Next Generation Relay Autotuners – Analysis and Implementation at ABB

Abstract: For a long time, a method which tunes a robust controller automatically has been researched. In this thesis, a method to estimate processes using a short experiment and low order time delayed models is described. The goal was to achieve a model that could be used for PI- and PID-tuning in an autotuner. Through a simulation study, various experiment designs were tested to find an optimal experiment for model identification. The method was implemented in the ABB AC 800M controller. Using a simulation study and ABB’s AC 800M controller the proposed method was shown to be successful in estimating models for a variety of processes. Furthermore, the proposed method was shown to be more robust and have a shorter experiment time than the autotuner that is currently used.