Controlling AVR System Based on Optimal FOPID Controllers: A Comparative Study

In this study different schemes of Fractional Order PID (FOPID) controllers are suggested to maintain the Automatic Voltage Regulator (AVR), the controllers' gains are selected using Gorilla Troops Optimization (GTO) and the fitness function Integral Time Absolute Error (ITAE) is used to monitor and obtain the efficient system behavior.The transient analysis is adopted to adjust and obtain the desired response.the nonlinear FOPID faces these signals with a small period and lowest settling time 0.164 sec., it is superior to conventional FOPID by 75.226% and superior to arctan FOPID by 81.898% in simulation time equal to 5 seconds, it reaches its peak value fast (t=0.126seconds) with a very small value equal to 0.00103 then it will obey the system to a stable level of its desired response efficiently, then the robustness analysis's are tested by adding two external disturbances signals with values equal to 0.3 v, the three controllers suggested conventional FOPID, arctan FOPID, and the nonlinear FOPID controller try to fix the deviation done by these signals, the nonlinear FOPID faces these signal with small time till reach to the stable desired values.The second one is utilized by varying the original gains model for two parts of the system amplifier and sensor to 25% from its real value, the best performance also appeared in the nonlinear controller if compared to the other two controllers in adjusting the system response in a small period of time.