I made transfer function for current-controlled boost converter in MATLAB by calculus and AC-sweep. They match each other, but doesn`t match discrete element model. Why?

What could be wrong? Do I miss to take in account something?

Step response of converter made of discrete SimPowerSystem elements and obtained transfer function are different when I put them in a single simulation. When I apply PI-regulator they behave different and final duty cycle value is different to calculated one for transfer function.

Answer 1

[SimTec]

Hello Pavel, I am trying to get the transfe function of the boost converter with peak current mode as well but using AC sweep does not work at all and provide insane frequency response.can you tell me more how did you implement it. in my case i used a plecs to simulate the circuit and simulink to control the circuit and then the AC sweep block