus3294 2 месяца назад +1

    thank you Professor.

  • @Bosco12ful
    @Bosco12ful Год назад +2

    Excellent prof.

  • @user-ee4xf1rk6o
    @user-ee4xf1rk6o Год назад +1

    Thank you for the video, and your insights.
    I am curious, why when you have talked about AC inductors you stated that to achieve high currents you must air gap the core?
    In most application, the designing constraints are current and inductance -> same stored energy in different solutions. By using un gap core we can achieve the desired inductance by much lower number of turns (in comparison to gapped core) and which results in low magnetic field with a high current.

    • @sambenyaakov
      @sambenyaakov  Год назад

      In most applications the requirement is NOT energy but L and I. The enegy is the consequence. Furthermore, energy density is B^2/mu, so air is a better magnetic energy storage than high mu material, contra-intuition .

  • @karastom2304
    @karastom2304 Год назад +1

    Thanks so Professor Sam, I do learn something new each time I watch you.
    I do have questions
    1- the dc current across inductor will make it saturate? Is like you have DC voltage across zero ohm , so this will saturate core , and the average voltage across inductors should be zero
    2- how can I calculate temperature rise due to dc resistance of the winding
    Thanks so much

    • @sambenyaakov
      @sambenyaakov  Год назад

      1, DC current moves B up the BH curve an may cause saturation
      2. The power is I^2*Rdc and there is an experimental equation for temp rise as function of the dissipated power and total surface area.

  • @thabomabuse456
    @thabomabuse456 Год назад +1

    Hello Sir great Video, If I am designing an inverter and I want to put an LC filter at the output of my inverter would you recommend a AC inductor or a DC inductor?

    • @sambenyaakov
      @sambenyaakov  Год назад

      As I pointed out in the video, there is really no differece between the two. If the LC filter has to pass a high current, there will be a need for an air gap. Not so in a common mode filter in which the in and out currents cancel each other.

  • @argcargv
    @argcargv Год назад +1

    Have permanent magnets been used to bias inductors to increase the energy capacity with dc bias?

    • @sambenyaakov
      @sambenyaakov  Год назад +1

      Good question. Yes. Such components were offered by a company sometime ago, but the line was dropped due to luck of interest.

  • @MrHeatification
    @MrHeatification Год назад +1

    great video, thanks very much Sir

  • @kecsrobi6854
    @kecsrobi6854 Год назад +1

    IF i have to design an inductor for a SMPS should i use stranded wire or 1 more wire?
    Asking since 1 end will be at DC while the other one will be switching all the time so it is effectively in AC.
    Skin effect is the thing that is my fear

    • @sambenyaakov
      @sambenyaakov  Год назад

      The two ends have the same current which matters. You need Litz wire if the ripple component is large and of high frequency that skin and proximity effects are substantial.

  • @BigA1
    @BigA1 Год назад +1

    By extension, should we gap the core of a transformer that is excited purely by AC (ie no DC component present). If I understand you correctly, the magnetising inductance will be enhanced for a given core size by having a gap.

    • @sambenyaakov
      @sambenyaakov  Год назад

      Not so. A gap will allow higher stored energy (which a tranformer does not need, input=output at any instance) while reducing inductance and hence increasing magnetization current.

  • @jimmylightfinger1216
    @jimmylightfinger1216 Год назад +2

    Thank you. Inductors, transformers, and motors are my weak spots.

    • @sambenyaakov
      @sambenyaakov  Год назад

      Happy to hit the target 🙂👍🙏

  • @akhilkchandran1202
    @akhilkchandran1202 Год назад +1

    Thank you professor...I would like to know how practical selection of core is done and inductor is fabricated... please do a video on the same

  • @dor7sh
    @dor7sh Год назад +1

    Thank you prof.👍

  • @32bits-of-a-bus59
    @32bits-of-a-bus59 Год назад +1

    “Thanks for comment. Please indicate to what minute or slide of the presentation you are referring to.”
    ruclips.net/video/AfTTO4m1ti8/видео.html Here, you say that everything here is constant, which allows you to factor it out of the derivative, but later you admit that μ depends on H and therefore on I, which depends on t. Therefore, it should have been differentiated with that in mind, in my opinion.
    PS: I'm re-posting to the main thread as it seems to me that youtube does not generate a notification when a reply is made to a reply.

    • @sambenyaakov
      @sambenyaakov  Год назад +1

      Good idea to repost it. If L is defined as incremental inductance Ld than still V=Ld(di/dt) . See doi.org/10.36227/techrxiv.14975082.v1

    • @32bits-of-a-bus59
      @32bits-of-a-bus59 Год назад

      @@sambenyaakov Thank you for the paper. I'm going to read thru it.

  • @biswajit681
    @biswajit681 Год назад +1

    Hi sir could you please make a video on LLC Resonant converter Control methodology

    • @sambenyaakov
      @sambenyaakov  Год назад

      Have you seen ruclips.net/video/amRqIgH10Rg/видео.html ?

  • @rosatouabi5543
    @rosatouabi5543 Год назад

    Thank you so much

  • @tamaseduard5145
    @tamaseduard5145 Год назад +2

    🙏👍❤

  • @32bits-of-a-bus59
    @32bits-of-a-bus59 Год назад +1

    Dear professor, thank you for another great video. However, I'm puzzled why the differentiation of the Faraday's law was not carried out like this, considering that μ is a function of H and consequently of I:
    V(t) = n∙dΦ/dt = n∙d(μ(I)∙A∙n∙I)/l)/dt = A∙n^2/l ∙ d(μ(I)∙I)/dt
    = (A∙n^2/l)∙( dμ/dI∣_I(t)∙dI/dt∙I(t) + μ(I(t))∙dI/dt)
    = (A∙n^2/l)∙( I(t) ∙ dμ/dI∣_I(t) + μ(I(t)) )∙dI/dt
    writing μ' for dμ/dI:
    = (A∙n^2/l)∙( I(t)∙μ'(I(t)) + μ(I(t)) )∙dI/dt = L(I(t))∙dI/dt (*)
    the inductance L(I) would depend on the instantaneous current and would be equal to
    L(I) = (A∙n^2/l)∙(I∙μ'(I) + μ(I))
    if we wanted to write V(t) = L(I(t)) ∙ dI(t)/dt. If, on the other hand, we would adopt that
    V(t) = d(LL(I(t))∙I(t))/dt
    the LL inductance would be defined differently. Namely, by carrying out the derivative, we get
    V(t) = LL'(I(t))∙I'(t)∙I(t) + LL(I(t))∙I'(t) = (LL'(I(t))∙I(t) + LL(I(t))) ∙ I'(t)
    Comparing it with (*) we see that
    L(I) = LL'(I)∙I + LL(I)
    which hold if we defined LL(I) = (A∙n^2/l)∙μ(I).
    So, which of the inductance definition do you like more? L(I) or LL(I)? I'd go for LL(I) for its simplicity despite it requires us to modify the formula for voltage across the inductor to V=d(LL(I)∙I)/dt.

    • @sambenyaakov
      @sambenyaakov  Год назад +1

      Thanks for comment. Please indicate to what minute or slide of the presentation you are referring to.

    • @32bits-of-a-bus59
      @32bits-of-a-bus59 Год назад

      @@sambenyaakov ruclips.net/video/AfTTO4m1ti8/видео.html Here you say that everything here is constant, which allows you to factor it out of the derivative, but later you admit that μ depends on H and therefore on I, which depends on t. Therefore, it should have been differentiated with that in mind, in my opinion.