Tool/software:
I have started working on current fed topology to design a boost converter for motor control application. I started my work with TIDA 00951 but the design is now obsolete. I have currently shifted to current fed half bridge topology with active clamping and active voltage doubler.
I have tested the design for 2kW but even with careful hardware design and active clamp it seems like you cannot get rid of mosfet turn off overshoot at higher loads. For this purpose i have shifted my focus to achieve ZCS and i am trying to use secondary mosfet switching to achieve. Still in development and working from scratch. Unfortunately i cannot find any paper for this kind of approach that i am using. Any reference would be highly appreciated?
For simulation i am using PSIM. Now steady state simulation is fine but i am trying to implement soft start in it. I cannot find any support of current fed from TI in terms of simulation. With all said, i hope you guys have a sketch of my design.
I have two main concerns, with what i have described above about ZCS using secondary switching, is there any reference for that in current fed?
And How to i tune my close loop system as i cannot tune it using step response as i am using soft start and i will hand over to close loop control after the soft start is done. During soft start sequence i do have to check certain parameters and turn in sync fets, so i cannot use PI control in soft start.
When soft start is done I get this overshoot from PI control and my system turns off because of overvoltage protection. So how do i tune this system. Can i change my PI gain parameters after certain soft start sequence?