Sr.Diego
Newbie level 1
Hi guys, I am a beginner-intermediate engineering student and I am currently developing a six-pulse three-phase full wave rectifier with output capacitor parallel to a purely resistive load. The problem I have had is that the equation (which I deduced) that I use for the calculation of capacitance as a function of ripple factor (rf) does not coincide with the simulation ripple factor.
The equation is:
C=1 / (6*4√3*R*f*(rf))
To obtain the equation, I based an analysis on a single-phase full-wave rectifier with parallel capacitor (in a book) and I made a similar analysis with the three-phase case.
The values I have for my rectifier are: VLLrms=141.42 , f=20Hz , R=8 ohm , rf =0.03=3%.
that gives me according to my formula: C=5mF.
I'm checking the ripple factor with Matlab, using the formula:
rf=((VoutRMS/VoutDC)²-1)^½ or √((VoutRMS/VoutDC)²-1) in Matlab simulation rf = √((190.9/190.7)²-1) 4.58%
Matlab simulation : VLLin(ab)=yellow , VoutDC =blue.
I don't know what happens. suddenly:
The formula is not correct?
Am I checking the ripple factor wrong?
All aids are welcome and appreciated, Thank you very much :-D:-D:-D:-D
The equation is:
C=1 / (6*4√3*R*f*(rf))
To obtain the equation, I based an analysis on a single-phase full-wave rectifier with parallel capacitor (in a book) and I made a similar analysis with the three-phase case.
The values I have for my rectifier are: VLLrms=141.42 , f=20Hz , R=8 ohm , rf =0.03=3%.
that gives me according to my formula: C=5mF.
I'm checking the ripple factor with Matlab, using the formula:
rf=((VoutRMS/VoutDC)²-1)^½ or √((VoutRMS/VoutDC)²-1) in Matlab simulation rf = √((190.9/190.7)²-1) 4.58%
Matlab simulation : VLLin(ab)=yellow , VoutDC =blue.
I don't know what happens. suddenly:
The formula is not correct?
Am I checking the ripple factor wrong?
All aids are welcome and appreciated, Thank you very much :-D:-D:-D:-D