Whale Optimized PID Controllers for LFC of Two Area Interconnected Thermal Power Plants

This paper elaborates the application of new nature inspired algorithm; ‘Whale Optimization Algorithm (WOA)’ in load frequency control of two area interconnected non-reheat thermal power plants. Two number of PID controllers have been considered in the investigated system and the parameters of the controllers have been tuned/optimized using WOA. The design problem has been formulated as the constrained optimization problem with upper and lower bounds of controller’s parameters. The integral of time multiplied absolute error (ITAE) has been taken as an objective function in the present work. The parameters of controllers (K_P, K_I, K_D), minimum damping ratio (MDR), the values of performance indices (ITAE, ISTE, ISE, IAE), settling times and overshoots of Δf₁, Δf₂ and ΔP_Tie have also been evaluated for the system under investigation using WOA. The simulation results include the dynamic responses of Δf₁, Δf₂ and ΔP_Tie for different step load changes from 0.1p.u. to 0.5p.u in area 1 by keeping constant 0.1p.u. step load change in area 2. It has been observed that smooth and better dynamic responses with fewer oscillations, less settling times and less overshoots can be achieved for the system using WOA.