Type-2 fuzzy-based adaptively predictive controlled variable frequency transformer coordinated to SMES for improved load frequency control

Abstract

Traditionally, phase shifters powered by power electronics are used in conjunction with energy storage devices to improve the load frequency control. Conventional phase shifters provide minimal inertia and offer a significant threat to power quality due to harmonics. This study suggests the type-2 fuzzy based adaptively predictive controlled variable frequency transformer (F2-APC-VFT) as a phase shifter to work in coordination with superconducting magnetic energy storage (SMES) for improved load frequency control. To assess the effectiveness of coordinated control, a two-area, four-machine linked power system with F2-APC-VFT installed in succession with the connecting line near to area one and SMES in the other area is employed. A type-2 fuzzy controller is used to tune the cost function weights of the adaptive predictive controller (APC). A simulation study is conducted in MATLAB to show the effectiveness of the suggested strategy. Tuning the cost function weights with a type-2 fuzzy controller considerably impacts in minimising the frequency and tie-power deviations. The effectiveness of the F2-APC is verified by comparing its performance with that of an adaptive neuro fuzzy inference system (ANFIS) controller and constant weight-based adaptive predictive controller (C-APC).