Hi,
I am working on a system where complimentary ePWM A/B outputs are used to control a half bridge driver. I'm using the Time Base, Counter Compare, Action Qualifier and Dead time IP Blocks to generate the complimentary outputs.
I want to use the CMPSS to detect overcurrent/voltage events and shut down the bridge by putting the gates in a known state until the firmware deems it safe to restart.
I initially implemented the CMPSS => ePWM XBAR => One Shot Trip Zone flow. However, I started blowing up bridges on trip conditions. The trip zone didn't enforce the dead times and changed the high/low channel signals at the same time which created a shoot through condition. My understanding is this is because the trip zone block falls after the Action Qualifier.
I've been able to implement a software based approach using the "EPWM_setActionQualifierContSWForceAction" function. This approach adheres to the dead time requirements.
However....
I feel like I must be able to tie this flow together via hardware modules so it is more responsive. And it seems like maintaining dead times must be a pretty bread and butter requirement.
Any suggestions on how to do this without getting the cpu involved?
Thanks,
-Colin
