Lets assume that delta IL = 3A
if the switching frequency es 10khz, the capacitive reactance will be Xc = 0.0397 ohm, it makes sense to asume that the current ripple will go to the capacitor, since it has a much lower impedance.
But if we change the capacitor value from 400uF to 400nF now Xc = 39.78.
For the 5ohmresistor that will be around 2.6A which means an instant voltage change of 13.3V.
In that case, it would b more accurate to say that the capacitor has a too low capacitance to storage the energy or a too high impedance at that frequency?
Or are those numbers just wrong?