Project 1 - Loss calculation for a DC/DC converter-MATLAB
Design of boost converter, and calculating the loss of different components including power switching device and deriving efficiency of boost converter. This is applicable in power supply industry, electric vehicles etc where DC-DC converter is required to boost the voltage from DC source.
Assumed Design Parameters :
Vin = 100V
Vout = 200V
Fsw = 20kHZ
L = 200uF
C = 400uF
R = 10 ohms
rL = 10 m ohms
rC = 2 m ohms
rd= 5 m ohm
Duty Cycle:
Vout/Vin = 1/(1-D)
200/100 = 1 / (1-D)
2 = 1 / (1-D)
2*(1-D) = 1
(1-D) = ½
(1-D) = 0.5
D = 1-0.5
D = 0.5
DC DC boost converter model:-
result:-
diode voltage & current:-
zoom in:-
mosfet voltage & current:-
zoom in:-
The Loss Calculation of boost converter:
The Boost converter has four types of losses. They are:
Conduction losses
Diode losses
Induction losses
Capacitor losses
Conduction Losses:
Conduction Losses: Pc= I² * Rds *D
p= Power Dissipation
I= Current through MOSFET
R= Resistance in Ohm
D=Duty Cycle
Im = Pi/Vi = (V^2/R)/Vi
= ((100)^2/10) / 100
Im =10
Pc= 10^2 * 0.023 * 0.5
Conduction loss Pc = 1.15w
Diode losses:
Diode Losses: P= Vf * I* (1-D)
Vf= forward voltage
I= Current output
D=Duty Cycle= Vout / Vin
P = 19.55 * 1 * (1-0.5)
= 9.775
Diode losses P = 9.7 W
Induction Losses:
Pd= I² * R + { (rl / 12) (D* Vin / F*L)}
I= Current output
D=Duty Cycle= Vout / Vi
F= Frequency
L= Inductance value
Pd = 1^2 * 10 +{(0.0008 * 5000}
Inductor loss Pl = 10W
Capacitance losses:
Pc= {rc* D*(1-D) I² + {rc / 12(1-D)}}*{(Din / C*F)}
I= Current output
D=Duty Cycle= Vout / Vi
F= Frequency
C= Capacitance value
Pc = 2*0.5*0.5 + {(2*0.0001*0.5*0.5*100) / (400*50*1*10^-6)}
Pc = 0.7085W
Total Losses= Pcon+Pd+Pi+Pc
=5+9.775+1.4+0.7085
Total losses=11.74585 W
Efficiency Of Converter:
The Efficiency Of converter is determined by using below formula:
Efficiency = (Pin -Ploss / Pin ) 100
From the data
Pin= Vin * I
I= Vin / R
=100 / 10
I= 10 Amps
Pin = vin * I
=100 * 10
Pin=1000 W
Efficiency = (Pin -Ploss / Pin )100
= 1000-11.74 / 1000 100
Efficiency = 98 %