LTspicePowerSim

Active-clamp forward — PI regulation

LTspicePowerSim's 200 V to 12 V active-clamp forward, its current-mode loop and dead-time block replaced by a PI switch and its complement.

Press Run: the example simulates in your browser. Open and simulate takes it to the full app, where you can change it.

Try this

Shrink the clamp capacitor to 10 nF and watch the switch-node peak rise from 250 V to 278 V. Then press Run again.