Performance Assessment Of PID Controllers

Monitoring and evaluation of control performance in industrial processes have now been attracted more and more attention in the past years, especially for PID controllers which are interested, and it's necessary to study the performance of the PID controller, which is widely used in industrial most control loops. Two performance assessment methods are studied in this paper. The first method is based on minimum variance proposed by Harris. A time series model is identified from the routine operation data and a feedback-invariant form is extracted from the model for the control system, which is used for estimating minimum variance. Then the minimum variance method is applied in assessing against the estimator of minimum variance, performance assessment of PID control systems is researched. The second method is based on the internal model control (IMC) idea. The disturbance rejection performance and robustness of an IMC controlled system are set as the desired performance and are compared with a practical for the expectations, anti-jamming performance and robust performance of the PID controller is evaluated. Finally, combining simulation with industrial model, the practicality and simplicity of this performance assessment method is illustrated by applying it in the main temperature control system, which is a typical control system in power generation.