PI/PD controller design

Question 1

What is the effect of C(s)G(s) from a PI controller

Answer 1

Changing Ti adds gain at lower frequencies but minimises extra lag at Wc
-this leads to lower steady state error
Changing K changes gains at all frequencies

Question 2

What is the effect of C(s)G(s) from a PD controller

Answer 2

Changing Td adds phase around 1/Td