I'd connect top of PID to left side of pulse generator, to represent controlling pulse generator's input, instead of where you have it which is its output .
And i'd add arrowheads to PID so it's intuitive that bottom is PID input and top is output.
Likewise add arrowheads to pulse generator.
The point is you let PID control the pulse width to make correct average voltage over at VC.. That's the basis of feedback control - continually measure , compare, adjust.