I have designed boost converter with Peak current mode control in PLECS. I have used the method of k factor approach to design the compensator. the bode plot transfer function of the power stage is used to select the crossover frequency of 40KHz as I am using a switching frequency of 2.2MHz and from this, I defined my compensator which shows a good bode plot(). the bode plot of the complete system is perfectly matching my expectation as you can see in the figure. however, when I run the same circuit in PLECS with the compensator I get a huge oscillation and non-stable system and the compensator() is meant to stabilize my system ( I could not upload the file in stackoverflow). my question how can the frequency domain analysis works perfectly but when it comes to time domain( circuit) the system is completely wrong? I have used a crossover frequency of 5KHz and shows the good result which means that my control loop does not show good behavior when it comes to higher crossover frequency which goes against my understanding that says I Can choose any crossover frequency as long as it is tenth less than the switching frequency. the bode plot of the compensated circuit(circuit with the compensator) is : the circuit: the cross over freqquency where it is unstable is 40KHz, I have chosen phase margin 60 and with the k factor approach I calculated the pole zeros and gain of the comensator
Modelling current mode SMPS is in fact a fair bit harder than voltage mode, whatever the "everyone knows" knowledge says. It's often easier to USE and you have "known good" formulas but these tend to throw away the current amplifier part, or "simplifies" it away..
If you have two feedback loops in parallel, eliminating one and saying it doesn't matter is largely a hand-waving excercise. You can often get good enough approximation of the result and the manufactures often do not provide the necessary information to model the current mode loop. So it's not totally unreasonable to drop the current loop response because you don't have a reasonable way of modelling it anyway.
What I'd recommend is going over to Texas Instruments web page and trying their webench tool suite to design a similar power supply. If you use same/similar the same inductor/capacitor/transistor and a current mode controller, the feedback loop should be pretty close to what you do need. You probably need to change the voltage divider to provide the correct feedback value which does affect the loop somewhat but the webench lets you play with the feedback values on component level.
If you're interested in the complexities of properly modelling current mode SMPS controller, check "UNDERSTANDING AND APPLYING CURRENT-MODE CONTROL THEORY" by Robert Sheehan plus his other white papers. Other methods are presented in some textbooks such as "Switching Power Supply Design & Optimization" by Sanjay Maniktala. These all rely on the manufacturer actually disclosing waveform details and specs of the controller current mode amplifier which is often not given.