Design of fuzzy gain scheduler for superheater temperature control in power plant

Steam temperature Control is one of the most challenging control loops in a power plant boiler because it is highly nonlinear and has a long dead time and time lag. Proper control of Superheated steam temperature is extremely important as high temperature can damage the superheater or high pressure turbine and low temperature will reduce the efficiency of power plant. Therefore, the Superheated temperature is to be controlled by adjusting the flow of spray water to within +/-10 deg C during transient states and +/-5 deg C at the steady state. In this paper, the Control using fuzzy gain adaptation of PID controller is presented. Fuzzy rules are utilized on-line to determine the controller parameters based on error and its first time derivative. Simulation and experimental results of the proposed scheme show good performances compared to the PID controller with fixed parameters in terms of dynamic and steady state characteristics of all loops. Simulations are performed using MATLAB/SIMULINK.