Derivative Control
- CIMON (Unlicensed)
Derivative (D) control generates the MV in proportion to the rate of change in the error so as to eliminate the deviation (offset).
By adding the Derivative control, quick corrective action can be obtained at the beginning of upset condition.
After the deviation occurs in the derivative action, the amount of time it takes for the MV of the derivative action becomes the MV of the proportional action is called the "derivative time".
If the derivative time is set too long, oscillations will occur and the control loop will run unstable. If the derivative time is set 0, the derivative control does not function properly.
The Derivative Control is used with PI (Proportional + Integral) control or PID (Proportional + Integral + Derivative) control. The Derivative Action is never used alone.