Project 1 - Loss calculation for a DC/DC converter-MATLAB

To design a boost converter and calculate its loss of different components including the power switching device and derive the efficiency of the boost converter.

Let us say

Vin=100Vand we need the output voltage of 200V and the output power needed is

Pout=2kW

then the output current would be Iout=20A

then the load resistor is designed to be

let us see the block diagram of the boost converter that we want to design

let us design the inductor for the above boost converter

for calculating the inductor we need to know what is the ripple current

a good estimation for the inductor ripple current is 20% to 40% of the output current

let us assume 20%

then

Now let us calculate the inductance of the boost converter

now we have to calculate the value of capacitance

for calculating the value of capacitance we need to know the duty cycle of the boost converter

Duty cycle

by the calculated values let us model the boost converter in MATLAB/Simulink

we can observe the output voltage is 200.6which is approximately equal to 200V that what we have desired and the output current is 20.6 which is approximately equal to 20A so we achieved the desired output let us see the voltage and currents of MOSFET and Diode

we can observe that the during switch off the diode exhibits the reverse voltage characteristics the peak current in the diode is 300A

let us see the MOSFET results

we can observe that the peak voltage and current values are above 300

so we have to select the MOSFET that can withstand a voltage of 300

the spike at the starting is eliminating snubber and a DC link Capacitance

let us go to INFINEON to select the MOSFET for this application

the above MOSFET is connected in series to reach the operating region

now let us calculate the losses

Conduction Losses:

when the integrated high-side MOSFET turns on, the load current flows through it. The drain to source channel resistance causes power dissipation

The Rdson for the selected MOSFET is 0.00023ohms we have to connect the MOSFETs in series in order to reach the peak voltage sp the Rdson is equal to 0.00023

then the conduction loss is given by

Diode Losses:

The forward voltage of the diode is given by 0.8

then the diode loss is given by

Induction losses

Capacitance Losses:

now let us calculate the Total power losses in the above converter

Now the efficiency of the boost converter is given by

the input power is 100 x 20 which is 2000W

the output power is given by 195.8 x 19.58 which is 3833.764

now considering the power losses the efficiency is given by

the efficiency of the above boost converter is 0.91682 which is equal to 91.6882

Conclusion:

The Boost Converter is designed and modeled in Simulink and the switching device is selected from the retailer as well as the power losses of different components and also the switching device is determined as well as the efficiency of the designed converter is calculated.