Hi,
Thanks for posting at Infineon Community.
Please refer to page No. 12 in the below reference application note.
https://www.infineon.com/dgdl/InfineonApplicationNote_PFCCCMBoostConverterDesignGuide-AN-v02_00-EN.p...
Steps to Derive FET RMS Current.
1. Calculate Duty Cycle for PFC CCM Mode (Below shown final result)
D = 1-VIN/VO
2. Calculate Inductor RMS Current (Below shown final result)
ILRMS = (PO/VRMS X ƞ)
3. RMS current during one switching period can be calculated using below formula
IQRMS = ILRMS X √D
Since all quantities are a function of wt due to sin input. The above equation can be written as below.
IQRMS (ωt) = ILRMS (ωt) X √D(ωt)
By substituting, step 1 and 2 into 3 below equation can be derived
IQRMS (ωt) = ((√2 X PO |sinωt|)/(VRMS X ƞ) X (√1-(√2 X VRMS X |sinωt|)/VO)
4. By Integrating mean square value of the above equation we can get the resultant FET RMS equation as below
Note: PF Considered as 1
Thanks,
SPCH.
Hi,
Thanks for posting at Infineon Community.
Please refer to page No. 12 in the below reference application note.
https://www.infineon.com/dgdl/InfineonApplicationNote_PFCCCMBoostConverterDesignGuide-AN-v02_00-EN.p...
Steps to Derive FET RMS Current.
1. Calculate Duty Cycle for PFC CCM Mode (Below shown final result)
D = 1-VIN/VO
2. Calculate Inductor RMS Current (Below shown final result)
ILRMS = (PO/VRMS X ƞ)
3. RMS current during one switching period can be calculated using below formula
IQRMS = ILRMS X √D
Since all quantities are a function of wt due to sin input. The above equation can be written as below.
IQRMS (ωt) = ILRMS (ωt) X √D(ωt)
By substituting, step 1 and 2 into 3 below equation can be derived
IQRMS (ωt) = ((√2 X PO |sinωt|)/(VRMS X ƞ) X (√1-(√2 X VRMS X |sinωt|)/VO)
4. By Integrating mean square value of the above equation we can get the resultant FET RMS equation as below
Note: PF Considered as 1
Thanks,
SPCH.
