Briefly explain the purpose served by each term in a PID con

Briefly explain the purpose served by each term in a PID controller.

Solution

1. P in PID: It can be used to change transient behaviour of a system. By varying Kp value transient response can be varied according to requirement. According to Kp value damping coefficient changes resulting in transient response variations.

2. I in PID: Integral controller adds a pole in to the system. Thus it incrases the type number. The steady state error reduces as the type of system increases. So Integral controller is used to reduce steady state error.

3. D in PID: Propotional controller and Integral controller effects the stability of the system. In derivative controller, one zero is added into the system. This reduces the type number. This will increase the steady state error but increases stability of the system.

According to requirement the three can be adjusted in a PID controllrt to have better transient, steady state nature along with stability.