Robust FOPID controller for load frequency control using Particle Swarm Optimization

In this paper, design of Fractional order proportional - integral - derivative (FOPID) controller is designed for load frequency control (LFC) of power system. The performance of FOPID controller is compared with proportional - integral - derivative (PID) and proportional - integral (PI) controllers. The comparison is made based on various time domain performance indices such as Integral of absolute error (IAE), Integral of square error (ISE), Integral of time absolute error (ITAE), Integral of time square error (ITSE) and integral of square time square error. When load frequency control of power system is to design for open communication network, delay occur in area control error (ACE) signal. Delay issues in damping frequency oscillation w.r.t. change in load variation are also discussed. Particle Swarm Optimization (PSO) technique is being used to tune the parameters of the controllers. It is shown that FOPID controller has better dynamic performance than other controllers.