Hi Sam. Have a nice day. I have in the past months did learn some more about pwm, class d and special the design of feedback for class d in different systems, one of these is a flying cap inverter do not what I want, it does work with -100dB distortion levels between 20 and 30 kHz, but the capacitor voltage does not stay on zero, I have bipolar supply and two 180 degree triangle carrier. Have feedback pré and post. I did read some papers about the stability of capacitor voltages and see much the use of special modulation technologies keeping it oke. I see also resistors are used for this. I use three gate driver ic,s and two of them only high side drive is used with cascaded bootstraps, and one both sections on ground level.. Possible a delay in it can cause the problem, maybe some kind of dc servo can be used to correct pwm. All start nice and on zero, slowly in time, the two sections get overlapping each other and the fundamental carrier get not suppressed anymore, it starts fine. It is for audio. Thank you for help and pray with me for world peace. If I see right on this video you do talk about this solution.
There is a need for an active ( feedback) of the cap voltage and a startup arrangement that will ensure balance at turn on. Look up TI application notes and reference design on that.
@@sambenyaakov Hi Sam, I have now all done, it works fine but the shoot trough does not, I have include a deadtime, but I need delay who is not the same as with half bridge amps, To get a balanced output I have need for a delay circuit who do delay opposite or so. Here on page 2 and 4 you see what I mean. Looks like I need switch it on and of depentend on negative or positive voltage. Maybe you can give a hint, I have tryed some, it does work but delay is for both on and off, I need delay in rising signal and a delay in falling signal who extent the other signal, normally it does not both falling and rising get delayed, I do need not such and can not find out how to do that, did using diodes but no luck, get shoot through in falling signal from comparator. I can use bigger caps but then I get uge deatime in only the rising signal and distortion. Here is link to article uia.brage.unit.no/uia-xmlui/bitstream/handle/11250/2787318/Paper%20III.pdf?sequence=7 Thanks in advace.
Hello Professor, Great video as always. Would be great if you can make a video on working of NPC circuit, especially the working of three level T-NPC PFC circuit. Thanks !
Thats great! When I studied, the flying cap inverter was the last the typical multilevel topologies I wanted to think. T, NPC, Cascaded-H, etc I understood. But the not ground referenced cap made me afraid😆 these days. Greetings from Germany!
Thank you Professor for explanation...can you please suggest any arrangement for start up operation. Also, is there any possibility of high voltage stress (equal to Vin) across upper switch (connected between +Vin and Flying cap+) during start up when all capacitors are at 0V potential?
That would be interesting for me two, but I didn't find the next video Professor mentioned. I see this topology useful for "digital" voltage in a DAC because of a minimal value of a current ripple. What I can suggest is two C/2 capacitors from Vdd to C, and from C to GND.
Thanks Professor, your explanation really makes more sense than looking around in the internet :)
Thanks
You explain very easily and not too many teadous calculations does make it interesting for people who are just looking for understanding purposes
Thanks for comment.
What a great explanation, we are great to have you here and for free lol. Thank you Prof. Sam!!!
Thanks🙂
This video provides helpful bisics for 3-level. Thank you Prof Sam!
Thanks
Thank you Professor! very intuitive and helpful explanations!
👍😊
Thank you professor for your clear explanation!
Thanks
Amazing! Thank you prof!
😊🙏
Hi Sam. Have a nice day. I have in the past months did learn some more about pwm, class d and special the design of feedback for class d in different systems, one of these is a flying cap inverter do not what I want, it does work with -100dB distortion levels between 20 and 30 kHz, but the capacitor voltage does not stay on zero, I have bipolar supply and two 180 degree triangle carrier. Have feedback pré and post. I did read some papers about the stability of capacitor voltages and see much the use of special modulation technologies keeping it oke. I see also resistors are used for this. I use three gate driver ic,s and two of them only high side drive is used with cascaded bootstraps, and one both sections on ground level.. Possible a delay in it can cause the problem, maybe some kind of dc servo can be used to correct pwm. All start nice and on zero, slowly in time, the two sections get overlapping each other and the fundamental carrier get not suppressed anymore, it starts fine. It is for audio. Thank you for help and pray with me for world peace. If I see right on this video you do talk about this solution.
There is a need for an active ( feedback) of the cap voltage and a startup arrangement that will ensure balance at turn on. Look up TI application notes and reference design on that.
@@sambenyaakov Hi Sam, I have now all done, it works fine but the shoot trough does not, I have include a deadtime, but I need delay who is not the same as with half bridge amps, To get a balanced output I have need for a delay circuit who do delay opposite or so. Here on page 2 and 4 you see what I mean. Looks like I need switch it on and of depentend on negative or positive voltage. Maybe you can give a hint, I have tryed some, it does work but delay is for both on and off, I need delay in rising signal and a delay in falling signal who extent the other signal, normally it does not both falling and rising get delayed, I do need not such and can not find out how to do that, did using diodes but no luck, get shoot through in falling signal from comparator. I can use bigger caps but then I get uge deatime in only the rising signal and distortion.
Here is link to article uia.brage.unit.no/uia-xmlui/bitstream/handle/11250/2787318/Paper%20III.pdf?sequence=7
Thanks in advace.
Hello Professor,
Great video as always.
Would be great if you can make a video on working of NPC circuit, especially the working of three level T-NPC PFC circuit. Thanks !
Good subject will try
Excellent introduction to this topic-- thanks. How does duty cycle control change with higher-levels such as the 4-level you showed at the end?
Hi Professor,
How to model the 3 levels buck converter I mean the small-signal model, is it the same as buck converter?
Yes. Using same concept .
Thats great! When I studied, the flying cap inverter was the last the typical multilevel topologies I wanted to think. T, NPC, Cascaded-H, etc I understood. But the not ground referenced cap made me afraid😆 these days.
Greetings from Germany!
Thanks for sharing your thoughts.
Very very useful !. I really appreciate this presentation, thank you very much professor.
Thanks😊
Excellent summary. Thank you.\
🙂👍🏻🙏
Thank you Professor for explanation...can you please suggest any arrangement for start up operation. Also, is there any possibility of high voltage stress (equal to Vin) across upper switch (connected between +Vin and Flying cap+) during start up when all capacitors are at 0V potential?
Perhaps will cover startup in a forthcoming video
That would be interesting for me two, but I didn't find the next video Professor mentioned. I see this topology useful for "digital" voltage in a DAC because of a minimal value of a current ripple. What I can suggest is two C/2 capacitors from Vdd to C, and from C to GND.
thank you Professor for this explaination, i have question. Why the voltage of capacitor is equal to Vin/2 and ont equal to Vin?
During operation it stays at 1/2
Thank you a lot, this video really helpful
Thanks
Thank you for the video. I don't yet understand how to calculate D1 and D2 from the duty cycle D.. ?
What would happen if instead of having 3 levels, you have more ?
Can use a standard synchronous buck controller for this 3 level configuration ?
Plus cap voltage control
i don't think you understand what intuitive means
Please enlighten me. Please send a link to your presumably excellent intutive videos.
What a rude fuck