I have developed an averaged circuit utilizing a PWL voltage source for the control voltage pin of the CPM-CCM converter shown below however, when I try and construct an uncompensated closed loop control system I get some very undesirable behavior and I cannot reproduce the open loop behavior. The waveform for the open loop is shown below:

But the uncompensated closed loop is showing a ton of noise and cannot reach the 20V output for the second phase.

I have my control signal set to 5 and 20 V which I can adjust with a voltage divider on the output easily enough but these waveforms are not very stable and I can't reach 20 V for the closed loop. I am trying to get the transient response down first before I dive into the frequency response (i.e. compensator design). Is there something obvious I am missing in my bare bones control loop?

 

What is Vcc value?

 

Hey shteii01,

Have put a little more work into the circuit and it is behaving slightly better. Vcc is set to 5 volts using a regulator as shown below in the updated circuit. My issues now have to do primarily with stability and inductor saturation. Here are the waveforms at the moment.

As you can see I am not stable at the 20V operating point and there is a HUGE issue with the step voltage change from 20V to 5V (I'm pretty sure a current of 220 amps or so is bad ha)

I would run an ac simulation to see where my frequency response is but...the simulation fails due to not being able to find an dc operating point despite my adventures within nodeset commands and initial conditions.