A fuzzy controller based on self-tuning rules for the nuclear steam generator water level

Abstract

It was demonstrated that the fuzzy control method could be applied successfully to control and regulate the nuclear steam generator water level through previous works. However, this method has some limitations from the fact that its performance largely depends on the tuning method and how to settle the rule base. In this work, a fuzzy control algorithm based on self-tuning rules is investigated to find the optimal tuning point and to generate the control rule automatically. It adopts an on-line iterative method and the objective error function which contains the variation errors of all time-steps. The triangular membership functions based on the mass flow rate and water level errors are applied. And also, a forgetting factor is used to account for an exponential decay of the past data in tracking the slow drift in system parameters. Thus it controls the steam generator water level from low power to full power with a little transients. This control algorithm is validated by computer simulations.