PWM Generator and Boost Converter

Hi all,

I am building a PWM generator and boost converter diagram. When i vary the input (Duty Cycle) to the PWM Generator, it should control my IGBT switch that is part of my boost converter. However, i tried varying my duty cycle and the output to my boost converter remained the same.

I would appreciate if someone can help me and explain what went wrong by taking a look at the schematic attached below.

Thank you in advance!