Problem
FIGURE a shows a flow control system that is controlled by a P + I controller. The control objective is to maintain a constant flow rate, Q0, for varying values of input flow rate, Q2. The system can be represented by the block diagram shown in FIGURE b.
Assume that the following initial conditions apply.
Dv = 2000 ε = 0
I = 1000 C = 0.2
Q2 = 1000 Ki = 0.8
Show that following a permanent step disturbance in Q2 from 1000 m3 h-1 to 1200 m3 h-1, the resulting offset is eliminated.
You should continue your calculations until Qo is within 4 m3 h-1 of its final value for two successive calculations.* Derive any formulae used.
