Mohammad Ali Khaniki - Department of Control Engineering, K.N. Toosi University of Technology, Tehran, Iran.
Mohammad Hadi - Department of Energy Engineering, Sharif University of Technology, Tehran, Iran.
Mohammad Manthouri - Department of Electrical and Electronic Engineering, Shahed University, Tehran, Iran.

One of the most important equipment in the power system is the Automatic Voltage Regulator (AVR) or synchronous generator excitation. The goal of the system is to maintain the terminal voltage of the synchronous generator in the desired level. AVR is inherently uncertain. Hence, the proposed controller should be able to handle the problem. In this paper, Fractional Order Fuzzy PID (FOFPID) controller has been employed to control the system. In order to enhance the performance of the controller, Grasshopper Optimization Algorithm (GOA) is used to tune the parameters of the controller. Unlike other methods, the gains of FOFPID controller are not constant and alter in different operating conditions. The robustness of the controller has been investigated and the comparative results show that the proposed controller has a better performance against other methods.Automatic Voltage Regulator (AVR), Synchronous generator excitation, Fractional-order fuzzy PID (FOFPID) controller, Grasshopper Optimization Algorithm (GOA), Uncertainty

Automatic voltage regulator (AVR), Synchronous Generator Excitation, Fractional-order Fuzzy PID (FOFPID) Controller, Grasshopper Optimization Algorithm (GOA), Uncertainty