Thank you for your great presentation. But i have any questions. What about resonant frequency of converter, in this point our converter has lower impedance, and yes Middlebrook Criteria need to be satisfied in all frequency domain less that our Fsw. Can you explain, because your Impedance calculation don't reflect this, and cutoff frequency off your filter is designed only using needed attenuation and don't exclude intersection between peak of filter impedance and lower impedance of converter at resonant frequency, and if i understand correctly, this model of converter don't use variable negative resistance like real converter is. Thanks you very much and please correct me if i misunderstood something!
Hello Robert, I'm trying to duplicate your results using LTSpice and i'm only coming up with a max current from the FFT at 100Khz as ~456mA not 645mA. Could you point out the initial similation that gave you those results?
Hi Robert. Make sure you do a long enough transient simulation to where it comes to steady state. Then zoom in the the end and you need enough cycles Maybe 50 cycle or more so the the FFT will be accurate enought. One other thing the effects LTspice is the engine you use. There are two simulator. The first simulator is aimed at speed at the expense of accuracy. So in somewhere in the command you can select to use the more accurate slice engine. Hope yhe helps
@@RobertBolanos Hello Robert, Thanks for the information. I just tried the settings that you described and I'm getting the same results. I ran the simulation for 500ms and zoomed in on the latter portion of the steady state window for the output current source (or current source being injected into the line) and FFT'd the window region only and ~ 456mA. Now, I'm assuming that the FFT of the current source shouldn't matter if the dampening network along with the filter inductor and capacitor were connected as we are only looking to see the value of the 100kHz harmonic of the current being injected... correct? I also see in your images that you have the source voltage at 28V but sometimes at 0V, does this matter? I wouldn't think so, but again, I'm trying to correlate your measurements against mine. I'm looking at using another spice engine - Q-Spice (new Michael Englehardt simulator). Would it matter which simulator I tried? Has anyone else duplicated this issue or Roberts results?
Yes, all of these simulation can easily be done in LTSPICE. All you need to do is plot the current in the input voltage source, expand or zoom in where it reaches steady state and then do the FFT.
@@RobertBolanos thank you so much sir for your valuable answer, i can indeed see the FFT when applied after the current reached a steady state, however in the FFT i can see a large spike wich looks li a gaussian from 0 to 20KHZ ( its peak is 1.8mA at 238HZ ) knowing that the fondamental of my signal is at 25Khz with amplitude 0.1mA i don't know why? is it beacause the current that i send is too slow (25kHz) and to take too much time to get to a steady state ?
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Can you please do a LTspice simulation of the filter for Conducted Emissions ? Common Mode and Differential Mode.
Love your channel! Can you please do how to implement the Current Mode Control ?
thank you Robert for your excellent explanation 👍🏻
Thank you Dongolanmed!
Can you please do a LTspice simulation of the filter for CE ? Common Mode and Differential Mode.
Great video sir, thanks. Learn a lot.
I am glad you liked it!
Thank you for your great presentation.
But i have any questions. What about resonant frequency of converter, in this point our converter has lower impedance, and yes Middlebrook Criteria need to be satisfied in all frequency domain less that our Fsw. Can you explain, because your Impedance calculation don't reflect this, and cutoff frequency off your filter is designed only using needed attenuation and don't exclude intersection between peak of filter impedance and lower impedance of converter at resonant frequency, and if i understand correctly, this model of converter don't use variable negative resistance like real converter is.
Thanks you very much and please correct me if i misunderstood something!
Excellent
Thank you! Cheers!
can damping be applied to the input filter circuit of PFC circuit ? if Cd > 5-10 Cf will it affect PF? please answer this question. thank you.
thank you Robert
Thank you for watching!
The RC damp is ur snubber?
Yes, you can think of it as a damper or a snubber!
Hello Robert,
I'm trying to duplicate your results using LTSpice and i'm only coming up with a max current from the FFT at 100Khz as ~456mA not 645mA. Could you point out the initial similation that gave you those results?
Hi Robert. Make sure you do a long enough transient simulation to where it comes to steady state. Then zoom in the the end and you need enough cycles Maybe 50 cycle or more so the the FFT will be accurate enought. One other thing the effects LTspice is the engine you use. There are two simulator. The first simulator is aimed at speed at the expense of accuracy. So in somewhere in the command you can select to use the more accurate slice engine. Hope yhe helps
@@RobertBolanos Hello Robert, Thanks for the information. I just tried the settings that you described and I'm getting the same results. I ran the simulation for 500ms and zoomed in on the latter portion of the steady state window for the output current source (or current source being injected into the line) and FFT'd the window region only and ~ 456mA. Now, I'm assuming that the FFT of the current source shouldn't matter if the dampening network along with the filter inductor and capacitor were connected as we are only looking to see the value of the 100kHz harmonic of the current being injected... correct? I also see in your images that you have the source voltage at 28V but sometimes at 0V, does this matter? I wouldn't think so, but again, I'm trying to correlate your measurements against mine. I'm looking at using another spice engine - Q-Spice (new Michael Englehardt simulator). Would it matter which simulator I tried? Has anyone else duplicated this issue or Roberts results?
@@robertthurman8412 Hi Robert. Can you send me your LTspice file to rbola35618@aol.com. I would like to take a look at it.
I have played with Qspice. It is very fast. Only disadvantage is no parts datasbase.
@@RobertBolanos Yes, I noticed that too. I'm trying it out now with some of the models that I imported into LTSpice.
LTspice is not capable of such simulation it can not consider the curent into the bus
Yes, all of these simulation can easily be done in LTSPICE. All you need to do is plot the current in the input voltage source, expand or zoom in where it reaches steady state and then do the FFT.
@@RobertBolanos thank you so much sir for your valuable answer, i can indeed see the FFT when applied after the current reached a steady state, however in the FFT i can see a large spike wich looks li a gaussian from 0 to 20KHZ ( its peak is 1.8mA at 238HZ ) knowing that the fondamental of my signal is at 25Khz with amplitude 0.1mA i don't know why? is it beacause the current that i send is too slow (25kHz) and to take too much time to get to a steady state ?