I am performing small signal analysis in PLECS for boost converter with current control. The response (iL/D) what I get via simulations in PLECS is different from the one I obtain analytically from MATLAB. The graph shape looks similar but it looks like it is shifted in PLECS. I tried using discrete components (diode, switch, inductor) and also using boost converter block in PLECS to see any difference. There was a shift of 20dB but still the gain graph is in the negative side. I am unable to understand why the graph is shifted and what factors are affecting it in PLECS?
The response (iL/D) what I get via simulations in PLECS is different from the one I obtain analytically from MATLAB
In your PLECS model you have not configured the analysis as iL/D. Rather you are measuring iL_ref/iL. Is that what you intended? See the attached modified model which computes iL/D when the Manual Switch is in the lower position and you run the “iL/d Impulse” Analysis. Boost_CurrentControl_BL.plecs (37.2 KB). If the results differ a bit, then perhaps double check the operating conditions and component values.
For the iL_ref/iL analyses - in your model the steady-state analysis converges to a false steady-state condition. You can confirm this by looking at the duty cycle and current waveforms. Maybe this is because the time-constant of your controller is close (~2x) the PWM frequency with a naturally sampled carrier.
You can improve the steady-state convergence by increasing the number of initial cycles. Change the Manual Switch to the upper position and run some of the other Analyses to confirm.
