Advanced Power Electronics and Control Systems

A: Increasing adaptation gain tends to chase noise and widens spectral regrowth under fast fading. Raising drain voltage shifts AM–PM but usually pushes memory effects harder at the band edges. More aggressive CFR lowers peaks but injects wideband distortion that shows up exactly where ACLR is measured. Narrowing the DPD model to just beyond occupied bandwidth limits out-of-band overfitting so the correction energy stays where the mask is tight.

A: At 650 V and 12 A the overlap energy isn't negligible, so 1 W undershoots by an order. Counting only turn-on ignores a comparable turn-off term at these edges. Using V·Irms·D is a conduction model and inflates loss with the wrong physics. Half V times I times total transition time per edge, doubled for on and off then scaled by 200 kHz, lands in the high-teens watt range.

A: Rectifier timing issues show up as heating and efficiency loss more than a clean overvoltage spike. Magnetizing drift is slow and tracks temperature, not immediate light-load jumps. Dead-time errors raise loss and noise but don't selectively overshoot only at no load. Skip-cycle operation moves the effective switching point into a high-gain region of the LLC tank, letting the output rise until OVP clamps it.

A: A faster PLL on a weak grid injects angle noise into the current controller and erodes phase margin. Tracking distorted voltage makes the inverter follow harmonics rather than reject them. DC-link dynamics are dominated by power flow and won't be fixed by PLL speed. Lowering PLL bandwidth or using a decoupled scheme limits angle perturbations feeding the current loop.