Mathematical Representation of a Proportional Controller

Proportional Controller

In engineering and process control system, proportional controller is applied to the controlled variable to minimize the error proportionally to the difference between the desired value (setpoint, SP) and the measured value (process variable, PV). And from this technique or algorithm, we can create a proportional controller. This controller compares two values, difference SP and PV and the actual value, and minimizes the fluctuation of process variable. This is the fastest among the other controller but it can not always bring the desired set point of the system....

Proportional Controller Feedback Diagram

feedback diagram of proportional controller...

Working of Proportional Controller

The proportional controller initially compares the Set Point (SP) value with the actual Process Variable (PV) value. Following this, the system’s feedback loop becomes operational, continuously monitoring the system’s output and comparing it to the desired output. As necessary, the inputs are modified to minimize the disparity between the output and the desired value....

Gain Factor and Controller Output

Gain factor and controller output both are the two most important terms in a P controller....

Mathematical Representation of a Proportional Controller

Proportional controller produces output which is proportional to the error signal(E). So at a time ‘t’ the equation can be written as ,...

Tuning of Proportional Controller

Tunning refers the adjustment of Kp value to get most efficient output of process variable. The choice of Kp value effects the controller in terms of stability, speed overshot etc. Let’s consider a simple example of tuning process....

Examples of Proportional controller

P only controller or proportional controller is a closed loop feedback control system, where the controller adjust its output based on the difference between setpoint and process variable. So here are some examples of P only controller along with explanation and diagram....

Application of Proportional Controller

Proportional control often used in industrial automation such as speed control, pressure control, flow control, PH control, level control, position control. But their are some major use of P controller, which described below....

Advantages and Disadvantages of Proportional Control

Some advantages and disadvantages are as follows:...

Conclusion

Proportional controller or commonly known as P-only controller is straight forward and simplest control strategy to implement. Although it works on closed loop feedback control system. It offers quick and state error signal response with it’s limitations, like problem in tuning, it need to tune manually, which is a bit difficult. It cannot perfectly eliminate steady state error or gain factor, so their is always a small residual error that remains even when the system stabilizes. Despite all this pros and cons, P-only controller is an essential tool in control engineering and provides a basis for further refinement and optimization through more complex control strategies....

FAQs on Proportional controller

1. What is P-only controller ?...