Hybrid Fuzzy-PID Application in Boilers to Obtain Optimum Efficiency


1 Electrical Engineering Department, Central Tehran Branch, Islamic Azad University, Tehran, Iran.

2 Electrical Engineering Department, South Tehran Branch, Islamic Azad University, Tehran, Iran.


Many real time processes have complex, uncertain and nonlinear dynamics. Boilers are nonlinear, time varying, multi-input multi-output (MIMO) systems, whose states generally vary with operating conditions. The major problem in controlling that system is that its drum water pressure and steam flow dynamics include an integrator that results a critically stable behavior. Conventional controller previously used have a set of limitations, e.g. empirical tuning of their parameters when the operating conditions of the controlled process are changed. The application of fuzzy control scheme which is compounded with classic controller (PID) may provide more effective and flexible control of boilers in power stations. This research employing fuzzy logic systems due to their transparency and nonlinear features for controlling dynamics, uncertain and highly nonlinear boiler systems and PID controller due to its fast response


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