Question

Why are high gain systems generally better in reality?

Answer 1

Steady state Gain (K) is the steady state value that the system attains after being disturbed by a unit step input.

It is sometimes called sensitivity of the process.It describes how a process variable(PV) will change for a given change in controller output(CO).If a process has a large K, then a small change in the CO will cause the PV to move a large amount. If a process has a small Kp, the same CO change will move the PV a small amount.

Hence slow processes can be made to react faster by having a high Gain but having a too high gain can lead to instability in the process and therefore certain tuning rules are applied to tune the controller gain.