Tuning Three-Term Controllers for Power Station Processes

This paper presents a new approach for tuning three-term control loops encountered in power station processes. The proposed approach is based on the Pseudo-Derivative Feedback (PDF) control configuration. Simple methods are presented for tuning the PDF controller for dead-time processes. The methods are based on appropriate manipulations of the exponential dead-time term in the denominator of the closed-loop transfer function for a servo problem, and, subsequently, on appropriately matching the coefficients of corresponding powers of s in the numerators of the resulting transfer functions and those in their denominators. This technique gives simple algebraic systems of equations for the controller parameters. Simulation results obtained from their application on power station processes show that our methods provide improved performance as compared to known PI/PID controller tuning methods as well as sufficient robustness against parametric uncertainty. Key-Words: Power plant control, controller tuning, process control, dead-time processes.