OPTIMAL DESIGN OF FRACTION-ORDER PROPORTIONAL-DERIVATIVE PROPORTIONAL-INTEGRAL CONTROLLER FOR LFC OF THERMAL-THERMAL-WIND TURBINES CONSIDERING NONLINEARITIES

Abstract

The power system must be kept safe during load disturbances in order to control frequency instability during load disturbances change. Cascade Controller (CC) is employed to boost the performance of the power system mainly in the presence of nonlinear aspects. As a result, in this study, A proposed cascade fractional order proportional-derivative proportional integral (FOPDPI) controller is used to fine-tune the load frequency control (LFC) subjects of a three-area power system (thermal-thermal-wind) in the interconnected power system (IPS). As a third area in the studied model, renewable energy is used, such as high penetrating power wind turbines. The FOPDPI controller gains are adjusted using a recently published optimization scheme, such as the Harris hawk optimizer (HHO). To thoroughly test the efficiency and fitness of the proposed controller, the HHO-based FOPDPI and conventional PID controllers are applied to a three-area model with/without nonlinearities such as generation rate constraint (GRC), governor dead band (GDB), and boiler dynamics (BD) under different step load perturbation (SLP). The HHO algorithm's cost function is the Integral time multiply absolute error (ITAE) criterion. The investigation reveals that the proposed scheme HHO: FOPDPI provides greater stability than HHO: PID in both linearities by 58% and nonlinearity aspects by 62%.