Boost Converter Output Voltage Overshoot

[mengghee]

hiye everybody,

I am just wondering why is there an overshoot with my output voltage of my boost converter when my capacitor is smaller. and also, if i increase the size of the capacitor, the overshoot will reduce but my simulation time for it to reach steady state will be longer. why is that ? thank you

regards,
mengghee

 

[v_c]

With a smaller capacitor, it takes much shorter time to move the output voltage toward your set point. With a smaller capacitor, the lowpass filter formed by the output inductor and capacitor has a corner frequency larger than if the output cap was larger. This means that the output regulation will be more sloppy since you are letting more switching noise go into the controller.

When you increase the output filter capacitor, the lowpass filter has a much lower frequency so you get much lower ripple on the output and better regulation. However since the output capacitor is larger, it takes much more time to charge it to its equilibrium value. This means that you need to simulate more cycles until you see steady-state.

I hope this helps you out.

Best regards,
v_c