Abstract
In this research, the parameter values of the fractional order proportional-integral (FOPI) controller, which ensure the stability of the system, were calculated in a time-delay single area load frequency control (LFC) system with dynamic demand response (DDR). An efficient and simple graphical method had been applied to calculate all FOPI controller gains. For a given time delay, the method calculated all the compensating proportional-integral (PI) controller gains in the (𝐾𝑃, 𝐾𝐼) plane, which creates a stability region in the parameter space of the FOPI controller. This was done by equating the real and imaginary parts of the characteristic equation of the system to zero. Finally, for time-delayed single area LFC-DDR system with FOPI controller, results obtained were verified by using the timedomain simulation studies in Matlab/Simulink.