Question

In a closed-loop system, the process to be controlled is an integrating process with a transfer function \( \frac{1}{25} \). The controller proposed to be used is an integral controller with transfer function \( \frac{1}{T4s} \). When a step change in the set point is applied to such a closed system, the controlled variable will exhibit:

• A. Overdamped response
• B. Underdamped response
• C. Undamped response
• D. Unstable response

Hint:

Evaluate gain margins in closed-loop systems to avoid instability.

Answer 1

The Correct Option is D

Integrating processes combined with integral controllers can lead to instability due to excessive loop gain and lack of damping.