Project 1
SEPIC CONVERTER:
DESIGN PROCEDURE :
VIN =40V; VOUT=45V ,POUT =1KW.
DEL VOUT=1%VC
DEL IL=15%ILAVG
FSW=100KHZ.
STEPS:
VC1=VIN=40V
VOUT/VINPUT=D/(1-D)=0.529.
IL1=IIN=POUT/VIN=25 AMPS.
IL2=IOUT=POUT/VOUT=22.22 AMPS.
DEL IL1 =0.15*I INPUT =3.75 AMPS.
DEL IL2 =0.15* I OUTPUT=3.33 AMPS
L1 =VIN*D /FSW *DEL IL1=0.000554 HENRY.
L2 =VIN*D / FSW*DEL IL2 =0.000624 HENRY.
C2 =D*VOUT/R*FSW*DEL VO=0.02645 FARAD.
CINTERMEDIATE = VOUT *D /R*FSW*DEL VC1=0.0025 FARADS.
SCHEMATIC DIAGRAM:
DUTY RATIO AND PWM WAVEFORM:
INDUCTOR CURRENT WAVEFORM AND OUTPUT VOLTAGE WAVEFORM:
FIGURE 1 : SHOWS THE OUTPUT VOLTAGE OF 40VOLTS AND VC1=VIN =40VOLTS.
FIGURE 2: SHOWS THE L1 CURRENT OF 25 AMP WITH RIPPLE OF 3.75 AMPS& L2 CURRENT OF 22.22 AMP WITH RIPPLE OF 3.33 AMPS
MOSFET CURRENT AND VOLTAGE :
FIGURE 4 : MOSFET VOLTAGE RATING AND CURRENT RATINGS.
CHOOSE MOSFET OF VOLTAGE 100 VOLTS AND CURRENT OF 60 AMPERE SO THAT MOSFET CAN NOT DAMAGE WITH LESS REVERSE RECOVERY TIME.
BOOST CONVERTER:
DESIGN PROCEDURE :
VIN =25V; VOUT=40V ,POUT =600W.
DEL VOUT=1%VC
DEL IL=15%ILAVG
FSW=100KHZ.
STEPS:
R=VO^2/POUT=2.6OHM.
VOUT/VINPUT=1/(1-D)=0.375.
IL1=IIN/1-D =24AMPS.
DEL IL1 =0.15*I INPUT =5AMPS
L1 =VIN*D /FSW *DEL IL1=0.000001875 HENRY.
C2 =D*VOUT/R*FSW*DEL VO=0.0014645 FARAD.
SCHEMATIC:
VOLTAGE OUTPUT AND INDUCTOR WAVEFORMS:
FIGURE 5: SHOWS PWM AND DUTY RATIO. OUTPUT VOLTAGE OF 40 VOLTS AND INDUCTOR CURRENT 24 AMPS .
MOSFET CURRENT AND MOSFET VOLTAGE :
FIGURE 6: SHOWS MOSFET VOLTAGE AND CURRENT RATINGS. VOLTAGE OF 60 VOLTS AND CURRENT OF 40 AMPERE WILL BE THE CHOICE OF CONERN.
BUCK CONVERTOR:
DESIGN PROCEDURE :
VIN =45V; VOUT=30V ,POUT =500W.
DEL VOUT=1%VC
DEL IL=15%ILAVG
FSW=100KHZ.
STEPS:
R=VO^2/POUT=1.8 OHM.
VOUT/VINPUT=D=0.66
IL1=I0=VO/R=16.66AMPS
DEL IL1 =0.15*I INPUT =5AMPS
L1 =VOUT*1-D /FSW *DEL IL1=0.000528 HENRY.
C2 =1-D*VOUT/8*L*FSW^2*DEL VO=0.00001041645 FARAD.
SCHEMATIC DIAGRAM:
PWM, DUTY RATIO, INDUCTOR CURRENT, OUTPUT VOLTAGE :
FIGURE 9: SHOWS PWM PULSE, DUTY RATIO, OUTPUT VOLTAGE OF 30 VOLTS, AND INDUCTOR CURRENT OF 16.66 AMPERES.
MOSFET VOLTAGE AND CURRENT WAVEFORMS:
FIGURE 10: MOSFET VOLTAGE RATING OF 100 VOLTS AND CURRENT 30 AMPERES IS CHOSEN FOR BETTER PERFORMANCE.