Fuzzy-based intelligent controller for power generating systems

In this paper an intelligent fuzzy logic controller is proposed to control the frequency and voltage of a power generating system. The load frequency control (LFC) and automatic voltage regulator (AVR) are installed in each generator to control the real and reactive power flows. Due to rising and falling power demand, the real and reactive power balance is harmed and hence frequency and voltage get deviated from nominal value. This necessitates the need for an intelligent fuzzy controller to generate and deliver power in an interconnected system as economically and reliably as possible while maintaining the voltage and frequency within permissible limits. The conventional PID controllers employed for this task will have zero steady-state error but lead to large deviations in frequency and voltage under varying load conditions. The proposed method overcomes the drawbacks of a conventional fixed gain controller and improvement is achieved in terms of settling time, oscillations and overshoot. The single and two area LFC and AVR are modeled in MATLAB using the transfer function of the system. Fuzzy rules and membership functions are tuned based on the knowledge of experts and from previous experience about the plant behavior. The models are simulated for different load conditions and regulations in order to demonstrate the effectiveness of the proposed controller. Simulation results emphasise the improved performance in comparison with fixed gain controllers.