Proportional controller
1. What is P-only controller ?
P-only controller a short form of proportional controller, is a closed loop feedback controller adjust the output proportionally to error between setpoint and process variable.
2. What is steady state error ?
Steady state error is the difference between the desired value and the actual value of a system output.
3. When a P-only controller should be used ?
P-only controller should be used in system with requirement of simple dynamic and quick response. They are often used as a starting point of control system design, and can be effective in many industrial and engineering applications.
4. What happens if the proportional gain (Kp) is set too low in a P controller?
If Kp is too low, the P controller will respond slowly to errors and may not effectively reduce the error to zero. The system’s response may be sluggish, leading to prolonged settling times.
5. What is proportional band ?
Proportional band(PB) is a range ot error value over which the proportional action takes places to control a system. It is expressed by percentage of the total error.
PB = 100/ Kp
6. What is setpoint ?
In industrial automation and control set point is a desired or targeted value for an process variable.
Proportional Controller in Control System
Controller is a combination of hardware device and software program in control system that manages the flow of data from one entity to another and generates required output . Their are several techniques or algorithms that uses in automation system to control a system. One of the type that is used in PID controller is Proportional controller or P-only controller. This is the simplest closed loop feedback control.