Boost converter multisim simulation error

[zazas321]

Hello guys. I am trying to simulate a boost converter specifications given:

Vin=12V
Rload=100
Vout=24V
F=100kHz
Current and voltage ripple = 5%
Vdiode=0.7V


In the simulation, Vout is measured at arround 22V instead of 24V and the ripples are tiny bit smaller than calculated
Based on the requirements I have calculated values for inductor and capacitor. I have simulated the circuit and it seems that there is a slight error between my calculations and the simulation. I have tried experimenting with the multisim and different duty cycles and it seems that the higher duty cycle I use, the more error I get in the simulation. I know that the efficiency is going down as you increase the duty cycle in real life, but I assume that multisim does not take into account and simulates the ideal scenario where the efficiency is 100%. Does anyone know what could be the problem?

 

[crutschow]

Those differences between calculated and simulated values seem reasonable.

The efficiency is affected by the MOSFET and diode switching losses, which are indeed simulated.

If you want 100% efficiency then you need to use perfect switches and diodes.

 

[zazas321]

Thanks for the answer

 

[audioguru]

Multisim and you did not read the datasheet of the very slow 1N4001 rectifier.
The 1N4001 is a 100Hz rectifier and does almost nothing at 100kHz. Use a very fast 1 Amp 1N5819 Schottky diode instead.