Delay after applying "step time" for DC Boost converter with controller

Hi, In the attache model, I slightly modified the model to monitor the inductor current and to more easily manually switch from constant reference voltage to a step reference voltage. The "delay" you are experiencing is normal. This boost converter has a pretty large output capacitor that needs to be charged up to the input voltage through the diode. During this initial transient switching is ineffective and you can clearly see a very large inductor current spike. This phenomenon is called "inrush current" and, for the boost converter, it prevents the output voltage from being controllable until the output capacitor has a voltage Vc greater than the input voltage Vin. In practice, you have tried to change the output voltage through a step reference voltage while the boost converter is still uncontrollable. As a recommendation, you should set the lower limit of the output of the PI controller (that is the minimum duty cycle) to 0.1-0.15 as a rule of thumb. Set the upper limit to 0.85-0.9 to keep the operation far from the low-efficiency region. It is not recommended to operate the boost converter with full 0-1 duty cycle. Hope this helps, Antonino